MACK Pengajuan SEC - Merrimack Pharmaceuticals, Inc.- Laporan Tahunan, Pernyataan Kuasa, Prospektus

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SEC Filings

All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Merrimack Pharmaceuticals, Inc.

SEC Filings (Chronological Order)

Halaman ini menyediakan daftar lengkap dan kronologis dari Pengajuan SEC, tidak termasuk pengajuan kepemilikan yang kami sediakan di tempat lain.

May 20, 2024	15-12G	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File No. 001-35409 Merrimack Pharmaceuticals, Inc. (Exact name of registrant as specifie
May 15, 2024	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
May 10, 2024	25	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 25 NOTIFICATION OF REMOVAL FROM LISTING AND/OR REGISTRATION UNDER SECTION 12(b) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File No. 001-35409 Issuer: Merrimack Pharm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 25 NOTIFICATION OF REMOVAL FROM LISTING AND/OR REGISTRATION UNDER SECTION 12(b) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File No. 001-35409 Issuer: Merrimack Pharmaceuticals, Inc. Exchange: Nasdaq Capital Market (Exact name of Issuer as specified in its charter, and name of Exchange where security is listed and/
May 10, 2024	EX-99.1	Merrimack Pharmaceuticals, Inc. Announces Stockholder Approval of Plan of Dissolution And Cash Liquidating Dividend Amount of $15.10 Per Share of Common Stock EXHIBIT 99.1 Merrimack Pharmaceuticals, Inc. Announces Stockholder Approval of Plan of Dissolution And Cash Liquidating Dividend Amount of $15.10 Per Share of Common Stock Cambridge, MA, May 10, 2024 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) announced that the stockholders at a Special Meeting held today overwhelmingly approved adopting a Plan
May 10, 2024	8-K	Current Report UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 10, 2024 (May 10, 2024) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorp
May 9, 2024	8-K	Current Report UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 9, 2024 (May 8, 2024) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorpor
May 9, 2024	EX-99.1	Merrimack Pharmaceuticals, Inc. Announces Anticipated Final Cash Dividend Amount of Initial Liquidating Distribution, Subject to Receipt of Stockholder Approval of Plan of Dissolution EX-99.1 EXHIBIT 99.1 Merrimack Pharmaceuticals, Inc. Announces Anticipated Final Cash Dividend Amount of Initial Liquidating Distribution, Subject to Receipt of Stockholder Approval of Plan of Dissolution Cambridge, MA, May 9, 2024 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced that the Board of Directors intends to declare a liquida
May 9, 2024	DEFA14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 9, 2024 (May 8, 2024) Merrima UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 9, 2024 (May 8, 2024) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorpor
April 30, 2024	DEFA14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2024 (April 30, 2024) M UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2024 (April 30, 2024) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
April 30, 2024	EX-99.1	Merrimack Pharmaceuticals Announces Notification of Plan to Voluntary Delist Comon Stock on NASDAQ Subject to Receipt of Stockholder Approval of Plan of Dissolution Company Updates Potential Range of Initial Liquidating Distribution and Additional Di EXHIBIT 99.1 Merrimack Pharmaceuticals Announces Notification of Plan to Voluntary Delist Comon Stock on NASDAQ Subject to Receipt of Stockholder Approval of Plan of Dissolution Company Updates Potential Range of Initial Liquidating Distribution and Additional Dividend Information Cambridge, MA, April 30, 2024 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Co
April 30, 2024	8-K	Current Report UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2024 (April 30, 2024) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
April 1, 2024	DEFR14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defi
March 27, 2024	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2024 (March 27, 2024) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
March 27, 2024	DEFA14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2024 (March 27, 2024) M UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2024 (March 27, 2024) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
March 27, 2024	EX-99.1	Merrimack Receives $225 Million Milestone Payment from Ipsen Special Meeting of Stockholders to Approve Plan of Dissolution Scheduled for Friday, May 10, 2024 at 10:00 a.m. Eastern Standard Time EXHIBIT 99.1 Merrimack Receives $225 Million Milestone Payment from Ipsen Special Meeting of Stockholders to Approve Plan of Dissolution Scheduled for Friday, May 10, 2024 at 10:00 a.m. Eastern Standard Time Cambridge, MA, March 27, 2024 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced that it has received a $225 million payment which
March 22, 2024	DEFA14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defini
March 21, 2024	10-K/A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) ☒ Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. For the fiscal year ended December 31, 2023 ☐ Transition rep UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) ☒ Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. For the fiscal year ended December 31, 2023 ☐ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. Commission file number 001-35409 MERRIMACK PHARMACEUTICALS, INC. (Exact na
March 21, 2024	DEF 14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a
March 7, 2024	EX-4.5	Description of the Registrant’s Securities Registered under Section 12 of the Exchange Act Exhibit 4.5 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED The following description of the securities of Merrimack Pharmaceuticals, Inc. (“us,” “our,” “we” or the “Company”) registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), is intended as a summary only and therefore is not a complete desc
March 7, 2024	EX-99.1	Merrimack Reports Full Year 2023 Financial Results EXHIBIT 99.1 Merrimack Reports Full Year 2023 Financial Results Cambridge, MA, March 7, 2024 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced its full year 2023 financial results for the period ended December 31, 2023. “As Ipsen reported in February, the U.S. Food and Drug Administration has approved the supplemental new drug applicati
March 7, 2024	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported):March 7, 2024 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Commi
March 7, 2024	EX-21.1	Subsidiaries of the Registrant Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name Jurisdiction of Incorporation Merrimack Pharmaceuticals UK Limited* Merrimack Securities Corporation* UK Massachusetts * wholly owned
March 7, 2024	425	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported):March 7, 2024 Merrimack Pharmaceut UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported):March 7, 2024 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Commi
March 7, 2024	EX-4.5(1)	First Amendment to Section 382 Rights Agreement Exhibit 4.5(1) FIRST AMENDMENT TO SECTION 382 RIGHTS AGREEMENT This First Amendment to Section 382 Rights Agreement (the “First Amendment”) is made as of December 2, 2022 by and between MERRIMACK PHARMACEUTICALS, INC. (the “Company” and COMPUTERSHARE TRUST COMPANY, N.A. as Rights Agent (the “Rights Agent”), amending the Section 382 Rights Agreement by and between the Company and the Rights Agent d
March 7, 2024	10-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-35409 Merrimack Pharm
March 7, 2024	EX-97.1	Policy for the Recovery of Erroneously Awarded Compensation adopted November 30, 2023 Exhibit 97.1 MERRIMACK PHARMACEUTICALS, INC. POLICY FOR THE RECOVERY OF ERRONEOUSLY AWARDED COMPENSATION 1. OVERVIEW In accordance with the applicable rules of The Nasdaq Stock Market (the “Nasdaq Rules”), Section 10D and Rule 10D-1 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) (“Rule 10D-1”), the Board of Directors (the “Board”) of Merrimack Pharmaceuticals, Inc. (the “C
March 5, 2024	PRE 14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a
February 14, 2024	SC 13G/A	MACK / Merrimack Pharmaceuticals, Inc. / 22NW Fund, LP - AMENDMENT NO. 4 TO THE SCHEDULE 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. 4)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 590328209 (CUSIP N
February 13, 2024	DEFA14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 13, 2024 Merrimack Pharm UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 13, 2024 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
February 13, 2024	EX-99.1	Merrimack Reports Ipsen Announcement of Approval By The US FDA of Onivyde EXHIBIT 99.1 Merrimack Reports Ipsen Announcement of Approval By The US FDA of Onivyde® (Irinotecan Liposome Injection) Plus 5 Fluorouracil/Leucovorin and Oxaliplatin (NALIRIFOX) as a First-Line Treatment for Metastatic Pancreatic Ductal Adenocarcinoma (mPDAC) • FDA Approval Triggers $225 Million Milestone Payment from Ipsen to Merrimack • Merrimack Expects to Hold Special Meeting of Stockholders
February 13, 2024	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 13, 2024 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
January 25, 2024	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / Newtyn Management, LLC Activist Investment SC 13D/A 1 formsc13da.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 4) Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Noah G Levy Newtyn Management, LLC 60 East 42nd St, 9th Floor New York, NY 10165 (21
January 25, 2024	EX-99.1	Joint Filing Agreement of the Reporting Persons, dated as of January 25, 2024, among the Reporting Persons (filed herewith). EX-99.1 2 ex99-1.htm Exhibit 99.1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Merrimack Pharmaceuticals, Inc. and further agree that this Joint Filing Agreement be included as an Exh
December 13, 2023	SC 13D/A	MACK / Merrimack Pharmaceuticals Inc / Western Standard LLC - SC 13D/A Activist Investment SC 13D/A 1 d623576dsc13da.htm SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 5)* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Eric D. Andersen Western Standard, LLC 5757 Wilshire Boulevard, Suite
November 2, 2023	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 2, 2023 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (C
November 2, 2023	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merri
November 2, 2023	EX-99.1	Merrimack Reports Third Quarter 2023 Financial Results EXHIBIT 99.1 Merrimack Reports Third Quarter 2023 Financial Results Cambridge, MA, November 2, 2023 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) [(“Merrimack” or the “Company”)] today announced its third quarter 2023 financial results for the period ended September 30, 2023. “During the third quarter we saw interest income on our cash and short term investments offset a signifi
August 14, 2023	SC 13D/A	MACK / Merrimack Pharmaceuticals Inc / Western Standard LLC - SC 13D/A Activist Investment SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 4)* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Eric D. Andersen Western Standard, LLC 5757 Wilshire Boulevard, Suite 636 Los Angeles, CA 90036 (310
August 3, 2023	EX-99.1	Merrimack Reports Second Quarter 2023 Financial Results Exhibit 99.1 Merrimack Reports Second Quarter 2023 Financial Results Cambridge, MA, August 3, 2023 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) [(“Merrimack” or the “Company”)] today announced its second quarter 2023 financial results for the period ended June 30, 2023. “We were excited to see the announcement from Ipsen that the U.S. Food and Drug Administration (FDA) had acce
August 3, 2023	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
August 3, 2023	8-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 3, 2023 Merrimack Pharmace UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 3, 2023 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Com
June 7, 2023	8-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 7, 2023 (June 6, 2023) Merri UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 7, 2023 (June 6, 2023) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorp
May 4, 2023	EX-99.1	Merrimack Reports First Quarter 2023 Financial Results Exhibit 99.1 Merrimack Reports First Quarter 2023 Financial Results Cambridge, MA, May 4, 2023 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced its first quarter 2023 financial results for the period ended March 31, 2023. “During the first quarter of 2023 our operating expenses remained consistent with prior quarters and were reduced b
May 4, 2023	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
May 4, 2023	8-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2023 Merrimack Pharmaceuti UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2023 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Commis
April 21, 2023	DEF 14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 DEF 14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.
April 21, 2023	DEFA14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Ame UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confide
April 7, 2023	PRE 14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 PRE 14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.
March 9, 2023	10-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-35409 Merrimack Pharm
March 9, 2023	EX-99.1	Merrimack Reports Full Year 2022 Financial Results EX-99.1 Exhibit 99.1 Merrimack Reports Full Year 2022 Financial Results Cambridge, MA, March 9, 2023 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced its full year 2022 financial results for the period ended December 31, 2022. “We are encouraged by the results of the NAPOLI 3 trial as reported by Ipsen in November 2022 and the guidance
March 9, 2023	8-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 9, 2023 Merrimack Pharmaceu UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 9, 2023 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Comm
March 9, 2023	EX-4	First Amendment to Section 382 Rights Agreement Exhibit 4.5.1 FIRST AMENDMENT TO SECTION 382 RIGHTS AGREEMENT This First Amendment to Section 382 Rights Agreement (the “First Amendment”) is made as of December 2, 2022 by and between MERRIMACK PHARMACEUTICALS, INC. (the “Company” and COMPUTERSHARE TRUST COMPANY, N.A. as Rights Agent (the “Rights Agent”), amending the Section 382 Rights Agreement by and between the Company and the Rights Agent da
March 9, 2023	EX-4	Description of the Registrant’s Securities Registered under Section 12 of the Exchange Act Exhibit 4.5 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED The following description of the securities of Merrimack Pharmaceuticals, Inc. (“us,” “our,” “we” or the “Company”) registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), is intended as a summary only and therefore is not a complete desc
March 9, 2023	EX-21	Subsidiaries of the Registrant Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name Jurisdiction of Incorporation Merrimack Pharmaceuticals UK Limited* Merrimack Securities Corporation* UK Massachusetts * wholly owned
February 14, 2023	SC 13G/A	MACK / Merrimack Pharmaceuticals Inc / Point72 Asset Management, L.P. - SCHEDULE 13G/A, AMENDMENT #1 Passive Investment SC 13G/A 1 pt7213ga.htm SCHEDULE 13G/A, AMENDMENT #1 240.13d-102 Schedule 13G - Information to be included in statements filed pursuant to 240.13d-1(b), (c), and (d) and amendments thereto filed pursuant to 240.13d-2. Securities and Exchange Commission, Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* (Name of Issuer) Merrimack Pharmaceuticals, Inc.
February 13, 2023	SC 13G/A	MACK / Merrimack Pharmaceuticals Inc / 22NW Fund, LP - AMENDMENT NO. 3 TO THE SCHEDULE 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. 3)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 590328209 (CUSIP N
December 5, 2022	EX-99.1	Merrimack Pharmaceuticals Extends Section 382 Net Operating Loss Rights Plan Exhibit 99.1 Merrimack Pharmaceuticals Extends Section 382 Net Operating Loss Rights Plan December 5, 2022 CAMBRIDGE, Mass.?(BUSINESS WIRE)?Dec. 5, 2022? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (the ?Company? or ?Merrimack?), announced today that its Board of Directors (the ?Board?) has extended the Section 382 net operating loss rights plan (the ?Plan?) that was adopted in 2019. The Plan i
December 5, 2022	EX-10.1	Amendment to Section 382 Rights Plan dated December 2, 2022. Exhibit 10.1 FIRST AMENDMENT TO SECTION 382 RIGHTS AGREEMENT This First Amendment to Section 382 Rights Agreement (the ?First Amendment?) is made as of December 2, 2022 by and between MERRIMACK PHARMACEUTICALS, INC. (the ?Company? and COMPUTERSHARE TRUST COMPANY, N.A. as Rights Agent (the ?Rights Agent?), amending the Section 382 Rights Agreement by and between the Company and the Rights Agent dat
December 5, 2022	8-K	Regulation FD Disclosure, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 5, 2022 (December 2, 2022) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction o
November 30, 2022	EX-FILING FEES	Filing Fee Table* EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) MERRIMACK PHARMACEUTICALS, INC.
November 30, 2022	S-8	As filed with the Securities and Exchange Commission on November 30, 2022 S-8 As filed with the Securities and Exchange Commission on November 30, 2022 Registration No.
November 9, 2022	EX-99.1	Merrimack provides Ipsen report that Onivyde® regimen demonstrated statistically significant improvement in overall survival in previously untreated metastatic pancreatic ductal adenocarcinoma EX-99.1 Exhibit 99.1 Merrimack provides Ipsen report that Onivyde® regimen demonstrated statistically significant improvement in overall survival in previously untreated metastatic pancreatic ductal adenocarcinoma Cambridge, MA, November 9, 2022 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) [(“Merrimack” or the “Company”)] announced that Ipsen, SA (“Ipsen”) issued a press releas
November 9, 2022	8-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 9, 2022 (November 9, 202 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 9, 2022 (November 9, 2022) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction o
November 3, 2022	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 3, 2022 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (C
November 3, 2022	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merri
November 3, 2022	EX-99.1	Merrimack Reports Third Quarter 2022 Financial Results Exhibit 99.1 Merrimack Reports Third Quarter 2022 Financial Results Cambridge, MA, November 3, 2022 /Business Wire/ ? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) [(?Merrimack? or the ?Company?)] today announced its third quarter 2022 financial results for the period ended September 30, 2022. ?During the third quarter we continued to see the benefits of reduced operating expenses? said Gary Croc
August 4, 2022	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 4, 2022 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Com
August 4, 2022	SC 13G	MACK / Merrimack Pharmaceuticals Inc / Point72 Asset Management, L.P. - SCHEDULE 13G Passive Investment 240.13d-102 Schedule 13G - Information to be included in statements filed pursuant to 240.13d-1(b), (c), and (d) and amendments thereto filed pursuant to 240.13d-2. Securities and Exchange Commission, Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No. )* (Name of Issuer) Merrimack Pharmaceuticals, Inc. (Title of Class of Securities) Common Stock, $0.01 Par
August 4, 2022	EX-99.1	Merrimack Reports Second Quarter 2022 Financial Results Exhibit 99.1 Merrimack Reports Second Quarter 2022 Financial Results Cambridge, MA, August 4, 2022 /Business Wire/ ? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) [(?Merrimack? or the ?Company?)] today announced its second quarter 2022 financial results for the period ended June 30, 2022. ?We are pleased to report continued reductions in operating expenses as we remain focused on conserving cash
August 4, 2022	EX-99.1	JOINT FILING AGREEMENT Exhibit 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, and that all subsequent amendments to this statement on Schedule 13G may be filed on behalf of each of the undersigned without the necessi
August 4, 2022	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
August 3, 2022	EX-99.1	Merrimack provides Ipsen report of results from Phase III RESILIENT trial evaluating Onivyde® in second-line monotherapy for small cell lung cancer EXHIBIT 99.1 Merrimack provides Ipsen report of results from Phase III RESILIENT trial evaluating Onivyde? in second-line monotherapy for small cell lung cancer Cambridge, MA, August 3, 2022 /Business Wire/ ? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) [(?Merrimack? or the ?Company?)] announced that Ipsen, SA (?Ipsen?) has issued a press release today reporting its primary analysis of the resul
August 3, 2022	8-K	Financial Statements and Exhibits, Other Events UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 3, 2022 (August 3, 2022) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
June 9, 2022	8-K	Submission of Matters to a Vote of Security Holders UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 9, 2022 (June 6, 2022) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorp
May 5, 2022	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
May 5, 2022	EX-99.1	Merrimack Reports First Quarter 2022 Financial Results Exhibit 99.1 Merrimack Reports First Quarter 2022 Financial Results Cambridge, MA, May 5, 2022 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) [(“Merrimack” or the “Company”)] today announced its first quarter 2022 financial results for the period ended March 31, 2022. “During the first quarter of 2022 we continued to see reductions in our operating expenses and were able to close
May 5, 2022	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2022 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Commis
April 27, 2022	8-K	Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 27, 2022 (April 22, 2022) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
April 27, 2022	EX-3.1	Amendment to Amendend and Restated Bylaws of the Registrant dated April 22, 2022. Exhibit 3.1 AMENDMENT TO AMENDED AND RESTATED BYLAWS OF MERRIMACK PHARMACEUTICALS, INC. 1. Section 1.3 of Article I of the Amended and Restated Bylaws of Merrimack Pharmaceuticals, Inc. is hereby amended and replaced in its entirety to read as follows: ?1.3 Special Meetings. (a) Special meetings of stockholders for any purpose or purposes may be called at any time by only the Board of Directors, t
April 27, 2022	DEF 14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 DEF 14A 1 d265511ddef14a.htm DEF 14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐
March 9, 2022	EX-4.5	Description of the Registrant’s Securities Registered under Section 12 of the Exchange Act Exhibit 4.5 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED The following description of the securities of Merrimack Pharmaceuticals, Inc. (?us,? ?our,? ?we? or the ?Company?) registered under Section 12 of the Securities Exchange Act of 1934, as amended (the ?Exchange Act?), is intended as a summary only and therefore is not a complete desc
March 9, 2022	EX-21.1	Subsidiaries of the Registrant Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name Jurisdiction of Incorporation Merrimack Pharmaceuticals UK Limited* Merrimack Securities Corporation* UK Massachusetts * wholly owned
March 9, 2022	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 9, 2022 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Comm
March 9, 2022	10-K	UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-35409 Merrimack Pharm
March 9, 2022	EX-99.1	Merrimack Reports Full Year 2021 Financial Results Exhibit 99.1 Merrimack Reports Full Year 2021 Financial Results Cambridge, MA, March 9, 2022 /Business Wire/ ? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (?Merrimack? or the ?Company?) today announced its full year 2021 financial results for the period ended December 31, 2021. ?During 2021 we have continued to reduce our operating expenses and remain focused on conserving cash to ensure that w
February 14, 2022	EX-99.1	Joint Filing Agreement Exhibit 99.1 Joint Filing Agreement The undersigned hereby agree that the Statement on Schedule 13G dated February 14, 2022 with respect to the Common Stock, $0.01 par value per share, of Merrimack Pharmaceuticals, Inc., and any amendments thereto executed by each and any of the undersigned shall be filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rul
February 14, 2022	SC 13G/A	MACK / Merrimack Pharmaceuticals Inc / Nantahala Capital Management, LLC - SC 13G/A Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securities) 590328209 (CUSIP Number) December 31, 2021 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the ru
February 14, 2022	SC 13G/A	MACK / Merrimack Pharmaceuticals Inc / 22NW, LP - AMENDMENT NO. 2 TO THE SCHEDULE 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. 2)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 590328209 (CUSIP N
November 4, 2021	EX-99.1	Merrimack Reports Third Quarter 2021 Financial Results Exhibit 99.1 Merrimack Reports Third Quarter 2021 Financial Results Cambridge, MA, November 4, 2021, /Business Wire/ ? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (?Merrimack? or the ?Company?) today announced its third quarter 2021 financial results for the period ended September 30, 2021. ?Both Ipsen Pharmaceuticals and Elevation Oncology publicly announced updates during the last three month
November 4, 2021	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 4, 2021 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (C
November 4, 2021	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merri
August 5, 2021	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 5, 2021 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Com
August 5, 2021	EX-99.1	Merrimack Reports Second Quarter 2021 Financial Results Exhibit 99.1 Merrimack Reports Second Quarter 2021 Financial Results Cambridge, MA, August 5, 2021, /Business Wire/ ? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (?Merrimack? or the ?Company?) today announced its second quarter 2021 financial results for the period ended June 30, 2021. ?We are pleased to report continued reductions in our operating expenses as well as positive overall cashflow
August 5, 2021	EX-99.1	Merrimack Reports Second Quarter 2021 Financial Results Exhibit 99.1 Merrimack Reports Second Quarter 2021 Financial Results Cambridge, MA, August 5, 2021, /Business Wire/ ? Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (?Merrimack? or the ?Company?) today announced its second quarter 2021 financial results for the period ended June 30, 2021. ?We are pleased to report continued reductions in our operating expenses as well as positive overall cashflow
August 5, 2021	10-Q	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
August 5, 2021	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 5, 2021 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Com
June 14, 2021	8-K	Submission of Matters to a Vote of Security Holders UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 14, 2021 (June 10, 2021) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Inco
May 6, 2021	10-Q	Quarterly Report - 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
April 22, 2021	DEF 14A	2021 Incentive Award Plan (as set forth on Annex A in the Company’s Definitive Proxy Statement for the 2021 Annual Meeting of Stockholders, filed on April 22, 2021) Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ? Defi
March 11, 2021	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 11, 2021 (March 10, 2021) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
March 11, 2021	EX-99.1	Merrimack Reports Full Year 2020 Financial Results EX-99.1 Exhibit 99.1 Merrimack Reports Full Year 2020 Financial Results Cambridge, MA, March 10, 2021 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced its full year 2020 financial results for the period ended December 31, 2020. “We are pleased that both Ipsen Pharmaceuticals and Elevation Oncology continue to pursue separate clinical s
March 10, 2021	EX-21.1	Subsidiaries of the Registrant Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name Jurisdiction of Incorporation Merrimack Pharmaceuticals UK Limited* Merrimack Securities Corporation* UK Massachusetts * wholly owned
March 10, 2021	10-K	Annual Report - 10-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-35409 Merrimack Pharm
March 10, 2021	EX-4.5	Description of the Registrant’s Securities Registered under Section 12 of the Exchange Act Exhibit 4.5 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED The following description of the securities of Merrimack Pharmaceuticals, Inc. (?us,? ?our,? ?we? or the ?Company?) registered under Section 12 of the Securities Exchange Act of 1934, as amended (the ?Exchange Act?), is intended as a summary only and therefore is not a complete desc
February 12, 2021	SC 13G/A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securi UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securities) 590328209 (CUSIP Number) December 31, 2020 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the ru
February 12, 2021	SC 13G/A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* Merrimack Pharmaceuticals In (Name of Issuer) Common Stock, no par value (Title of Class of Securities) 590328209 (CUSIP Number) 12/31/2020 (Date of Event Which Requires Filing of This Statement) Check the appropriate box to designate the rule pursuant
February 12, 2021	SC 13G/A	SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 )* Merrimack Pharmaceuticals Inc (Name of Issuer) Common Stock (Title of Class of Securities) 590328209 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to whi
December 3, 2020	EX-99.1	JOINT FILING AGREEMENT EX-99.1 Exhibit 99.1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Merrimack Pharmaceuticals, Inc. and further agree that this Joint Filing Agreement be included as an Exhibit thereto.
December 3, 2020	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / Western Standard LLC - SC 13D/A Activist Investment SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 3)* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Eric D. Andersen Western Standard, LLC 5900 Wilshire Boulevard, Suite 650 Los Angeles, CA 90036 (310
December 2, 2020	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / Newtyn Management, LLC - SC 13D/A Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 3) Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Noah G Levy Newtyn Management, LLC 60 East 42nd St, 9th Floor New York, NY 10165 (212) 446-2460 (Name, Address
November 5, 2020	8-K	Regulation FD Disclosure - 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 5, 2020 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (C
November 5, 2020	EX-99.1	Merrimack Reports Third Quarter 2020 Financial Results EX-99.1 Exhibit 99.1 Merrimack Reports Third Quarter 2020 Financial Results Cambridge, MA, November 5, 2020 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced its third quarter 2020 financial results for the period ended September 30, 2020. “We are pleased that both Ipsen Pharmaceuticals and Elevation Oncology continue to enroll patients
November 4, 2020	10-Q	Quarterly Report - 10-Q Q3 2020 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merri
August 7, 2020	8-K	Regulation FD Disclosure UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2020 (August 7, 2020) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
August 7, 2020	EX-99.1	Cambridge, MA, August EX-99.1 Exhibit 99.1 Cambridge, MA, August 6, 2020 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (“Merrimack” or the “Company”) today announced its second quarter 2020 financial results for the period ended June 30, 2020. “We are pleased by recent news releases from both Ipsen Pharmaceuticals and Elevation Oncology, which are conducting separate programs which could result in mi
August 7, 2020	10-Q	Quarterly Report - 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
July 27, 2020	EX-99	JOINT FILING AGREEMENT JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Merrimack Pharmaceuticals, Inc.
July 27, 2020	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / Newtyn Management, LLC - SC 13D/A Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 2) Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Noah G Levy Newtyn Management, LLC 60 East 42nd St, 9th Floor New York, NY 10165 (212) 446-2460 (Name, Address
July 24, 2020	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / Western Standard, LLC - SC 13D/A Activist Investment SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 2)* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Eric D. Andersen Western Standard, LLC 5900 Wilshire Boulevard, Suite 650 Los Angeles, CA 90036 (310
July 24, 2020	EX-99.1	JOINT FILING AGREEMENT EX-99.1 Exhibit 99.1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Merrimack Pharmaceuticals, Inc. and further agree that this Joint Filing Agreement be included as an Exhibit thereto.
May 28, 2020	8-K	Submission of Matters to a Vote of Security Holders 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 28, 2020 (May 28, 2020) Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of In
May 7, 2020	10-Q	Quarterly Report - 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
April 22, 2020	DEF 14A	MACK / Merrimack Pharmaceuticals, Inc. DEF 14A - - DEF 14A DEF 14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.
April 10, 2020	PRE 14A	MACK / Merrimack Pharmaceuticals, Inc. PRE 14A - - PRE 14A PRE 14A Table of Contents Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.
March 30, 2020	8-K	Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2020 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation)
March 30, 2020	EX-2.1	Asset Purchase Agreement, dated as of March 27, 2020, between Merrimack Pharmaceuticals, Inc. and Celator Pharmaceuticals, Inc. EX-2.1 Exhibit 2.1 Execution Version ASSET PURCHASE AGREEMENT by and between CELATOR PHARMACEUTICALS, INC. and MERRIMACK PHARMACEUTICALS, INC. Dated as of March 27, 2020 TABLE OF CONTENTS ARTICLE I PURCHASE AND SALE OF THE TRANSFERRED ASSETS 1 1.1. Purchase and Sale of Assets 1 1.2. Excluded Assets 2 1.3. Assumption of Liabilities 3 1.4. Retained Liabilities 4 1.5. Closing Date Consideration 4 1.6
March 13, 2020	S-8	MACK / Merrimack Pharmaceuticals, Inc. S-8 - - S-8 S-8 As filed with the Securities and Exchange Commission on March 13, 2020 Registration No.
March 12, 2020	EX-21.1	Subsidiaries of the Registrant Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name Jurisdiction of Incorporation Merrimack Pharmaceuticals UK Limited* Merrimack Securities Corporation* UK Massachusetts * wholly owned
March 12, 2020	10-K	MACK / Merrimack Pharmaceuticals, Inc. 10-K - Annual Report - 10-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-35409 Merrimack Pharm
March 12, 2020	EX-4.5	Description of the Registrant’s Securities Registered under Section 12 of the Exchange Act Exhibit 4.5 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED The following description of the securities of Merrimack Pharmaceuticals, Inc. (“us,” “our,” “we” or the “Company”) registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), is intended as a summary only and therefore is not a complete desc
February 21, 2020	8-K	Shareholder Director Nominations 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 19, 2020 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporatio
February 14, 2020	SC 13G	MACK / Merrimack Pharmaceuticals, Inc. / Nantahala Capital Management, LLC - SC 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securities) 590328209 (CUSIP Number) December 31, 2019 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rul
February 14, 2020	SC 13G/A	MACK / Merrimack Pharmaceuticals, Inc. / Biotechnology Value Fund L P - AMENDMENT NO 2 TO THE SCHEDULE 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. 2)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securities) 590328209 (CUSIP Number) Dec
February 14, 2020	EX-99.1	Joint Filing Agreement Exhibit 99.1 Joint Filing Agreement The undersigned hereby agree that the Statement on Schedule 13G dated February 14, 2020 with respect to the shares of Common Stock of Merrimack Pharmaceuticals, Inc., and any further amendments thereto executed by each and any of the undersigned shall be filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k)
February 12, 2020	SC 13G	MACK / Merrimack Pharmaceuticals, Inc. / DIMENSIONAL FUND ADVISORS LP - SCHEDULE 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* MERRIMACK PHARMACEUTICALS IN (Name of Issuer) Common Stock (Title of Class of Securities) 590328209 (CUSIP Number) December 31, 2019 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which
December 3, 2019	8-A12G	MACK / Merrimack Pharmaceuticals, Inc. 8-A12G - - 8-A12G 8-A12G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Merrimack Pharmaceuticals, Inc. (Exact name of registrant as specified in its charter) Delaware 04-3210530 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Ide
December 3, 2019	EX-4.1	Section 382 Rights Agreement, dated as of December 3, 2019, between Merrimack Pharmaceuticals, Inc. and Computershare Trust Company, N.A., as Rights Agent. EX-4.1 Exhibit 4.1 SECTION 382 RIGHTS AGREEMENT dated as of December 3, 2019 between MERRIMACK PHARMACEUTICALS, INC. and COMPUTERSHARE TRUST COMPANY, N.A. as Rights Agent TABLE OF CONTENTS Section 1. Definitions 1 Section 2. Appointment of Rights Agent 6 Section 3. Issue of Right Certificates 7 Section 4. Form of Right Certificates 8 Section 5. Countersignature and Registration 9 Section 6. Transf
December 3, 2019	EX-99.1	MERRIMACK PHARMACEUTICALS ADOPTS SECTION 382 NET OPERATING LOSS RIGHTS PLAN EX-99.1 Exhibit 99.1 MERRIMACK PHARMACEUTICALS ADOPTS SECTION 382 NET OPERATING LOSS RIGHTS PLAN CAMBRIDGE, MA, December 3, 2019 /Business Wire/ – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) (the “Company” or “Merrimack”), announced today that its Board of Directors (the “Board”) has adopted a Section 382 net operating loss rights plan (the “Plan”) and declared a dividend distribution of one Pr
December 3, 2019	8-K	Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 3, 2019 Merrimack Pharmaceuticals, Inc. (Exact name of registrant as specified in its charter) Delaware 001-35409 04-3210530 (State or other jurisdiction of incorporation
December 3, 2019	EX-3.1	Certificate of Designation of Series Z Junior Preferred Stock of the Registrant, as filed with the Secretary of State of the State of Delaware on December 3, 2019 (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K filed on December 3, 2019) EX-3.1 Exhibit 3.1 CERTIFICATE OF DESIGNATION OF SERIES Z JUNIOR PARTICIPATING PREFERRED STOCK OF MERRIMACK PHARMACEUTICALS, INC. (Pursuant to Section 151 of the General Corporation Law of the State of Delaware) In accordance with Section 151 of the Delaware General Corporation Law, the undersigned corporation hereby certifies that the following resolution was adopted by the Board of Directors (th
November 19, 2019	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / JFL Capital Management, LLC - AMENDMENT NO. 6 TO THE SCHEDULE 13D Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 6)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Joseph
November 12, 2019	10-Q	MACK / Merrimack Pharmaceuticals, Inc. 10-Q - Quarterly Report - 10-Q Al cost UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-354
October 21, 2019	8-K	Submission of Matters to a Vote of Security Holders 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 17, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation
September 30, 2019	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / Western Standard, LLC - SC 13D/A Activist Investment SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* (Amendment No. 1) Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Eric D. Andersen Western Standard, LLC 5900 Wilshire Boulevard, Suite 650 Los Angeles, CA 90036 (310
September 30, 2019	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / Newtyn Management, LLC - SC 13D/A Activist Investment SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* (Amendment No. 1) Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Noah G Levy Newtyn Management, LLC 60 East 42nd St, 9th Floor New York, NY 10165 (212) 446-2460 (Nam
September 26, 2019	DEF 14A	MACK / Merrimack Pharmaceuticals, Inc. DEF 14A - - DEF 14A DEF 14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.
September 26, 2019	CORRESP	MACK / Merrimack Pharmaceuticals, Inc. CORRESP - - CORRESP +1 617 526 6000 (t) +1 617 526 5000 (f) wilmerhale.com September 26, 2019 Via EDGAR Submission United States Securities and Exchange Commission Division of Corporation Finance Office of Mergers and Acquisitions 100 F Street, N.E. Washington, D.C. 20549 Attention: Nicholas P. Panos Re: Merrimack Pharmaceuticals, Inc. PRER14A preliminary proxy statement filing made on Schedule 14A Filed Sept
September 24, 2019	DFAN14A	MACK / Merrimack Pharmaceuticals, Inc. DFAN14A - - UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☐ Filed by a Party other than the Registrant ☒ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confide
September 24, 2019	EX-99.1	TERMINATION OF Joint Filing and Solicitation Agreement September 24, 2019 Exhibit 99.1 TERMINATION OF Joint Filing and Solicitation Agreement September 24, 2019 Each of the undersigned is a party to that certain Joint Filing and Solicitation Agreement, dated March 13, 2019, as amended on July 24, 2019 (the “Joint Filing and Solicitation Agreement”). Each of the undersigned hereby agrees that the Joint Filing and Solicitation Agreement is terminated effective immediately
September 24, 2019	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / JFL Capital Management, LLC - AMENDMENT NO. 5 TO THE SCHEDULE 13D Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 5)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Joseph
September 24, 2019	EX-99.2	JOINT FILING AGREEMENT Exhibit 99.2 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including additional amendments thereto) with respect to the common stock, $0.01 par value per share, of Merrimack Pharmaceuticals, Inc., a Delaware corporation
September 20, 2019	EX-99.1	Merrimack Pharmaceuticals Announces Changes to Board of Directors Company Enters into Cooperation Agreement with Newtyn Management and Western Standard Independent Directors Noah Levy of Newtyn and Eric Andersen of Western Standard to Be Added to Mer EX-99.1 Exhibit 99.1 Merrimack Pharmaceuticals Announces Changes to Board of Directors Company Enters into Cooperation Agreement with Newtyn Management and Western Standard Independent Directors Noah Levy of Newtyn and Eric Andersen of Western Standard to Be Added to Merrimack Board, Effective Immediately Newtyn and Western Have Agreed to Vote for Merrimack Slate of Nominees for 2019 Annual Meetin
September 20, 2019	8-K	Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Entry into a Material Definitive Agreement, Financial Statements and Exhibits 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 17, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporati
September 20, 2019	EX-10.1	Cooperation Agreement, dated as of September 18, 2019, by and among the Registrant, Newtyn Management, LLC, Newtyn Partners, LP, Newtyn TE Partners, LP, Noah G. Levy, Newtyn Capital Partners, LP, Ledo Capital, LLC, Western Standard, LLC, Western Standard Partners, LP, Western Standard Partners QP, LP and Eric D. Andersen (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed on September 20, 2019) EX-10.1 Exhibit 10.1 Execution Version COOPERATION AGREEMENT This Cooperation Agreement (this “Agreement”), effective as of September 18, 2019 (the “Effective Date”), is entered into by and among Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Company” or “Merrimack”), the entities and persons listed on Exhibit A hereto (the “Exhibit A Parties”) and any entity or person that hereafte
September 20, 2019	DEFA14A	MACK / Merrimack Pharmaceuticals, Inc. DEFA14A - - 8-K 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 17, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporati
September 20, 2019	EX-10.1	Cooperation Agreement, dated as of September 18, 2019, by and among the Company, Newtyn Management, LLC, Newtyn Partners, LP, Newtyn TE Partners, LP, Noah G. Levy, Newtyn Capital Partners, LP, Ledo Capital, LLC, Western Standard, LLC, Western Standard Partners, LP, Western Standard Partners QP, LP and Eric D. Andersen EX-10.1 Exhibit 10.1 Execution Version COOPERATION AGREEMENT This Cooperation Agreement (this “Agreement”), effective as of September 18, 2019 (the “Effective Date”), is entered into by and among Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Company” or “Merrimack”), the entities and persons listed on Exhibit A hereto (the “Exhibit A Parties”) and any entity or person that hereafte
September 20, 2019	EX-99.1	Press Release, dated September 19, 2019 EX-99.1 Exhibit 99.1 Merrimack Pharmaceuticals Announces Changes to Board of Directors Company Enters into Cooperation Agreement with Newtyn Management and Western Standard Independent Directors Noah Levy of Newtyn and Eric Andersen of Western Standard to Be Added to Merrimack Board, Effective Immediately Newtyn and Western Have Agreed to Vote for Merrimack Slate of Nominees for 2019 Annual Meetin
September 20, 2019	PRER14A	MACK / Merrimack Pharmaceuticals, Inc. PRER14A - - PRER14A PRER14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.
September 19, 2019	DEFA14A	MACK / Merrimack Pharmaceuticals, Inc. DEFA14A - - DEFA14A DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Pro
September 19, 2019	EX-99.3	JOINT FILING AGREEMENT EX-99.3 Exhibit 99.3 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Merrimack Pharmaceuticals. and further agree that this Joint Filing Agreement be included as an Exhibit thereto. In e
September 19, 2019	EX-99.3	JOINT FILING AGREEMENT EX-99.3 Exhibit 99.3 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Merrimack Pharmaceuticals. and further agree that this Joint Filing Agreement be included as an Exhibit thereto. In e
September 19, 2019	SC 13D	MACK / Merrimack Pharmaceuticals, Inc. / Newtyn Management, LLC - SC 13D Activist Investment SC 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Noah G Levy Newtyn Management, LLC 60 East 42nd St, 9th Floor New York, NY 10165 (212) 446-2460 (Name, Address and Telep
September 19, 2019	EX-99.1	COOPERATION AGREEMENT EX-99.1 Exhibit 99.1 Execution Version COOPERATION AGREEMENT This Cooperation Agreement (this “Agreement”), effective as of September 18, 2019 (the “Effective Date”), is entered into by and among Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Company” or “Merrimack”), the entities and persons listed on Exhibit A hereto (the “Exhibit A Parties”) and any entity or person that hereafte
September 19, 2019	EX-99.1	COOPERATION AGREEMENT EX-99.1 Exhibit 99.1 Execution Version COOPERATION AGREEMENT This Cooperation Agreement (this “Agreement”), effective as of September 18, 2019 (the “Effective Date”), is entered into by and among Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Company” or “Merrimack”), the entities and persons listed on Exhibit A hereto (the “Exhibit A Parties”) and any entity or person that hereafte
September 19, 2019	EX-99.2	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) (C EX-99.2 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Noah G Levy Newtyn Management, LLC 60 East 42nd St, 9th Floor New York, NY 10165 (212) 446-2460 (Name, Address and Tele
September 19, 2019	SC 13D	MACK / Merrimack Pharmaceuticals, Inc. / Western Standard, LLC - SC 13D Activist Investment SC 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Eric D. Andersen Western Standard, LLC 5900 Wilshire Boulevard, Suite 650 Los Angeles, CA 90036 (310) 929-4301 (Name, Ad
September 19, 2019	EX-99.2	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) (C EX-99.2 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934* Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Eric D. Andersen Western Standard, LLC 5900 Wilshire Boulevard, Suite 650 Los Angeles, CA 90036 (310) 929-4301 (Name, A
September 5, 2019	DEFA14A	MACK / Merrimack Pharmaceuticals, Inc. DEFA14A - - DEFA14A DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Pro
August 26, 2019	DEFA14A	MACK / Merrimack Pharmaceuticals, Inc. DEFA14A - - DEFA14A DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Pro
August 22, 2019	DFAN14A	MACK / Merrimack Pharmaceuticals, Inc. DFAN14A - - EXHIBIT 1 - LETTER TO STOCKHOLDERS begin 644 ex1todfan14a12042002082219.pdf M)5!$1BTQ+C,-)?\-,2 P(&]B:@T\/ TO5&ET;&4@/[ $T :0!C '( M;P!S &\ 9@!T " 5P!O '( 9 @ "T ( U #$ ,P P #8 ,@ T %\ ,P N M &0 ;P!C '@I#2]0W.[[M[^./E=?+G[^W5^]O+KV^OJ]7>'GY1;6U\5MM7UU]]? MN1NSL[)7][O]4G59WFU?[[KNQ+\OWXWKOZU=>QO!]?R\\7&'/^?);Q M/G;N\'\TSS?MO Z+^&VA!,!R.2G^O"UF^3D"VM\!0G]^?);7RM#[<)WA; ME9W(\KWY9-NVZ^=TWKSHT%6:>79%XGL3ABS63Y96E:?Z^]\>R3\FN] M?Q^!
August 22, 2019	DFAN14A	MACK / Merrimack Pharmaceuticals, Inc. DFAN14A - - UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☐ Filed by a Party other than the Registrant ☒ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confide
August 19, 2019	PRRN14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. 2) Filed by the Registrant ☐ Filed by a Party other than the Registrant ☒ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confid
August 19, 2019	CORRESP	August 19, 2019 O L S H A N 1325 AVENUE OF THE AMERICAS ● NEW YORK, NEW YORK 10019 TELEPHONE: 212.
August 16, 2019	PRER14A	MACK / Merrimack Pharmaceuticals, Inc. PRER14A - - PRER14A PRER14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.
August 16, 2019	DEFA14A	MACK / Merrimack Pharmaceuticals, Inc. DEFA14A - - DEFA14A DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Pro
August 16, 2019	CORRESP	MACK / Merrimack Pharmaceuticals, Inc. CORRESP - - CORRESP +1 617 526 6000 (t) +1 617 526 5000 (f) wilmerhale.com August 16, 2019 Via EDGAR Submission United States Securities and Exchange Commission Division of Corporation Finance Office of Mergers and Acquisitions 100 F Street, N.E. Washington, D.C. 20549 Attention: Nicholas P. Panos Re: Merrimack Pharmaceuticals, Inc. PREC14A preliminary proxy statement filing made on Schedule 14A Filed August
August 13, 2019	CORRESP	August 13, 2019 O L S H A N 1325 AVENUE OF THE AMERICAS ● NEW YORK, NEW YORK 10019 TELEPHONE: 212.
August 13, 2019	PRRN14A	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. 1) Filed by the Registrant ☐ Filed by a Party other than the Registrant ☒ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confid
August 6, 2019	PREC14A	MACK / Merrimack Pharmaceuticals, Inc. PREC14A - - UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☐ Filed by a Party other than the Registrant ☒ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confide
August 5, 2019	PREC14A	MACK / Merrimack Pharmaceuticals, Inc. PREC14A - - PREC14A PREC14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.
July 26, 2019	8-K	Changes in Registrant's Certifying Accountant 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 24, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
July 24, 2019	EX-99.1	JOINDER AGREEMENT Exhibit 99.1 JOINDER AGREEMENT This JOINDER AGREEMENT (this “Joinder”) is made and entered into as of July 24, 2019 by and among JFL Partners Fund LP, JFL Capital Management LP, JFL Capital Holdings LLC, JFL Capital Management LLC, Joseph F. Lawler, 22NW Fund, LP, 22NW, LP, 22NW Fund GP, LLC, Aron R. English, Jason M. Aryeh and Kenneth Lin (collectively, the “Existing Members”) and 22NW GP, Inc. (
July 24, 2019	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / JFL Capital Management, LLC - AMENDMENT NO. 4 TO THE SCHEDULE 13D Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 4)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) JOSEPH
July 17, 2019	EX-16.1	Letter from PricewaterhouseCoopers LLP, dated July 17, 2019, to the Securities and Exchange Commission regarding statements included in this Current Report on Form 8-K EX-16.1 Exhibit 16.1 July 17, 2019 Securities and Exchange Commission 100 F Street, N.E. Washington, DC 20549 Commissioners: We have read the statements made by Merrimack Pharmaceuticals, Inc. (copy attached), which we understand will be filed with the Securities and Exchange Commission, pursuant to Item 4.01 of Form 8-K of Merrimack Pharmaceuticals, Inc. dated July 15, 2019. We agree with the sta
July 17, 2019	8-K	Financial Statements and Exhibits, Changes in Registrant's Certifying Accountant 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 15, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
July 17, 2019	EX-10.7	Transition, Separation and Release of Claims Agreement, dated as of June 25, 2019, by and between the Registrant and Jean M. Franchi (incorporated by reference to Exhibit 10.7 to the Registrant’s Quarterly Report on Form 10-Q filed on July 17, 2019) Exhibit 10.7 TRANSITION, SEPARATION AND RELEASE OF CLAIMS AGREEMENT This Transition, Separation and Release of Claims Agreement (the “Agreement”) is being provided to Jean M. Franchi (“Executive”) on June 14, 2019 (the “Receipt Date”) and is made as of the Agreement Effective Date (as defined below) by and between Executive and Merrimack Pharmaceuticals, Inc. (the “Company”) (together, the “Partie
July 17, 2019	EX-10.9	Transition, Separation and Release of Claims Agreement, dated as of June 25, 2019, by and between the Registrant and Richard Peters (incorporated by reference to Exhibit 10.9 to the Registrant’s Quarterly Report on Form 10-Q filed on July 17, 2019) Exhibit 10.9 TRANSITION, SEPARATION AND RELEASE OF CLAIMS AGREEMENT This Transition, Separation and Release of Claims Agreement (the “Agreement”) is being provided to Richard Peters (“Executive”) on June 14, 2019 (the “Receipt Date”) and is made as of the Agreement Effective Date (as defined below) by and between Executive and Merrimack Pharmaceuticals, Inc. (the “Company”) (together, the “Parties
July 17, 2019	EX-10.8	Transition, Separation and Release of Claims Agreement, dated as of June 25, 2019, by and between the Registrant and Jeffrey A. Munsie (incorporated by reference to Exhibit 10.8 to the Registrant’s Quarterly Report on Form 10-Q filed on July 17, 2019) Exhibit 10.8 TRANSITION, SEPARATION AND RELEASE OF CLAIMS AGREEMENT This Transition, Separation and Release of Claims Agreement (the “Agreement”) is being provided to Jeffrey A. Munsie (“Executive”) on June 14, 2019 (the “Receipt Date”) and is made as of the Agreement Effective Date (as defined below) by and between Executive and Merrimack Pharmaceuticals, Inc. (the “Company”) (together, the “Part
July 17, 2019	EX-10.5	Separation and Release of Claims Agreement, dated as of April 12, 2019, by and between the Registrant and Sergio L. Santillana Exhibit 10.5 SEPARATION AND RELEASE OF CLAIMS AGREEMENT This Separation and Release of Claims Agreement (the “Agreement”) is made as of the Effective Date (as defined below) between Merrimack Pharmaceuticals, Inc. (the “Company”) and Sergio L. Santillana (“Executive”) (together, the “Parties”). WHEREAS, the Company and Executive are parties to the Employment Agreement dated as of May 4, 2017 (the
July 17, 2019	EX-10.6	Transition, Separation and Release of Claims Agreement, dated as of June 25, 2019, by and between the Registrant and Daryl C. Drummond (incorporated by reference to Exhibit 10.6 to the Registrant’s Quarterly Report on Form 10-Q filed on July 17, 2019) Exhibit 10.6 TRANSITION, SEPARATION AND RELEASE OF CLAIMS AGREEMENT This Transition, Separation and Release of Claims Agreement (the “Agreement”) is being provided to Daryl C. Drummond (“Executive”) on June 14, 2019 (the “Receipt Date”) and is made as of the Agreement Effective Date (as defined below) by and between Executive and Merrimack Pharmaceuticals, Inc. (the “Company”) (together, the “Part
July 17, 2019	EX-10.1	Stock Purchase Agreement, dated as of May 7, 2019, by and among the Registrant, HNKK Holdings Limited and Silver Creek Pharmaceuticals, Inc. Exhibit 10.1 STOCK PURCHASE AGREEMENT This Stock Purchase Agreement (this “Agreement”) is made and entered into as of May 7, 2019 (the “Effective Date”) by and among HNKK Holdings Limited, a company registered in the British Virgin Islands (“Purchaser”), Merrimack Pharmaceuticals, Inc., a Delaware corporation (“Seller”), and Silver Creek Pharmaceuticals, Inc., a Delaware corporation (the “Company”
July 17, 2019	10-Q	MACK / Merrimack Pharmaceuticals, Inc. 10-Q - Quarterly Report - 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
July 12, 2019	8-K	Entry into a Material Definitive Agreement, Completion of Acquisition or Disposition of Assets 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 12, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
July 1, 2019	8-K/A	Costs Associated with Exit or Disposal Activities 8-K/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdictio
July 1, 2019	8-K	Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers Form 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 25, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Juris-diction of Incorporat
July 1, 2019	8-K	Entry into a Material Definitive Agreement, Financial Statements and Exhibits Form 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 28, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporati
July 1, 2019	EX-2.1	Amendment No. 2 to Asset Purchase Agreement, dated as of June 28, 2019, by and between the Registrant and 14ner Oncology, Inc. (incorporated by reference to Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on July 1, 2019) EX-2.1 Exhibit 2.1 AMENDMENT NO. 2 TO ASSET PURCHASE AGREEMENT This AMENDMENT NO. 2 TO ASSET PURCHASE AGREEMENT (this “Amendment”) is entered into as of June 28, 2019, by and between 14ner Oncology, Inc., a Delaware corporation (the “Buyer”), and Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Seller”). The Buyer and Seller are referred to collectively herein as the “Parties.” Capita
June 24, 2019	EX-2.1	Amendment No. 1 to Asset Purchase Agreement, dated as of June 24, 2019, by and between the Registrant and 14ner Oncology, Inc. (incorporated by reference to Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on June 24, 2019) EX-2.1 Exhibit 2.1 AMENDMENT NO. 1 TO ASSET PURCHASE AGREEMENT This AMENDMENT NO. 1 TO ASSET PURCHASE AGREEMENT (this “Amendment”) is entered into as of June 24, 2019, by and between 14ner Oncology, Inc., a Delaware corporation (the “Buyer”), and Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Seller”). The Buyer and Seller are referred to collectively herein as the “Parties.” Capita
June 24, 2019	8-K	Entry into a Material Definitive Agreement, Financial Statements and Exhibits 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
May 30, 2019	8-K	Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Costs Associated with Exit or Disposal Activities 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (C
May 30, 2019	EX-2.1	Asset Purchase Agreement, dated as of March 27, 2020, by and between the Registrant and Celator Pharmaceuticals, Inc. (incorporated by reference to Exhibit 2.1 to the Registrant’s Current Report on Form 8-K filed on March 30, 2020) EX-2.1 Exhibit 2.1 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) would likely cause competitive harm to the Company, if publicly disclosed. Double asterisks denote omissions. ASSET PURCHASE AGREEMENT by and between 14NER ONCOLOGY, INC. and MERRIMACK PHARMACEUTICALS, INC. Dated as of May 28, 2019 TABLE OF CONTENTS ARTICLE I PURCHASE A
May 30, 2019	EX-99.1	Merrimack Pharmaceuticals Announces Completion of Strategic Review, Preservation of Ipsen Milestones and Special Cash Dividend EX-99.1 Exhibit 99.1 Merrimack Pharmaceuticals Announces Completion of Strategic Review, Preservation of Ipsen Milestones and Special Cash Dividend Cambridge, Mass., May 30, 2019 – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) today announced the completion of its review of strategic alternatives, following which the Company’s Board of Directors is implementing a series of measures designed to ex
May 13, 2019	SC 13G/A	MACK / Merrimack Pharmaceuticals, Inc. / Newtyn Management, LLC - SC 13G/A Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Merrimack pharmaceuticals INC. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) May 3, 2019 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the
May 13, 2019	EX-1	JOINT FILING AGREEMENT Exhibit A JOINT FILING AGREEMENT In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of them of a statement on Schedule 13G (including amendments thereto) with respect to the Common Stock, $0.
May 10, 2019	8-K	Financial Statements and Exhibits, Results of Operations and Financial Condition 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 10, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (C
May 10, 2019	EX-99.1	Merrimack Reports First Quarter 2019 Financial Results EX-99.1 Exhibit 99.1 Merrimack Reports First Quarter 2019 Financial Results Cambridge, Mass., May 10, 2019 – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK), an oncology company focused on biomarker-defined cancers, today announced its first quarter 2019 financial results for the period ended March 31, 2019. “We continue to focus our efforts on completing the review of our strategic alternatives th
May 10, 2019	10-Q	MACK / Merrimack Pharmaceuticals, Inc. 10-Q Quarterly Report 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
April 30, 2019	8-K	Costs Associated with Exit or Disposal Activities 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 25, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation)
April 30, 2019	10-K/A	MACK / Merrimack Pharmaceuticals, Inc. 10-K/A Annual Report 10-K/A 10-K/A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.
April 17, 2019	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / JFL Capital Management, LLC - AMENDMENT NO. 3 TO THE SCHEDULE 13D Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 3)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Joseph
April 16, 2019	8-K	Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Termination of a Material Definitive Agreement 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 10, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation)
March 14, 2019	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / JFL Capital Management, LLC - AMENDMENT NO. 2 TO THE SCHEDULE 13D Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. )1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) JOSEPH
March 14, 2019	EX-99.1	JOINT FILING AND SOLICITATION AGREEMENT Exhibit 99.1 JOINT FILING AND SOLICITATION AGREEMENT WHEREAS, certain of the undersigned are stockholders, direct or beneficial, of Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Company”); WHEREAS, JFL Partners Fund LP, JFL Capital Management LP, JFL Capital Holdings LLC, JFL Capital Management LLC and Joseph F. Lawler (together, “JFL Capital”), 22NW Fund, LP, 22NW, LP, 22NW Fund G
March 14, 2019	EX-99.2	POWER OF ATTORNEY Exhibit 99.2 POWER OF ATTORNEY Know all by these presents, that the undersigned hereby constitutes and appoints Joseph F. Lawler the undersigned’s true and lawful attorney-in-fact to take any and all action in connection with (i) the undersigned’s beneficial ownership of, or participation in a group with respect to, securities of Merrimack Pharmaceuticals, Inc., a Delaware corporation (the “Compan
March 6, 2019	S-8	Form S-8, File No. 333-230084 S-8 As filed with the Securities and Exchange Commission on March 6, 2019 Registration No.
March 6, 2019	8-K	Financial Statements and Exhibits, Results of Operations and Financial Condition 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 6, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
March 6, 2019	EX-99.1	Merrimack Reports Fourth Quarter and Full Year 2018 Financial Results EX-99.1 Exhibit 99.1 Merrimack Reports Fourth Quarter and Full Year 2018 Financial Results Cambridge, Mass., March 6, 2019 – Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK), a clinical-stage oncology company focused on biomarker-defined cancers, today announced its fourth quarter and full year 2018 financial results for the period ended December 31, 2018. “Last quarter, we engaged external advisors
March 6, 2019	EX-10.28	Consent and Amendment No. 1 to Loan and Security Agreement, dated as of December 27, 2018, by and among the Registrant, the several banks and other financial institutions or entities from time to time parties thereto and Hercules Capital, Inc. Exhibit 10.28 CONSENT AND AMENDMENT NO. 1 TO LOAN AND SECURITY AGREEMENT This CONSENT AND AMENDMENT NO. 1 TO LOAN AND SECURITY AGREEMENT (this “Amendment”), is dated as of December 27, 2018 and is entered into by and among (a) MERRIMACK PHARMACEUTICALS, INC., a Delaware corporation (“Borrower”) and (b) HERCULES CAPITAL, INC., a Maryland corporation in its capacity as administrative agent for itsel
March 6, 2019	10-K	MACK / Merrimack Pharmaceuticals, Inc. 10-K (Annual Report) UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-35409 Merrimack Pharm
March 6, 2019	EX-21.1	Subsidiaries of the Registrant Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name Jurisdiction of Incorporation Merrimack Pharmaceuticals UK Limited* Merrimack Securities Corporation* UK Massachusetts * wholly owned
February 15, 2019	8-K	Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 11, 2019 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporatio
February 14, 2019	SC 13G/A	MACK / Merrimack Pharmaceuticals, Inc. / Biotechnology Value Fund L P - AMENDMENT NO. 1 TO THE SCHEDULE 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. 1)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securities) 590328209 (CUSIP Number) Dec
February 14, 2019	SC 13G	MACK / Merrimack Pharmaceuticals, Inc. / Newtyn Management, LLC Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Merrimack pharmaceuticals INC. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) December 31, 2018 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designat
February 8, 2019	SC 13G	MACK / Merrimack Pharmaceuticals, Inc. / 22NW, LP Passive Investment SC 13G 1 j117190sc13g.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Merrimack Pharmaceuticals In (Name of Issuer) Common Stock, no par value (Title of Class of Securities) 590328209 (CUSIP Number) 12/31/2018 (Date of Event Which Requires Filing of This Statement) Check the appropriate box to desi
December 19, 2018	SC 13D/A	MACK / Merrimack Pharmaceuticals, Inc. / JFL Capital Management, LLC - AMENDMENT NO. 1 TO THE SCHEDULE 13D Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 1)1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) Joseph
November 7, 2018	EX-99.1	Merrimack Reports Third Quarter 2018 Financial Results and Provides Strategic Update Following Portfolio Review – Company to initiate corporate restructuring, including ~60% reduction in force and significant reduction in operating expenses; potentia EX-99.1 Exhibit 99.1 Merrimack Reports Third Quarter 2018 Financial Results and Provides Strategic Update Following Portfolio Review – Company to initiate corporate restructuring, including ~60% reduction in force and significant reduction in operating expenses; potential to extend runway into at least 2H 2022 to preserve ability to capture Ipsen milestones – – Has engaged external advisors to eva
November 7, 2018	8-K	Financial Statements and Exhibits, Results of Operations and Financial Condition 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2018 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation
November 7, 2018	10-Q	MACK / Merrimack Pharmaceuticals, Inc. 10-Q (Quarterly Report) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2018 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merri
November 2, 2018	EX-99.1	JOINT FILING AGREEMENT Exhibit 99.1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including additional amendments thereto) with respect to the common stock, $0.01 par value per share, of Merrimack Pharmaceuticals, Inc., a Delaware corporation
November 2, 2018	SC 13D	MACK / Merrimack Pharmaceuticals, Inc. / JFL Capital Management, LLC - SCHEDULE 13D Activist Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. )1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 590328209 (CUSIP Number) JOSEPH
August 7, 2018	8-K	Financial Statements and Exhibits, Results of Operations and Financial Condition Form 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2018 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporat
August 7, 2018	EX-99.1	Merrimack Reports Second Quarter 2018 Financial Results – $18 million milestone payment received from Shire; Company continues to strengthen cash position from non-dilutive sources – – Two clinical readouts anticipated in 2018: randomized Phase 2 SHE EX-99.1 Exhibit 99.1 Merrimack Reports Second Quarter 2018 Financial Results – $18 million milestone payment received from Shire; Company continues to strengthen cash position from non-dilutive sources – – Two clinical readouts anticipated in 2018: randomized Phase 2 SHERLOC study of MM-121 in metastatic non-small cell lung cancer and Phase 1 study of MM-310 in solid tumors – – Conference call at
August 7, 2018	EX-3.1	Restated Certificate of Incorporation of the Registrant, as amended (incorporated by reference to Exhibit 3.1 to the Registrant’s Quarterly Report on Form 10-Q filed on August 7, 2018) Exhibit 3.1 RESTATED CERTIFICATE OF INCORPORATION OF merrimack pharmaceuticals, inc. Merrimack Pharmaceuticals, Inc. (the “Corporation”), a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware, does hereby certify as follows: The current name of the Corporation is Merrimack Pharmaceuticals, Inc. The original Certificate of
August 7, 2018	10-Q	MACK / Merrimack Pharmaceuticals, Inc. 10-Q (Quarterly Report) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2018 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
July 3, 2018	8-K	Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 2, 2018 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (C
July 3, 2018	EX-10.1	Loan and Security Agreement, dated as of July 2, 2018, by and among the Registrant, certain subsidiaries of the Registrant from time to time party thereto, the several banks and other financial institutions or entities from time to time parties thereto and Hercules Capital, Inc. (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed on July 3, 2018) EX-10.1 Exhibit 10.1 LOAN AND SECURITY AGREEMENT THIS LOAN AND SECURITY AGREEMENT is made and dated as of July 2, 2018 and is entered into by and between MERRIMACK PHARMACEUTICALS, INC., a Delaware corporation, and each of its Qualified Subsidiaries (collectively referred to as “Borrower”), the several banks and other financial institutions or entities from time to time parties to this Agreement (
June 15, 2018	8-K	Submission of Matters to a Vote of Security Holders 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 12, 2018 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (
May 8, 2018	EX-99.1	Merrimack Reports First Quarter 2018 Financial Results – Three clinical readouts expected in 2018, including data from two randomized Phase 2 studies – – Conference call at 8:30 am ET today – EX-99.1 Exhibit 99.1 Merrimack Reports First Quarter 2018 Financial Results – Three clinical readouts expected in 2018, including data from two randomized Phase 2 studies – – Conference call at 8:30 am ET today – Cambridge, Mass., May 8, 2018 — Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK), a clinical-stage oncology company focused on biomarker-defined cancers, today announced its first quarter 2
May 8, 2018	8-K	Financial Statements and Exhibits, Results of Operations and Financial Condition 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2018 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporation) (Co
May 8, 2018	EX-10.2	Eighth Amendment of Lease, dated as of February 15, 2018, by and between the Registrant and ARE-MA Region No. 59, LLC (incorporated by reference to Exhibit 10.2 to the Registrant’s Quarterly Report on Form 10-Q filed on May 8, 2018) Exhibit 10.2 EIGHTH AMENDMENT OF LEASE This Eighth Amendment of Lease (this “Eighth Amendment”) is made and entered into as of February 15, 2018 (the “Effective Date”), by and between ARE-MA REGION NO. 59, LLC, a Delaware limited liability company (“Landlord”), as successor-in-interest to DWF IV One Kendall, LLC, as successor-in-interest to RB Kendall Fee, LLC (“Original Landlord”), and MERRIMACK
May 8, 2018	10-Q	MACK / Merrimack Pharmaceuticals, Inc. 10-Q (Quarterly Report) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2018 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35409 Merrimack
April 27, 2018	DEFA14A	MACK / Merrimack Pharmaceuticals, Inc. DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State
April 27, 2018	DEF 14A	MACK / Merrimack Pharmaceuticals, Inc. DEF 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy State
April 26, 2018	PRER14A	MACK / Merrimack Pharmaceuticals, Inc. PRER14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defi
April 26, 2018	CORRESP	MACK / Merrimack Pharmaceuticals, Inc. CORRESP CORRESP Merrimack Pharmaceuticals, Inc. One Kendall Square, Suite B7201 Cambridge, MA 02139 April 26, 2018 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attention: Dorrie Yale Re: Merrimack Pharmaceuticals, Inc. Preliminary Proxy Statement on Schedule 14A Filed April 13, 2018 File No. 001-35409 Ladies and Gentlemen: On behalf
April 13, 2018	PRE 14A	MACK / Merrimack Pharmaceuticals, Inc. PRE 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State
April 10, 2018	EX-99.1	Joint Filing Agreement Exhibit 99.1 Joint Filing Agreement The undersigned hereby agree that the Statement on Schedule 13G dated April 10, 2018 with respect to the shares of Common Stock of Merrimack Pharmaceuticals, Inc., and any further amendments thereto executed by each and any of the undersigned shall be filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k)(1)
April 10, 2018	SC 13G	MACK / Merrimack Pharmaceuticals, Inc. / Biotechnology Value Fund L P - THE SCHEDULE 13G Passive Investment UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. )1 Merrimack Pharmaceuticals, Inc. (Name of Issuer) Common Stock, $0.01 par value (Title of Class of Securities) 590328209 (CUSIP Number) Apri
March 29, 2018	8-K	Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers Form 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2018 Merrimack Pharmaceuticals, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 001-35409 04-3210530 (State or Other Jurisdiction of Incorporat
March 12, 2018	S-8	Form S-8, File No. 333-223577 S-8 As filed with the Securities and Exchange Commission on March 12, 2018 Registration No.

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