SEC Form 3
FORM 3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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1. Name and Address of Reporting Person*
CROCKER GARY L

(Last) (First) (Middle)
C/O MERRIMACK PHARMACEUTICALS, INC.
ONE KENDALL SQUARE, SUITE B7201

(Street)
CAMBRIDGE MA 02139

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
01/31/2012
3. Issuer Name and Ticker or Trading Symbol
MERRIMACK PHARMACEUTICALS INC [ MACK ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
X Director 10% Owner
Officer (give title below) Other (specify below)
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Series C Convertible Preferred Stock (1) (1) Common Stock 59,863 (1) D
Series D Convertible Preferred Stock (2) (2) Common Stock 463,654 (2) D
Series E Convertible Preferred Stock (3) (3) Common Stock 46,676 (3) D
Series F Convertible Preferred Stock (4) (4) Common Stock 41,900 (4) D
Series G Convertible Preferred Stock (5) (5) Common Stock 313,266 (5) D
Series C Convertible Preferred Stock (1) (1) Common Stock 15,863 (1) I By Crocker Enterprises, LLC
Series D Convertible Preferred Stock (2) (2) Common Stock 30,000 (2) I By Crocker Enterprises, LLC
Series E Convertible Preferred Stock (3) (3) Common Stock 300,000 (3) I By Crocker Ventures, LLC
Series C Convertible Preferred Stock (1) (1) Common Stock 184,975 (1) I By Wife
Series D Convertible Preferred Stock (2) (2) Common Stock 35,714 (2) I By Wife
Series C Convertible Preferred Stock (1) (1) Common Stock 79,000 (1) I By Daughter
Series D Convertible Preferred Stock (2) (2) Common Stock 21,429 (2) I By Daughter
Series E Convertible Preferred Stock (3) (3) Common Stock 28,332 (3) I By Daughter
Series F Convertible Preferred Stock (4) (4) Common Stock 23,300 (4) I By Daughter
Series G Convertible Preferred Stock (5) (5) Common Stock 22,000 (5) I By Daughter
Series C Convertible Preferred Stock (1) (1) Common Stock 79,000 (1) I By Son
Series D Convertible Preferred Stock (2) (2) Common Stock 21,429 (2) I By Son
Series E Convertible Preferred Stock (3) (3) Common Stock 28,332 (3) I By Son
Series F Convertible Preferred Stock (4) (4) Common Stock 23,300 (4) I By Son
Series G Convertible Preferred Stock (5) (5) Common Stock 22,000 (5) I By Son
Series F Convertible Preferred Stock (4) (4) Common Stock 450,000 (4) I By Trust
Stock Option (right to buy) (6) 04/22/2014 Common Stock 50,000 1.25 D
Stock Option (right to buy) (6) 08/30/2014 Common Stock 35,000 1.25 D
Stock Option (right to buy) (6) 08/03/2015 Common Stock 35,000 1.71 D
Stock Option (right to buy) (6) 08/01/2016 Common Stock 50,000 2.47 D
Stock Option (right to buy) (6) 10/04/2017 Common Stock 35,000 2.59 D
Stock Option (right to buy) (6) 09/21/2018 Common Stock 35,000 1.81 D
Stock Option (right to buy) (6) 11/04/2019 Common Stock 50,000 2.12 D
Stock Option (right to buy) (6) 05/02/2021 Common Stock 66,250 5.54 D
Explanation of Responses:
1. Each share of Series C Convertible Preferred Stock will automatically convert into one share of Common Stock upon the closing of the issuer's initial public offering. The shares have no expiration date.
2. Each share of Series D Convertible Preferred Stock will automatically convert into one share of Common Stock upon the closing of the issuer's initial public offering. The shares have no expiration date.
3. Each share of Series E Convertible Preferred Stock will automatically convert into one share of Common Stock upon the closing of the issuer's initial public offering. The shares have no expiration date.
4. Each share of Series F Convertible Preferred Stock will automatically convert into one share of Common Stock upon the closing of the issuer's initial public offering. The shares have no expiration date.
5. Each share of Series G Convertible Preferred Stock will automatically convert into one share of Common Stock upon the closing of the issuer's initial public offering. The shares have no expiration date.
6. This option is fully vested.
/s/ Jeffrey A. Munsie, attorney-in-fact 02/01/2012
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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