Form: 4

Statement of changes in beneficial ownership of securities

October 20, 2015

FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN 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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(Print or Type Responses)
1. Name and Address of Reporting Person *
MPM BIOVENTURES V, L.P.
  2. Issuer Name and Ticker or Trading Symbol
Cerecor Inc. [CERC]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O MPM ASSET MANAGEMENT, 450 KENDALL STREET
3. Date of Earliest Transaction (Month/Day/Year)
10/20/2015
(Street)

CAMBRIDGE, MA 02142
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 10/20/2015   C   595,436 A (1) 595,436 I See Footnote (2)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series B Convertible Preferred Stock (1) 10/20/2015   C     16,672,224   (1)   (1) Common Stock 595,436 $ 0 0 I See Footnote (2)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MPM BIOVENTURES V, L.P.
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
MPM ASSET MANAGEMENT INVESTORS BV5 LLC
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
MPM BIOVENTURES V GP LLC
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
MPM BIOVENTURES V LLC
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
GADICKE ANSBERT
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
EVNIN LUKE
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
KAILIAN VAUGHN M
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
Scopa James Paul
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    
Foley Todd
C/O MPM ASSET MANAGEMENT
450 KENDALL STREET
CAMBRIDGE, MA 02142
    X    

Signatures

 By Ansbert Gadicke, member of MPM BioVentures V LLC, the managing member of MPM BioVentures V GP LLC /s/ Ansbert Gadicke   10/20/2015
**Signature of Reporting Person Date

 By Ansbert Gadicke, member of MPM BioVentures V LLC, the managing member of MPM BioVentures V GP LLC, the general partner of MPM BioVentures V, L.P. /s/ Ansbert Gadicke   10/20/2015
**Signature of Reporting Person Date

 By Ansbert Gadicke, member of MPM BioVentures V LLC, the manager of MPM Asset Management Investors BV5 LLC /s/ Ansbert Gadicke   10/20/2015
**Signature of Reporting Person Date

 /s/ Luke Evnin   10/20/2015
**Signature of Reporting Person Date

 /s/ Todd Foley   10/20/2015
**Signature of Reporting Person Date

 /s/ Ansbert Gadicke   10/20/2015
**Signature of Reporting Person Date

 /s/ Vaughn M. Kailian   10/20/2015
**Signature of Reporting Person Date

 /s/ James Paul Scopa   10/20/2015
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(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).
(1) The shares of Series B Convertible Preferred Stock (the "Series B Shares") automatically converted into Common Stock on a 1-for-0.03571 basis and had no expiration date.
(2) The shares are held as follows: 573,170 by MPM BioVentures V, L.P. ("BV V") and 22,266 by MPM Asset Management Investors BV5 LLC ("AM BV5"). MPM BioVentures V GP LLC ("BV GP") is the general partner of BV V. MPM BioVentures V LLC ("BV LLC") is the managing member of BV GP and AM BV5. Ansbert Gadicke, Luke Evnin, Vaughn M. Kailian, James Paul Scopa and Todd Foley are the members of BV LLC. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.

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