Sec Form 4 Filing - Dybbs Michael @ Dimension Therapeutics, Inc. - 2015-10-27

Insider filing report for Changes in Beneficial Ownership
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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
Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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1. Name and Address of Reporting Person
Dybbs Michael
2. Issuer Name and Ticker or Trading Symbol
Dimension Therapeutics, Inc. [ DMTX]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
X __ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last) (First) (Middle)
C/O NEW LEAF VENTURE PARTNERS, 7 TIMES SQUARE, SUITE 3502
3. Date of Earliest Transaction (MM/DD/YY)
10/27/2015
(Street)
NEW YORK, NY10036
4. If Amendment, Date Original Filed (MM/DD/YY)
6. Individual or Joint/Group Filing (Check Applicable Line)
__ X __ Form filed by One Reporting Person
_____ 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 10/27/2015 C 1,097,745 A 1,097,745 I See Footnote ( 2 )
Common Stock 10/27/2015 P 961,538 A $ 13 2,059,283 I See Footnote ( 2 )
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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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
(MM/DD/YY)
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 Preferred Stock ( 1 ) 10/27/2015 C 3,208,711 ( 1 ) ( 1 ) Common Stock 1,097,745 ( 1 ) 0 I See Footnote ( 2 )
Reporting Owners
Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Dybbs Michael
C/O NEW LEAF VENTURE PARTNERS
7 TIMES SQUARE, SUITE 3502
NEW YORK, NY10036
X
Signatures
/s/ Mary Thistle, as Attorney-in-Fact for Michael Dybbs 10/29/2015
Signature of Reporting Person Date
Explanation of Responses:
( 1 )The Series B Preferred Stock automatically converted into Common Stock, for no additional consideration, on a 2.923-for-1 basis at the closing of the Issuer's initial public offering, and had no expiration date.
( 2 )These securities are held by New Leaf Ventures III, L.P. ("NLV-III") and New Leaf Growth Fund I, L.P. ("NLGF"). New Leaf Venture Associates III, L.P. ("NLVA-III") is the general partner of NLV-III and New Leaf Venture Management III, L.L.C. ("NLVM-III") is the general partner of NLVA-III. New Leaf Growth Associates I, L.P. ("NLGA") is the general partner of NLGF and NLVM-III is the general partner of NLGA. Reporting Person is employed by New Leaf Venture Partners, L.L.C., which is affiliated with the above entities and disclaims beneficial ownership of the shares held by NLV-III and NLGF except to the extent of his pecuniary interests therein if any.

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