Sec Form 4 Filing - MIGAUSKY GEORGE V @ Dimension Therapeutics, Inc. - 2017-11-07

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
MIGAUSKY GEORGE V
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 DIMENSION THERAPEUTICS, INC., 840 MEMORIAL DRIVE, 4TH FLOOR
3. Date of Earliest Transaction (MM/DD/YY)
11/07/2017
(Street)
CAMBRIDGE, MA02139
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
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
Stock Option (Right to Buy) $ 4.09 11/07/2017 D 55,772 ( 1 ) 06/02/2025 Common Stock 55,772 ( 1 ) 0 D
Stock Option (Right to Buy) $ 7.08 11/07/2017 D 32,069 ( 2 ) 05/18/2026 Common Stock 32,069 ( 2 ) 0 D
Stock Option (Right to Buy) $ 1.15 11/07/2017 D 17,000 ( 3 ) 05/24/2027 Common Stock 17,000 ( 3 ) 0 D
Reporting Owners
Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
MIGAUSKY GEORGE V
C/O DIMENSION THERAPEUTICS, INC.
840 MEMORIAL DRIVE, 4TH FLOOR
CAMBRIDGE, MA02139
X
Signatures
/s/ Mary Thistle, as Attorney-in-Fact for George V. Migausky 11/07/2017
Signature of Reporting Person Date
Explanation of Responses:
( 1 )This stock option, which vests in equal monthly installments over 48 months beginning June 3, 2015, was assumed by Ultragenyx Pharmaceutical Inc. ("Ultragenyx"), and converted in accordance with the exchange ratio as set forth in the Agreement and Plan of Merger dated October 2, 2017 between the Issuer, Ultragenyx and Mystic River Merger Sub Inc., a direct, wholly-owned subsidiary of Ultragenyx.
( 2 )These options were assumed by Ultragenyx and converted in accordance with the exchange ratio as set forth in the Merger Agreement.
( 3 )These options, which vest in full on the earlier of May 25, 2018 or the Issuer's next annual meeting of stockholders, subject to the director's continued service on the Board, were assumed by Ultragenyx and converted in accordance with the exchange ratio as set forth in the Merger Agreement.

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