Ownership Submission
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, 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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(Print or Type Responses)
1. Name and Address of Reporting Person *
Mehra Anand
  2. Issuer Name and Ticker or Trading Symbol
Spark Therapeutics, Inc. [ONCE]
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)
SOFINNOVA VENTURES, 3000 SAND HILL ROAD, 4-250
3. Date of Earliest Transaction (Month/Day/Year)
05/30/2018
(Street)

MENLO PARK, CA 94025
4. If Amendment, Date 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
(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 05/31/2018   M   1,500 A (1) 1,500 D  
Common Stock               481,270 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
Stock Option (right to buy) $ 81.53 05/30/2018   A   4,000     (3) 05/29/2028 Common Stock 4,000 $ 0 4,000 D  
Restricted Stock Units (4) 05/30/2018   A   1,500     (5)   (5) Common Stock 1,500 $ 0 1,500 D  
Restricted Stock Units (4) 05/31/2018   M     1,500   (6)   (6) Common Stock 1,500 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Mehra Anand
SOFINNOVA VENTURES
3000 SAND HILL ROAD, 4-250
MENLO PARK, CA 94025
  X      

Signatures

 /s/ Nathalie Auber, attorney-in-fact for Anand Mehra   06/01/2018
**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) Each restricted stock unit converted into one share of Spark Therapeutics, Inc. common stock.
(2) The securities are owned directly by Sofinnova Venture Partners VIII, L.P. ("SVP VIII"). Sofinnova Management VIII, L.L.C. ("SM VIII"), the general partner of SVP VIII, and Anand Mehra, a director of the Issuer, James I. Healy, and Michael Powell, the managing members of SM VIII, may be deemed to have shared voting and dispositive power over the shares owned by SVP VIII. Such persons and entities disclaim beneficial ownership over the shares owned by SVP VIII except to the extent of any pecuniary interest therein.
(3) 100% of the shares vest on the one-year anniversary of the grant date.
(4) Each restricted stock unit represents a contingent right to receive one share of Spark Therapeutics, Inc. common stock.
(5) 100% of the restricted stock units vest on the one-year anniversary of the grant date. Vested shares will be delivered to the reporting person on the vesting date.
(6) On May 31, 2017, the reporting person was granted 1,500 restricted stock units that vest on the one-year anniversary of the grant date. Vested shares are delivered to the reporting person on the vesting date.

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