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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1. Name and Address of Reporting Person * Laufer Ron   2. Issuer Name and Ticker or Trading Symbol CATABASIS PHARMACEUTICALS INC [CATB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O MEDIMMUNE VENTURES, INC., ONE MEDIMMUNE WAY 3. Date of Earliest Transaction (Month/Day/Year) 06/30/2015 (Street) GAITHERSBURG, MD 20878 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 06/30/2015   C   1,079,115 A (1) 1,079,115 I See Footnote (2) Common Stock 06/30/2015   C   330,098 A (1) 1,409,213 I See Footnote (2) Common Stock 06/30/2015   P   223,439 A $ 12 1,632,652 I See Footnote (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 A Preferred Stock

(1)

06/30/2015

C

13,866,666

(1)

(1)

Common Stock

1,079,115

$ 0

0

I

See Footnote (2)

Series B Preferred Stock

(1)

06/30/2015

C

4,241,780

(1)

(1)

Common Stock

330,098

$ 0

0

I

See Footnote (2)

Stock Option (right to buy)

$ 12.21

06/30/2015

A

11,094

(3)

06/29/2025

Common Stock

11,094

$ 0

11,094

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Laufer Ron C/O MEDIMMUNE VENTURES, INC. ONE MEDIMMUNE WAY GAITHERSBURG, MD 20878	X	X

Signatures

/s/ Andrea Matthews, attorney-in-fact for Ron Laufer		06/30/2015
**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 Series A and Series B Preferred Stock converted into Common Stock on a 1-for-12.85 basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series A and B Preferred Stock were convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares had no expiration date.
(2)	These shares are owned directly by MedImmune Ventures, Inc. Dr. Laufer is the Senior Managing Partner of MedImmune Ventures, Inc., and as a result, Dr. Laufer may be deemed to hold voting, dispositive and investment power over the shares held by MedImmune Ventures, Inc. Dr. Laufer disclaims beneficial ownership of such shares except to the extent of any pecuniary interest therein.
(3)	This option was granted on June 30, 2015 and vests over three years, with one-third of the shares vesting on each anniversary of the grant date until the third anniversary of the grant date.

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