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 * ARCH VENTURE FUND VI LP   2. Issuer Name and Ticker or Trading Symbol Bellerophon Therapeutics, Inc. [BLPH] 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) 8725 WEST HIGGINS ROAD, SUITE 290 3. Date of Earliest Transaction (Month/Day/Year) 02/19/2015 (Street) CHICAGO, IL 60631 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 02/19/2015   P   212,666 A $ 12 965,660 D (1) (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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ARCH VENTURE FUND VI LP 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO, IL 60631		X
ARCH VENTURE PARTNERS VI LP 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO, IL 60631		X
ARCH VENTURE PARTNERS VI LLC 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO, IL 60631		X
CRANDELL KEITH 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO, IL 60631		X
BYBEE CLINTON 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO, IL 60631		X

Signatures

/s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of the general partner of the general partner of ARCH		02/23/2015
**Signature of Reporting Person		Date
/s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of the general partner of the general partner of GPLP		02/23/2015
**Signature of Reporting Person		Date
/s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of GPLLC		02/23/2015
**Signature of Reporting Person		Date
/s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell		02/23/2015
**Signature of Reporting Person		Date
/s/ Mark McDonnell, as Attorney-in-Fact for Clinton Bybee		02/23/2015
**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)	ARCH Venture Partners VI, L.P. (the "GPLP"), as the sole general partner of ARCH Venture Fund VI, L.P. ("ARCH"), may be deemed to beneficially own certain of the shares held by ARCH. The GPLP disclaims beneficial ownership of all shares held by ARCH in which the GPLP does not have an actual pecuniary interest. ARCH Venture Partners VI, LLC (the "GPLLC"), as the sole general partner of the GPLP, may be deemed to beneficially own certain of the shares held by ARCH.
(2)	The GPLLC disclaims beneficial ownership of all shares held by ARCH in which it does not have an actual pecuniary interest. The managing directors of the GPLLC, Robert T. Nelsen, Keith Crandell and Clinton Bybee (together, the "Managing Directors"), are deemed to have voting and dispositive power over the shares held by ARCH, and may be deemed to beneficially own certain of the shares held by ARCH. The Managing Directors disclaim beneficial ownership of all shares held by ARCH in which they do not have an actual pecuniary interest.

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