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 * ALTA BIOPHARMA PARTNERS III LP   2. Issuer Name and Ticker or Trading Symbol CHIMERIX INC [CMRX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) Stockholder (Last) (First) (Middle) ONE EMBARCADERO CENTER, 37TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 04/16/2013 (Street) SAN FRANCISCO, CA 94111 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 04/16/2013   C   826,474 A (1) 826,474 I (2) See Footnote (2) Common Stock 04/16/2013   C   688,729 A (3) 1,515,203 I (2) See Footnote (2) Common Stock 04/16/2013   C   550,982 A (4) 2,161,829 (5) I (2) 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

Series D Preferred Stock

(1)

04/16/2012

C

2,933,986

(1)

(1)

Common Stock

826,474

$ 0

0

I (2)

See Footnote (2)

Series E Preferred Stock

(3)

04/16/2012

C

2,444,990

(3)

(3)

Common Stock

688,729

$ 0

0

I (2)

See Footnote (2)

Series F Preferred Stock

(4)

04/16/2012

C

1,955,991

(4)

(4)

Common Stock

550,982

$ 0

0

I (2)

See Footnote (2)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ALTA BIOPHARMA PARTNERS III LP ONE EMBARCADERO CENTER, 37TH FLOOR SAN FRANCISCO, CA 94111				Stockholder
ALTA BIOPHARMA PARTNERS III GMBH & CO BETEILIGUNGS KG ONE EMBARCADERO CENTER, 37TH FLOOR SAN FRANCISCO, CA 94111				Stockholder
ALTA EMBARCADERO BIOPHARMA PARTNERS III LLC ONE EMBARCADERO CENTER, 37TH FLOOR SAN FRANCISCO, CA 94111				Stockholder

Signatures

See Signatures Included in Exhibit 99.2		04/16/2013
**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)	Upon the closing of the Issuer's initial public offering, every 3.55 shares of Series D Preferred Stock automatically converted into 1 share of Common Stock for no additional consideration and had no expiration date.
(2)	See attached Exhibit 99.1
(3)	Upon the closing of the Issuer's initial public offering, every 3.55 shares of Series E Preferred Stock automatically converted into 1 share of Common Stock for no additional consideration and had no expiration date.
(4)	Upon the closing of the Issuer's initial public offering, every 3.55 shares of Series F Preferred Stock automatically converted into 1 share of Common Stock for no additional consideration and had no expiration date.
(5)	Includes an aggregate of 95,644 shares issued as payment of accrued dividends on the Series F Preferred Stock held as follows: 87,602 shares held by Alta Biopharma Partners III, L.P., 5,883 shares held by Alta Biopharma Partners III GmbH & Co. Beteiligungs KG and 2,159 shares held by Alta Embarcadero Biopharma Partners III, LLC.

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