SCHEDULE 13G

(Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1 (b), (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2 (b)

(Amendment No. 1)*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   VV IV serves as the sole general partner of VSF IV and owns no securities of the Issuer directly.   BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VSF IV; however, they disclaim beneficial ownership of the shares held by VSF IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   VV IV serves as the sole general partner of VSF IV and owns no securities of the Issuer directly.   BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VSF IV; however, they disclaim beneficial ownership of the shares held by VSF IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Consists of options to acquire 57,585 shares of Common Stock held directly by BGA for the benefit of VVIV.

(3)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV; and (iii) options to acquire 57,585 shares of Common Stock held directly by BGA for the benefit of VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(4)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3) This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

10

(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

13

(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

14

(1)   This Schedule 13G is filed by Versant Side Fund IV, L.P., a Delaware limited partnership (“VSF IV”), Versant Venture Capital IV, L.P., a Delaware limited partnership (“VVC IV”), Versant Ventures IV, LLC, a Delaware limited liability company (“VV IV”), Brian G. Atwood (“BGA”), Samuel D. Colella (“SDC”), Ross A. Jaffe (“RAJ”), William J. Link (“WJL”), Rebecca B. Robertson (“RBR”), Camille D. Samuels (“CDS”), Bradley J. Bolzon (“BJB”), Charles M. Warden (“CMW”), Robin L. Praeger (“RLP”), Kirk G. Nielsen (“KGN”) and Kevin J. Wasserstein (“KJW” and together with VSF IV, VVC IV, VV IV, BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP and KGN, collectively, the “Reporting Persons”).  The Reporting Persons expressly disclaim status as a “group” for purposes of this Schedule 13G.

(2)   Includes: (i) 13,600 shares held by VSF IV; (ii) 2,159,289 shares held by VVC IV.  BGA, SDC, RAJ, WJL, RBR, CDS, BJB, CMW, RLP, KGN and KJW are directors and/or members of VV IV and share voting and dispositive power over the shares held by VVC IV; however, they disclaim beneficial ownership of the shares held by VVC IV except to the extent of their pecuniary interests therein. The information with respect to the ownership of the Common Stock by the Reporting Persons filing this statement on Schedule 13G is provided as of December 31, 2012.

(3)   This percentage is calculated based upon 26,139,267 shares of Common Stock outstanding as of November 12, 2012 as set forth in the Issuer’s most recent 10-Q filed with the Securities and Exchange Commission on November 14, 2012.

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Introductory Note: This Statement on Schedule 13G is filed on behalf of the Reporting Persons, in respect of shares of Common Stock, par value $0.001 per share (“Common Stock”), of Clovis Oncology, Inc. (the “Issuer”).

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

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Exhibit(s):

A - Joint Filing Statement

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EXHIBIT A

JOINT FILING STATEMENT

We, the undersigned, hereby express our agreement that the attached Schedule 13G (or any amendments thereto) relating to the Common Stock of Clovis Oncology, Inc. is filed on behalf of each of us.

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