Common use of Section Headings and References Clause in Contracts

Section Headings and References. The section headings are for the convenience of the parties and in no way alter, modify, amend, limit or restrict the contractual obligations of the parties. Any reference in this agreement to a particular section or subsection shall refer to a section or subsection of this Agreement, unless specified otherwise. Executed as of the date first written above. AGIOS PHARMACEUTICALS, INC. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Title: Chief Executive Officer /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇ Address: ▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ /s/ ▇▇▇ ▇▇▇ ▇▇▇ ▇▇▇ Address: The ▇▇▇▇▇▇▇▇ Family Institute for Breast Cancer Research ▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇ /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Address: ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ /s/ ▇▇▇▇▇▇▇ ▇▇ ▇▇▇▇▇▇▇ ▇▇ Address: ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Newton, MA 02459 ARCH VENTURE FUND VII, L.P. By: ARCH Venture Partners VII, L.P. Its: General Partner By: ARCH Venture Partners VII, LLC Its: General Partner By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Name: Title: FLAGSHIP VENTURES FUND 2007, L.P. By: Flagship Ventures 2007 General Partner LLC Its: General Partner By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Name: Title: THIRD ROCK VENTURES, L.P. By: Third Rock Ventures GP, L.P. Its: General Partner By: TRV GP, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇▇▇▇▇ Name: Title: Manager PRINCESS ▇▇▇▇▇▇▇▇ HOSPITAL FOUNDATION By: /s/ ▇▇▇▇ ▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇ Title: President and CEO BIOTECHNOLOGY VALUE FUND, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BIOTECHNOLOGY VALUE FUND II, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BVF INVESTMENTS, L.L.C. By: BVF Partners, L.P. Its: Manager By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President INVESTMENT 10, LLC By: BVF Partners, L.P. Its: Attorney-in-fact By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President CELGENE EUROPEAN INVESTMENT COMPANY LLC By: /s/ ▇▇▇▇ ▇’▇▇▇▇▇ Name: ▇▇▇▇ ▇’▇▇▇▇▇ Title: Managing Director HAWKES BAY MASTER INVESTORS (CAYMAN) LP By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Hawkes Bay Master Investors (Cayman) LP SALTHILL INVESTORS (BERMUDA) L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Investors (Bermuda) L.P. SALTHILL PARTNERS, L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Partners, L.P. WUXI PHARMATECH HEALTHCARE FUND I L.P. By: /s/ ▇▇▇▇▇▇ ▇▇ For and on behalf of WuXi PharmaTech Investments (Cayman) INC. As General Partner for and on behalf of WuXi PharmaTech Fund I General Partner L.P. FIDELITY SELECT PORTFOLIOS: PHARMACEUTICALS PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SELECT PORTFOLIOS: BIOTECHNOLOGY PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY ADVISOR SERIES VII: FIDELITY ADVISOR BIOTECHNOLOGY FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY MT. ▇▇▇▇▇▇ STREET TRUST: FIDELITY GROWTH COMPANY FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CONTRAFUND: FIDELITY ADVISOR NEW INSIGHTS FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SECURITIES FUND: FIDELITY SMALL CAP OPPORTUNITIES FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CAPITAL TRUST: FIDELITY SMALL CAP INDEPENDENCE FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer ARCH Venture Fund VII, L.P. c/o ARCH Venture Partners ▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Suite 290 Chicago, IL 60631 Flagship Ventures Fund 2007, L.P. ▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Third Rock Ventures, L.P. ▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ ATTN: ▇▇▇▇▇ ▇▇▇▇▇ Princess ▇▇▇▇▇▇▇▇ Hospital Foundation 8th Floor, ▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇ ▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇, ▇▇▇▇▇▇ Attn: ▇▇▇▇ ▇▇▇▇▇, President and CEO Celgene European Investment Company LLC ▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇ With a copy to: Celgene Corporation ▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: Legal Department WuXi PharmaTech Healthcare Fund I L.P. c/o WuXi AppTec Co. Ltd. ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇ ▇▇▇ Qiao Free Trade Zone Shanghai 200131 P.R.CHINA Attn: ▇▇ ▇▇ Fidelity Select Portfolios: Pharmaceuticals Portfolio c/o Fidelity Investments ▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Attn: ▇▇▇▇▇▇ ▇▇▇▇ With a copy (which shall not constitute notice) to:

Section Headings and References. The section headings are for the convenience of the parties and in no way alter, modify, amend, limit or restrict the contractual obligations of the parties. Any reference in this agreement to a particular section or subsection shall refer to a section or subsection of this Agreement, unless specified otherwise. Executed as of the date first written above. COMPANY: AGIOS PHARMACEUTICALS, INC. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Title: Chief Executive Officer FOUNDERS: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇ Address: ▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ /s/ ▇▇▇ ▇▇▇ ▇▇▇ ▇▇▇ Address: The ▇▇▇▇▇▇▇▇ Family Institute for Breast Cancer Research ▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇ /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Address: ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ /s/ ▇▇▇▇▇▇▇ ▇▇ ▇▇▇▇▇▇▇ ▇▇ Address: ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Newton, MA 02459 Second Amended and Restated Investor Rights Agreement PURCHASERS: ARCH VENTURE FUND VII, L.P. By: ARCH Venture Partners VII, L.P. Its: General Partner By: ARCH Venture Partners VII, LLC Its: General Partner By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Name: Title: FLAGSHIP VENTURES FUND 2007, L.P. By: Flagship Ventures 2007 General Partner LLC Its: General Partner By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Name: Title: THIRD ROCK VENTURES, L.P. By: Third Rock Ventures GP, L.P. Its: General Partner By: TRV GP, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇▇▇▇▇ Name: Title: Manager PRINCESS ▇▇▇▇▇▇▇▇ HOSPITAL FOUNDATION By: /s/ ▇▇▇▇ ▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇ Title: President and CEO Second Amended and Restated Investor Rights Agreement BIOTECHNOLOGY VALUE FUND, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BIOTECHNOLOGY VALUE FUND II, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BVF INVESTMENTS, L.L.C. By: BVF Partners, L.P. Its: Manager By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President INVESTMENT 10, LLC By: BVF Partners, L.P. Its: Attorney-in-fact By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President Second Amended and Restated Investor Rights Agreement CELGENE EUROPEAN INVESTMENT COMPANY LLC By: /s/ ▇▇▇▇ ▇’▇▇▇▇▇ Name: ▇▇▇▇ ▇’▇▇▇▇▇ Title: Managing Director HAWKES BAY MASTER INVESTORS (CAYMAN) LP By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Hawkes Bay Master Investors (Cayman) LP SALTHILL INVESTORS (BERMUDA) L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Investors (Bermuda) L.P. SALTHILL PARTNERS, L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Partners, L.P. Second Amended and Restated Investor Rights Agreement WUXI PHARMATECH HEALTHCARE FUND I L.P. By: /s/ ▇▇▇▇▇▇ ▇▇ For and on behalf of WuXi PharmaTech Investments (Cayman) INC. As General Partner for and on behalf of WuXi PharmaTech Fund I General Partner L.P. Second Amended and Restated Investor Rights Agreement FIDELITY SELECT PORTFOLIOS: PHARMACEUTICALS PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SELECT PORTFOLIOS: BIOTECHNOLOGY PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY ADVISOR SERIES VII: FIDELITY ADVISOR BIOTECHNOLOGY FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY MT. ▇▇▇▇▇▇ STREET TRUST: FIDELITY GROWTH COMPANY FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CONTRAFUND: FIDELITY ADVISOR NEW INSIGHTS FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SECURITIES FUND: FIDELITY SMALL CAP OPPORTUNITIES FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CAPITAL TRUST: FIDELITY SMALL CAP INDEPENDENCE FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer ARCH Venture Fund VII, L.P. c/o ARCH Venture Partners ▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Suite 290 Chicago, IL 60631 Flagship Ventures Fund 2007, L.P. ▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Third Rock Ventures, L.P. ▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ ATTN: ▇▇▇▇▇ ▇▇▇▇▇ Princess ▇▇▇▇▇▇▇▇ Hospital Foundation 8th Floor, ▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇ ▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇, ▇▇▇▇▇▇ Attn: ▇▇▇▇ ▇▇▇▇▇, President and CEO Celgene European Investment Company LLC ▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇ With a copy to: Celgene Corporation ▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: Legal Department WuXi PharmaTech Healthcare Fund I L.P. c/o WuXi AppTec Co. Ltd. ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇ ▇▇▇ Qiao Free Trade Zone Shanghai 200131 P.R.CHINA Attn: ▇▇ ▇▇ Fidelity Select Portfolios: Pharmaceuticals Portfolio c/o Fidelity Investments ▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Attn: ▇▇▇▇▇▇ ▇▇▇▇ With a copy (which shall not constitute notice) to:Treasurer

Section Headings and References. The section headings are for the convenience of the parties and in no way alter, modify, amend, limit or restrict the contractual obligations of the parties. Any reference in this agreement to a particular section or subsection shall refer to a section or subsection of this Agreement, unless specified otherwise. Executed as of the date first written above. AGIOS COMPANY: CONSTELLATION PHARMACEUTICALS, INC. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer [Signature Page to Fifth Amended and Restated Investor Rights Agreement] S.R. ONE, LIMITED By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇, ▇▇., Ph.D. Title: Vice President and Partner [Signature Page to Fifth Amended and Restated Investor Rights Agreement] THIRD ROCK VENTURES, L.P. By: Third Rock Ventures GP, L.P., its general partner By: TRV GP, LLC, its general partner By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇ Title: Partner [Signature Page to Fifth Amended and Restated Investor Rights Agreement] TOPSPIN BIOTECH FUND II, LP By: /s/ ▇▇▇ ▇. ▇▇▇▇▇▇▇ Name: ▇▇▇ ▇. ▇▇▇▇▇▇▇ Title: Managing Director TOPSPIN FUND LP By: /s/ ▇▇▇ ▇. ▇▇▇▇▇▇▇ Name: ▇▇▇ ▇. ▇▇▇▇▇▇▇ Title: Managing Director MSSB C/F ▇▇▇ ▇ ▇▇▇▇▇▇▇ By: /s/ ▇▇▇ ▇. ▇▇▇▇▇▇▇ Name: ▇▇▇ ▇. ▇▇▇▇▇▇▇ Title: Managing Director THE COLUMN GROUP, LP By: The Column Group GP, LP Its: General Partner By: The Column Group, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇ Title: Chief Financial Officer PONOI CAPITAL, L.P. By: Ponoi Management, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇ Title: Chief Financial Officer THE REGENTS OF THE UNIVERSITY OF CALIFORNIA By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇ Bachher Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇ AddressTitle: Chief Investment Officer [Signature Page to Fifth Amended and Restated Investor Rights Agreement] VENROCK ASSOCIATES V, L.P. By: Venrock Management V, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇ Authorized Signatory VENROCK PARTNERS V, L.P. By: Venrock Partners Management V, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇ Name; ▇▇▇▇▇ ▇. ▇▇▇▇▇ Authorized Signatory VENROCK ENTREPRENEURS FUND V, L.P. By: VEF Management V, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇ Authorized Signatory [Signature Page to Fifth Amended and Restated Investor Rights Agreement] CASDIN PARTNERS MASTER FUND LP By: /s/ ▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇ ▇▇▇▇▇▇ Title: Managing Partner CASDIN VENTURE OPPORTUNITIES FUND, L.P. By: Casdin Venture Opportunities Fund GP, LLC, its General Partner By: /s/ ▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇ ▇▇▇▇▇▇ Title: Managing Partner [Signature Page to Fifth Amended and Restated Investor Rights Agreement] ALEXANDRIA VENTURE INVESTMENTS, LLC, a Delaware limited liability company By: Alexandria Real Estate Equities, Inc., a Maryland corporation, managing member By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ Name: ▇▇▇▇▇ /s/ ▇▇▇ ▇▇▇ ▇▇▇ ▇▇▇ Address: The ▇▇▇▇▇▇▇▇ Family Institute for Breast Cancer Research Title: VP – Corporate Counsel SPUR VENTURES II, L.P. By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇ Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇ Title: Member of General Partner [Signature Page to Fifth Amended and Restated Investor Rights Agreement] SM CP LLC By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: Manager [Signature Page to Fifth Amended and Restated Investor Rights Agreement] GRANT AND ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇▇COMMUNITY PROPERTY TRUST, ▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇ U/D/T 8/84 By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ AddressTitle: Trustee ▇▇▇▇▇▇▇▇ FAMILY PARTNERS I By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: General Partner [Signature Page to Fifth Amended and Restated Investor Rights Agreement] ▇▇▇▇▇ ▇. AND ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇ 2004 TRUST By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇ Title: Trustee By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇ Title: Trustee [Signature Page to Fifth Amended and Restated Investor Rights Agreement] MERITZ NS GLOBAL BIO FUND By: Meritz Securities Co., Ltd. Its: Co-managing general partner By: /s/ Song Min-Kyu Name: Song Min-Kyu Title: Deputy General Manager By: NS Investment Co., Ltd. Its: Co-managing general partner By: /s/ Tae-▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ /s/ ▇▇▇▇▇▇▇ ▇▇ ▇▇▇▇▇▇▇ ▇▇ AddressName: ▇▇▇ ▇Tae-▇▇▇▇▇▇ ▇▇▇▇ NewtonTitle: Managing Director By: Paratus Investment Co., MA 02459 ARCH VENTURE FUND VIILtd. Its: Co-managing general partner By: /s/ ▇▇▇▇-▇▇ ▇▇▇ Name: ▇▇▇, ▇▇▇▇-▇▇ Title: Managing Director VENROCK HEALTHCARE CAPITAL PARTNERS II, L.P. By: ARCH Venture Partners VII, L.P. Its: General Partner By: ARCH Venture Partners VIIVHCP Management II, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇ Authorized Signatory VHCP CO-INVESTMENT HOLDINGS II, LLC By: VHCP Management II, LLC Its: Manager By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇ Authorized Signatory [Signature Page to Fifth Amended and Restated Investor Rights Agreement] CORMORANT PRIVATE HEALTHCARE FUND I, LP By: /s/ ▇▇▇▇▇ ▇▇▇▇ By: Cormorant Private Healthare GP, LLC By: ▇▇▇▇▇ ▇▇▇▇, Managing Member of the GP CORMORANT GLOBAL HEALTHCARE MASTER FUND, LP By: /s/ ▇▇▇▇▇ ▇▇▇▇ By: Cormorant Global Healthcare GP, LLC By: ▇▇▇▇▇ ▇▇▇▇, Managing Member of the GP CRMA SPV, L.P. By: /s/ ▇▇▇▇▇ ▇▇▇▇ By: Cormorant Asset Management, LLC By: ▇▇▇▇▇ ▇▇▇▇, CEO/CIO Its: Attorney-in-Fact [Signature Page to Fifth Amended and Restated Investor Rights Agreement] PRECISION ONCO LIMITED By: /s/ Yuan Sun Name: Yuan Sun Title: Director HH CTL HOLDINGS LIMITED By: /s/ Colm ▇▇▇▇ ▇’▇▇▇▇▇▇▇ Name: Colm ▇▇▇▇ ▇’▇▇▇▇▇▇▇ Title: FLAGSHIP VENTURES FUND 2007Director DEERFIELD SPECIAL SITUATIONS FUND, L.P. By: Flagship Ventures 2007 Deerfield Mgmt, L.P. General Partner By: ▇.▇. ▇▇▇▇▇ Capital, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇ Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇ Title: Authorized Signatory [Signature Page to Fifth Amended and Restated Investor Rights Agreement] ORBIMED PRIVATE INVESTMENTS VI, LP By: OrbiMed Capital GP VI LLC, its General Partner By: OrbiMed Advisors LLC its Managing Member By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇ Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇ Title: THIRD ROCK VENTURESMember ORBIMED GLOBAL HEALTHCARE MASTER FUND, L.P. By: Third Rock Ventures GPOrbiMed Global Healthcare GP LLC, L.P. Its: its General Partner By: TRV GPOrbiMed Advisors LLC, its Managing Member By: /s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇ Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇ Title: Member [Signature Page to Fifth Amended and Restated Investor Rights Agreement] PONOI CAPITAL II, LP By: Ponoi II Management, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇ Name: Title: Manager PRINCESS ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇ HOSPITAL FOUNDATION Title: Chief Financial Officer FIDELITY MT. ▇▇▇▇▇▇ STREET TRUST: FIDELITY SERIES GROWTH COMPANY FUND By: /s/ ▇▇▇▇ ▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇ Title: President and CEO BIOTECHNOLOGY VALUE FUND, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BIOTECHNOLOGY VALUE FUND II, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BVF INVESTMENTS, L.L.C. By: BVF Partners, L.P. Its: Manager By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President INVESTMENT 10, LLC By: BVF Partners, L.P. Its: Attorney-in-fact By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President CELGENE EUROPEAN INVESTMENT COMPANY LLC By: /s/ ▇▇▇▇ ▇’▇▇▇▇▇ Name: ▇▇▇▇ ▇’▇▇▇▇▇ Title: Managing Director HAWKES BAY MASTER INVESTORS (CAYMAN) LP By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Hawkes Bay Master Investors (Cayman) LP SALTHILL INVESTORS (BERMUDA) L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Investors (Bermuda) L.P. SALTHILL PARTNERS, L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Partners, L.P. WUXI PHARMATECH HEALTHCARE FUND I L.P. By: /s/ ▇▇▇▇▇▇ ▇▇ For and on behalf of WuXi PharmaTech Investments (Cayman) INC. As General Partner for and on behalf of WuXi PharmaTech Fund I General Partner L.P. FIDELITY SELECT PORTFOLIOS: PHARMACEUTICALS PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SELECT PORTFOLIOS: BIOTECHNOLOGY PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY ADVISOR SERIES VII: FIDELITY ADVISOR BIOTECHNOLOGY FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer Authorized Signatory FIDELITY MT. ▇▇▇▇▇▇ STREET TRUST: FIDELITY GROWTH COMPANY FUND By: /s/ ▇▇▇▇ ▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇ Title: Authorized Signatory FIDELITY GROWTH COMPANY COMMINGLED POOL By: Fidelity Management Trust Company, as Trustee By: /s/ ▇▇▇▇ ▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇ Title: Authorized Signatory [Signature Page to Fifth Amended and Restated Investor Rights Agreement] MOUNTAIN ▇▇▇▇ LIMITED By: /s/ ▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CONTRAFUND: FIDELITY ADVISOR NEW INSIGHTS FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SECURITIES FUND: FIDELITY SMALL CAP OPPORTUNITIES FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CAPITAL TRUST: FIDELITY SMALL CAP INDEPENDENCE FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer ARCH Venture Fund VII, L.P. c/o ARCH Venture Partners ▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Suite 290 Chicago, IL 60631 Flagship Ventures Fund 2007, L.P. ▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Third Rock Ventures, L.P. ▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ ATTN: ▇▇▇▇▇ ▇▇▇▇▇ Princess ▇▇▇▇▇▇▇▇ Hospital Foundation 8th Floor, ▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇ Title: Director This Amendment to the Fifth Amended and Restated Investor Rights Agreement (the “Amendment”) is made as of the 21st day of June, 2018, by and among Constellation Pharmaceuticals, Inc., a Delaware corporation (the “Corporation”), and the other signatories hereto. Capitalized terms used and not otherwise defined herein shall have the meanings ascribed to such terms in the Fifth Amended and Restated Investor Rights Agreement, dated as of March 22, 2018, by and among the Corporation and the investors identified therein (the “▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇, ▇▇▇▇▇▇ Attn: ▇▇▇▇ ▇▇▇▇▇, President and CEO Celgene European Investment Company LLC ▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇ With a copy to: Celgene Corporation ▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: Legal Department WuXi PharmaTech Healthcare Fund I L.P. c/o WuXi AppTec Co. Ltd. ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇ ▇▇▇ Qiao Free Trade Zone Shanghai 200131 P.R.CHINA Attn: ▇▇ ▇▇ Fidelity Select Portfolios: Pharmaceuticals Portfolio c/o Fidelity Investments ▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Attn: ▇▇▇▇▇▇ ▇▇▇▇ With a copy (which shall not constitute notice) to:”).

Section Headings and References. The section headings are for the convenience of the parties and in no way alter, modify, amend, limit or restrict the contractual obligations of the parties. Any reference in this agreement to a particular section or subsection shall refer to a section or subsection of this Agreement, unless specified otherwise. Executed as of the date first written above. AGIOS PHARMACEUTICALS, INC. By: /s/ J▇▇▇ ▇. ▇▇▇▇▇▇▇▇ J▇▇▇ ▇. ▇▇▇▇▇▇▇▇ President and Chief Executive Officer By: /s/ J▇▇▇ ▇▇▇▇▇▇ J▇▇▇ ▇▇▇▇▇▇ Chairman and Managing Director By its General Partner, Venrock Management IV, LLC By its General Partner, Venrock Partners Management, LLC By its General Partner, VEF Management IV, LLC By: /s/ A▇▇▇▇▇ ▇▇▇▇ Name: A▇▇▇▇▇ ▇▇▇▇ Title: Member Signature Page to Second Amended and Restated Investor Rights Agreement Each by its General Partner, AGTC Partners, L.P. By its General Partner, NewcoGen Group Inc. By: /s/ N▇▇▇▇▇ ▇. ▇▇▇▇▇▇ Name: N▇▇▇▇▇ ▇. ▇▇▇▇▇▇ Title: President Each by its Manager, NewcoGen Group Inc. By: /s/ N▇▇▇▇▇ ▇. ▇▇▇▇▇▇ Name: N▇▇▇▇▇ ▇▇▇▇▇▇ Title: President By: Polaris Venture Management Co. IV, L.L.C. its general partner By: /s/ W▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇ Name: W▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇ Title: Attorney-in-fact By: Polaris Venture Management Co. IV, L.L.C. its general partner By: /s/ W▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇ Name: W▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇ Title: Attorney-in-fact By: Atlas Venture Associates V, L.P. their general partner By: Atlas Venture Associates V, Inc. its general partner By: /s/ J▇▇▇▇▇ ▇▇▇▇▇▇ H▇▇▇▇ Name: Title: Vice President By: Atlas Venture Associates VI, L.P. their general partner By: Atlas Venture Associates VI, Inc. its general partner By: /s/ J▇▇▇▇▇ ▇▇▇▇▇▇ H▇▇▇▇ Name: Title: Vice President By: Atlas Venture Associates VI, L.P. its managing limited partner By: Atlas Venture Associates VI, Inc. its general partner By: /s/ J▇▇▇▇▇ ▇▇▇▇▇▇ H▇▇▇▇ Name: Title: Vice President /s/ F▇▇▇▇ ▇▇▇ F▇▇▇▇ ▇▇▇ By: Name: Title: By: Name: Title: /s/ F▇▇▇▇ ▇▇▇ F▇▇▇▇ ▇▇▇ G▇▇▇▇▇ ▇▇▇▇ P▇▇▇▇▇▇ ▇▇▇▇ S▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇Venrock Associates 3▇ ▇▇▇▇▇▇▇▇▇ Title: Chief Executive Officer /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇ Address: ▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ /s/ ▇▇▇ ▇▇▇ ▇▇▇ ▇▇▇ Address: The ▇▇▇▇▇▇▇▇ Family Institute for Breast Cancer Research ▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇ /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ Address: ▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇-▇▇▇▇ Flagship Ventures: Applied Genomic Technology Capital Fund, L.P. AGTC Advisors Fund, L.P. NewcoGen Group LLC NewcoGen Equity Investors LLC NewcoGen PE LLC NewcoGen Elan LLC ST NewcoGen LLC NewcoGen Long Reign Holding LLC 1▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ /s/ ▇▇▇▇▇▇▇ ▇▇ ▇▇▇▇▇▇▇ ▇▇ Address: ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Newton, MA 02459 ARCH VENTURE FUND VII, L.P. By: ARCH Venture Partners VII, L.P. Its: General Partner By: ARCH Venture Partners VII, LLC Its: General Partner By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Name: Title: FLAGSHIP VENTURES FUND 2007, L.P. By: Flagship Ventures 2007 General Partner LLC Its: General Partner By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Name: Title: THIRD ROCK VENTURES, L.P. By: Third Rock Ventures GP, L.P. Its: General Partner By: TRV GP, LLC Its: General Partner By: /s/ ▇▇▇▇▇ ▇▇▇▇▇ Name: Title: Manager PRINCESS ▇▇▇▇▇▇▇▇ HOSPITAL FOUNDATION By: /s/ ▇▇▇▇ ▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇ Title: President and CEO BIOTECHNOLOGY VALUE FUND, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BIOTECHNOLOGY VALUE FUND II, L.P. By: BVF Partners, L.P. Its: General Partner By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President BVF INVESTMENTS, L.L.C. By: BVF Partners, L.P. Its: Manager By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President INVESTMENT 10, LLC By: BVF Partners, L.P. Its: Attorney-in-fact By: BVF, Inc. Its: General Partner By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇ ▇▇▇▇▇▇▇ Title: President CELGENE EUROPEAN INVESTMENT COMPANY LLC By: /s/ ▇▇▇▇ ▇’▇▇▇▇▇ Name: ▇▇▇▇ ▇’▇▇▇▇▇ Title: Managing Director HAWKES BAY MASTER INVESTORS (CAYMAN) LP By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Hawkes Bay Master Investors (Cayman) LP SALTHILL INVESTORS (BERMUDA) L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Investors (Bermuda) L.P. SALTHILL PARTNERS, L.P. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Vice President and Counsel By: Wellington Management Company, LLP, as Investment Advisor for and on behalf of Salthill Partners, L.P. WUXI PHARMATECH HEALTHCARE FUND I L.P. By: /s/ ▇▇▇▇▇▇ ▇▇ For and on behalf of WuXi PharmaTech Investments (Cayman) INC. As General Partner for and on behalf of WuXi PharmaTech Fund I General Partner L.P. FIDELITY SELECT PORTFOLIOS: PHARMACEUTICALS PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SELECT PORTFOLIOS: BIOTECHNOLOGY PORTFOLIO By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY ADVISOR SERIES VII: FIDELITY ADVISOR BIOTECHNOLOGY FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY MT. ▇▇▇▇▇▇ STREET TRUST: FIDELITY GROWTH COMPANY FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CONTRAFUND: FIDELITY ADVISOR NEW INSIGHTS FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY SECURITIES FUND: FIDELITY SMALL CAP OPPORTUNITIES FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer FIDELITY CAPITAL TRUST: FIDELITY SMALL CAP INDEPENDENCE FUND By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇: Deputy Treasurer ARCH Venture Fund VII, L.P. c/o ARCH Venture Partners ▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Suite 290 Chicago, IL 60631 Flagship Ventures Fund 2007, L.P. ▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Third Rock VenturesPolaris Venture Partners IV, L.P. Polaris Venture Partners Entrepreneurs’ Fund IV, L.P. 1▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ ATTN: ▇▇▇Atlas Venture Fund V, L.P. Atlas Venture Parallel Fund V-A, C.V. Atlas Venture Entrepreneurs’ Fund V, L.P. Atlas Venture Fund VI, L.P. Atlas Venture Entrepreneurs’ Fund VI, L.P. Atlas Venture Fund VI GmbH & Co. KG 8▇▇ ▇▇▇▇▇ Princess ▇▇▇▇▇▇▇▇ Hospital Foundation 8th Floor, ▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Attn: ▇▇General Electric Capital Corporation 4▇▇ ▇▇▇▇▇, President and CEO Celgene European Investment Company LLC ▇▇ ▇▇, Suite 23 Norwalk, CT 06851-1177 F▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: 6 ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇ With a copy to: Celgene Corporation ▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ Summit, NJ 07901 Attention: Legal Department WuXi PharmaTech Healthcare Fund I L.P. c/o WuXi AppTec Co. Ltd. ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇ Qiao Free Trade Zone Shanghai 200131 P.R.CHINA Attn: ▇▇▇ ▇▇ Fidelity Select Portfolios: Pharmaceuticals Portfolio c/o Fidelity Investments ▇▇ ▇HBM BioVentures (Cayman) Ltd. C▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇▇ 2▇▇▇ ▇▇▇▇ ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ F▇▇▇▇ ▇▇▇ 6 ▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇ G▇▇▇▇▇ ▇▇▇▇ 1▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ Brookline, MA 02445 P▇▇▇▇▇▇ ▇▇▇▇ 3▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇ Attn: S▇▇▇▇▇ ▇▇▇▇▇▇▇▇ 7▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇ With ▇▇▇▇▇ ▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇▇ This AMENDMENT NO. 1 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT (“Amendment”), dated as of August 13, 2007, amends that certain Second Amended and Restated Investor Rights Agreement (“Agreement”), dated as of July 11, 2007, by and among Adnexus Therapeutics, Inc., a copy Delaware corporation (which the “Company”), the Purchasers (as defined therein), the Common Stockholders (as defined therein), General Electric Capital Corporation (“GE”) and Comerica Bank. Capitalized terms used and not defined herein shall not constitute notice) to:have the meanings set forth in the Agreement.