Deerfield Special Situations Fund Form 4 CONSTELLATION PHARMACEUTICALS / James E Flynn ownership change

Joint Filer Information

Names:	Deerfield Mgmt, L.P., Deerfield Management Company, L.P.,  Deerfield Special Situations Fund, L.P.
Address:	780 Third Avenue, 37th Floor New York, NY 10017
Designated Filer:	James E. Flynn
Issuer and Ticker Symbol:	Constellation Pharmaceuticals, Inc. [CNST]
Date of Event Requiring Statement:	July 23, 2018

The undersigned, Deerfield Mgmt, L.P., Deerfield Management Company, L.P., and Deerfield Special Situations Fund, L.P. are jointly filing the attached Statement of Changes in Beneficial Ownership on Form 4 with James E. Flynn with respect to the beneficial ownership of securities of Constellation Pharmaceuticals, Inc.

Signatures:

DEERFIELD MGMT, L.P.

By: J.E. Flynn Capital, LLC, General Partner

By:/s/ Jonathan Isler

Jonathan Isler, Attorney-In-Fact

DEERFIELD MANAGEMENT COMPANY, L.P.

By: Flynn Management LLC, General Partner

By:/s/ Jonathan Isler

Jonathan Isler, Attorney-In-Fact

DEERFIELD SPECIAL SITUATIONS FUND, L.P.

By: Deerfield Mgmt, L.P., General Partner

By: J.E. Flynn Capital, LLC, General Partner

By:/s/ Jonathan Isler

Jonathan Isler, Attorney-In-Fact