Joint Filer Information

Names:	Deerfield Mgmt, L.P., Deerfield Management Company, L.P., Deerfield International Master Fund, L.P., Deerfield Partners, L.P.
Address:	780 Third Avenue, 37th Floor New York, NY  10017
Designated Filer:	James E. Flynn
Issuer and Ticker Symbol:	Proteon Therapeutics, Inc.  [PRTO]
Date of Event Requiring Statement:	November 30, 2017

The undersigned, Deerfield Mgmt, L.P., Deerfield Management Company, L.P., Deerfield International Master Fund, L.P. and Deerfield Partners, 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 Proteon Therapeutics, Inc.

Signatures:

DEERFIELD MGMT, L.P. By: J.E. Flynn Capital, LLC, General Partner By: /s/ Jonathan Isler        Jonathan Isler, Attorney-In-Fact	DEERFIELD INTERNATIONAL MASTER 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
DEERFIELD MANAGEMENT COMPANY, L.P. By: Flynn Management LLC, General Partner By: /s/ Jonathan Isler        Jonathan Isler, Attorney-In-Fact	DEERFIELD PARTNERS, 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