13G Filing: Jim Tananbaum’s Foresite Capital Buys More Shares of Aerie Pharmaceuticals Inc (AERI)

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exhibit A

Agreement of Joint Filing

The undersigned hereby
agree that a single Schedule 13G (or any amendment thereto) relating to the common stock of the Issuer shall be filed on behalf
of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13G.

Date:  February 19, 2016
FORESITE CAPITAL FUND II, L.P.
By: FORESITE CAPITAL MANAGEMENT II, LLC
Its: General Partner
By: /s/ James Tananbaum
Name: James Tananbaum
Title: Managing Member
FORESITE CAPITAL MANAGEMENT II, LLC
By: /s/ James Tananbaum
Name: James Tananbaum
Title: Managing Member
FORESITE CAPITAL FUND III, L.P.
By: FORESITE CAPITAL MANAGEMENT III, LLC
Its: General Partner
By: /s/ James Tananbaum
Name: James Tananbaum
Title: Managing Member
FORESITE CAPITAL MANAGEMENT III, LLC
By: /s/ James Tananbaum
Name: James Tananbaum
Title: Managing Member
JAMES TANANBAUM
By: /s/ James Tananbaum
Name: James Tananbaum

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