EXHIBIT A
Agreement of Joint Filing
Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934,
the undersigned hereby agree that only one statement containing the information
required by Schedule 13D need be filed with respect to the ownership by each of
the undersigned of shares of stock of Rigel Pharmaceuticals, Inc.
Dated: May 8, 2003
MPM BIOVENTURES III, L.P. MPM BIOVENTURES III-QP, L.P.
By: MPM BioVentures III GP, L.P., By: MPM BioVentures III GP, L.P.,
its General Partner its General Partner
By: MPM BioVentures III LLC, By: MPM BioVentures III LLC,
its General Partner its General Partner
By: /s/ Xxxx Xxxxx By: /s/ Xxxx Xxxxx
---------------------------------- ----------------------------------
Name: Xxxx Xxxxx Name: Xxxx Xxxxx
Title: Series A Member Title Series A Member
MPM BIOVENTURES III GMBH & CO. MPM BIOVENTURES III PARALLEL
BETEILIGUNGS KG FUND, L.P.
By: MPM BioVentures III GP, L.P., in its By: MPM BioVentures III GP, L.P.,
capacity as the Managing Limited its General Partner
Partner By: MPM BioVentures III LLC,
By: MPM BioVentures III LLC, its General Partner
its General Partner
By: /s/ Xxxx Xxxxx By: /s/ Xxxx Xxxxx
---------------------------------- ---------------------------------
Name: Xxxx Xxxxx Name: Xxxx Xxxxx
Title: Series A Member Title: Series A Member
MPM ASSET MANAGEMENT MPM BIOVENTURES III GP, L.P.
INVESTORS 2003 BVIII LLC
By: MPM BioVentures III LLC,
its General Partner
By: /s/ Xxxx Xxxxx By: /s/ Xxxx Xxxxx
---------------------------------- ---------------------------------
Name: Xxxx Xxxxx Name: Xxxx Xxxxx
Title: Series A Member Title Series A Member
MPM BIOVENTURES III LLC MPM BIOEQUITIES MASTER FUND, L.P.
By: /s/ Xxxx Xxxxx By: MPM BioEquities GP, L.P.,
---------------------------------- its General Partner
Name: Xxxx Xxxxx By: MPM BioEquities GP LLC,
Title: Manager its General Partner
By: /s/ Xxxx Xxxxx
---------------------------------
Name: Xxxx Xxxxx
Title: Series A Member
MPM BIOEQUITIES GP, L.P. MPM BIOEQUITIES GP, LLC
By: MPM BioEquities GP, LLC By: /s/ Xxxx Xxxxx
its General Partner ---------------------------------
Name: Xxxx Xxxxx
Title: Manager
By: /s/ Xxxx Xxxxx
----------------------------------
Name: Xxxx Xxxxx
Title: Manager
By: /s/ Xxxx Xxxxx By: /s/ Xxxxxxx Xxxxxxx
---------------------------------- ---------------------------------
Name: Xxxx Xxxxx Name: Xxxxxxx Xxxxxxx
By: /s/ Xxxxxxxx Xxxxxxxxx By: /s/ Xxxxxx Xxxxxx
---------------------------------- ---------------------------------
Name: Xxxxxxxx Xxxxxxxxx Name: Xxxxxx Xxxxxx
By: /s/ Xxxxxx Xxxxxx By: /s/ Xxxx Xxxxx, III
---------------------------------- ---------------------------------
Name: Xxxxxx Xxxxxx Name: Xxxx Xxxxx, III
By: /s/ Xxxxxxx Xxxxxxxxx By: /s/ Xxxx xxx Xxxxxx
---------------------------------- ---------------------------------
Name: Xxxxxxx Xxxxxxxxx Name: Xxxx xxx Xxxxxx
By: /s/ Xxxx Xxxxxxx
----------------------------------
Name: Xxxx Xxxxxxx
