EXHIBIT 1
AGREEMENT REGARDING JOINT FILING
The undersigned, Biotechnology Value Fund, L.P., a Delaware limited
partnership, Biotechnology Value Fund II, L.P., a Delaware limited
partnership, BVF Investments, L.L.C., a Delaware limited liability company,
BVF Partners L.P., a Delaware limited partnership, and BVF Inc., a Delaware
corporation, hereby agree and acknowledge that the information required by
Schedule 13G, to which this Agreement is attached as an exhibit, is filed on
behalf of each of them. The undersigned further agree that any amendments or
supplements thereto shall also be filed on behalf of each of them.
Dated: April 26, 2001
BIOTECHNOLOGY VALUE FUND, L.P.
By: BVF Partners L.P., its general partner
By: BVF Inc., its general partner
By: /s/ XXXX X. XXXXXXX
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Xxxx X. Xxxxxxx
President
BIOTECHNOLOGY VALUE FUND II, L.P.
By: BVF Partners L.P., its general partner
By: BVF Inc., its general partner
By: /s/ XXXX X. XXXXXXX
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Xxxx X. Xxxxxxx
President
BVF INVESTMENTS, L.L.C.
By: BVF Partners L.P., its manager
By: BVF Inc., its general partner
By: /s/ XXXX X. XXXXXXX
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Xxxx X. Xxxxxxx
President
BVF PARTNERS L.P.
By: BVF Inc., its general partner
By: /s/ XXXX X. XXXXXXX
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Xxxx X. Xxxxxxx
President
BVF INC.
By: /s/ XXXX X. XXXXXXX
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Xxxx X. Xxxxxxx
President
