EX-99 4 ex_1sc13da2-valentis.txt EXHIBIT 1 EXHIBIT 1 --------- JOINT FILING AGREEMENT Each of the undersigned hereby acknowledges and agrees, in compliance with the provisions of Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, that the Schedule 13D to which this Agreement is attached as an Exhibit (the "Schedule 13D"), and any amendments thereto, will be filed with the Securities and Exchange Commission jointly on behalf of the undersigned. This Agreement may be executed in one or more counterparts. Dated: February 2, 2004 PERSEUS-SOROS BIOPHARMACEUTICAL FUND, LP By: Perseus-Soros Partners, LLC, General Partner By: SFM Participation, L.P., Managing Member By: SFM AH LLC General Partner By: Soros Fund Management LLC, Managing Member By: /s/ John F. Brown -------------------------------- Name: John F. Brown Title: Assistant General Counsel PERSEUS-SOROS PARTNERS, LLC By: SFM Participation, L.P. Managing Member By: SFM AH LLC General Partner By: Soros Fund Management LLC, Managing Member By: /s/ John F. Brown -------------------------------- Name: John F. Brown Title: Assistant General Counsel CUSIP NO. 91913E104 PAGE 2 PERSEUS BIOTECH FUND PARTNERS, LLC By: Perseuspur EC, L.L.C. Managing Member By: Perseuspur, LLC Member By: /s/ Rodd Macklin -------------------------------- Name: Rodd Macklin Title: Secretary and Treasurer SFM PARTICIPATION, L.P. By: SFM AH LLC General Partner By: Soros Fund Management LLC, Managing Member By: /s/ John F. Brown -------------------------------- Name: John F. Brown Title: Assistant General Counsel SFM AH LLC By: Soros Fund Management LLC, Managing Member By: /s/ John F. Brown -------------------------------- Name: John F. Brown Title: Assistant General Counsel MR. FRANK H. PEARL By: /s/ Rodd Macklin -------------------------------- Name: Rodd Macklin Title: Attorney-in-Fact (1) MR. GEORGE SOROS By: /s/ John F. Brown -------------------------------- Name: John F. Brown Title: Assistant General Counsel SOROS FUND MANAGEMENT LLC By: /s/ John F. Brown -------------------------------- Name: John F. Brown Title: Assistant General Counsel PERSEUSPUR, LLC By: /s/ Rodd Macklin -------------------------------- Name: Rodd Macklin Title: Secretary and Treasurer CUSIP NO. 91913E104 PAGE 3 PERSEUS EC, L.L.C. By: Perseuspur, LLC Member By: /s/ Rodd Macklin -------------------------------- Name: Rodd Macklin Title: Secretary and Treasurer (1) A Power of Attorney, dated April 9, 2003, appointing Rodd Macklin to act on behalf of Frank H. Pearl has been filed with the Securities and Exchange Commission. (2) A Power of Attorney, dated October 30, 2002, appointing each of Armando T. Belly, Jodye Anzalotta, John F. Brown, Maryann Canfield, Richard D. Holahan, Jr. and Robert Soros to act on behalf of George Soros has been filed with the Securities and Exchange Commission.