Exhibit 10.21 FORM OF REGISTRATION RIGHTS AGREEMENT Registration Rights Agreement, dated as of May 7, 2002 (this "Agreement"), by and among Bioenvision, Inc., a Delaware corporation (the "Company"), and the Purchasers (as defined below). W I T N E S S...Registration Rights Agreement • May 28th, 2002 • Bioenvision Inc • Pharmaceutical preparations • New York
Exhibit 4.2 FORM OF WARRANT NEITHER THIS WARRANT NOR THE SECURITIES ISSUABLE UPON EXERCISE HEREOF HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND SUCH SECURITIES MAY NOT BE OFFERED, SOLD, TRANSFERRED,...Warrant Agreement • May 28th, 2002 • Bioenvision Inc • Pharmaceutical preparations • New York
Exhibit 10.20 FORM OF SECURITIES PURCHASE AGREEMENT Securities Purchase Agreement (together with the schedules and exhibits hereto, this "Agreement"), dated as of May 7, 2002, by and between Bioenvision, Inc., a Delaware corporation (the "Company"),...Securities Purchase Agreement • May 28th, 2002 • Bioenvision Inc • Pharmaceutical preparations • New York
