X0303 4 2009-10-08 0 0000707511 REGENERX BIOPHARMACEUTICALS INC RGN 0001163608 CAVAZZA PAOLO VIA TESSERETE 10 LUGANO V8 00000 SWITZERLAND 0 0 1 0 Common Stock 2009-10-08 4 P 0 1219512 0.82 A 8175110 I Indirect Common Stock 12011185 I Indirect Common Stock 984615 I Indirect Common Stock Warrant (right to buy) 1.12 2009-10-08 4 J 0 1 0 A 2010-04-15 2014-09-30 Common Stock 609756 1 I Indirect These 1,219,512 shares (the ?Shares?) were acquired on October 8, 2009 pursuant to a purchase agreement dated as of September 30, 2009 with the Issuer that provides that the Issuer, rather than Chaumiere Consultadoria e Servicos SDC Unipessoal L.d.a. (?Chaumiere?), has all voting rights in respect of the Shares through September 30, 2012, and that Chaumiere may not transfer the Shares through September 30, 2012 except for transfers to Affiliates (as defined therein). 1,052,631 of these shares were acquired on April 13, 2009 pursuant to a purchase agreement with the Issuer that provides that the Issuer, rather than Chaumiere, has all voting rights in respect of the shares through April 30, 2012, and that Chaumiere may not transfer the shares through April 30, 2012 except for transfers to Affiliates (as defined therein). 1,034,482 of these shares were acquired on December 10, 2008 pursuant to a purchase agreement with the Issuer that provides that the Issuer, rather than Chaumiere, has all voting rights in respect of such shares through December 31, 2011, and that Chaumiere may not transfer such shares through December 31, 2011 except for transfers to Affiliates (as defined therein). 2,500,000 of these shares were acquired on February 29, 2008 pursuant to a purchase agreement with the Issuer that provides that the Issuer shall have the right to repurchase the shares at any time until December 31, 2009, for $2.00 per share, or at any time between January 1, 2010 and December 31, 2010, for $2.50 per share. Furthermore, the purchase agreement provides that the Issuer, rather than Chaumiere, has all voting rights in respect to the shares through December 31, 2010, and that Chaumiere may not transfer such shares through December 31, 2010 except for transfers to Affiliates (as defined therein). Securities directly owned by Chaumiere, which is an indirect wholly-owned subsidiary of Aptafin S.p.A. (?Aptafin?). Aptafin is owned by Paolo Cavazza and members of his family. 307,692 of these shares were acquired on June 22, 2005 pursuant to a purchase agreement with the Issuer that provides that Defiante (as defined below) may not dispose of the shares for a five-year period (the ?Holding Period?), that the Issuer, rather than Defiante, has all voting rights in respect of the shares during the Holding Period, and that the Issuer shall have the right to repurchase the shares within 30 days of the expiration of the Holding Period at a price of $5.00 per share, provided that the Issuer may only repurchase an amount of shares that would leave Defiante, when combined with all of its affiliates, with no less than 30.1% of the Issuer?s shares of Common Stock. Securities directly owned by Defiante Farmaceutica S.A. (?Defiante?). Defiante is 58% directly owned by Sigma Tau Finanziaria S.p.A. (?Sigma Tau?) and 42% directly owned by Sigma Tau?s wholly-owned subsidiary, Sigma Tau International S.A. Paolo Cavazza directly and indirectly owns 38% of Sigma Tau. Securities directly owned by Sigma Tau. This warrant was issued by the Issuer to Chaumiere in consideration of Chaumiere?s purchase of the Shares. This warrant and the shares issuable upon exercise of this warrant are subject to the same transfer and voting restrictions as are the Shares described in explanation (1) above. /s/ Fabio Poma, Attorney-in-fact 2009-10-12