AMENDMENT TO THE EXCHANGE AGREEMENT AND LETTER OF TRANSMITTAL TO TENDER AND TO ENTER INTO CERTAIN AGREEMENTS IN RESPECT OF 9% CONVERTIBLE SUBORDINATED NOTES DUE 2004 OF HYBRIDON PURSUANT TO ITS OFFER TO EXCHANGE DATED FEBRUARY 6, 1998, AS AMENDED BY...Exchange Agreement and Letter of Transmittal • March 30th, 1998 • Hybridon Inc • Biological products, (no disgnostic substances)
