Press Release May 16, 2006

Bioenvision and Mayne Pharma Announce Marketing and Distribution Agreement

BOSTON, May 16, 2006 — Bioenvision Inc. and Mayne Pharma Limited recently announced that they have entered into a Marketing and Distribution Agreement for the innovative new cancer product, Evoltra® (clofarabine). Under the agreement, Bioenvision granted Mayne Pharma exclusive rights to market Evoltra for certain haematological malignancies in Australia and New Zealand. Bioenvision will receive milestone payments and a percentage of Mayne's net sales revenue.

Goodwin Procter partner Christopher Denn represented Bioenvision in this transaction.