DOR BioPharma says that it has received an unsolicited buyout proposal from fellow US firm Cell Therapeutics and has made an offer that is worth around $50 million.

The proposal would see Cell Therapeutics issue 29 million of its shares to DOR investors, representing 19.9% of its outstanding stock at its closing price from last Friday of $1.73. In addition, it would offer $15 million in stock or cash if the US Food & Drug Administration approves DOR's New Drug Application for orBec (oral beclomethasone dipropionate), for the treatment of intestinal Graft-versus-Host Disease, a common serious complication of bone marrow transplantation for cancer.

However, DOR said that it cannot consider the offer at this present time as the company had signed a letter of intent which grants Sigma-Tau Pharmaceuticals, a unit of Italy’s Sigma-Tau group, exclusive rights to negotiate an alliance for orBec and other development programmes up until March this year. Under the terms of that agreement, Sigma-Tau had agreed to purchase $1 million of DOR shares for about $0.25 cents per share, and paid an additional $2 million in cash.

In September last year, Cell Therapeutics licensed out rights to Xyotax (poliglumex paclitaxel) – which is in Phase III studies as a treatment for non-small cell lung cancer in women – to Novartis, which also took out a $111.5 million option to develop pixantrone, a drug in Phase III that is designed to improve the treatment of haematological cancers. It is now looking for more products ands Dan Eramian told The Seattle Times that acquiring DOR would "springboard us back into building a commercial presence" with a potentially marketable product. The company may also pursue "other acquisitions in the field of hematology," he added.