US drugmaker Celgene won an important new indication for its Thalomid product yesterday after the Food and Drug Administration gave the company the go-ahead to market it for multiple myeloma, a form of blood cancer.

Thalomid (thalidomide) is officially approved only to treat leprosy, but is believed to be used off-label already in multiple myeloma patients, helping it rack up sales of $388 million last year. As a result the new approval, while welcome, is unlikely to spark any significant increase in sales of the drug.

But while Thalomid has been widely used in multiple myeloma, a study reported in March revealed that it was unable to extend survival in patients with this cancer, highlighting the need for new treatments.

Celgene has its own follow-up to Thalomid, Revlimid (lenalidomide), on the market for myelodysplastic syndromes, a group of blood disorders that can develop into cancer. While the company was forced to suspend a trial of Revlimid in multiple myeloma last year after an increase in blood clots was seen in patients taking the drug – something also highlighted in a black box warning on Thalomid’s label - the programme soon got back on track and Celgene is hoping for an FDA verdict on its application by June 30.

Revlimid would be used in patients who failed therapy with first-line treatments for multiple myeloma.

Thalidomide, originally used as a treatment for morning sickness, was taken off the market in the 1960s because women who took it during pregnancy had a much higher rate of severe birth defects. However, studies suggesting it might help against cancer led to its reintroduction - with strict controls - for treating complications of leprosy in 1998.

Multiple myeloma, is the second-most common blood cancer after non-Hodgkin's lymphoma and affects roughly 50,000 people in the USA, with around 14,500 new cases diagnosed each year. About 12,000 Americans are expected to die of multiple myeloma in 2006, according to Celgene.