Celgene's shares took a plunge yesterday (thursday) after investors shrank back on news that the group has pulled its application in Europe to expand the scope of Revlimid for multiple myeloma (MM).

Revlimid (lenalidomide) is already available in Europe in combination with dexamethasone for the treatment of patients with MM who have received at least one prior therapy.

Celgene is also seeking permission to market the drug for the maintenance treatment of newly diagnosed MM patients who have not progressed following initial treatment with melphalan, prednisone and Revlimid, or maintenance therapy following autologous stem cell transplantation.

However, in a regulatory update the drugmaker explained that it is temporarily withdrawing the application because regulators have asked for "more mature data" to help better determine the drug's benefit-risk ratio. 

The application will be resubmitted once this additional data has been collected, however, the firm gave no hint as to how long this might take.

Submissions for Revlimid in newly diagnosed MM are continuing as planned in Switzerland, Australia and other core markets, and the application should be with US regulators sometime next year.

Elsewhere, the group said its New Drug Application for pomalidomide plus low-dose dexamethasone for patients with relapsed and refractory MM was accepted for standard review by the US Food and Drug Administration, with a decision expected by February next year.