Shares in US group Cephalon were given a boost before the weekend as investors welcomed news that the Food and Drug Administration has issued a green light for the group’s Treanda for a rare type of cancer.

Specifically, the chemotherapy Treanda (bendamustine) has been approved as an orphan drug to treat patients with chronic lymphocytic leukemia, a slow-progessing cancer of the blood and bone marrow of which there are expected to be around 15,000 new cases in the US this year, according to the American Cancer Society.

Approval was based on data from an international 301-patient trial, in which patients receiving Treanda had better clinical outcomes compared to those given the standard CLL therapy chlorambucil. As well as a significantly higher overall response rate (59% of the Treanda group versus 26% in the chlorambucil arm), patients treated with Cephalon’s drug experienced significantly longer progression-free survival (18 months vs six months, respectively), the group said.

Commenting on the green light, Bruce Cheson, Professor of Medicine at Georgetown University Hospital, Washington, DC, said Treanda is “an effective new option that offers a delay in disease progression, an important goal for patients with chronic lymphocytic leukaemia”.

And investors will likely be watching the progress of Treanda, which is also under review by US regulators for the treatment of indolent non-Hodgkin's lymphoma, very carefully over the coming months, given that patent protection on Cepahlon’s flaship blockbuster sleep drug Provigil (modafinil), which brings in a large chunk of the group’s revenues, runs out in just a few years’ time.