EpiCept shares plunged more than 40% yesterday as investors shrank back on news that US regulators have refused to file a marketing application for its leukaemia drug Ceplene.

The company said it had received a refusal to file letter from the US Food and Drug Administration regarding its application to market Ceplene (histamine dihydrochloride) in combination with interleukin-2 for the remission maintenance and prevention of relapse of patients with acute myeloid leukaemia.

In its preliminary review of the drug’s NDA, the agency concluded that the application did not establish its therapeutic contribution, and recommended that an additional confirmatory pivotal trial confirming its overall survival benefit be conducted.

EpiCept said it is “surprised and obviously very disappointed” by the decision, presumably particularly as Ceplene has been issued with a green light by regulators in Europe. But the company noted that it intends to request a meeting with the FDA “as soon as possible” to discuss its comments on the submission.

“The Ceplene/IL-2 regimen, which is being rolled out to patients in the European Union, is the only approved treatment that has been shown to prevent relapse of AML patients, of whom the majority will die within a year should a relapse occur,” said Jack Talley, the company’s president and chief executive.

Moreover, he said “the results of the Ceplene Phase III AML study, which demonstrated a statistically significant improvement in leukaemia free survival without impacting patients' quality of life and no treatment related mortality, together with the supporting data we generated for the application deserved a detailed review”.