Antisoma plc announced that its aptamer drug AS1411 has been granted orphan drug status in both the United States and the European Union for the treatment of acute myeloid leukaemia (AML). The grants will provide seven years of market exclusivity in the US and ten years of exclusivity in the EU if AS1411 is approved for use in AML. Positive phase II data for AS1411 in AML were presented at the 2008 ASH and 2009 ASCO meetings. Addition of AS1411 to high-dose cytarabine increased response rates without significantly increasing side-effects in patients with relapsed or refractory AML. Phase IIb trials are now planned: the first is expected to start in early 2010. Should this yield positive findings, rapid progress into a registration trial is anticipated. AS1411 already has orphan drug status in both the US and the EU for the treatment of renal cancer. A phase II trial in renal cancer is ongoing, and expected to report initial data before the end of this year.

Antisoma plc, Annual General Meeting, Nov 10, 2009

Antisoma plc announced that, following discussions with FDA and trial investigators, it plans to amend the primary endpoint in the ACCEDE study of AS1413. The ACCEDE study is an ongoing randomised, controlled phase III trial that compares AS1413 plus cytarabine with daunorubicin plus cytarabine in patients newly diagnosed with secondary acute myeloid leukaemia. The primary endpoint of the trial will continue to be based on remission rate, defined as the proportion of patients who achieve complete remission (CR) or complete remission with incomplete blood count recovery (CRi). However, the requirement for confirmation of remission before further intervention will be removed. The revised primary endpoint will therefore be initial remission rate rather than confirmed remission rate. Confirmed remission rate will become a secondary endpoint, alongside duration of remission and overall survival. Antisoma's decision to change the primary endpoint will mean that the ACCEDE study is no longer covered by a Special Protocol Assessment (SPA). FDA has confirmed, however, that the amendment will have no impact on whether a New Drug Application (NDA) based on results from ACCEDE would be accepted for filing.