Merck Serono, a division of Merck KGaA, and its US affiliate, EMD Serono, Inc has temporarily suspended the clinical programme for Stimuvax (BLP25 liposome vaccine) in all recruiting studies worldwide as a result of a suspected unexpected serious adverse reaction (SUSAR). This decision was taken in alignment with the US Food and Drug Administration's (FDA) clinical hold placed on the Investigational New Drug (IND) application for Stimuvax.

A patient participating in a phase-II exploratory clinical trial with the therapeutic cancer vaccine in patients with multiple myeloma developed encephalitis. The patient was randomized to an experimental arm of Stimuvax in combination with an intensified schedule of low-dose cyclophosphamide, which is not used in the other Stimuvax studies.

Effective immediately, the company has temporarily suspended recruitment into and treatment of patients already enrolled into the recruiting Stimuvax clinical trials. This action is a precautionary measure while we are diligently investigating the cause of this adverse event.

The phase-III clinical programme, consisting of the non-small cell lung cancer (NSCLC) studies START and INSPIRE and the breast cancer study STRIDE, is impacted as well as the other recruiting studies.

The company considers patient safety of paramount importance and will continue to work closely with the regulatory authorities, particularly with the US FDA, to evaluate the implications of the adverse reaction on the clinical development programme for Stimuvax and determine the most suitable course of action.

Merck is investigating the use of Stimuvax (BLP25 liposome vaccine) in the treatment of NSCLC and breast cancer.