Pharmaceutical Business review

Seattle Genetics Discontinues Dacetuzumab Phase IIb Clinical Trial

Seattle Genetics has discontinued the SeaGen MARINER phase IIb clinical trial based on a determination that the trial would be unlikely to meet its primary endpoint of complete response rate in the dacetuzumab combination arm as compared to the placebo combination arm.

The SeaGen MARINER trial was a randomised, double-blind phase IIb clinical trial of dacetuzumab or placebo in combination with Rituxan (rituximab) plus ifosfamide, carboplatin and etoposide (R-ICE) chemotherapy for patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL).

The SeaGen MARINER trial was initiated in December 2007, designed to accrue 224 relapsed or refractory DLBCL patients, of which approximately two-thirds were enrolled. Patients were treated with either R-ICE plus dacetuzumab or R-ICE plus placebo. The interim analysis was conducted on data from approximately half of the 224 total patients who were to be enrolled on the trial.

The trial was closed based upon a recommendation by the Independent Data Monitoring Committee (IDMC) following a pre-specified interim analysis. As a result of the closure, dacetuzumab will no longer be provided to patients enrolled on the trial.

Dacetuzumab is a humanised monoclonal antibody that targets the CD40 antigen, which is expressed on most B lineage hematologic malignancies, as well as some solid tumors. Seattle Genetics is developing dacetuzumab under a worldwide collaboration agreement with Genentech, a wholly owned unit of the Roche Group.

The company said that an oral presentation of a phase Ib clinical trial evaluating dacetuzumab in combination with Rituxan and Gemzar (gemcitabine) will be made on December 7, 2009 at the American Society of Hematology, in New Orleans, LA.

Clay Siegall, president and CEO of Seattle Genetics, said: “We are disappointed that the interim analysis of the phase IIb clinical trial resulted in discontinuation of the study, especially given the unmet medical need for DLBCL patients.

“In collaboration with Genentech, we will conduct a detailed analysis of data from the SeaGen MARINER trial. In addition, we are continuing four ongoing phase Ib studies of dacetuzumab for non-Hodgkin lymphoma and multiple myeloma.”