GlaxoSmithKline's (GSK's) Phase III trial of the MAGE-A3 cancer immunotherapeutic, the DERMA trial, has failed to meet its primary endpoint as it did not extend disease-free survival (DFS) period when compared with placebo in the overall MAGE-A3 positive trial population.
The DERMA study, which is a randomised, blinded and placebo-controlled study includes Agenus's QS-21 Stimulon adjuvant, a component of GSK's novel adjuvant system AS15.
The Phase III trial evaluated the efficacy and safety of the MAGE-A3 cancer immunotherapeutic in Stage IIIB/C melanoma patients with macroscopic nodal disease, whose tumours expressed the MAGE-A3 gene and also had their tumours removed surgically.
The MAGE-A3, a tumour-specific antigen, is expressed in about 65% of tumors in Stage III melanoma patients.
GSK intends to continue the DERMA trial until the second co-primary endpoint is assessed and will be in line with the Independent Data Monitoring Committee's (IDMC) unanimous recommendation.
The co-primary endpoint is designed to identify a subset of MAGE-A3 positive patients that may benefit from the treatment, and results from this analysis are expected to be available in 2015.
Agenus chairman and CEO Garo Armen said: "In the near future, we expect to report results of several other QS-21 Stimulon adjuvant containing programmes."
Agenus expects to report Phase II data for HerpV, a QS-21 Stimulon containing investigational therapeutic vaccine for genital herpes, during the fourth quarter of 2013.
On the other hand, GSK expects to announce Phase III results from MAGRIT, the MAGE-A3 non-small cell lung cancer clinical trial during the first half of 2014 and also provide an update to the RTS,S programme for the prevention of malaria.
Agenus's QS-21 Stimulon adjuvant, a saponin extracted from the bark of the Quillaja saponaria tree, has become essential for several investigational therapeutic vaccines intended to treat cancer and degenerative disorders.