GlaxoSmithKline’s cancer vaccine has failed to meet its first co-primary endpoint in a Phase III melanoma clinical trial.
The drugs giant notes that an independent analysis of the DERMA study of its MAGE-A3 cancer immunotherapeutic showed that it did not significantly extend disease-free survival in stage IIIB/C melanoma patients with macroscopic nodal disease, whose tumours expressed the MAGE-A3 gene when compared to placebo. The aforementioned gene is expressed in about 65% of stage III melanomas.
However GSK is not giving up and in line with the Independent Data Monitoring Committee’s unanimous recommendation, it will continue the DERMA trial until the second co-primary endpoint is assessed. This endpoint, DFS in the gene signature positive sub-population, is designed to identify a subset of MAGE-A3 positive patients that may benefit from the treatment. Results from this analysis are expected in 2015.
Until then, GSK will remain blinded to all safety and efficacy data and the company noted that the IDMC raised no concern for the continuation of the trial. "We remain committed to identifying a patient sub-population who may benefit from this investigational treatment," said Vincent Brichard, head of immunotherapeutics at GSK Vaccines.
GSK is also investigating the MAGE-A3 vaccine in another Phase III study against non-small cell lung cancer in Stage IIIB/C melanoma patients with macroscopic nodal disease. The first data from this trial are expected in the first half of 2014.
Commenting on the news, Savvas Neophytou, an analyst at Panmure Gordon, said that when the broker put a ‘buy’ rating on GSK in December 2012, “we pointed to 14 pipeline opportunities which provided significant option value. We had identified MAGE-A3 as one of three particularly transformative opportunities”.
In that context, “it is disappointing to see that the drug had failed its first of three phase III trial read-outs for the treatment of melanoma”, he added. The analyst views the failure “as a missed upgrading opportunity but it is unlikely, in our view, to trigger downgrades”.