GlaxoSmithKline's Experimental Cancer Vaccine Failed in Treating Melanoma

An experimental cancer vaccine developed by GlaxoSmithKline failed to help patients suffering from melanoma, according to Reuters.

Britain's biggest drug maker said that it would continue with the Phase III trial of its MAGE-A3 therapeutic vaccine to see if it benefited a subset of patients with a particular genetic signature. The said experimental drug failed during its late-stage clinical trial.

There were two joint targets during the trial, known as co-primary endpoints, looking at both the broad population and a patient subset, so it is possible the treatment will yet to prove effective for a small number of people suffering from the deadly skin cancer. The said drug is also being tested for lung cancer.

The vaccine is one of the two particularly high-risk developmental GSK products that industry analysts believe could, in theory, become multi-billion dollar sellers. The other is a heart drug called darapladib, designed to fight clogged arteries in a different way to statins.

However, analysts have been wary of modeling firm sales forecasts, given the above average risk of failure and as a result GSK stock fell only one percent by 1410 GMT. Shares in its U.S partner Agenus, however, slumped 33 percent, reflecting the high hopes riding on the project at the small biotech firm. Agenus provides one of the components in GSK's vaccine.

"Already low consensus expectations for the product are now likely to fall further," said Citigroup analyst Andrew Baum. He currently forecasts sales of only 149 million pounds ($233 million) in 2018 or the MAGE-A3 vaccine in both melanoma and lung cancer. This figure is about half the industry consensus.

Other companies, including Bristol-Myers Squibb, Roche and Merck & Co, have had some recent notable successes in clinical trials of innovative drugs to boost the immune system, but GSK is still pushing the scientific boundaries with its MAGE-A3 vaccine.