PhIII fail further dents hopes for GSK's cancer vaccine

Last month GlaxoSmithKline ($GSK) CEO Andrew Witty gave an upbeat assessment of the prospects of the MAGE-A3 cancer vaccine, with the executive saying the product has several chances to succeed. Now it has one fewer after the vaccine missed its primary endpoints in a Phase III lung cancer trial.

GSK CEO Andrew Witty

The blow comes 6 months after MAGE-A3 missed the first of its co-primary endpoints in a Phase III trial of melanoma patients. As in melanoma, GSK is now looking to see if a subpopulation of patients with non-small cell lung cancer respond to the vaccine, but the likelihood of MAGE-A3 living up to its early hype is becoming ever more remote. Reuters reports Citi analyst Andrew Baum estimates the chance of success in the subpopulation is 10%, and his peers are equally downbeat on its prospects.

"With a further read-out pending, we are not pinning much hope on the product," Panmure Gordon analyst Savvas Neophytou wrote in a note seen by the Irish Independent. Despite the previous Phase III failure diminishing expectations, the data still contributed GSK's stock dropping more than 1% on the day it was released. As in September, GSK's partner Agenus ($AGEN)--which provides the adjuvant used in MAGE-A3--suffered the most, with its stock plummeting by more than 10%.

Data from the subpopulation is expected in 2015. By then Agenus should have reported how its own vaccines against glioma and genital herpes fared in Phase II trials, and Pfizer ($PFE) may also have presented data on an Alzheimer's treatment that uses the same adjuvant as MAGE-A3.

- here's Reuters' coverage
- check out WSJ's piece (sub. req.)
- read the Independent's article
- and FierceBiotech's take

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