The decision comes less than two weeks after GSK
said the MAGE-A3 therapeutic vaccine did not help patients with
non-small cell lung cancer in the Phase III study overall, but it
was still looking for improvements among patients with a particular
In the event, scientists analyzing the trial decided there was
insufficient treatment effect to pinpoint benefit in such
Vincent Brichard, head of immunotherapeutics at GSK Vaccines, who
announced the decision on Wednesday, said he was "extremely
disappointed" by the result.
Identifying a sub-group for whom MAGE-A3 would work had been
considered a long shot by investors. Nonetheless, Citi analyst
Andrew Baum said the latest setback removed "important optionality"
for future sales and profits.
A second trial testing the vaccine in melanoma, which also failed to
help patients overall, will continue to investigate benefits in
sub-populations. However, the commercial opportunity in melanoma is
only 20 to 30 percent that of lung cancer, according to Citi.
The outcome of the melanoma research is expected in 2015.
Unlike traditional preventative vaccines, the MAGE-A3 treatment was
designed for people with established disease, helping their immune
systems to prevent the return of disease after surgery.
Other companies, including Bristol-Myers Squibb Co, Roche Holding AG
and Merck & Co Inc, have had some recent notable successes in
clinical trials of innovative drugs to boost the immune system, but
GSK's vaccine-based approach is different and has met with less
[to top of second column]
Shares in Britain's biggest drugmaker were 0.7 percent lower at
0750 GMT, underperforming a 0.3 percent decline in the European
MAGE-A3 is one of two high-risk, high-reward research projects that
GSK has invested heavily in over recent years — so far, to little
Its experimental heart drug darapladib, which fights clogged
arteries in a novel way, has also failed to hit its goals in a
late-stage clinical trial, although GSK still hopes a second study
U.S.-based Agenus Inc has contributed technology to GSK's MAGE-A3
vaccine and its shares are sensitive to news on the project. The
vaccine contains Agenus' QS-21 Stimulon adjuvant, or booster.
(Editing by Paul Sandle and David Holmes)
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