Thursday's news that the MAGE-A3 therapeutic vaccine
did not help patients with non-small cell lung cancer in a
late-stage study is a further blow to the high-risk, high-reward
project after a similar setback in melanoma in September.
Unlike traditional preventative vaccines, the MAGE-A3 treatment is
designed for people with established disease, helping their immune
systems to prevent the return of disease after surgery.
The large Phase III study, involving more than 2,000 lung cancer
patients, found that the experimental therapy did not help patients
live longer without their disease recurring.
Nonetheless, GSK plans to continue the clinical trial in the hope of
finding a sub-population that will benefit. It is also doing the
same with patients suffering from melanoma and results of analyses
looking at these sub-sets of patients with particular genetic
profiles are expected in 2015.
Vincent Brichard, head of immunotherapeutics at GSK Vaccines, said
the company was disappointed by the outcome but remained committed
to the project.
Shares in GSK fell by 2 percent by 0945 GMT, underperforming a 0.7
percent decline in the European drugs sector.
Many investors had been expecting a disappointing read-out from the
lung cancer study, following the earlier setback in melanoma, and
there are doubts as to whether GSK will be able to prove the vaccine
works for a smaller group of genetically selected patients.
But despite the problems GSK Chief Executive Andrew Witty painted a
surprisingly upbeat picture of prospects for MAGE-A3 at full-year
results last month. Witty described the cancer vaccine and another
drug for heart disease called darapladib that has also disappointed
in tests as among the most promising in the company's pipeline.
10 PERCENT CHANCE
Citi analyst Andrew Baum said he estimated there was a 10 percent
probability that MAGE-A3 could result in a significant benefit in a
gene-signature defined population group, which would still be a
As a result, Citi has a
risk-adjusted sales forecast for the product of 216 million pounds
($360 million) in 2022.
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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 vaccine-based approach.
So-called immunotherapy, in which the body's own immune system is
enlisted to fight tumor cells, is a hot area of pharmaceutical
research and development at the moment, although cancer vaccines
have proved difficult to develop over the years.
U.S.-based Agenus has contributed technology to the GSK vaccine and
its shares are sensitive to news on the project. The vaccine
contains Agenus' QS-21 Stimulon adjuvant, or booster.
Although news on MAGE-A3 and darapladib has been disappointing for
GSK, the company's overall drug research has been improving
recently, with notable new drug approvals in 2013 for HIV, cancer
and respiratory disease.
GSK, which is the only major drugmaker to report its internal rate
of return on R&D investment, said last month that returns had now
reached 13 percent, up from 12 percent two years earlier and 11
percent in 2010. It has set a target of reaching 14 percent.
(Additional reporting by Sarah Young; editing by David Goodman and
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