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Targeted therapies promise new
hope for brain cancer patients
While primary brain tumors are relatively rare, the
chances of survival for patients with the disease are very low, even with the
best treatment options currently available. However, significant progress is
being made with research into the disease and innovative new therapies may be
able to improve survival rates for brain cancer patients.
The most aggressive and most common form of brain cancer is known as
glioblastoma multiforme (GBM), accounting for over half of all brain tumors
diagnosed each year. Datamonitor predicts that there will be around 26,000 new
cases of GBM diagnosed in the seven major markets (US, Japan, France, Germany,
Italy, Spain and the UK) in 2007. In the US alone, around 14,000 people will die
from brain cancer in 2007.
For GBM patients, standard treatment currently involves surgical removal of the
tumor followed by radiotherapy and chemotherapy. The favored brand of
chemotherapy for most physicians is Schering-Plough's Temodar (temozolomide).
While survival is low for most GBM patients treated in this way (on average,
just over 14 months), this mode of treatment is commonly used in all of the
seven major markets.
Targeted therapies
In comparison to some other types of cancer, brain tumors are less prevalent.
Therefore, from a drug developer's point of view, targeting the disease may not
be considered as commercially viable compared to the four major types of cancer
- breast, prostate, lung and colorectal cancer.
However, there are several incentives for drug developers to focus on brain
cancer. The poor survival prospects with currently available treatment options
mean that there could be rapid uptake of a new brain cancer drug providing just
a modest improvement in survival. There is also a significant opportunity in the
market for a second-line therapy to be used if and when the disease relapses
after standard treatment fails.
In addition, while the uptake of some new cancer drugs has been rather limited
in more cost-conservative healthcare markets like the UK, these reimbursement
restrictions may not extend to brain cancer due to the low number of patients
with the disease. The rarity of the disease also entitles drug developers to
several regulatory benefits, such as tax breaks.
Consequently, there has been a considerable amount of R&D activity in brain
cancer, and there are several innovative drugs currently in the development
pipeline. Many of these drugs are targeted therapies which, rather than
indiscriminately destroying cells like traditional chemotherapy, are intended to
specifically destroy or prevent the growth of cancer cells.
Personalized treatment
Some of the more promising targeted therapies in the pipeline for brain cancer
include Genentech/Roche's Avastin (bevacizumab) and AstraZeneca's Recentin (cediranib)
which are currently in Phase II clinical trials. These drugs both work by
preventing the growth of new blood vessels from the tumor, therefore starving it
of oxygen and nutrients and preventing it from growing. However, as these drugs
have not yet entered Phase III trials, it is likely to be at least another two
years before they are available to brain cancer patients.
While there is generally a great deal of optimism amongst brain cancer experts
surrounding targeted therapies, it appears unlikely that Temodar will be
superseded in the near future as the number one drug therapy for brain cancer.
Physicians interviewed by Datamonitor envisage targeted therapies being used
alongside Temodar, rather than directly replacing it.
Advances in diagnostic methods mean that a more detailed picture of the nature
of brain cancer is beginning to emerge. For example, it is now known that
certain proteins are present in the tumor cells of some brain cancer patients,
but not in others, due to the differing genetic characteristics of these
patients. Consequently, it is likely that some patients will benefit more than
others from particular treatments. This could lead to personalized drug therapy
for individual brain cancer patients, "tailor-made" according to the particular
characteristics of that patient's disease - in theory this specificity in
treatment should lead to much better treatment outcomes.
Related research:
• Stakeholder Opinions: Primary Brain Cancer
• Pipeline/Commercial Insight: Molecular Targeted Cancer Therapies - More drugs
on the market, more targets in the pipeline
• Commercial Insight: Top 20 Cancer Therapy Brands - Sales of targeted therapies
overtake cytotoxics in 2006
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