(Adds more information on Bristol-Myers Phase III plan in final
By Bill Berkrot
May 14 When the world's leading cancer doctors
meet in Chicago next month, new treatments from Merck & Co,
Bristol-Myers Squibb Co and Roche Holding AG that help the
immune system fight disease are expected to capture much of the
The drugs, known as anti-PD-1 or anti-PDL1 therapies, are
biotech medicines that work by blocking a tumor's ability to
camouflage itself, thereby allowing T cells in the immune system
to recognize and attack the cancer.
They have shown great promise against advanced melanoma -
the deadliest of skin cancers - as well as advanced lung and
kidney cancers, with relatively mild side effects, generating
excitement among researchers and investors.
At the American Society of Clinical Oncology meeting in
Chicago beginning May 30, researchers will for the first time
present data on Roche's anti-PDL1 drug in advanced
bladder cancer for which there have been few advances in
Merck will have no less than 16 studies involving
its highly touted anti PD-1 drug, MK-3475, including a first
look at the drug as an initial lung cancer treatment. Early data
released on Wednesday showed 36 percent of 45 patients had an
initial immune response to the treatment. Merck will also
provide results from the first trial of the drug in head and
Brief summaries, or abstracts, of thousands of studies to be
presented at the ASCO meeting were released on Wednesday.
"This area should represent a major advance in cancer
therapy and patient survivability," said Len Yaffe, portfolio
manager for the healthcare fund StockDoc Partners. "Wall Street
is increasingly recognizing the multibillion-dollar potential
for cancer immunotherapies."
The potential for lasting effects of these drugs will be on
display in a pair of studies involving the Bristol-Myers
anti PD-1 drug nivolumab.
Researchers will present follow-up data from a 107-patient
nivolumab study in metastatic melanoma showing that 41 percent
were still alive after three years, an apparent leveling off
from the 48 percent survival rate after two years.
Three-year survival with advanced melanoma was virtually
unheard of prior to the advent of cancer immunotherapy.
In a trial of patients whose advanced kidney cancer had
progressed following prior treatments, the mean overall survival
was 25.5 months for the 2 milligram nivolumab dose.
Past kidney cancer studies of drugs currently in use have
demonstrated a mean survival of about 14 months, said Fouad
Namouni, Bristol's head of global development for nivolumab.
MOST LIKELY TO BENEFIT
As drugmakers face greater scrutiny over how they price new
therapies - with immuno-oncology expected to be among the most
expensive - several studies will aim to identify which patients
are most likely to benefit from the new treatments.
Researchers can now perform a test to determine the degree
to which the PD-L1 protein is expressed on the surface of cancer
cells. On a 0 to 3 scale, a score of 0 or 1 is considered PD-L1
negative, while 2 or 3 is deemed PD-L1 positive.
If early data is confirmed in larger trials, this class of
immunotherapies could become standalone treatments for some
patients, while PD-L1 negative patients may require combination
or alternative therapies, according to some researchers.
In a small, Phase I study of Bristol's nivolumab in
previously untreated patients with advanced lung cancer, five
out of 10 PD-L1 positive patients saw their tumors shrink by at
least 30 percent. No such responses were seen among 7 PD-L1
negative patients. Roche also saw half of the 20 PD-L1 positive
patients in its bladder cancer trial respond to its drug.
Namouni said Bristol would focus on PD-L1 positive patients
only in a large Phase III lung cancer trial of previously
untreated subjects. Its Phase III studies of those who had
received prior treatments will include PD-L1 negative patients.
(Reporting by Bill Berkrot; Editing by Michele Gershberg and