(Adds analyst comment, details on rival PD-1 inhibitors)
By Ransdell Pierson
Aug 26 Pfizer Inc said Tuesday it will
test its Xalkori lung cancer drug with Merck & Co's
experimental immunotherapy pembrolizumab, in hopes the
combination will improve the outcomes for patients taking the
approved Pfizer therapy.
The largest U.S. drugmakers said the combination study will
begin in 2015 and be conducted by Pfizer. Financial terms of the
deal were not disclosed.
Xalkori, which has annual sales of $400 million and is also
known by its chemical name, crizotinib, was approved in 2011 for
lung cancer patients who have a specific mutation in the
so-called ALK gene, as determined by an approved diagnostic
The mutation occurs in a small percentage of patients with
non small cell lung cancer, the most common form of lung cancer.
It makes them good candidates for treatment with Xalkori, a
targeted drug that can help shrink or slow tumor growth for
Pembrolizumab works by removing the brakes from the immune
system, allowing it to detect and destroy cancer cells.
The differing mechanisms of action from combination therapy
are meant to deliver a one-two punch to cancer cells.
The Merck drug, called a PD-1 inhibitor, is expected to be
approved within months in the United States and to become a
blockbuster treatment for melanoma, and possibly later for lung
cancer and other types of cancer, depending on results of
ongoing clinical trials.
Merck, Bristol-Myers Squibb, Swiss drugmaker Roche
and AstraZeneca Plc are leading the charge in
developing PD-1 inhibitors or similar immunotherapies. Some
industry analysts believe the medicines will capture combined
annual sales of up to $30 billion by 2025.
Merck and Pfizer previously said they would collaborate in
combination trials of pembrolizumab both with Pfizer's approved
Inlyta (axitinib) treatment for kidney cancer, and with an
experimental drug called PF-2566 that Pfizer is evaluating in
numerous cancer types. PF-2566 stimulates activity of 4-1BB
(CD-137), a protein involved in regulation of immune cell
"For Pfizer, these collaborations help secure their drugs in
a market that is going under a paradigm shift" toward
immunotherapies, said Morningstar analyst Damien Conover. "I see
it more of a defensive move to make sure Pfizer's drugs are
being used in the anti-PD-1 space, instead of being bypassed."
Merck is not studying pembrolizumab in combination with its
own experimental drugs, but has other combination studies
planned or underway with a growing number of drugmakers,
Merck is also conducting a study of its PD-1 inhibitor in
combination with its own older melanoma drug, Sylatron.
Shares of Pfizer and Merck were both up about 0.6 percent in
morning trading on the New York Stock Exchange.
(Editing by Bernadette Baum and Dan Grebler)