(Corrects generic name of Yervoy to ipilimumab in paragraph 12)
By Deena Beasley
April 19 Merck & Co Inc's Keytruda,
approved for treating melanoma, was shown in a trial to shrink
tumors in nearly half of advanced lung cancer patients with high
levels of a protein used by tumors to evade the body's own
The company said it has filed for U.S. Food and Drug
Administration approval of the drug as a treatment for patients
with non-small cell lung cancer (NSCLC) whose disease has
worsened despite previous treatment.
Keytruda, also known as pembrolizumab, belongs to a new
class of drugs designed to help the immune system fend off
cancer by blocking a protein known as Programmed Death receptor
(PD-1), or a related target known as PD-L1.
On Friday, Bristol-Myers Squibb Co said a trial of
its PD-1 inhibitor, Opdivo, was stopped early after the drug
proved to work better than chemotherapy in previously treated
patients with non-squamous NSCLC. Opdivo is already approved for
treating the less-common squamous NSCLC, as well as metastatic
Merck said its FDA lung cancer filing is for patients with
both squamous and non-squamous NSCLC.
Lung cancer, which kills nearly 160,000 Americans annually,
is seen as the biggest opportunity for the PD-1 drugs, which
analysts expect to reach billions of dollars in sales.
Merck's Phase 1 study of 495 patients with NSCLC, the most
common form of the disease, found that 45 percent of patients
with high levels of PD-L1 responded to Keytruda, compared with
16.5 percent of patients with PD-L1 levels of 1 percent to 49
For patients with PD-L1 below 1 percent, the response rate -
defined as tumor shrinkage of at least 30 percent - was 10.7
Researchers said about a quarter of trial patients had PD-L1
expression in at least half of their tumor cells. Overall, 19
percent of trial patients responded to the drug.
Side effects of Keytruda included thyroid problems. One
patient died from pneumonitis, or lung inflammation, which was
seen in 3.6 percent of trial patients.
The Merck results were presented at a meeting of the
American Association for Cancer Research and published in the
New England Journal of Medicine.
Researchers also presented results from a trial showing that
Keytruda improved the length of time before advanced skin cancer
worsened by 42 percent and extended patient survival by 34
percent compared with treatment with ipilimumab, a different
immunotherapy sold by Bristol-Myers under the brand name Yervoy.
(Reporting by Deena Beasley; Editing by Dan Grebler)