(Adds analysts' comments, share movement)
By Manas Mishra
May 23 (Reuters) - Merck & Co said on Wednesday its drug Keytruda helped patients with a certain type of lung cancer live longer and prevented the disease from spreading, helping to solidify its position in the lucrative cancer market.
Keytruda, already approved for other types of cancer, is being studied in a late-stage trial as a first-line treatment, in combination with chemotherapy, for metastatic squamous non-small cell lung cancer (sNSCLC) patients.
Merck said the combination therapy met its main trial goals when compared to patients who were on chemotherapy alone, according to an interim analysis.
The company's shares were up 1 percent at $59.04 in midday trading.
Earlier this month, Merck reported data from an interim analysis of the trial that met a secondary goal of overall response rate, or the portion of patients with a reduction in tumor size.
Merck had submitted a marketing application to the U.S. Food and Drug Administration for the sNSCLC indication recently.
"We doubted that Merck would submit the study for FDA approval based on overall response rate if it did not have confidence in the primary endpoints," said BMO Capital Markets analyst Alex Arfaei.
Analysts were looking for the latest data to support the company's application for an expanded approval.
Vamil Divan from Credit Suisse said, "We already knew Keytruda showed a benefit on overall response rate, but prolonging survival is obviously what matters."
Credit Suisse estimates that the areas in which Keytruda has now shown positive data represent a market opportunity of $6.6 billion in first-line non-small cell lung cancer in the United States.
Keytruda is the only immunotherapy approved in the United States to treat lung cancer patients who have not received prior treatment.
Merck has been expanding its position into the lung cancer market through Keytruda. Also jockeying for a piece of the lucrative market are drugmakers Bristol-Myers Squibb, Roche and AstraZeneca, which are advancing their rival immunotherapies.
Merck said the new data will be shared with the U.S. Food and Drug Administration as part of its push to expand the drug's label, and would be presented at an upcoming medical conference, the company said. (Reporting by Manas Mishra in Bengaluru; Editing by Shailesh Kuber)