Merck Shares Dip After Keytruda Trial For Small Cell Lung Cancer Posts Uneven Results

Merck said its Keytruda cancer treatment increased survival rates for patients with extensive small cell lung cancer when combined with chemotherapy, but noted the results weren't statistically significant.

Merck & Co.  (MRK) - Get Report shares traded lower Tuesday after the drugmaker said a late-stage trial of its blockbuster Keytruda cancer treatment failed to increase patient survival rates.

Merck said a phase 3 trial study involving patients with extensive stage small-cell lung cancer, a less-common form of the disease, indicated improvement in overall survival rates when Keytruda was combined with chemotherapy, but added the results weren't statistically significant.

 “Results of KEYNOTE-604 demonstrated the potential of KEYTRUDA, in combination with chemotherapy, to improve outcomes for patients newly diagnosed with extensive stage small cell lung cancer, a highly aggressive malignancy,” said Dr. Roy Baynes, senior vice president and head of global clinical development and the chief medical officer for Merck Research Laboratories. “We sincerely thank the patients and investigators for their participation in this study and are committed to helping patients who face difficult-to-treat types of lung cancer.”  

Merck shares were marked 0.9% lower in early trading Tuesday to change hands at $90.70 each, a move that would trim the stock's six-month gain to around 8%.

Keytruda, which was first approved in 2014, is Merck's most important drug, notching more than $3 billion in sales over the third quarter, accounting for around a quarter of the group's top line.

Last month, Merck extended its reach into the oncology sector with the $2.7 billion purchase of Woburn, Massachusetts-based ArQule, which focuses on research and development of targeted therapeutics to treat cancers and rare diseases.