(Corrects headline and paragraph 2 to clarify that overall survival analysis is continuing, not that the treatment failed to extend overall survival)
(Reuters) -Merck and Eisai’s experimental combination treatment helped extend the time certain patients with advanced kidney cell cancer lived without their disease progressing, according to interim data from a late-stage study.
The combination of Merck’s Welireg and Eisai’s Lenvima has not yet shown statistical significance in extending overall survival – the trial’s other primary endpoint – when compared to Exelixis’ approved treatment Cabometyx, the drugmakers said on Tuesday.
Overall survival, which measures the length of time patients live after diagnosis or start of treatment, is a key indicator of how well a treatment works.
Merck and Eisai said they would continue to evaluate overall survival (OS) in a subsequent analysis after a trend toward improvement was observed in the interim analysis.
“We believe OS will be important for physicians in this setting, given risk that greater toxicity with lenvatinib (Lenvima) compared to cabozantinib (Cabometyx) could negatively impact OS,” Leerink Partners analysts said.
The combination also helped a higher proportion of patients achieve a substantial reduction or complete disappearance of tumors compared to those treated with Cabometyx, the companies said.
Renal cell carcinoma (RCC) is the most common type of kidney cancer, typically affecting men 60 years and older.
The trial enrolled about 708 patients whose cancer had progressed following immunotherapy.
The safety profile of the combination was consistent with previous studies, the companies said.
Separately, Merck said certain kidney cancer patients on a combination of Welireg and its blockbuster immunotherapy Keytruda lived longer without any symptoms of the disease after treatment, compared to those on Keytruda and placebo.
The company said the late-stage trial involved 1,841 patients with clear cell RCC whose kidney or a part of it was surgically removed.
Welireg-Keytruda combination is now set up to inherit the large market currently served exclusively by Keytruda, Leerink Partners analysts said.
They project Merck’s U.S. revenue in the indication to grow to $6.3 billion from $2.3 billion, and $5.4 billion in 2029 after Keytruda loses market exclusivity.
(Reporting by Mariam Sunny in Bengaluru; Editing by Shinjini Ganguli and Sriraj Kalluvila)
