Merck & Co. Inc.'s Keytruda has shown promising results in treating bladder cancer and a rare sub-type of melanoma, researchers said at the European Cancer Congress.
In three clinical trials, 19% of the 84 patients with the rare and frequently fatal mucosal melanoma responded to the immunotherapy, while 33% of patients with other forms of advanced melanoma responded to treatment. Seventy-two percent of non-mucosal melanoma patients are still alive without their disease progressing, said Marcus Butler, the medical oncologist who led the studies of the drug, also known as pembrolizumab.
"At this stage, we don't know why some mucosal melanoma patients responded to pembrolizumab, while others did not. This is an important question and research is ongoing," he said in a statement, adding that these findings show the rare cancer should not be excluded from study. "Immunotherapy for melanoma has revolutionized treatment of the disease."
In another presentation at the conference, oncologist Andrea Necchi said that Keytruda is the first therapy to show a significant survival advantage over chemotherapy for second-line treatment of advanced bladder cancer. In a phase 3 trial, 21% of patients treated with Keytruda saw tumors shrink or disappear, compared to 11% of chemotherapy patients. Necchi also found that Keytruda patients also had a lower incidence of treatment-related side effects, at 61% compared to 90% of chemotherapy patients.
Keytruda is already approved by the FDA to treat non-small cell lung cancer, and Merck recently won approval to expand into combination therapy.
On Jan 20., Merck settled a patent infringement lawsuit brought by Bristol-Myers Squibb Co. over similarities between Keytruda and BMS' Opdivo. Under the terms of the agreement, Merck will make a $625 million payment to BMS and its partner Ono Pharmaceutical Co. Ltd., along with a percentage of Keytruda royalties through the end of 2026.
BMS has struggled to broaden Opdivo's scope, and recently took a combination therapy of the drug and Yervoy, a medicine used to treat melonoma, off the FDA's accelerated approval track. However, in a Jan. 26 earnings call, CEO Giovanni Caforio expressed confidence in the company's progress into combination therapy and said he was excited about Yervoy's prospects in melanoma.
BMS Chief Commercial Officer Murdo Gordon said during the call that the company was also preparing for a potential launch into bladder cancer treatment this year.