Keytruda Fails To Increase Survivability In Stomach Cancer Clinical Trial

Another attempt to expand the use of Keytruda has failed, due to a lack of benefits in the results of a clinical trial designed to show whether the cancer drug could be used as a second-line treatment for stomach malignancies. 

Merck & Co. issued a press release earlier this month, indicating that Keytruda failed to show adequate increases in overall survival rates to justify upgrading it from a third-line gastric cancer drug to a second-line treatment. The announcement comes just months after the FDA halted two similar clinical trials pitting the medication against multiple myeloma due to safety issues.

This latest clinical trial, known as KEYNOTE-061, was a randomized open-label phase 3 study involving 592 patients. Merck put Keytruda up against Abraxane (paclitaxel) as the sole treatment for patients with advanced gastric or GEJ adenocarcinoma. All of the patients failed to go into remission following first-line treatment with platinum and fluoropyrimidine doublet therapy. However, the drug failed to perform as well as Abraxane when it came to patient survival rates.

Merck indicated it is still running another clinical trial testing Keytruda in combination with chemotherapy for treatment of the same gastrointestinal cancers.

In August, the FDA issued a safety alert announcing that it had halted two other Keytruda clinical trials, KEYNOTE-183 and KEYNOTE-185 involving the use of Keytruda to treat multiple myeloma, due to a number of patient deaths.

In KEYNOTE-183, the FDA found that the use of Keytruda, in combination with dexamethasone and either of two immunomodulatory agents; lenalidomide or pomalidomide, led to a 61% increased risk of death. The agency found that 29 patients in the Keytruda arm of the clinical trial died, compared to only 21 deaths among the control patients, who did not receive the drug.

KEYNOTE-185’s results were even worse. That clinical trial, involving about 300 patients, saw an even higher risk, with more than twice as many Keytruda patients dying than those in the control group, 19 to 9. That trial also showed that 54% of the patients given a Keytruda-based drug combination had a 54% chance of severe adverse health effects, compared to only 39% in the control group.

There are a number of other multiple myeloma clinical trials ongoing that either involve Keytruda or similar drugs, known as PD-1/PD-L1 cancer drugs. The FDA is investigating those trials to determine if there is a safety issue with them as well.

The FDA is asking healthcare professionals and patients who experience any adverse events or side effects during Keytruda treatment to report them to the FDA’s MedWatch Adverse Event Reporting Program.