Merck and Eisai Come Up Short in the Clinic with Liver Cancer Combination Therapy

In a disappointing turn of events, Merck and Eisai announced on August 3 that their efforts to treat unresectable hepatocellular carcinoma (uHCC) with Keytruda and Lenvima did not meet the primary endpoints in the Phase 3 Leap-002 Trial. The recent lack of success is just another in the growing list of snags Merck has recently run into with Keytruda. 

Continued Issues for Keytruda

The latest blow to Keytruda was based on data from the Phase 3 Leap-002 Trial, which studied the combination of Merck’s Keytruda and Eisai’s Lenvima to treat uHCC, a notoriously tricky treatment area. The trial compared Keytruda and Lenvima in combination with Lenvima as a monotherapy. The results showed that there were not enough statistically significant improvements in patient outcomes to meet primary endpoints. 

This recent hangup is not the first the companies have run into the search for uHCC approval for the combination. After applying for accelerated approval of Keytruda and Lenvima, the companies received notice in July 2020 that the FDA denied their application, citing the combination of the two drugs did not demonstrate more effective results than available therapies. The Keytruda and Lenvima cocktail faced tough competition after Roche’s Tecentriq, combined with Avastin, gained FDA approval with stellar results in treating uHCC. 

Alongside its most recent hiccup with Eisai, Merck announced another stumbling block after a Phase 3 clinical trial studying Keytruda alongside chemotherapy to treat castration-resistant prostate cancer did not meet primary endpoints. 

Merck also studied Keytruda alongside its AstraZeneca-partnered Lynparza to treat castration-resistant prostate cancer. In March, the company announced the two drugs in combination did not demonstrate a greater benefit than approved drugs, so Merck abandoned the Phase 3 trial. 

Related Article: Oncology Research Collaboration between Kelun-Biotech and MSD

Moving Forward After Discouraging Results

When Keytruda first gained approval in 2014, the drug went on a wrecking path in the following years, gaining approval in numerous indications as a monotherapy and in combination with other therapies. The recent difficulties, however, might be a sign of what is to come for the drug. 

Despite the hangups, the higher-ups at Merck and Eisai still have faith in the combination and its future in immuno-oncology. Keytruda, combined with Lenvima, is approved to treat advanced endometrial carcinoma in patients who fit certain criteria.

Corina Dutcus, M.D., Senior Vice President, Clinical Research, Oncology at Eisai Inc., said, “While results evaluating the combination are not what we had hoped for, we will continue to contribute to the care of patients with unresectable HCC by applying valuable knowledge from the LEAP-002 trial.”

On a positive note for Eisai, the trial showed the patients treated with just Lenvima demonstrated longer overall survival rates compared to previous trials using Lenvima as monotherapy for uHCC. These results are surprising but have little effect because the FDA already approved Lenvima as a first-line treatment for uHCC.

Author

Reed Slater