FDA approves Keytruda for rare mesothelioma

Merck recently achieved a significant milestone with its immuno-oncology drug, Keytruda. The U.S. Food and Drug Administration (FDA) approved Keytruda as a first-line treatment in combination with chemotherapy for patients suffering from advanced malignant pleural mesothelioma. This approval marks the first instance of Keytruda being authorized for any line of treatment for this disease in the United States.

The green light from the FDA is based on robust Phase 2/3 clinical trial data. The results revealed that Keytruda, when used alongside chemotherapy, reduced the risk of death by 21% compared to chemotherapy alone. Specifically, patients treated with Keytruda experienced a median overall survival of 17.3 months, while those who were only administered chemotherapy had a median overall survival of 16.1 months. These survival outcomes were deemed statistically significant.

Merck highlighted that the addition of Keytruda to chemotherapy also led to an improvement in progression-free survival (PFS). Even though both the Keytruda plus chemotherapy group and the chemotherapy-only group reported a median PFS of 7.1 months, Merck's spokesperson emphasized the 0.8 hazard ratio as a sign of a "statistically significant improvement in PFS."

The overall response rate among patients receiving Keytruda was notably higher at 52%, in contrast to 29% for those who were treated solely with chemotherapy. Importantly, Merck stated that the safety profile of this combination treatment was comparable to that observed in other patients who have received Keytruda with pemetrexed and platinum-based chemotherapy.

This major approval coincides with a series of crucial updates in the field of immuno-oncology, many of which were shared during the European Society for Medical Oncology conference. For instance, in a study involving liver cancer, it was found that patients experienced longer periods without disease progression when treated with Keytruda and Eisai’s VEGF inhibitor Lenvima, along with a localized chemotherapy procedure. In this study, patients who received the combination treatment had a median progression-free survival of 14.6 months, compared to 10 months for those who only underwent the procedure with placebos.

Meanwhile, the oncology community and investors are keenly observing new developments from competitors such as Summit Therapeutics and Akeso. These companies have released promising data from China, indicating that their monoclonal antibody treatment outperformed Keytruda in lung cancer patients. Summit, which holds the U.S. rights to the drug ivonescimab, is currently conducting a global Phase 3 trial to verify these findings.

In summary, the FDA's approval of Keytruda for first-line treatment of advanced malignant pleural mesothelioma is a groundbreaking development for Merck. Supported by compelling clinical data, this new indication broadens Keytruda's therapeutic reach and underscores its potential in improving survival outcomes for patients with this challenging form of cancer. As the landscape of cancer treatment continues to evolve, ongoing trials and new competitors will likely shape the future of immuno-oncology.