Phase 3 Keytruda, Chemotherapy Mesothelioma Trial Shows Promising Results

Research & Clinical Trials

Written by Michelle WhitmerEdited By Walter PachecoScientifically Reviewed By Anna Nowak, Ph.D.

Pharmaceutical company Merck says use of its immunotherapy drug Keytruda in conjunction with chemotherapy increases the survival rate for people with advanced pleural mesothelioma, according to the latest results of a phase 3 clinical trial.

The results were announced in June at the annual meeting of the American Society of Clinical Oncology. They showed Merck’s use of the anti-PD-1 treatment combined with chemotherapy reduced the patient’s risk of death by 21%. 

Clinical trial results of the multimodal treatment using immunotherapy and chemo also showed a median overall survival of 17.3 months in comparison to 16.1 months when only treating patients with chemotherapy.

“These results support the potential of Keytruda plus chemotherapy as a new first-line option for patients with advanced pleural mesothelioma who currently have limited treatment options,” said Dr. Gregory Lubiniecki, vice president of Global Clinical Development for Merck Research Laboratories.

“These data demonstrate our commitment to improving outcomes for patients with different types of thoracic cancer through our expansive clinical development program and research evaluating Keytruda in new, difficult-to-treat tumors,” Lubiniecki added. 

Combined Therapy Improves Progression-Free Survival

The Canadian Cancer Trials Group, in collaboration with the National Cancer Institute, Merck and Intergroupe Francophone de Cancerologie Thoracique, sponsored the clinical trial. Phase 3 of the trial enrolled 440 patients with advanced pleural mesothelioma. Results of the study have yet to be posted to the National Cancer Institute’s clinical trials site.

Patients in the trial randomly received Keytruda, pemetrexed and cisplatin, or they were only given pemetrexed and cisplatin, which are the two chemotherapy drugs. Researchers said progression-free survival among patients who received Keytruda greatly improved. 

“At 12 months, the estimated progression-free survival rate was 26% for Keytruda plus chemotherapy versus 17% for chemotherapy alone,” the study said.

Results showed patients who received Keytruda presented side effects, including fatigue, nausea and febrile neutropenia (fever with lower white blood cell counts). About 16% of patients who experienced side effects with Keytruda were taken off the immunotherapy medication.

The U.S. Food and Drug Administration approved Keytruda in 2020 for the treatment of mesothelioma. There are currently more than 1,600 trials studying the drug’s effectiveness against multiple forms of cancer. 

In the later stages of the asbestos-related cancer, many mesothelioma patients are ineligible for surgery. The introduction of Keytruda and other immunotherapy treatments for mesothelioma has broadened the possibility of continued treatment for the rare and aggressive cancer.

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