Merck Halts Keytruda Cancer Trials Due to Reported Adverse Events, Including One Patient Death

While Keytruda is widely used to treat various forms of cancer, studies in recent years have frequently linked the Merck drug to severe side effects.

Two Keytruda clinical trials were ended early, after the study data showed that the drug provides no benefit for the treatment of lung and skin cancer, and increased the risks of potentially serious side effects for the patients.

Merck announced the discontinuation of two phase 3 clinical trials, the KEYNOTE-867 and KEYNOTE-630 on August 29.  In a press release regarding the decision, the pharmaceutical company said the cancer drug failed to prevent a patient’s risk of the cancer worsening and it led to higher rates of adverse health events, including at least one death.

Keytruda is a monoclonal antibody cancer therapy, known as a PD-1 drug, which helps the body’s immune system fight tumor cells. There are currently more than 1,600 trials studying Keytruda for different types of cancers and treatment settings.

The U.S. Food and Drug Administration (FDA) has approved Keytruda for various types of cancer over the years, including lung, head and neck, bladder, colorectal, gastric, esophageal, cervical, kidney, and liver cancer, as well as Hodgkin lymphoma, melanoma and B-cell lymphoma cancers.

KEYNOTE-867 was designed to test Keytruda combined with radiation for lung cancer, including cases that can’t be operated on. KEYNOTE-630 tested Keytruda for patients with cutaneous squamous cell carcinoma combined with radiation, compared to those undergoing radiation alone.

According to Merck, the interim analysis indicated the benefit-risk profile did not support continuing either trial. The decision was based on the independent review and recommendation from the Data Monitoring Committee.

The early findings indicated Keytruda did not improve a patient’s survival without recurring cancer or overall survival compared to a placebo. In fact, patients had a higher likelihood of experiencing a number of potential Keytruda side effects, including immune-mediated pneumonia, colitis, hepatitis, liver toxicity, endocrine conditions like adrenal insufficiency, inflamed pituitary, thyroid disorders, type 1 diabetes, inflamed kidneys and death.

This isn’t the first data showing Keytruda may lead to serious side effects. In 2018, the FDA added restrictions to the Keytruda warning label, indicating the drug shouldn’t be used for some bladder cancers. The warning indicates it may lower a patient’s chance of survival when used alone.

More recently, a case study published in the New England Journal of Medicine indicated infants may experience severe immune-related enteritis when exposed to Keytruda during pregnancy.

Federal regulators scheduled a panel of outside advisors to meet in September to review data on the side effects and potential restrictions of Keytruda for the treatment of stomach cancer. Patients using Keytruda to treat stomach cancer face a 20% increased risk of death compared to chemotherapy.