Merck reports positive results for Keytruda plus chemotherapy in endometrial cancer

Merck – known as MSD outside the US and Canada – has reported positive results from a phase 3 study of its anti-PD-1 therapy Keytruda (pembrolizumab) in combination with chemotherapy for certain patients with endometrial cancer.

The NRG-GY018 trial met its primary endpoint, demonstrating that Keytruda plus standard of care chemotherapy (carboplatin and paclitaxel) significantly improved progression-free survival as a first-line treatment in patients with stage 3 to 4 or recurrent endometrial carcinoma versus chemotherapy alone.

This result was seen across patients whose cancer was either mismatch repair proficient (pMMR) or mismatch repair deficient (dMMR), the company said.

In the pMMR cohort of 591 evaluable patients, after a median follow-up of 7.9 months, the Keytruda regimen significantly reduced the risk of disease progression or death by 46% compared to chemotherapy alone.

The dMMR cohort of 225 evaluable patients saw a 70% reduced risk with the combination therapy compared to chemotherapy alone after a median follow-up of 12 months.

Globally, endometrial cancer is the sixth most common cancer in women and the 15th most common cancer overall. In the US alone, it is estimated there will be approximately 66,000 new cases of uterine cancer and approximately 13,000 deaths from the disease this year.

“Endometrial cancer is the most common type of gynaecological cancer, and patients with advanced stage or recurrent disease face a poor prognosis with limited treatment options,” said Dr Ramez Eskander, principal investigator and gynecologic oncologist, University of California San Diego, Moores Cancer Center.

Keytruda already has two approved indications for certain patients with endometrial cancer in the US as a combination treatment with Eisai’s Lenvima (lenvatinib) and as a single agent.

Dr Eliav Barr, senior vice president, head of global clinical development and chief medical officer at Merck Research Laboratories, said: “Results from this trial show that Keytruda plus chemotherapy, if approved, may represent an important new first-line immunotherapy option for patients with stage 3 to 4 disease, and could extend the use of Keytruda to more patients earlier in their treatment journey.”

The company said results from the trial will be presented at the 2023 Society of Gynecologic Oncology Annual Meeting on Women’s Cancer, as well as published in the New England Journal of Medicine. It will also be discussing the data with regulatory authorities worldwide.