Ongoing Trial Shows Positive Response Rates With MEK Inhibitor Combo in Ovarian Cancer Subset

Analysis of recent data from the RAMP-201 study demonstrated positive response rates with avutometinib alone and in combination with defactinib in patients with recurrent low-grade serous ovarian cancer.

In particular, in 29 patients treated with avutometinib and defactinib, the objective response rate was 28%, meaning that these patients partially or completely responded to treatment, according to a press release from Verastem, the manufacturer of avutometinib. In addition, this rate was 27% in patients with mutant KRAS disease and 29% in wild-type KRAS disease.

“Preliminary data from the ongoing Phase 2 RAMP 201 study demonstrate that the combination of avutometinib with defactinib yields encouraging response rates with a well-tolerated safety profile in women with heavily pretreated recurrent low-grade serous ovarian cancer,” said Dr. Susana Banerjee, lead investigator on the study, consultant medical oncologist at the Royal Marsden NHS Foundation Trust in England and team leader for women’s cancer at the Institute of Cancer Research in London, said in the press release. “The contribution of defactinib, rates of tumor shrinkage in both mutant and wild-type KRAS (low-grade serous ovarian cancer), and a high rate of disease control observed to date are important initial findings that led to the decision to proceed with the combination regimen.” “

Most patients in the study had tumor regression and had an overall disease control rate (defined as stable disease plus partial response to therapy) of 93%, according to the press release. Notably, 62% of patients with evaluable data were still on the combination treatment after at least five months of follow-up.

In patients treated with avutometinib alone, the overall response rate was 7% in the 30 patients with evaluable data with an overall disease control rate of 90%

According to the press release, the researchers observed no new side effects for either treatment group. The most common side effects associated with treatment with avutometinib and defactinib were nausea, diarrhea, blurred vision, increase in blood creatine phosphokinase (indicating stress or damage to the heart, muscle tissue or brain), rash, swelling of the legs and tiredness. Nine percent of patients discontinued treatment because of side effects.

“(Low-grade serous ovarian cancer) is a difficult-to-treat disease with an urgent need for more effective and tolerable therapies,” said Dr. Rachel N. Grisham, Division Chief of Ovarian Cancer and Director of Westchester Gynecologic Medical Oncology at Memorial Sloan Kettering Cancer Center in New York, in the publication. “The majority of patients with (low-grade serous ovarian cancer) have advanced disease and experience chronic symptoms of their cancer.”

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