Precision Medicine Trial Shows Drug Combination Is Effective in Rare Cancers

A precision medicine clinical trial has found that a drug combination of dabrafenib and trametinib can effectively be used to treat rare forms of cancer. The results from the NCI-MATCH trial, co-led by the National Cancer Institute (NCI) and the ECOG-ACRIN Cancer Research Group, showed that the drug combination, which was designed to target cancers with certain BRAF gene mutations, was effective in 35 patients with 17 distinct tumor types.

The results of the single-arm phase 2 study (Arm H) were presented at the 2019 American Society of Clinical Oncology Annual Meeting.¹ The trial assigned patients to a targeted therapy based on genetic alterations identified in pretreatment biopsies.

“NCI-MATCH’s Arm H met its primary endpoint with an overall objective response rate of 33 percent,” lead researcher April K.S. Salama, MD, a medical oncologist at Duke University, said in a statement. “These results are especially relevant given that this was a heterogeneous cohort of heavily pre-treated patients who had meaningful clinical benefit.”

The patients received dabrafenib 150 mg orally twice a day and trametinib 2 mg orally once a day on 28-day cycles until disease progression or intolerable toxicity. Every 2 cycles, restaging was performed.

The study included patients with solid tumors, lymphomas, or multiple myeloma who had progressed on prior treatment. Nearly half (48%) of the patients in the study had received at least 3 prior therapies. All 35 patients enrolled had the BRAF V600E variant; 2 of the patients were ineligible, so only 33 patients were evaluated.

The confirmed objective response rate was 33.3%, with a median duration of response of 12 months. Histiocytic sarcoma, cholangiocarcinoma, and mixed adenoneuroendocrine carcinoma of unknown primary were among the histologies that had a duration of response longer than 12 months. The median progression-free survival was 9.4 months and median overall survival has not been reached.

Adverse events (AEs) were comparable with those in previous studies on dabrafenib and trametinib with no new AEs reported.

“NCI-MATCH is an ongoing and dynamic trial,” said Alice Chen, MD, a medical oncologist at the NCI, head of the NCI’s Early Clinical Trials Development Program, and NCI study chair for the overall NCI-MATCH trial. “Its signal-finding approach will likely influence how cancer clinical trials are designed and conducted in the future, as treatments that show promise may advance to more definitive studies.”

Reference

Salama AKS, Li S, Macrae ER, et al. Dabrafenib and trametinib in patients with tumors with BRAF V600E/K mutations: results from the molecular analysis for therapy choice (MATCH) Arm H. Presented at: 2019 American Society of Clinical Oncology Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract 3002.