The first patient has been enrolled in the phase 3 ATOM study, a trial designed to evaluate Kimmtrak (tebentafusp) compared to observation in patients with non-metastatic uveal melanoma who are at high risk of relapse. This study seeks to determine if the benefits seen with Kimmtrak in metastatic settings can translate to a significant reduction in relapse risk for patients who have received treatment for primary uveal melanoma.
The ATOM trial is a randomized study where patients are assigned to either receive Kimmtrak or undergo observation. The primary endpoint is to evaluate the effectiveness of Kimmtrak in preventing or delaying relapse in patients with primary uveal melanoma at high risk of relapse, compared with observation. Secondary endpoints include overall survival, safety, tolerability, and health-related quality of life.
Study Design and Patient Population
The trial plans to enroll 290 patients with uveal melanoma who have previously received definitive treatment by surgery or radiation therapy. Eligible patients must have HLA-A*02:01-positive disease, adequate organ function, and an ECOG performance status of 0 or 1. According to Immunocore, the manufacturer of Kimmtrak, approximately 50% of patients will eventually relapse with metastatic disease despite definitive local therapy.
Kimmtrak's Mechanism and Previous Approval
Kimmtrak is a drug that binds to specific antigens on the surface of uveal melanoma cells, helping the immune system to destroy cancer cells. It was previously approved by the FDA for patients with unresectable or metastatic uveal melanoma based on the phase 3 IMCgp100-202 trial. That trial included patients with metastatic uveal melanoma who had not been previously treated and were randomized to receive Kimmtrak or investigator's choice of Yervoy (ipilimumab), Keytruda (pembrolizumab), or dacarbazine.
Clinical Significance and Unmet Need
Uveal melanoma is a rare form of melanoma that develops in the uvea of the eye. It is the most common type of eye cancer among adults. Currently, there are no standard treatment options available to prevent relapse in patients who have undergone primary treatment. Mohammad Dar, chief medical officer at Immunocore, stated that decreasing the likelihood of relapse following definitive therapy would be a groundbreaking advancement in treatment.
Safety and Tolerability
In the IMCgp100-202 trial, side effects associated with Kimmtrak included fever (4%), rash (18%), and itching (5%). Cytokine release syndrome was reported in less than 1% of patients and was well managed. These findings suggest a manageable safety profile for Kimmtrak.
Dr. Paul Nathan, consultant medical oncologist and ATOM study coordinator, noted, "The study addresses a key question — whether the benefit seen with [Kimmtrak] in HLA-A*02:01-positive patients with metastatic uveal melanoma will translate to a significant reduction in risk of relapse for patients who have received treatment for primary uveal melanoma and are at high risk of relapse."
