FDA Approves Tebentafusp-tebn for the Treatment of Unresectable or Metastatic Uveal Melanoma

The FDA has granted approval to tebentafusp-tebn (Kimmtrak) for the treatment of HLA-A*02:01–positive adult patients with unresectable or metastatic uveal melanoma.¹

The approval was supported by data from the phase 3 IMCgp100-202 trial, in which treatment with tebentafusp-tebn resulted in a significant benefit in overall survival (OS) compared with investigator's choice of treatment in the frontline setting (HR, 0.51; 95% CI, 0.37-0.71; P < .0001). The FDA previously granted tebentafusp with Breakthrough Therapy Designation for unresectable or metastatic uveal melanoma in February 2021.

“Today’s approval of Kimmtrak is a historic milestone and the culmination of years of dedication by the Immunocore team, patients, and our health care partners,” said Bahija Jallal, chief executive officer of Immunocore, in a press release. “Every year in the United States, hundreds of people are diagnosed with metastatic uveal melanoma who, until now, had no approved treatment options. Kimmtrak is the first therapy to demonstrate a survival benefit to patients with this disease and we are focused on making Kimmtrak available as quickly as possible.”

The multicenter, randomized, IMCgp100-202 trial enrolled patients with local histologic or cytologic confirmation of metastatic uveal melanoma who were at least 18 years of age, who have HLA-A*02:01 positivity, an ECOG performance status of 0 or 1, and at least 1 measurable lesion per RECIST v1.1 criteria.²

Patients could not have received prior systemic or liver-directed therapy for metastatic disease, nor could they have had symptomatic central nervous system metastases, active autoimmune disease for which they are receiving glucocorticoids, or have been administered systemic immunosuppressive treatment.

Patients were randomized 2:1 to receive tebentafusp or investigator's choice of treatment, which included either single-agent pembrolizumab (Keytruda), ipilimumab (Yervoy), or dacarbazine.

Because intrapatient dose escalation of tebentafusp had been found to reduce toxicity, patients were given the drug intravenously (IV) at a dose of 20 μg on day 1, 30 μg on day 8, and 68 μg weekly thereafter. During the dose escalation, patients were monitored overnight following treatment for the first 3 weeks.

Patients in the control group were administered IV pembrolizumab at a dose of 2 mg/kg of body weight to a maximum of 200 mg per dose or a fixed dose of 200 mg on day 1 of each 21-day treatment cycle. Patients administered ipilimumab received an IV dose of 3 mg/kg on day 1 of each 21-day cycle for a maximum of 4 doses. IV dacarbazine was administered at a dose of 1000 mg/m2 of body surface area on day 1 of each 21-day cycle.

Treatment-related adverse events (AEs) were found to be manageable and consistent with the proposed mechanism. The most common grade 3 or higher AEs were rash (18%), pyrexia (4%), and pruritus (5%).

Among 245 patients treated with tebentafusp, grade 3 cytokine release syndrome (CRS) occurred in <1% of patients and was generally well-managed, with no grade 4 or fatal CRS events reported. A boxed warning for tebentafusp is included for CRS because it could become serious or life-threatening if not managed appropriately, according to the study investigators.

“Uveal melanoma is a devastating disease that has historically resulted in death within a year of metastasis for our patients,” said John Kirkwood, MD, director of the Melanoma Center at the UPMC Hillman Cancer Center, in a press release. “The approval of Kimmtrak (tebentafusp-tebn) represents a major paradigm shift in the treatment of metastatic uveal melanoma, and for the first time offers hope to those with this aggressive form of cancer.”

References

1. Immunocore announces FDA approval of KIMMTRAK (tebentafusp-tebn) for the treatment of unresectable or metastatic uveal melanoma. News release. Immunocore Holdings Limited; January 26, 2022. Accessed January 26, 2022. https://yhoo.it/3r1C3fk
2. Nathan P, Hassel JC, Rutkowski P, et al. Overall survival benefit with tebentafusp in metastatic uveal melanoma. N Engl J Med. 2021;385(13):1196-1206. doi:10.1056/NEJMoa2103485