NEW YORK – The US Food and Drug Administration on Wednesday approved Immunocore's T-cell receptor therapy tebentafusp-tebn (Kimmtrak) for the treatment of HLA-A*02:01-positive adult patients with unresectable or metastatic uveal melanoma.
This is the first T-cell receptor, or TCR, therapy and the first treatment for metastatic uveal melanoma to receive regulatory approval in the US. The approval was based on data from a Phase III trial of tebentafusp, which showed the drug improved overall survival for HLA-A*02:01-positive advanced uveal melanoma patients over investigator's choice of pembrolizumab (Merck's Keytruda) or ipilimumab (Bristol Myers Squibb's Yervoy), or dacarbazine chemotherapy.
At one year, the overall survival rate on tebentafusp was 73 percent compared to 57.5 percent for the investigator's choice drugs. The median overall survival for patients taking tebentafusp was 21.7 months compared to 16 months in the comparator arm.
The FDA-approved label for the drug contains a boxed warning for the risk of potentially serious or life-threatening risk of cytokine release syndrome with tebentafusp treatment. In a call to discuss the approval on Wednesday, Immunocore's chief medical officer, Mohammed Dar, said most cases of cytokine release syndrome seen in the pivotal trial were mild to moderate and manageable.
"Every year in the US, hundreds of people are diagnosed with metastatic uveal melanoma who, until now, had no approved treatment options," Immunocore CEO Bahija Jallal said in a statement. "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."
Tebentafusp is a bispecific protein that targets gp100, an antigen expressed in melanoma cells that are HLA-A*02:01-positive. Once the targeted cells are identified, the drug binds to them and redirects T cells to attack the gp100-expressing melanoma cells. "We're also proud to have developed the world's first approved TCR therapeutic, which we believe validates the strength of our platform and opens doors for us to explore further breakthrough discoveries in TCR therapeutics for the treatment of other cancers and diseases with high unmet need," Jallal added.
At the 2021 American Association for Cancer Research virtual annual meeting, lead researcher on the pivotal tebentafusp trial Jessica Hassel said HLA-A*02:01 typing is not routine for uveal melanoma patients. However, HLA typing is well-established in most university hospitals and commercial labs also offer such testing.
Ralph Torbay, head of commercial operations at Immunocore, said during the call that the company's commercialization team for tebentafusp is "US launch ready." Immunocore also plans to partner with other companies to make the drug available in more than 22 countries including Canada, Israel, and countries in Central and Eastern Europe.
The FDA reviewed tebentafusp under its Project Orbis, an international partnership between health regulators in the US, UK, Australia, and other countries aimed at speeding up access to innovative drugs around the world. Through the initiative, UK-based Immunocore's marketing authorization submission for the drug has also been accepted by the European Medicines Agency, the UK's Medicines and Healthcare Regulatory Agency, Health Canada, and Australia's Department of Health Therapeutic Goods Administration.
Immunocore also has a global early-access program for tebentafusp, through which more than 200 uveal melanoma patients in 13 countries have already received the drug. The company estimated that approximately 1,000 advanced uveal melanoma patients will be eligible for the drug each year in the US and in certain priority European markets.