Ocular melanoma or uveal melanoma is the most common tumor of eyes in adults. Every year, hundreds of people are diagnosed with this disease. For decades, no effective therapy for the disease existed. Many ocular melanoma patients, thus, have to be treated with the drugs for the treatment of cutaneous melanoma. The ineffective treatment has led to a devastating situation: about 50% of patients develop unresectable or metastatic disease after the diagnosis, usually resulting in death within a year. 

The FDA approved the ilfe-extending drug 

On January 26, 2022, the FDA approved tebentafusp-tebn, the first drug to treat metastatic uveal melanoma in adults, based on phase 3 clinical trial results that demonstrated survival benefit to the patients. 

The approval of this new drug is a milestone advance. For the first time in the history of this disease, it offers patients the only therapeutic option that brings hope to them and provides the opportunity to extend their lives. 

The new drug is the first TCR-based immunotherapeutic

Tebentafusp-tebn is a novel form of immunotherapy that uses an engineered bispecific T-cell receptor (TCR) antibody to redirect the body’s T cells to fight cancer. It is the first TCR-based immunotherapeutic approved by the FDA to treat a solid tumor, representing a breakthrough in cancer treatment. 

The bispecific TCR antibody can specifically bind with the gp100 molecule on cancer cells and the CD3 molecule on the T cells, allowing the body’s immune system to recruit many more T cells to join the fight and kill gp100-expressing cancer cells more effectively. 

Decades of research efforts are behind the new immunotherapy

Scientists and clinical researchers have paved the way for the successful launch of Tebentafusp-tebn with decades of relentless research on the TCR. Dr. Tak Mak at the University of Toronto and Mark Davis at the Stanford University School of Medicine are the two scientists who made the breakthrough discoveries of the T-cell receptor (TCR) structure, which has formed a critical part of contemporary TCR immunotherapy. In October 2021, both received the Szent-Györgyi Prize for Progress in Cancer Research from the National Foundation for Cancer Research (NFCR). 

The new drug won’t work for every patient. 

The new drug has a limitation: it only works for patients with a specific HLA (human leukocyte antigens) type. About 40-50% of the patients have the required HLA molecules, and only these HLA-A*0201-positive patients would qualify for the treatment. Therefore, patients need to talk to their doctors to see if they have the HLA-A*0201 type before starting the treatment with the new drug.