A Promising New Immunotherapy for Advanced Melanoma

A small, early-phase trial of a new immunotherapy yielded “durable responses” for patients with advanced melanoma and ocular melanoma. 

Each year some 2,000 to 2,500 people in the United States are diagnosed with ocular melanoma, a serious cancer of the eye. 

In about half of those diagnosed with this form of cancer, also called uveal melanoma or intraocular melanoma, the disease spreads, often to the liver. The prognosis for patients with metastatic ocular melanoma is poor, with median survival of just two to eight months. 

So the report at the American Association for Cancer Research (AACR) Annual Meeting 2015 in April, of results from a phase I/IIa clinical trial of a new type of immunotherapy – albeit in a small group of 17 patients with advanced melanoma and ocular melanoma – is promising.

The trial was of a first-in-class immunotherapy called IMCgp100. This therapeutic has “two functional ends,” explained Mark R. Middleton, PhD, professor of experimental cancer medicine at the University of Oxford in the United Kingdom. “The targeting end attaches to melanoma cells and the effector end locks on to any neighboring killer T cell [a type of immune cell], resulting in directed destruction of the tumor.”

In essence, IMCgp100 connects the immune cells to the melanoma cells, encouraging them to destroy the cancer.

“Among these patients, we observed lasting tumor responses for both cutaneous and ocular melanoma,” said Dr. Middleton. “Importantly, responses were even observed in patients with advanced melanoma that was resistant to the immune checkpoint inhibitors that have recently become standard of care in many locations.”

Among the 17 patients, three partial responses and one complete response were observed; two of the partial responses are still ongoing and have lasted more than 18 months, Dr. Middleton and his colleagues reported. The complete response in one patient with advanced ocular melanoma lasted over four months.

“It is too early to say if IMCgp100 is particularly effective in ocular melanoma, although the results are encouraging. These observations will be investigated further, both clinically and experimentally,” said Dr. Middleton. “We look forward to continuing to follow all the patients who remain on the trial and to enrolling more patients to firmly establish the utility of IMCgp100 as a treatment for advanced melanoma.”

This study was funded by Immunocore. Dr. Middleton declared no conflicts of interest.