Patients with metastatic uveal melanoma (mUM) treated with IMCgp100 continued to experience a durable tumor response with a median follow up of 19.1 months, without yet reaching median overall survival (OS), according to new phase 1 research to be presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago. IMCgp100 is the wholly-owned, lead program from Immunocore Limited, a leading T-cell receptor (TCR) company focused on delivering first-in-class biological therapies that transform lives.
Although rare, uveal melanoma is the most common form of adult eye cancer. When it metastasises beyond the eye, less than half of patients will survive for one year. Of the 19 HLA-A*0201+ patients enrolled in phase 1 of the Phase 1/2 dose escalation trial, 17 were evaluated for efficacy. Among these patients, treatment with IMCgp100 was associated with an objective response rate of 18% (90% confidence interval [4,30]) and a 1-year overall survival rate of 74% (95% confidence interval [48,88]) at the time of data cut-off.
“Survival rates in uveal melanoma have remained largely unchanged for decades, and it is difficult to treat once it advances to metastatic disease,” Dr. Takami Sato, Department of Medical Oncology, Kimmel Cancer Center, Thomas Jefferson University and lead investigator, said in a company news release. “These data provide compelling evidence that IMCgp100 may offer hope to this underserved patient population.”
Additional exploratory survival analyses also indicated prolonged OS was associated with a number of pharmacodynamic outcomes, including lymphocyte trafficking, providing encouraging evidence supporting the proposed mechanism of action of IMCgp100.
“Immunocore is focused on transforming the lives of patients with some of the most challenging diseases, such as metastatic uveal melanoma, for which there is currently no standard of care,” said Andrew Hotchkiss, Chief Executive Officer at Immunocore. “Although these are early findings, we are encouraged by the emerging clinical data and focused on advancing our pivotal trials.”
The most common adverse events in the phase 1 arm included pruritus (severe itching of the skin; 90%), pyrexia (fever) and fatigue (84%), and hypotension (74%). Dose limiting toxicities were observed in 3 patients; all were reversible abnormalities in liver function tests (Grade 3 or 4 ALT/AST changes). There were no IMCgp100-related AEs that resulted in discontinuation or death.