Potential of Novel Combination Under Study in Metastatic Mucosal Melanoma
Posted: Monday, September 23, 2019
Can –1 plus –1 ever equal +2? In a way, that was what researchers set out to find in an open-label phase IB trial with the combination of VEGF inhibition and PD-1 blockade to 29 patients with chemotherapy-naive metastatic mucosal melanoma whose disease was refractory to either therapy alone. The results indicated “promising antitumor activity,” wrote lead author Xinan Sheng, MD, of Peking University Cancer Hospital and Institute in Beijing, and colleagues in the Journal of Clinical Oncology.
The patients received toripalimab, a humanized immunoglobulin G4 monoclonal antibody against PD-1, and the VEGF receptor inhibitor axitinib. The study’s primary objective was safety, and the most common treatment-related adverse events were of grade 1 or 2, including diarrhea, proteinuria, fatigue, and liver enzyme elevation. Although more than one-third of patients experienced events of grade 3 or more, the researchers deemed the combination tolerable.
One of the trial’s secondary objectives was efficacy. By the cutoff date, 14 patients had achieved an objective response, with a median progression-free survival time of 7.5 months (95% confidence interval, 3.7 months to not reached).
The study’s patients “were all Asian,” noted Dr. Sheng and his team. “This combination therapy must be validated in a randomized phase III trial that includes a non-Asian population before it can become a standard of care.”
Although mucosal melanomas are rare, they are more aggressive than other pathologic subtypes, with poorer 5-year survival. With no clear therapeutic guideline for this type of melanoma, the same regimens used for cutaneous melanoma are often tried, despite data suggesting this strategy may be less effective, according to the study authors.
Disclosure: The study authors’ disclosure information may be found at ascopubs.org.