Some mRCC patients have durable response after stopping immunotherapy
Some patients with metastatic renal cell carcinoma (mRCC) who respond to PD-1/PD-L1 immunotherapy can have persistent clinical benefit after treatment discontinuation due to immune-related adverse events.
Among 19 patients with mRCC who responded to and subsequently discontinued PD-1/PD-L1 immunotherapy due to an immune-related adverse event, eight patients (42 percent) had durable responses and remained off any additional therapy for at least 6 months. [ASCO GU 2017, abstract 467]
“One of the eight patients had a complete response, and the remaining seven had a partial response,” reported Dr Rana R. McKay of the University of California San Diego, California, US. “These patients were on treatment for a median period of 11 months. Their median time subsequently off treatment was 20 months.”
Patients in the study (74 percent male; median age, 68 years) received PD-1/PD-L1 immunotherapy mostly as monotherapy (63 percent). The median time on immunotherapy was 5.5 months.
“Immune-related adverse events leading to immunotherapy discontinuation included arthritis, uveitis, arthropathy, hypophysitis, myositis, blepharitis, hepatitis, rash, pericarditis, and amylase and lipase elevations,” said McKay.
“It is very reassuring to see that some patients may continue to benefit from immunotherapy even after treatment discontinuation due to adverse events. These findings call into question the current standard of continuous treatment with immunotherapy,” said ASCO expert Dr Sumanta Pal of the City of Hope Cancer Center in Los Angeles, California, US.
Further studies are planned to validate the findings and investigate strategies to customize PD-1/PD-L1 immunotherapy in patients with advanced kidney cancer.