Salvage nivolumab–ipilimumab shows potential for some metastatic RCC patients
medwireNews: The combination of nivolumab and ipilimumab demonstrates antitumor activity and acceptable toxicity in patients with metastatic renal cell carcinoma (RCC) previously exposed to PD-1 or PD-L1 inhibitors, say the authors of a chart review.
They analyzed data from 45 patients treated with the PD-1 inhibitor nivolumab plus the CTLA-4 inhibitor ipilimumab at one of five US centers after receiving prior treatment with an immune checkpoint inhibitor (ICI) targeting the PD-1 pathway; participants had not previously received a CTLA-4 inhibitor.
During a median follow-up of 12 months, 20% of patients receiving the combination achieved an objective response, where all responses were partial and lasted for a median of 7 months. A further 16% of patients had stable disease, while 62% had progressive disease.
Median progression-free survival was 4 months, report Brian Rini (Vanderbilt University Medical Center, Nashville, Tennessee, USA) and colleagues in the Journal of Clinical Oncology.
And they emphasize: “It is important to note that although a small proportion of patients had an objective response to salvage ipilimumab and nivolumab, the responses […] were durable in the majority of responders, and several patients derived clinical benefit even without achieving RECIST-defined [partial response].”
Of the 23 patients who received ICI monotherapy immediately prior to the combination, three had a partial response to salvage nivolumab–ipilimumab, as did one of the six patients who received monotherapy with a VEGFR inhibitor.
By contrast, the five patients whose immediate prior treatment was an ICI combined with a VEGFR inhibitor all had progressive disease.
In total, 64% of patients experienced an immune-related adverse event (irAE) of any grade and 13% had a grade 3–4 event, which Rini et al describe as “acceptable.”
Nine percent of the study participants delayed treatment due to irAEs, while 13% discontinued as a result.
The researchers therefore believe that “[i]pilimumab and nivolumab may be an effective salvage treatment option for select patients with metastatic RCC with prior treatment with PD-1/PD-L1 inhibitors.”
But they highlight “the lack of complete responses, high rate of [progressive disease], and the potential for toxicity” and conclude that “[a]dditional investigation into this approach to define durability of response and benefit/risk is needed.”
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