Post-Progression Response to Nivolumab in Advanced Renal Cell Carcinoma
Nivulomab was shown to improve renal cell carcinoma tumor size in a subgroup of patients receiving treatment beyond Response Evaluation Criteria in Solid Tumors (RECIST) disease progression. The findings of the CheckMate 025 study, conducted by Bernard Escudier, MD, of Gustave Roussy in Villejuif, France, and colleagues, were published in European Urology.
The subgroup analysis focused on 406 patients treated with nivolumab from the phase III trial. In nearly 80%, disease progressed by RECIST. A total of 48% of these patients were eligible for treatment beyond RECIST disease progression (TBP), and 52% were not (NTBP). The TBP group received 3 mg/kg for at least 4 weeks after initial tumor progression, and the NTBP group was treated briefly for 0 to 4 weeks post initial disease progression.
Post progression analysis found that 13% of the TBP patients had a 30% or more reduction in tumor burden. As for toxicity, TBP patients had a lower incidence of treatment-related adverse events after than before disease progression (59% vs. 71%).
The researchers believe the initial tumor progression may be secondary to a transient antitumor immune cell response. Reduction in tumor size may not be observed if therapy is discontinued at first disease progression.