Nivolumab ( Opdivo ) has shown efficacy and acceptable safety in 2 open-label, multicenter studies ( CheckMate 032 and 275 ) and is approved for patients with metastatic urothelial carcinoma ( mUC ) after greater than or equal to 1 Platinum-based therapy.
Researchers have reported longer-term efficacy and safety results for patients with metastatic urothelial carcinoma in the phase 1/2 CheckMate 032 study who received Nivolumab monotherapy based on more than 2 years of follow-up.
Patients with metastatic urothelial carcinoma, regardless of programmed death-1 ligand 1 ( PD-L1 ) expression status, received Nivolumab 3 mg/kg intravenously every 2 weeks until progression or discontinuation.
Tumor PD-L1 membrane expression was assessed with Dako PD-L1 immunohistochemical staining.
Primary endpoint was objective response rate ( ORR; RECIST 1.1 ); other endpoints were safety, progression-free survival ( PFS ), overall survival ( OS ), and duration of response.
Of 78 treated patients ( median age 65.5 years; range, 31-85 ), 52 ( 66.7% ) had received greater than or equal to 2 prior therapies.
At a minimum follow-up of 24 months, 11 pts ( 14.1% ) remain on treatment. Treatment discontinuation was mainly due to disease progression ( 52 pts [ 66.7% ] ).
Tumor PD-L1 expression was evaluable in 68 patients ( 87.2% ); 26 ( 38.2% ) patients had greater than or equal to 1% and 42 ( 61.8% ) had less than 1% expression.
Updated overall response rate was 25.6%, with 1 additional complete response ( CR ) achieved for a CR rate of 8%.
Median duration of response was not reached.
ORR, 1- and 2-year progression free survival and overall survival rates were similar between the PD-L1 less than 1% and more than 1% subsets.
Grade 3 or 4 treatment-related adverse events ( TRAEs ) occurred in 22 patients ( 28.2% ); most frequent were ↑lipase ( 6.4% ), ↑amylase ( 5.1% ), and maculopapular rash ( 3.8% ).
One patient had a grade 5 TRAE ( pneumonitis ).
In conclusion, Nivolumab showed clinically meaningful, durable efficacy with promising long-term survival regardless of PD-L1 expression, and no new toxicity signals with longer-term follow-up in previously treated patients with metastatic urothelial carcinoma. ( Xagena )
Source: Genitourinary Cancers Symposium, 2018