Tumor, immune, and stromal characteristics associated with clinical outcomes with atezolizumab (atezo) + platinum-based chemotherapy (PBC) or atezo monotherapy (mono) versus PBC in metastatic urothelial cancer (mUC) from the phase III IMvigor130 study
Abstract No : 5011
Abstract Type : Clinical science symposium
Indication : Urothelial Carcinoma
Intervention : Atezolizumab
Company : Roche
Technology : Monoclonal antibody
The 851 biomarker-evaluable pts (BEP) were representative of the 1200 ITT pts. Biomarker results are shown in Table. PD-L1 IC2/3 was associated with significantly longer OS for atezo mono vs placebo + PBC and a combination of PD-L1 IC2/3, and high TMB (. 10 muts/Mb) identified a pt subset (» 14% of BEP) with particularly favorable outcomes with atezo mono vs placebo + PBC; similar results for PD-L1 and TMB were not seen with atezo + PBC vs placebo + PBC. APOBEC mutagenesis was associated with improved OS with atezo-containing regimens whereas high F-TBRS was associated with inferior OS with atezo mono.
These results reinforce the potential predictive nature of biomarkers associated with response/resistance to atezo and highlight potentially distinct biology driving benefit with atezo and atezo + PBC. These findings suggest a possible biomarker-directed approach to 1L mUC tx that warrants mechanistic interrogation and prospective validation.
Primary results showed that IMvigor130 met its co-primary PFS endpoint, supporting the combination of atezolizumab +/- platinum/gemcitabine as an important new treatment option for patients with untreated mUC. The findings from IMvigor130 suggests a possible biomarker-directed approach to 1L mUC treatment.