IMmotion150: Novel Radiological Endpoints and Updated Data From a Randomized Phase II Trial Investigating Atezolizumab With or Without Bevacizumab vs Sunitinib in Untreated Metastatic Renal Cell Carcinoma

Immunotherapy and VEGF-targeting therapies improve mRCC outcomes; however, new agents and combinations are needed because immune escape and/or resistance often develops. Here, we prospectively explore novel efficacy endpoints and report updated data from IMmotion150 (NCT01984242), a Ph II trial of atezolizumab (anti–PD-L1) with or without bevacizumab (anti-VEGF) vs sunitinib (TKI) in first-line mRCC.

Treatment-naive mRCC patients were randomized to atezolizumab 1200 mg IV q3w + bevacizumab 15 mg/kg IV q3w, atezolizumab 1200 mg IV q3w alone or sunitinib 50 mg PO QD 4 wk on/2 wk off. PD-L1 expression was scored on tumor-infiltrating immune cells (IC; VENTANA SP142 IHC assay). Coprimary endpoints were independent review facility (IRF)–assessed PFS (RECIST v1.1) in ITT and PD-L1+ (≥ 1% IC) patients. Other endpoints included investigator (INV)-assessed PFS by RECIST v1.1 and immune-modified RECIST (imRECIST) and patient-reported outcomes (PROs).

After a median 25.7 mo of follow-up, results remained consistent with the primary analysis (median follow-up, 20.7 mo), showing clinically meaningful benefit in IRF- and INV-PFS with atezolizumab + bevacizumab vs sunitinib in PD-L1+ patients (RECIST v1.1; Table). The INV-PFS (imRECIST) HR for atezolizumab + bevacizumab vs sunitinib was 0.78 in ITT patients and 0.47 in PD-L1+ patients (Table). Safety of atezolizumab + bevacizumab was consistent with the known safety profile of each agent alone; further follow-up showed no new safety signals. PROs will be presented.