The FDA on Friday approved Genentech’s Tecentriq (atezolizumab) and Tecentriq Hybreza (atezolizumab and hyaluronidase-tqjs) as adjuvant treatment for muscle-invasive bladder cancer patients with circulating tumor DNA after cystectomy, as determined by Natera’s Signatera MRD assay. The approval makes this the first ctDNA MRD-guided regulatory decision in bladder cancer. In the Phase III IMvigor011 trial, 250 MIBC patients who were ctDNA-positive on Signatera after cystectomy but had no radiographic disease were randomized to Tecentriq versus placebo. Disease-free survival was nearly doubled with Tecentriq (9.9 months vs 4.8 months), and median overall survival improved (32.8 months vs 21.1 months). Genentech and Natera also highlighted that Signatera received simultaneous FDA authorization as a companion diagnostic to identify patients likely to benefit, marking the first time the FDA cleared a blood-based MRD assay as a CDx. For clinicians, the label also frames a potential treatment-de-escalation pathway for ctDNA-negative patients by supporting safer omission of adjuvant immunotherapy following cystectomy.