Natera submitted its Signatera molecular residual disease assay to Japan’s PMDA as a companion diagnostic for Tecentriq (atezolizumab) in muscle-invasive bladder cancer. The submission leverages IMvigor011 data, where MRD-positive post-cystectomy patients showed nearly doubled disease-free survival on Tecentriq versus placebo. Regulators have already approved Signatera in colorectal cancer in Japan, and the new filing extends MRD-guided oncology into uro-oncology decisioning. Natera said the companion diagnostic goal is to bring validated ctDNA-driven treatment selection to Japanese practice. The move reinforces how MRD testing is transitioning from research into regulatory-defined clinical workflows, potentially changing which patients receive immunotherapy after surgery based on molecular residual risk.