Atezolizumab Receives FDA Approvals for MIBC With Molecular Residual Disease

The FDA approved atezolizumab (Tecentriq; Genentech) and atezolizumab and hyaluronidase-tqjs (Tecentriq Hybreza; Genentech) as adjuvant treatments for adults with muscle-invasive bladder cancer (MIBC) after cystectomy who have circulating tumor DNA molecular residual disease (ctDNA MRD) as determined by an FDA-authorized test. The FDA also announced that Signatera CDx (Natera, Inc) has received approval as a companion diagnostic test for adjuvant treatment with atezolizumab and atezolizumab and hyaluronidase in select patients from this population.¹

Atezolizumab is a humanized IgG1 monoclonal antibody that targets programmed cell death ligand 1 and has received FDA approval for multiple neoplastic conditions. It can be administered as a monotherapy or in combination with chemotherapy. Indications include locally advanced or metastatic urothelial carcinoma, metastatic non–small cell lung cancer, extensive-stage small cell lung cancer, metastatic triple-negative breast cancer, and unresectable or metastatic hepatocellular carcinoma.²

Atezolizumab’s efficacy and safety were evaluated in IMvigor011 (NCT04660344)³, a multicenter, randomized, double-blind, placebo-controlled phase 3 trial. A total of 250 patients—all of whom had MIBC and radical cystectomy with lymph node dissection and had MRD detected by serial ctDNA MRD evaluation of blood during the subsequent 12 months—were randomly assigned to the atezolizumab group (n = 167) or the placebo group (n = 83).^1,3,4

ctDNA-positive patients received 1680 mg intravenously (IV) every 4 weeks on day 1 of each 28-day cycle. Treatment continued for up to 12 cycles or 1 year—whichever occurred first—unless there was disease recurrence or unacceptable toxicity.^1,4

The primary end point was investigator-assessed disease-free survival (DFS). Overall survival (OS) was a secondary end point that was assessed in a hierarchical fashion to control for alpha.^1,3,4

According to the findings, a statistically significant improvement in DFS was observed. Those receiving atezolizumab achieved a median DFS of about 9.9 months (95% CI, 7.2–12.7) compared with 4.8 months (95% CI, 4.1–8.3) for those in the placebo group (hazard ratio [HR]: 0.64 [95% CI, 0.47–0.87]; p = .0047). Additionally, a statistically significant improvement in OS was also observed, with a median OS of about 32.8 months (95% CI, 27.7–not estimable [NE]) and 21.1 months (95% CI, 14.7–NE) in the atezolizumab and placebo arms, respectively (HR: 0.59 [95% CI, 0.39–0.90]; p-value = .0131).^1,4

Approximately 28% of the patients who received atezolizumab and 22% of those receiving placebo had adverse events (AEs) of grade 3 or 4 (related to atezolizumab or placebo in 7% vs. 4%). Approximately 3% and 2% of these respective patients had fatal AEs.⁴

According to the prescribing information for atezolizumab and for atezolizumab and hyaluronidase, warnings and precautions for immune-mediated AEs, infusion-related reactions, complications of allogeneic hematopoietic stem cell transplantation, and embryo-fetal toxicity are included.¹

The recommended atezolizumab dose administered IV is 840 mg every 2 weeks, 1200 mg every 3 weeks, or 1680 mg every 4 weeks for up to 1 year, unless there is disease recurrence or unacceptable toxicity. The recommended dosage of atezolizumab and hyaluronidase-tqjs is 1875 mg of atezolizumab and 30,000 units of hyaluronidase administered subcutaneously every 3 weeks for up to 1 year, unless there is disease recurrence or unacceptable toxicity. For patients with negative Signatera CDx test results, serial testing should be continued until they receive a positive test result or complete the recommended 12-month testing window.¹

REFERENCES

1. FDA approves atezolizumab for adjuvant treatment of muscle invasive bladder cancer in patients with molecular residual disease. FDA. News release. May 15, 2026. Accessed May 15, 2026. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-atezolizumab-adjuvant-treatment-muscle-invasive-bladder-cancer-patients-molecular

2. Aleem A, Shah H. Atezolizumab. StatPearls [Internet]. Updated October 29, 2024. Accessed May 15, 2026. https://www.ncbi.nlm.nih.gov/books/NBK567758/

3. A Study of Atezolizumab Versus Placebo as Adjuvant Therapy in Participants With High-risk Muscle-invasive Bladder Cancer (MIBC) Who Are ctDNA Positive Following Cystectomy (IMvigor011). ClinicalTrials.gov identifier: NCT04660344. Updated March 27, 2026. Accessed May 15, 2026. https://clinicaltrials.gov/study/NCT04660344

4. Powles T, Kann AG, Castellano D, et al. ctDNA-Guided Adjuvant Atezolizumab in Muscle-Invasive Bladder Cancer. N Engl J Med. 2025;393(24):2395-2408.doi:10.1056/NEJMoa2511885