TAPISTRY: A Phase II Study of Atezolizumab in Patients with Tumor Mutational Burden-High Tumors
Recommended Citation
Thomas DM, Kim JE, Barlesi F, Martens UM, Krzakowski M, Dziadziuszko R, Jeong JH, Daniele G, Wilson TR, Wu F, Simmons BP, Patel S, Sbirnac M, Kaul M, and Gadgeel SM. TAPISTRY: A Phase II Study of Atezolizumab in Patients with Tumor Mutational Burden-High Tumors. Clin Cancer Res 2026;32(6):1078-1086.
Document Type
Article
Publication Date
3-16-2026
Publication Title
Clinical cancer research
Keywords
Humans, Female, Male, Antibodies, Monoclonal, Humanized, Neoplasms, Mutation, Middle Aged, Adult, Aged, Biomarkers, Tumor, Young Adult, Aged, 80 and over, Adolescent, Tumor Burden, Child, B7-H1 Antigen
Abstract
PURPOSE: Patients with tumor mutational burden (TMB)-high tumors can derive benefit from atezolizumab, though previous studies have used inconsistent TMB cutoffs. We report data for atezolizumab in patients with TMB-high solid tumors from the phase II TAPISTRY multicohort trial, using TMB cutoffs of ≥13 and ≥16 mutations per megabase (mut/Mb).
PATIENTS AND METHODS: Patients with PD-L1 inhibitor-naïve, TMB-high (≥13 mut/Mb), advanced/metastatic solid tumors received atezolizumab every 21 days [1,200 mg for adults, 15 mg/kg (up to 1,200 mg/kg) for children]. The primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) for TMB ≥16 mut/Mb. Secondary endpoints (using TMB ≥13 mut/Mb) included IRC-assessed ORR, duration of response (DOR), progression-free survival (PFS), and safety.
RESULTS: As of November 9, 2023 (median survival follow-up: 9.8 months), 148 patients received treatment. Median age was 63 years, 31.8% of patients had >2 prior therapy lines, and the most common tumor types were colorectal (29.1%), breast (8.8%), and gastroesophageal (8.8%). IRC-assessed ORR was 22.3% [95% confidence interval (CI), 15-31.2] with TMB ≥16 mut/Mb (n = 112), and 20.2% (95% CI, 13.6-28.1) with TMB ≥13 mut/Mb (n = 129). Median IRC-assessed DOR was not estimable. Median IRC-assessed PFS was 2.8 (95% CI, 1.7-5.4) and 2.7 (95% CI, 1.5-4.2) months using TMB ≥16 and ≥13 mut/Mb, respectively. Adverse events were reported in 93.2% of patients, of which 53.4% were treatment-related (no grade 5) and 40.5% were grade ≥3.
CONCLUSIONS: Atezolizumab led to moderate antitumor activity in various TMB-high solid tumors. Safety was consistent with previous reports.
Medical Subject Headings
Humans; Female; Male; Antibodies, Monoclonal, Humanized; Neoplasms; Mutation; Middle Aged; Adult; Aged; Biomarkers, Tumor; Young Adult; Aged, 80 and over; Adolescent; Tumor Burden; Child; B7-H1 Antigen
PubMed ID
41511400
Volume
32
Issue
6
First Page
1078
Last Page
1086
