Atezolizumab may prolong survival in bladder cancer
The anti–PD-L1 immune checkpoint inhibitor atezolizumab confers survival gains in patients with locally advanced or metastatic urothelial carcinoma (mUC) treated with platinum-containing chemotherapy, according to long-term data from the phase III IMvigor211 trial.
The current analysis included the IMvigor211 intent-to-treat (ITT) population. This comprised mUC patients who progressed during or following platinum-based chemotherapy and then randomly assigned to receive either atezolizumab 1,200 mg or chemotherapy (vinflunine 320 mg/m2, paclitaxel 175 mg/m2, or docetaxel 75 mg/m2; choice of regimen at researchers’ discretion) intravenously every 3 weeks.
Compared with chemotherapy, atezolizumab yielded long-term durable remission over a median follow-up of 33 months. This was despite the primary analysis demonstrating no statistically significant effect on overall survival (OS).
OS rates at 24 months were more favourable with atezolizumab than with chemotherapy (23 percent vs 13 percent).
Results for safety were in line with the primary analysis, and no new signals emerged. Higher grade treatment-related adverse events (AEs) occurred more frequently among chemotherapy-treated patients (grade 3–4: 43 percent vs 22 percent), as were AEs that led to treatment discontinuation (18 percent vs 9 percent).
On the other hand, AEs of special interest, which tended to be grade 1–2, were more common among patients who received atezolizumab (35 percent vs 20 percent).
The findings support the use of atezolizumab in mUC patients treated with platinum-based chemotherapy, regardless of PD-L1 status.