Atezolizumab vs Durvalumab
## Overview
Atezolizumab and durvalumab are both anti-PD-L1 antibodies with engineered Fc regions to minimize ADCC. Their indication profiles are largely complementary: atezolizumab leads in HCC and SCLC, while durvalumab leads in stage III NSCLC maintenance and biliary tract cancer.
## Mechanism of Action
Both block PD-L1. Durvalumab additionally blocks PD-L1 binding to CD80 (B7.1) in addition to PD-1, potentially providing broader restoration of T-cell activation.
## Key Indication Differences
Atezolizumab + bevacizumab: standard first-line HCC. Atezolizumab + carboplatin/etoposide: standard SCLC. Durvalumab maintenance: standard stage III NSCLC post-CRT (PACIFIC). Durvalumab + tremelimumab + chemo: NSCLC (POSEIDON). Durvalumab in biliary tract cancer (TOPAZ-1: first IO approval in BTC).
## Pharmacokinetics
Atezolizumab: ~27-day half-life, q3w or q4w. Durvalumab: ~17-day half-life, q2w or q4w.
## Key Takeaways
- Atezolizumab: HCC first-line (with bevacizumab); SCLC; NSCLC combinations
- Durvalumab: stage III NSCLC post-CRT maintenance; biliary tract cancer; SCLC (CASPIAN)
- Both effective anti-PD-L1 agents with complementary indication sets
结论
Atezolizumab and durvalumab serve distinct clinical niches as anti-PD-L1 antibodies. Atezolizumab is preferred for HCC (with bevacizumab) and SCLC. Durvalumab is preferred for stage III NSCLC post-CRT maintenance and biliary tract cancer. Selection is driven by the specific cancer type and regimen context, not intrinsic pharmacological superiority.