IMpower133
Trial question
What is the role of first-line atezolizumab plus chemotherapy in patients with extensive-stage small cell lung cancer?
Study design
Multi-center
Double blinded
RCT
Population
Characteristics of study participants
35.0% female
65.0% male
N = 403
403 patients (142 female, 261 male).
Inclusion criteria: patients with extensive-stage small cell lung cancer who had not previously received treatment.
Key exclusion criteria: history of autoimmune disease; previous treatment with CD137 agonists or immune-checkpoint blockade therapies.
Interventions
N=201 atezolizumab (atezolizumab 1200 mg plus four 21-day cycles of carboplatin and etoposide).
N=202 placebo (matching placebo plus four 21-day cycles of carboplatin and etoposide).
Primary outcome
Median overall survival
12.3 months
10.3 months
12.3 months
9.2 months
6.2 months
3.1 months
0.0 months
Atezolizumab
Placebo
Significant
increase ▲
Significant increase in median overall survival (12.3 months vs. 10.3 months; HR 1.43, 95% CI 1.09 to 1.85).
Secondary outcomes
Significant increase in median progression-free survival (5.2 months vs. 4.3 months; HR 1.29, 95% CI 1.04 to 1.61).
Safety outcomes
No significant difference in adverse events.
Conclusion
In patients with extensive-stage small cell lung cancer who had not previously received treatment, atezolizumab was superior to placebo with respect to median overall survival.
Reference
Leora Horn, Aaron S Mansfield, Aleksandra Szczęsna et al. First-Line Atezolizumab plus Chemotherapy in Extensive-Stage Small-Cell Lung Cancer. N Engl J Med. 2018 Dec 6;379(23):2220-2229.
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