Abstract 4038
Background
The global Phase III IMpower132 study evaluated the addition of atezo to platinum-based pem combinations as 1L treatment (tx) for patients (pts) with metastatic non-squamous NSCLC tumours lacking sensitizing EGFR or ALK mutations. IMpower132 met its co-primary endpoint of PFS in the ITT population and showed numerical improvements in OS. We performed exploratory efficacy analyses to assess clinical benefit in key subgroups.
Methods
Previously untreated pts were randomized 1:1 to receive 4 or 6 cycles of either atezo 1200 mg + carbo AUC 6 or cis 75 mg/m2 + pem 500 mg/m2 (Arm APP) or carbo AUC 6 or cis 75 mg/m2 + pem 500 mg/m2 (Arm PP), followed by maintenance therapy with atezo 1200 mg + pem 500 mg/m2 (APP) or pem 500 mg/m2 alone (PP). Atezo maintenance tx could be continued beyond disease progression. We conducted exploratory efficacy analyses examining PFS and interim OS in clinically relevant pt subgroups (race, age, smoking history, and liver metastasis at baseline).
Results
578 pts were enrolled. The median follow-up at data cutoff (May 22, 2018) was 14.8 mo. Baseline characteristics were mostly balanced between tx arms. See table for PFS and interim OS data in key subgroups. Additional efficacy and safety data will be presented.
Conclusions
The addition of atezo to carbo or cis + pem resulted in numerical improvement in PFS and OS in most key clinical subgroups. Survival benefit appeared more pronounced in Asian pts, older pts, and never smokers. Further analyses may provide new insights into the mechanisms underlying these effects and may improve future tx options for pts globally.
| Table | |||||
|---|---|---|---|---|---|
| Population | APP | PP | |||
| n | Median PFS (95% CI), mo | n | Median PFS (95% CI), mo | HR (95% CI); P value | |
| ITT | 292 | 7.6 (6.6, 8.5) | 286 | 5.2 (4.3, 5.6) | 0.596 (0.494, 0.719); P < 0.0001a |
| Non-Asian | 221 | 6.9 | 221 | 5.0 | 0.65 (0.53, 0.81) |
| Asian | 71 | 10.2 | 65 | 5.3 | 0.42 (0.028, 0.63) |
| < 65 y | 153 | 6.9 | 167 | 4.4 | 0.63 (0.49, 0.80) |
| ≥ 65 y | 139 | 8.4 | 119 | 5.6 | 0.55 (0.42, 0.73) |
| Never smokers | 37 | 8.6 | 30 | 5.5 | 0.49 (0.28, 0.87) |
| Former/current smokers | 255 | 7.5 | 256 | 5.1 | 0.61 (0.50, 0.74) |
| No liver mets | 255 | 8.4 | 250 | 5.5 | 0.56 (0.46, 0.69) |
| Liver mets | 37 | 4.4 | 36 | 4.0 | 0.77 (0.47, 1.25) |
| n | Median OS | n | Median OS (95% CI), mo | HR (95% CI); P value | |
| ITT | 292 | 18.1 (13.0, NE) | 286 | 13.6 | 0.813 (0.644, 1.025) |
| Non-Asian | 221 | 13.0 | 221 | 11.0 | 0.82 (0.64, 1.06) |
| Asian | 71 | NE | 65 | NE | 0.68 (0.37, 1.24) |
| < 65 y | 153 | 18.8 | 167 | 14.2 | 0.89 (0.62, 1.21) |
| ≥ 65 y | 139 | 18.1 | 119 | 12.8 | 0.71 (0.50, 1.01) |
| Never smokers | 37 | 18.1 | 30 | 13.3 | 0.65 (0.32, 1.30) |
| Former/current smokers | 255 | 18.8 | 256 | 13.6 | 0.83 (0.65, 1.06) |
| No liver mets | 255 | 19.9 | 250 | 14.2 | 0.76 (0.59, 0.98) |
| Liver mets | 37 | 10.1 | 36 | 6.9 | 0.99 (0.57, 1.70) |
| a Stratified. | |||||
Clinical trial identification
NCT02657434
Editorial Acknowledgement
Steffen Biechele, PhD, of Health Interactions