Ethnic differences in non-small-cell lung cancer treatment: the Asian perspective

Results from the IMpower132 China cohort: Atezolizumab plus platinum-based chemotherapy in advanced non-small cell lung cancer

BACKGROUND

The global Phase III IMpower132 study evaluating atezolizumab plus pemetrexed and carboplatin or cisplatin (APP) versus pemetrexed plus carboplatin or cisplatin (PP) for first-line treatment of non-squamous advanced non-small cell lung cancer (NSCLC) met its co-primary progression-free survival (PFS) endpoint at the primary analysis in the intention-to-treat (ITT) population. Although the co-primary overall survival (OS) endpoint was not met, numerical OS improvement favoring APP over PP was observed at the final analysis. We report primary results for Chinese patients in IMpower132.

METHODS

Treatment-naive Chinese patients with non-squamous stage IV EGFR/ALK mutation-negative NSCLC were randomized 1:1 to receive 4 or 6 cycles of APP or PP, followed by maintenance atezolizumab plus pemetrexed or pemetrexed. Co-primary endpoints were investigator-assessed PFS and OS.

RESULTS

The ITT population included 163 Chinese patients (82 in the APP arm and 81 in the PP arm). At data cutoff (median follow-up, 11.7 months), the median PFS in the APP and PP arms was 8.3 and 5.8 months, respectively; the unstratified hazard ratio (HR) was 0.73 (95% CI: 0.50, 1.08). At the interim OS analysis, median OS was not estimable in either arm; the unstratified HR was 0.70 (95% CI: 0.40, 1.24). No new safety signals were observed.

CONCLUSION

Among Chinese patients in IMpower132, PFS benefit was seen with APP versus PP. Though interim OS data were immature, there was a trend toward OS benefit favoring APP versus PP. The safety profile of the APP was consistent with the known risks of the individual treatment components.

CLINICALTRIALS

gov: NCT02657434.

IMpower132: Atezolizumab plus platinum-based chemotherapy vs chemotherapy for advanced NSCLC in Japanese patients

IMpower132 explored the safety and efficacy of atezolizumab plus pemetrexed and platinum-based chemotherapy as first-line treatment for advanced non-small-cell lung cancer (NSCLC). Key eligibility criteria for the phase 3, open-label, IMpower132 study included age ≥18 y, histologically or cytologically confirmed advanced non-squamous NSCLC per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, Eastern Cooperative Oncology Group performance status of 0/1, and no prior systemic treatment for stage IV NSCLC. Patients received atezolizumab (1200 mg) plus pemetrexed (500 mg/m² ) and cisplatin (75 mg/m² ) or carboplatin (area under the concentration curve, 6 mg/mL/min) (APP arm) or chemotherapy alone (PP arm). The co-primary study endpoints were overall survival (OS) and investigator-assessed progression-free survival (PFS) per RECIST 1.1 in the intention-to-treat population. A subgroup analysis was conducted in Japanese patients. In the Japanese subgroup (n = 101), median OS was 30.8 (95% CI, 24.3 to not estimable) mo in the APP arm (n = 48) and 22.2 (95% CI, 15.7-30.8) mo in the PP arm (n = 53; hazard ratio [HR], 0.63 [95% CI, 0.36-1.14]). PFS was 12.8 (95% CI, 8.6-16.6) mo in the APP arm vs 4.5 (95% CI, 4.1-6.7) mo in the PP arm (HR, 0.33 [95% CI, 0.21-0.58]). Grade 3/4 treatment-related adverse events (TRAEs) occurred in 68.8% of APP arm patients and 44.2% of PP arm patients. Consistent with global study results, atezolizumab plus pemetrexed and platinum-based chemotherapy improved efficacy and was well tolerated in Japanese patients with advanced NSCLC despite a higher incidence of grade 3/4 TRAEs.