Asia subpopulation analysis from the phase III POLARIX trial.

Abstract

7558 Background: In the pivotal Phase III POLARIX trial, Pola-R-CHP demonstrated significantly improved progression-free survival (PFS) compared with R-CHOP, with a similar safety profile in patients with previously untreated DLBCL (Tilly et al. 2022). An Asia subpopulation analysis was included as part of the trial design; patients enrolled in Asia were analyzed for the purpose of registration in China of POLARIX (NCT03274492). Methods: Patients from mainland China, Hong Kong, Japan, South Korea, and Taiwan (enrolled during the global phase), and from the China extension cohort were included in the Asia subpopulation. POLARIX methods were previously described (Tilly et al. 2022). Briefly, patients with untreated DLBCL were randomized 1:1 using the same stratification factors to receive six cycles of Pola-R-CHP or R-CHOP, plus two cycles of rituximab alone. The purpose of this analysis was to evaluate consistency of PFS (defined as ≥50% risk reduction in PFS) in the Asia subpopulation with the global population. Results: Overall, 281 patients (intent-to-treat population; 150, 85, 31 and 15 patients in mainland China, Japan, South Korea and Taiwan, respectively) were analyzed (141 received Pola-R-CHP and 140 received R-CHOP); 160 patients from the global population and 121 from the China extension cohort. Median age was 63 (range 19–79) years, and most patients had an International Prognostic Index of 3–5 (61.9%). At the data cut-off of June 28, 2021, (median follow-up of 24.2 months) PFS was superior with Pola-R-CHP vs R-CHOP (hazard ratio [HR] 0.64; 95% confidence interval [CI]: 0.40–1.03) and met the consistency definition with the global population. The 2-year PFS rate was 74.2% (95% CI: 65.7–82.7) with Pola-R-CHP vs 66.5% (95% CI: 57.3–75.6) with R-CHOP. Other key efficacy results were similar to the global study results (Table). The safety profile was generally comparable for Pola-R-CHP vs R-CHOP, including rates of grade 3–4 adverse events (AEs; 72.9% vs 66.2%), serious AEs (32.9% vs 32.4%), grade 5 AEs (1.4% vs 0.7%), AEs leading to discontinuation of any study treatment (5.0% vs 7.2%), and incidence of peripheral neuropathy (all grades, 44.3% vs 50.4%), respectively. Key efficacy results. CR, complete response. Conclusions: The results from the Asia subpopulation of POLARIX were consistent with the global study, with a clinically meaningful improvement in PFS (risk of disease progression, relapse or death reduced by 36%) following treatment with Pola-R-CHP vs R-CHOP, and a comparable safety profile in Asian patients with previously untreated DLBCL. Clinical trial information: NCT03274492. [Table: see text]