Résumé
7061
Background: The prognosis and survival outcomes of pts with EN involvement remain a challenge for DLBCL management. In the Phase 3 POLARIX study (NCT03274492), Pola-R-CHP demonstrated significantly improved progression-free survival (PFS) compared with R-CHOP in previously untreated DLBCL (Tilly et al. 2022). This retrospective analysis assessed clinical outcomes and genomic patterns of pts with DLBCL and EN disease. Methods: POLARIX methods were previously described (Tilly et al. 2022). Using a data cutoff of June 15, 2022, this analysis assessed pts with EN involvement as determined by investigators. Additional outcomes and genomics analyses were performed on pts whose EN status was confirmed from documented radiographic lesions or bone marrow biopsy with denotation of EN disease sites. Hazard ratios (HRs) for investigator-assessed PFS were adjusted for age (≤60 vs >60) and sex. Cell of origin (COO) by NanoString, mutation analysis by whole exome sequencing, and global gene expression profiling by RNAseq were performed centrally. Results: In POLARIX, 616/879 pts (70%) had identified EN involvement. After a median follow-up of 39.7 months, pts showed improved PFS with Pola-R-CHP vs R-CHOP (HR 0.72, 95% confidence interval [CI]: 0.55–0.96), with a 2-year PFS of 75% vs 66%. A total of 556 pts (Pola-R-CHP, n=279; R-CHOP, n=277) had confirmed sites of EN involvement, defined as pts with EN radiographic lesions or bone marrow disease. In these pts, PFS favored Pola-R-CHP vs R-CHOP but the difference was not statistically significant (HR 0.84, 95% CI: 0.63–1.13). Of pts with confirmed EN disease, 429 had COO results (activated B-cell, 145 [34%]; germinal center B-cell, 223 [52%]; unclassified DLBCL, 61 [14%]). Mutation data and frequencies of select clinically relevant mutations (Ptashkin, 2023) across EN sites were available for 364 pts (Table). Gene expression data were available for 418 pts; genes involved in proliferation (E2F or PI3K signaling targets and checkpoint genes) and regulated by IRF4, OCT2 and XBP1, were commonly upregulated in pts with EN disease. Conclusions: Results in pts with DLBCL with EN involvement suggest superior PFS with Pola-R-CHP vs R-CHOP. Ongoing analyses will further assess the independent impact of EN status on outcome. POLARIX represents the largest cohort of pts with annotated EN disease and systematic genomic analysis, providing new insights into the genomics of these pts. Clinical trial information: NCT03274492 . [Table: see text]