Abstract P128

EHA-4448 REAL-WORLD OUTCOMES OF PEMBROLIZUMAB PLUS GVD AS SALVAGE THERAPY AND BRIDGE TO AUTOLOGOUS STEM CELL TRANSPLANTATION IN RELAPSED/REFRACTORY CLASSICAL HODGKIN LYMPHOMA: A MULTICENTER GATLA STUDY

Background: In a phase 2 study of 39 pts. with R/R classical Hodgkin lymphoma (R/R cHL) candidates for autologous stem cell transplantation (ASCT), pembrolizumab plus gemcitabine, vinorelbine and liposomal doxorubicin (P-GVD) achieved a complete metabolic response (CMR) rate of 95%, with 95% proceeding to ASCT, supporting P-GVD as a highly effective bridge to transplant.

Aims: To report real-world outcomes in a broader, unselected population of pts. with R/R cHL eligible for ASCT treated with P-GVD.

Methods: Retrospective multicenter study within the GATLA cooperative group of consecutive pts. with R/R cHL eligible for ASCT treated with P-GVD. Baseline characteristics, PET response, immune-related adverse events (irAEs) and transplant rates were analyzed.

Results: 52 pts. initiated P-GVD (median age 32 years, IQR 17–69). 46 (88.5%) received ABVD as first-line and 6 (11.5%) BV-AVD. AETHERA high-risk features were present in 88.5%: 69.2% primary refractory, 11.5% relapsed within the first year, 36.5% extranodal relapse; B symptoms in 65.4% and bulky disease in 32.7%. P-GVD was given as first salvage in 35 pts (67.3%) and second salvage in the remainder. PET assessment was available in 49 pts (94.2%); 3 discontinued after 1 cycle due to toxicity. After 2 cycles, 38 pts underwent PET/CT: 29 (76%) CR, 5 (13%) PR, 4 (11%) PD; 25 did not receive further P-GVD (CR 21, PR 2, PD 2). 13/38 received additional cycles and re-evaluated after 3–4 cycles (CR 8, PR 3, PD 2); 24 pts had PET/CT after 3–4 cycles total.

Overall, 36/49 pts (73.5%) achieved CMR. 36 (73.5%) proceeded to ASCT (30 CMR, 6 PR); 6 CMR pts did not undergo ASCT; 1 received allogeneic transplant; 4/36 relapsed post-ASCT. (Fig.1) Median follow-up 14.7 months (IQR 10.3–26.2); 3/52 died: 1 COVID-19 during P-GVD, 1 GVHD post-allogeneic transplant, 1 sudden death. IrAEs in 8/52 pts (15.4%), manageable with standard interventions.

Summary/Conclusion: P-GVD produced a CMR rate of 73.5% and enabled 77.6% to proceed to ASCT, lower than the 95% reported by Moskowitz et al. in the phase 2 trial. These differences likely reflect a less selected population, including 2nd salvage pts. and a higher proportion of primary refractory disease. Nonetheless, P-GVD remained an effective bridge to transplantation in routine practice, providing real-world context for PD-1–based chemo-immunotherapy as a bridge to ASCT. Our cooperative group is now conducting a prospective trial to more clearly define its safety profile and efficacy.