Abstract P123

Real-World Data on the Single-Agent Pembrolizumab Therapy in Relapsed / Refractory Classic Hodgkin Lymphoma Patients in the Czech Republic.

Background: Pembrolizumab has demonstrated significant anti-tumour activity and durable long-term disease control in patients (pts) with relapsed or refractory classic Hodgkin lymphoma (R/R cHL). Herein we present retrospective analysis on efficacy and safety of pembro treatment including optional approach with autologous hematopoietic stem cell transplantation (ASCT).

Patients and methods: Weˈve analysed data of 44 R/R cHL pts after at least 2 lines of treatment between June 2019 and May 2026 in the Czech Republic. Pembro was administered every 3 weeks until disease progression, unacceptable toxicity or a maximum of 35 cycles.

Results: There were 28 men and 16 women, median age was 65 years (20-83). Median number of previous therapies was 3 (2-13) and the majority of pts (71%) started pembro in an advanced stage of the disease (III-IV). The median number of pembro courses was 10 (1-35), and the median duration of treatment was 8.2 months. Response was evaluated in 41 pts (93%) and assessed per Lugano criteria. Overall response rate (ORR) was 68% with a complete response (CR) rate in 46% and a partial response (PR) in 22%. In the subgroup of pts ˂ 65 years the ORR was 75% (CR 60%, PR 15%) while pts ≥ 65 years had ORR 62% (CR 33%, PR 29%). The most common reason for withdrawal was disease progression (50%) and ASCT (16%). With a median follow-up (FU) of 22 months, the 2year progression-free survival (PFS) was 41% (median PFS 14 months) and the 2year overall survival (OS) 88% (median OS not reached). In the pts ˂ 65 years, the 2year PFS was 55% whilst in ≥ 65 years 32%, but the difference was not statistically significant (fig.1). Two pts with localized disease underwent radiation therapy after pembro and 7 of the responding pts in CR proceeded to ASCT and subsequent 8 cycles of pembro maintenance per treating physicianˈs discretion. All of them remain in CR at the last FU. Treatment-related adverse events were reported in 12 pts (27%), but only 4 cases (9%) were grade 3. Eight pts died (18%), one of COVID-19, one of pneumocystis pneumonia, but always in the context of progressive lymphoma.

Discussion: Even though response rates were lower in the subgroup of pts ≥ 65 years, pembro often represents the only reasonable therapeutical option for them in the 3rd line setting. For the younger pts it may represent an efficient salvage therapy prior to ASCT. Increasing use of protocols combining pembro with chemotherapy can change current therapeutical landscape.