Real Life Analysis of Brentuximab Vedotin (BV) Use As Consolidation Therapy in Patients with Hodgkin’s Lymphoma (HL) with High Risk of Relapse after Autologous Stem Cell Transplantation (ASCT). a Retrospective Analysis of the EBMT Lymphoma Working Party

Introduction: The gold standard treatment for patients (pts) with classical HL who fail first-line treatment is ASCT. However, a significant number of pts with high-risk relapsed/refractory (RR) HL will relapse after transplant. Most patients who relapse do so within the first 1–3-years following ASCT, providing a rationale for post-transplant consolidation strategies to mitigate relapse risk. The AETHERA trial demonstrated that post-ASCT consolidation with brentuximab vedotin (BV) in high-risk HL pts improved progression-free survival (PFS) compared to placebo. Three previous studies have reported real-life results of BV consolidation with similar results. Here, we present the largest series so far.

Methods: Information of pts older than 18y with HL who received BV as consolidation after first ASCT between May 2016 and January 2021 was downloaded from the EBMT database. The decision to use BV consolidation was made by the attending physician on an individual basis. Patients who received BV for disease relapse after ASCT were excluded from the study. The primary endpoint was 2 year PFS from ASCT.

Results: 309 pts (female 48%/male 52%) with HL were identified meeting the inclusion criteria. Median age at ASCT was 31y (18-70). The median number of therapy lines before ASCT was 2 (1-6), and 43% pts required >1 salvage treatment to achieve disease response. At the time of ASCT, 200 (66%) pts were in complete remission (CR), 81 (27%) in partial remission (PR), and 21 (7%) had refractory disease. Most pts (73%) received BEAM as conditioning regimen. Median time from ASCT to BV initiation was 2.2 months (0.1-16.7). A total of 55 (19%) pts relapsed after a median time of 8 months after BV initiation, and 24 of them were treated with an allogeneic transplantation. After a median follow-up of 20 months, 2 and 5-year PFS were 73.2% (95% CI 67.3-79.6) and 70.3% (95% CI 63.9-77.4) (Figure 1), and overall survival 95.1% (95% CI 92.1-98.2) and 91.3% (95% CI 86.7-96.1), respectively. The prognostic was excellent and significantly better for pts in CR at transplant than for those in PR or with progression disease (2-y PFS 83.5% [95%CI 77.3-90.2] vs. 57.2% [95% CI 45.6-71.8] and 63.6% [95% CI 45.3-89.5], respectively, p=0.001). No differences in OS were observed according to the disease status at ASCT. In comparison to AETHERA trial, the proportion of pts requiring >1 salvage therapy lines before transplant was similar (43% in both studies); however, in contrast to that trial, pts treated with >1 salvage therapy line had similar PFS than those treated with only one line (69.6% [95%CI 60.4-80.2] vs. 75.8% [95%CI 68.5-84.0], respectively, p=0.2). In our study, the number of pts with chemosensitive disease at ASCT was higher than in the AETHERA (93% vs. 72% CR + PR, and 66% vs. 37% CR). This fact could justify that the PFS observed in this real-life series was higher than this of the AETHERA trial (70.3% vs. 59%) and more similar to that reported in other real-life series.

Conclusions: This EBMT-registry study confirms the improved PFS of RR HL pts who underwent ASCT followed by BV consolidation compared to historical cohorts. The proportion of patients receiving ASCT in CR is higher than published in the AETHERA trial, which would suggest that more effective pre-transplant salvage schemes, possibly including BV, have been used.