Outcome of Patients with Hodgkin Lymphoma Treated with Brentuximab Vedotin for Relapse after Autologous Stem Cell Transplant: A Retrospective Analysis of the LWP-EBMT

Around half of patients with Hodgkin Lymphoma (HL) who progress or relapse through first line therapy can be cured with salvage chemotherapy followed by autologous stem cell transplant (ASCT). However, this leaves approximately 50% of patients that will relapse after ASCT. The pivotal phase II SG035-00303 trial demonstrated that these patients can be successfully treated with Brentuximab Vedotin (BV), and a proportion of them can be long term free of disease without any further intervention. The objective of the current study was to investigate whether these findings were borne out in the real world via interrogation of the EBMT registry.

We retrospectively analysed data for 101 patients with HL who had BV as their first treatment for relapse after ASCT from 2012 to 2019. The median age at ASCT was 34 years (range: 19-65), 60% being male and with 62% being in complete response (CR) at the time of ASCT. Carmustine, Etoposide, Cytarabine and Melphalan (BEAM) was the most common conditioning regimen, having been employed in 72% of the cases. The median time from ASCT to relapse was 10.1 months (interquartile range (IQR): 6.1-25.1). The median time on BV was 3.4 months (IQR: 2.1-5.24). BV treatment resulted in a best overall response rate (ORR) of 59% with a CR rate of 37%. At last follow-up only 2 patients remain on treatment with BV. The main reason for discontinuation of BV was progression which occurred in 37% of the patients. In 32 cases (33%) the treatment was stopped electively to proceed to a second transplant, and overall nearly a quarter (22%) completed the full treatment course. Only 5% of patients stopped due to toxicity (peripheral neuropathy 2 and neutropenia, infusion reaction and other, 1 each). Further therapy was given after BV in over half of evaluable patients (58%), with check point inhibitors (CPIs) being the most common agents used (24% of these). Nearly two thirds (64/101) of the patients received a second transplant, which were nearly all allogeneic stem cell transplant (alloSCT, 59/64), and most of these (49/59) with reduced intensity conditioning (RIC). 26% of the alloSCT recipients experienced grade II-IV acute graft versus host disease (GvHD) and 25% developed chronic GvHD. At last follow up, 62% of all patients were alive with a median follow-up of 25 months after starting BV. Of these, 27 had received a second transplant, who were mostly in CR at last follow up (26/27) and a further 22 had relapsed. There were 11 patients of the 63 still alive who continued to be responding to BV without further therapy with a median duration of response of 30 months.

In conclusion BV use for relapse after ASCT was well tolerated generally, with only a minority of patients stopping treatment due to toxicity. However, although almost two thirds of the patients achieved a response, further treatment was often needed after BV, notably with CPIs and most patients were consolidated with a RIC alloSCT. These results confirm that only a minority of patients can achieve a durable remission with BV alone.