Outcome of Hodgkin Lymphoma after Progression Following Autologous Stem Cell Transplantation

Background Clinical trials have demonstrated a high level of effectiveness for brentuximab vedotin (BV) for patients with relapsed or refractory classical Hodgkin lymphoma (HL); however, how patients fare in routine clinical practice if their HL recurs after autologous stem cell transplant (ASCT) is less clear. Our primary objective was to characterize overall survival (OS) and progression-free survival (PFS) among a cohort of real-world patients treated with BV after ASCT. The secondary objective was to characterize the outcome of treatment after failure of ASCT or ASCT and BV.

Methods We screened the population-based British Columbia Cancer Agency (BCCA) Lymphoid Cancer Database to identify patients with classical HL (excluding lymphocyte predominant HL) who were aged >16 years at initial diagnosis, staged and treated in BC, had primary treatment with ABVD or equivalent chemotherapy, underwent ASCT as part of first treatment for refractory or relapsed disease and relapsed again after ASCT. We excluded patients who have been treated at any time with a checkpoint inhibitor. We determined Kaplan-Meier estimates of overall (OS) and progression free survival (PFS) from the date of the progression that occurred after ASCT and, for those treated with the agent, after subsequent BV. Therapies given in sequence without a pause between therapies were considered part of the same line of therapy.

Results Between 1986 and 2015 93 patients experienced recurrence of HL after ASCT. Their median age at initial diagnosis was 30 years and 51% were male. After failure of ASCT 23 (25%) received radiation monotherapy and 61 received chemotherapy (66%), either as a single agent or in various combinations and of these 9 (10%) also received radiation; 6 (6%) received a second transplant (5 allogeneic and 1 repeat ASCT); and 5 refused or were too frail for treatment other than with corticosteroids. The median PFS and OS from the time of relapse after ASCT for these 93 patients were 7.1 (range 0.2-352) and 16.2 months (range 0.2-352), respectively. Of those 93, 17 patients received BV alone or BV+bendamustine at some point following ASCT. The median age of BV-treated patients was 33 years at the time of their original diagnosis and 29% were male. Among those 17 patients, 9 received single agent BV and 8, BV+bendamustine as part of a clinical trial. The median time from ASCT to the start of BV was 27.5 months. Counting ASCT as 2^nd line treatment, 10 individuals received BV as 3^rd line, 6 as 4^th line and 1 as 5^th line therapy. For all 17 patients the subsequent median PFS and OS from the time of BV initiation were 5.1 (range 1.5-34.6) and 18.8 months (range 2.4-40.5), respectively. 12 of these patients relapsed again and their subsequent median PFS and OS were 0.6 (range 0.5-29) and 3 (range 0.5-30) months, respectively. All 9 patients who received single agent BV relapsed again at a median of 2 months (range 1.2-9.7); 5 of the 8 patients treated with BV+bendamustine remain in remission 6 to 36 months later.

Conclusions These data highlight the poor prognosis for patients with relapsed or refractory cHL, particularly for those whose lymphoma recurs after brentuximab vedotin as well as the highly individualized management of patients whose lymphoma has recurred after ASCT. Future therapies that prevent or significantly delay relapse will help in alleviate the substantial clinical burden due to relapsed and refractory Hodgkin lymphoma.