Background: Standard of care treatment for patients with relapsed or refractory (rel/ref) Hodgkin lymphoma (HL) is salvage chemotherapy followed by autologous stem cell transplantation (ASCT) in chemosensitive patients. Brentuximab vedotin (BV) is an antibody drug conjugate that selectively induces apoptosis of CD30+ HL cells. Here we present updated post-ASCT follow-up in a previously reported multicenter phase II trial evaluating BV as first line salvage therapy prior to ASCT.
Patients and Methods: We conducted a prospective, multicenter (City of Hope, Cornell) phase II trial of BV as first line salvage therapy prior to ASCT in patients with rel/ref HL after induction therapy. Patients received 1.8 mg/kg of BV intravenously every 3 weeks for 4 cycles. This analysis is limited to patients who underwent ASCT. Endpoints include toxicities, stem cell collection, engraftment, and 2-yr post-ASCT progression-free and overall survival (PFS, OS).
Results: 37 patients were accrued and 36 were evaluable. The overall best response (CR+PR) rate to BV was 69% with 36% CR. 32 (89%) patients proceeded to ASCT. All 13 CR patients proceeded to ASCT without additional chemotherapy. 3/12 PR patients proceeded directly to ASCT, while 9 received additional chemotherapy. All patients with SD/PD received additional chemotherapy except for 1 patient who received XRT. 23 patients were in CR, 8 were in PR, and 1 patient had SD at ASCT.
All patients were primed with cyclophosphamide/G-CSF and 9 patients received plerixafor per institutional guidelines. The median stem cell collection days was 2 and median CD34 cells collected was 5.97 x 10^6. 19 patients received BEAM conditioning, 11 received CBV, and 2 received BEAM plus yttrium-90 labeled anti-CD25. The median time to neutrophil and platelet engraftment was 11 and 20 days, respectively. There were no Gr 3 or 4 post-ASCT toxicities through d+30. With a median follow up of 25.7 months, the 2-yr PFS was 72%, OS was 94%, and NRM was 3%. Patients who received only BV had 2-yr PFS of 80% vs 69% in patients who received BV followed by chemotherapy. Patients in CR at ASCT, had 2-yr PFS of 78% vs 56% for non-CR patients.
Conclusion: 89% of patients who received BV as first-line salvage therapy successfully underwent ASCT. Outcomes compare favorably with historical data, including patients who received BV salvage alone without chemotherapy. BV is a promising first-line salvage therapy for rel/ref HL patients undergoing ASCT.