Efficacy of Outpatient Haploidentical Transplantation in Patients with Refractory Hodgkin Lymphoma

Background: Hodgkin lymphoma (HL) is a neoplasm potentially curable with first-line chemotherapy. For relapsed or refractory (R/R) patients, rescue chemotherapy and autologous transplant remain the standard. R/R patients face a poor prognosis, and haploidentical hematopoietic stem cell transplantation (haplo-HSCT) offers a potentially curative option.

Methods: A retrospective single-center analysis was performed in adults with R/R HL who underwent haplo-HSCT from 2015 to 2022. Conditioning was based on cyclophosphamide 350 mg/m² plus fludarabine 25 mg/m² for 3 days, followed by either melphalan 140-200 mg/m2 or busulfan 8 mg/m2, GVHD prophylaxis was given with cyclophosphamide 40mg/m2 at day +3 and +4 after infusion of CD34+. The primary outcome was overall survival (OS). Secondary endpoints included engraftment rates, infections, and transplant-related mortality (TRM). Progression-free survival (PFS) and graft-versus-host disease (GVHD) incidence.

Results: 17 patients were included, 52.9% (n=9) female and 47% (n=8) male, with a median age of 27 years (range: 11 to 62). Eight (47%) presented relapse after a previous autologous hematopoietic stem cell transplant (auto-HSCT). The average number of prior lines of treatment was 5 (range, 3-7). Conditioning included melphalan 140 mg/m² in 70% of patients, 200 mg/ m² in 18%, and busulfan 8 mg/m² (11%). The median CD34+x10^6kg infused was 10 million (3 - 16 x10^6). Engraftment of neutrophils and platelets occurred in a median of 14.6 (12-19) and 15 (12-23) days, respectively. The median follow-up was 18 months.

The 4-year OS was 62%, and the median OS was not reached. The 4-year PFS was 42%, with a median PFS of 17 months (95% CI 0-40). The incidence of aGVHD at 100 days was 58%, with the skin being the most frequent organ affected; 42% (n=8), and 18% presented chronic GVHD (cGVHD) during the year of follow-up. Five patients (29%) presented clinically significant infectious complications, including BK virus, cytomegalovirus infection, sepsis due to E. Coli ESBL, and invasive aspergillosis. Four patients relapsed (25%). TRM at 100 days was 23.52% (n=4).

Conclusions: The results highlight the effectiveness of haplo-HSCTin patients with refractory Hodgkin Lymphoma. A high incidence of aGVHD and cGVHD and infectious complications were documented. Haplo-HSCT transplant is a viable option for patients; however, it is essential to prioritize quality of life and minimize the toxicities associated with it. Additional studies are needed to optimize treatment protocols and management of long-term complications.

Gomez-De Leon:Abbvie: Honoraria; Amgen: Honoraria; bms: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; Janssen: Honoraria; Sanofi: Honoraria, Other: Advisory board; Janssen: Other: Advisory board. Gomez-Almaguer:Roche: Speakers Bureau; Novartis: Consultancy, Other: Advisory board, Speakers Bureau; Tevas: Speakers Bureau; AbbVie: Research Funding, Speakers Bureau; Seattle Genetics: Research Funding; Sanofi: Speakers Bureau; BMS: Consultancy, Other: Advisory board, Speakers Bureau; Amgen: Consultancy, Other: Advisory board, Research Funding, Speakers Bureau; Astex Pharmaceuticals: Research Funding; Kartos Therapeutics: Research Funding; Blueprint Medicines: Research Funding; Janssen: Consultancy, Other: Advisory board, Speakers Bureau; Takeda: Consultancy, Other: Advisory board, Research Funding, Speakers Bureau; Incyte: Research Funding; Gilead/Forty Seven: Research Funding; ConstellationPharmaceuticals: Research Funding.