Allogeneic Stem Cell Transplantation As Consolidation Therapy in Patients with Relapsed-Refractory B-Cell Lymphoma Exposed to Bispecific Antibodies: A Study on Behalf of Grupo Español De Transplante y Terapia Celular (GETH-TC)

• Published in: Blood 2024-11, Vol.144 (Supplement 1), p.3565-3565
• Main Authors: Peña, Marta, Losi, Giulia, Salvino, Marco Aurelio, Qualls, David A., Crombie, Jennifer L., Mariotti, Jacopo, Bramanti, Stefania, Fabbri, Nicole, Serna, Angel, Serroukh, Yasmina I.M., Balaguer Rosello, Aitana, van der Poel, Marjolein W.M., Hsu, Ya Ting, Jiménez Ubieto, Ana, McKinnely, Christopher, Rius-Sansalvador, Blanca, Peña, Felipe, Lopez Corral, Lucia, Panizo, Carlos, Pérez-Simón, Jose Antonio, Rovira, Montserrat, Garzón, Sebastián, Kwon, Mi, Valcarcel, David, Varela, Rosario, Sanz, Jaime, Sanchez Salinas, Andres, Jurado, Manuel, Calbacho, Maria, Albo Lopez, Carmen, Perera Alvarez, Maria Del Mar, Heras, Inmaculada, Bento De Miguel, Leyre, Armand, Philippe, Sureda Balari, Anna, Mussetti, Alberto
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2024-201944

Background: B-cell non-Hodgkin lymphomas (B-NHL) encompass a heterogeneous group of malignancies with diverse prognosis. Some patients (pts) achieve long-term remission with standard therapies, but many experience relapse or refractory (R/R) disease. Recently, bispecific antibodies (BsAb) have emerged as a promising therapeutic approach. Allogeneic stem cell transplantation (alloHCT) may be a consolidative strategy for high-risk pts responding to BsAb, but T-cell activation prior alloHCT could affect both efficacy and safety. This study explored the impact of BsAb on alloHCT outcomes. Methods: We conducted a 11-center retrospective study including adult pts who received alloHCT as consolidative therapy following BsAb treatment for R/R B-NHL between February 2017 and July 2023. The primary endpoint was non-relapse mortality (NRM). Secondary endpoints included overall survival (OS), progression-free survival (PFS), relapse incidence/progression of disease (Rl/POD), acute graft-versus-host disease (aGVHD), chronic GVHD (cGVHD), and hematologic recovery. Propensity score matching was performed with a contemporary cohort of B-NHL pts not previously exposed to BsAb (n=101) before alloHCT from the Grupo Español de Transplante y Terapia Celular (GETH-TC). Results: A total number of 48 pts received BsAb prior to alloHCT. Median age was 58 years (range 22-73) and 31 (64.6%) pts were males. Thirty-six (75%) pts had stage III-IV at diagnosis, 12 (25%) had received an autologous transplant (ASCT) and 21 (43.8%), anti-CD19 CAR T-cell prior to BsAb. Median number of prior lines were 4 (range 3-11). Median time from diagnosis to alloHCT was 41 months (range 9 - 208). Glofitamab (n=22, [45.8%]) was the most used BsAb, followed by ondronextamab (n=13 [27.1%]), epcoritamab (n=11 [22.9%]), mosunetuzumab (n=1 [2.1%]) and antiCD3-CD22 (n=1 [2.1%]). Thirty-five (72.9%) BsAb were administered in monotherapy and 13 (27.1%) in combinations. The median number of BsAb' administered doses was 14 (range 4-24) and the median time between BsAb' last dose and alloHCT was 43 days (range 13 - 421). Disease status at alloHCT was complete response in 38 (79.2%), partial response in 7 (14.6%) and progressive disease in 3 (6.3%) pts. Twenty-two (45.8%) pts received grafts from matched unrelated, 16 (33.3%) from haploidentical and 10 (20.8%) from matched related donors. Stem cell source was peripheral blood in all but one pts (97.7%). Reduced intensity conditioning (RIC) regimens were used in 44