Prompt autologous stem cell transplantation (ASCT) is often curative in rituximab-naive patients with follicular lymphoma who have experienced early failure of first-line therapy and achieved a response to second-line therapy, suggest results from a registry-based study conducted by GELTAMO (the Spanish Lymphoma and Bone Marrow Transplant Group).
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“Overall, our results suggest that, whereas some patients might benefit from more aggressive therapies, such as allogenic stem cell transplantations, or novel drugs, such as immunomodulatory agents, monoclonal antibodies, phosphoinositide 3-kinase inhibitors, or even the application of bispecific T-cell engagers and chimeric antigen receptor T cells, there are a considerable number of patients in this high-risk [early therapy failure] subgroup that can be cured with ASCT, even in the absence of rituximab,” Ana Jiménez-Ubieto, MD, PhD, of the Hospital Universitario, 12 de Octubre, Madrid, Spain, and colleagues wrote.
The results are more favorable when ASCT is performed in patients experiencing early therapy failure, with less than 1 year from first relapse after primary treatment to ASCT.
“Early ASCT could be a hopeful option in patients with difficult access to rituximab,” the researchers wrote in Hematology/Oncology and Stem Cell Therapy.
Patients with follicular lymphoma who experience relapse or progression during or soon after first-line therapy have poor overall survival, and there is no standard therapy for this population, according to the researchers. Previous research has shown that ASCT prolongs survival in those who have received rituximab before transplantation, but benefit in the absence of this agent is unknown.
Dr. Jiménez-Ubieto and colleagues conducted a multicenter registry-based retrospective cohort study of 134 patients with nontransformed follicular lymphoma who underwent ASCT during 1989-2007 while in second complete or partial response to rescue chemotherapy and had not received rituximab.
Overall, 65% of the patients had experienced early therapy failure (relapse or progression within 2 years of starting first-line chemotherapy). Within this group, 78% underwent ASCT within 1 year, and 67% underwent ASCT while in second complete response. Median posttransplantation follow-up for the entire study cohort was 13.4 years.
Study results showed that patients who had experienced early therapy failure versus who had not had poorer 5-year progression-free survival (43% vs. 57%; P = .048) but similar 5-year overall survival (69% vs. 77%; P = .4). However, those patients with early therapy failure who underwent ASCT within 1 year had a statistically indistinguishable 5-year progression-free survival relative to counterparts without early therapy failure (48% vs. 66%; P = .44).
Additionally, the 48% progression-free survival seen in this subset was almost identical to the 49% seen in a historical cohort of patients with early therapy failure who similarly underwent ASCT within 1 year of first relapse but received rituximab before transplantation (Hematol Oncol. 2018;36[5]:765-72). This suggests “that the possible synergistic effect of rituximab plus ASCT is not as relevant if ASCT is offered soon in the course of the disease,” the researchers wrote.
Patients who had experienced early therapy failure achieved better overall survival if they underwent ASCT while in second complete response, as opposed to second partial response. Notably, 56% of those who underwent ASCT while in second complete response were alive at 13.7 years of follow-up and remained so long term.
The study was funded by the Foundation Research Institute at the Hospital Universitario 12 de Octubre. The researchers reported having no relevant conflicts of interest.
SOURCE: Jiménez-Ubieto A et al. Hematol Oncol Stem Cell Ther. 2019 Jul 9. doi: 10.1016/j.hemonc.2019.06.001.