Expanding Use of Cyclophosphamide After Transplantation in CLL
Posted: Thursday, January 2, 2020
Given the success of such treatments as ibrutinib, venetoclax, and idelalisib, some patients with chronic lymphocytic leukemia (CLL) no longer have to undergo allogeneic blood or marrow transplantation (allo-BMT). Conversely, because of new graft-versus-host disease (GVHD) prophylaxis strategies such as post-transplantation cyclophosphamide, patients who do not have matched donors are better situated to receive haploidentical allo-BMT, which remains the only current CLL treatment with curative potential. Results of a new study have showed that using cyclophosphamide after haploidentical allo-BMT seems to contribute to its success rate in terms of survival, just as it has been shown to do for matched-donor allo-BMT, explained Douglas E. Gladstone, MD, of Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, and colleagues.
In the journal Biology of Blood and Bone Marrow Transplantation, the authors presented their study of 64 consecutive patients with CLL, all of whom underwent nonmyeloablative haploidentical allo-BMT at Kimmel. The 4-year overall survival and progression-free survival rates were 52% and 37%, respectively. In six patients, engraftment failed.
Compared with the others, those patients for whom engraftment failed had less responsive disease “as reflected by their elevated marrow CLL (≥ 20%) involvement and higher percentage of partial remission and stable disease,” noted Dr. Gladstone and colleagues. “While it is generally accepted that [treatment-responsive] CLL patients should undergo allo-BMT, the response threshold that allows engraftment hasn’t been well defined. Our data suggest that CLL marrow involvement of less than 20% is permissive for engraftment in nonmyeloablative haploidentical allo-BMT and, [with post-transplantation cyclophosphamide,] provides long-term disease-free survival…. [It is] a safe and effective treatment option,” they concluded, reiterating their suggestion that response depth before allo-BMT—and not the specific treatment regimen before allo-BMT—affects survival.
Disclosure: For full disclosures of the study authors, visit bbmt.org.