Unlike for those with acute leukemia, patients with chronic lymphocytic leukemia who had disease progression after undergoing transplantation had a relatively good prognosis, with 2- and 5-year overall survival rates of 67% and 38%, investigators reported online April 6 in the Journal of Clinical Oncology.*
Patients with chronic lymphocytic leukemia (CLL) who experienced acute or chronic graft-versus-host disease (GVHD) had significantly longer overall survival (OS) than those who did not have GVHD (P = .04 and P = .05, respectively). “Nearly half our patients with active CLL after transplantation had chronic GVHD, and the association of chronic GVHD with achieving cure and its power to predict OS among patients for whom transplantation failed suggests that the GVL (graft-versus-leukemia) effect contributes to prolonged survival even in patients with a high burden of disease,” wrote Dr. Uri Rozovski and associates at the University of Texas MD Anderson Cancer Center, Houston (J. Clin. Oncol. 2015 Apr. 6 [doi:10.1200/JCO.2014.58.6750]).
A matched-pair analysis showed that patients who underwent allogeneic stem cell transplant (SCT) about the same time and did not relapse also had higher rates of acute and chronic GVHD (P = .004 and P = .011, respectively).
The retrospective review of the Bone Marrow Transplantation Program database identified 358 patients with CLL or RT who underwent SCT from 1998 to 2011. The study evaluated 72 patients who had disease progression at a median 74 months after SCT, most of whom received one to eight lines of treatment after relapse and had a median OS of almost 3 years from the time of progression. Multivariate analysis showed that low hemoglobin levels and the presence of Richter’s transformation (RT) were associated with shorter OS; chronic GVHD and response to the first post-SCT treatment predicted longer OS.
Patients with RT had a worse prognosis, with a median OS of 15 months (95% confidence interval, 2-28 months) and 2- and 5-year survival rates of 36% and 0%. Transplantation carried a significant risk for transformation: 16 (30%) patients with CLL developed RT after allogeneic SCT. Conversely, four patients with RT developed CLL after transplantation.
The authors note that even in patients who did not maintain a durable response, SCT was beneficial. The study cohort received a variety of salvage treatments, and patients who received ibrutinib responded well. “Because of the favorable outcomes with ibrutinib in relapsed/refractory CLL, we believe that ibrutinib might have a role in the treatment of disease progression following transplantation failure,” they wrote.
*Correction, 4/8/2015: A previous version of this article misstated the type of leukemia referenced in the study.