For patients with acute lymphoblastic leukemia carrying the Philadelphia chromosome and whose disease relapsed after allogeneic hematopoietic stem cell transplantation, the two-year overall survival rate nearly doubled from 2000-2004 to 2015-2019, according to a study published in Clinical Cancer Research.
Ali Bazarbachi, professor of medicine, associate dean for basic research, and director of the Bone Marrow Transplantation Program at the American University of Beirut, is the first and corresponding author.
In recent years, interventions and therapeutic strategies targeting post-transplant relapse in Ph+ ALL patients have emerged—including newer-generation tyrosine kinase inhibitors and immunotherapies such as Blincyto (blinatumomab), Besponsa (inotuzumab ozogamicin), and CAR T-cell therapy. In addition, due to higher donor availability and a progressive increase in the use of matched unrelated donors, second allogeneic HCT as salvage therapy is also an option.
To assess the most recent trends in survival after post-HCT relapse, Bazarbachi and colleagues within the Acute Leukemia Working Party of the European Society of Blood and Marrow
Transplantation conducted a retrospective, registry-based, multicenter study that included 899 adult patients with relapsed Ph+ ALL after allogeneic HCT over a period of 20 years (from 2000 to 2019).
The authors found a significant improvement in the two-year overall survival after relapse, which rose from 27.8% in patients who relapsed between 2000 and 2004 to 54.8% in those who relapsed between 2015 and 2019. The investigators also observed that survival increased with the length of time between HCT and relapse.
Notably, the survival improvement was observed despite a significant increase in patient age at the time of relapse (from 44 to 56 years).
A second allogeneic HCT within two years after relapse was performed in 13.9% of patients, resulting in a two-year OS from the date of the second transplant of 35.9%, with a progressive
decrease in the two-year relapse incidence from the date of the second transplant (74% in the 2000-2004 period and 33% in the 2015-2018 period).
