Allogeneic hematopoietic stem cell transplantation can safely and effectively treat patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN), especially during first remission, according to data presented at the 2023 ASH Annual Meeting & Exposition (Abstract 4988).
Results of the retrospective single-center analysis showed that median progression-free survival and median overall survival of patients treated with allogeneic hematopoietic stem cell transplantation in their first remission had still not been reached, after a median follow-up of 23.9 months. Conversely, patients receiving allogeneic hematopoietic stem cell transplantation in their second remission or later had a median progression-free survival and a median overall survival of 11.3 months and 12.6 months, respectively.
“Patients undergoing allogeneic hematopoietic stem cell transplantation in first remission had significantly improved outcomes than those who received allogeneic hematopoietic stem cell transplantation for relapsed disease,” said lead study author Muzaffar H. Qazilbash, MD, of the Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas MD Anderson Cancer Center, Houston.
As Dr. Qazilbash explained, BPDCN is a rare, aggressive hematologic malignancy arising from plasmacytoid dendritic cells. It commonly presents as skin lesions with or without bone marrow, lymph node, central nervous system (CNS), or systemic involvement. Although retrospective studies have shown durable remissions after allogeneic hematopoietic stem cell transplantation, according to Dr. Qazilbash, the data are still limited.
Research Details
For the retrospective study, Dr. Qazilbash and colleagues evaluated patients with BPDCN treated with allogeneic hematopoietic stem cell transplantation between September 2000 and June 2023 at a single institution. The primary endpoints were progression-free survival and overall survival.
The researchers included a total of 31 patients in the study, with a median age of 52 years (range = 16–76 years). Six patients had their disease confined to the skin, and four had CNS or cerebrospinal fluid involvement at diagnosis.
In addition, 4 patients had prior hematologic malignancies, 9 patients had a cytogenetic abnormality at baseline, and 13 patients (who were evaluated by a next-generation sequencing panel) had a TET2 mutation. A total of eight patients received the CD123-directed cytotoxin tagraxofusp-erzs alone or in combination as part of their induction regimen.
The median time from diagnosis to allogeneic hematopoietic stem cell transplantation was 6.2 months (range = 3.2–42.4 months). Matched unrelated donor was the most common donor type, at 39%, and fludarabine with busulfan-based conditioning was used in 55% of patients.
Key Results and Toxicity
As Dr. Qazilbash reported, the rates of 100-day and 1-year nonrelapse mortality were 9.7% and 23.1%, respectively. The 2-year progression-free survival and overall survival rates were 56% and 67%, respectively.
Allogeneic hematopoietic stem cell transplantation had a good safety profile, according to Dr. Qazilbash. No grade 3 or 4 cases of acute graft-vs-host disease were reported. Grade 2 cases of acute graft-vs-host disease occurred in 9 patients, whereas limited or extensive chronic graft-vs-host disease was seen in 6 of 28 evaluable patients.
According to Dr. Qazilbash, additional respective studies are needed to better define the role of allogeneic hematopoietic stem cell transplantation in patients with BPDCN.
Disclosure: Dr. Qazilbash reported financial relationships with Amgen, Angiocrine, Janssen, Bioline, and NexImmune. For full disclosures of the other study authors, visit ash.confex.com.
