Poor Outcomes for Patients With T‑Cell Prolymphocytic Leukemia After Allogenic Transplant

In a retrospective, multicenter analysis of patients diagnosed with T-cell prolymphocytic leukemia (T-PLL)—a rare T-cell malignancy—who underwent allogeneic transplant (allo-HCT) between 2002-2022, researchers indicated that outcomes for this patient population remain poor, with relapse being the most common cause of treatment failure. Allo-HCT is one of the few treatment options for this aggressive disease.

Researchers identified 35 adult patients with T-PLL with a median number of transplants of 1 (range, 1 to 2). The frontline therapies for the 35 participants were: (1) alemtuzumab (74%), (2) fludarabine (11%), (3) pentostatin (3%), and (4) unknown (11%). Most patients (66%) received an unrelated donor allo-HCT.

In their study, which had a median follow-up of 60.8 months, researchers determined that the most used conditioning regimen among the participants was busulfan and fludarabine, which was used in 66% of patients. Graft versus host disease (GVHD), a potentially serious post-transplant complication, was treated with methotrexate, sirolimus, and tacrolimus in 31% of patients. Of the patients with GVHD, researchers found that 46% had acute GVHD (aGVHD), while 37% had chronic GVHD (cGVHD). Of those with aGVHD, 56% had grade 2, 19% had grade 3, and no patients had grade 4 events.

Most of the patients with cGVHD had mild symptoms (69%), with no severe cGVHD among the study participants. The median time to max grade was 3.4 months for aGCVD and 12.7 months for cGVHD.

The median overall survival was 24 months and progression-free survival was 21.1 months. Disease progression (40%) and infections (11%) were the most common causes of death.

“The outcomes of T-PLL patients remain dismal despite allo-HCT, with relapse still being the most common cause of treatment failure,” the researchers concluded. “Novel therapies are needed for this rare and aggressive disease.”

Reference

Merrill M, Redd R, Singh S, et al. Outcomes of patients with t‑cell prolymphocytic leukemia after allogenic stem cell transplant: a multicenter retrospective study. Clin Lymphoma Myeloma Leuk. 2023;23(supp 1):S470.