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Authors of a recent review provide updates on stem cell transplants for myelofibrosis, with an emphasis on managing graft versus host disease and relapse.

Due to new transplant approaches, allogeneic hematopoietic stem cell transplant (HSCT) is now perceived as a safer therapeutic option in patients with myelofibrosis, even among older patients. Authors of a review published in the American Journal of Hematology emphasized the crucial role of early consideration and implementation of HSCT in improving clinical outcomes in this patient population.

Despite the approval of new therapies and “various other exciting non-transplant treatments in development, allogeneic HSCT remains at present the only curative therapy for patients with myelofibrosis,” wrote coauthors Haris Ali, MD, and Andrea Bacigalupo, MD.

The challenges associated with treating myelofibrosis include transplant-related mortality and the risk for relapse after HSCT. The authors aimed to provide a comprehensive review of current clinical data, new transplant platforms, and clinical updates, which can enhance patient outcomes.

“The number of patients undergoing an allogeneic HSCT annually is steadily increasing,” Dr. Ali and Dr. Bacigalupo wrote. “This reflects the fact that HSCT has become safer with the reduction in non-relapse mortality over the years, making the choice of an HSCT more attractive among hematologists caring for [patients with myeloproliferative neoplasms].”

Selecting Patients

Prior to HSCT, clinicians should conduct an in-depth assessment of organ functions, including cardiac, pulmonary, hepatic, and renal functions, as established by their institution’s predefined criteria. This evaluation ensures that patients can withstand the possible physiological stresses of the transplant process, such as toxicity of the conditioning regimen, increased risk of infection, graft versus host disease (GVHD), and cytopenia. Patients should also undergo a detailed psychosocial assessment, which is an integral component of this process.

“Following a thorough physical examination, we need to assess whether the patient’s disease justifies the risk from an allogeneic HSCT. Several prognostic scoring systems have been developed over the past years to identify patients who are likely to progress and are therefore at higher risk of morbidity and mortality,” the authors explained.

The dynamic international prognostic scoring system is the most widely used prognostic tool for patients with myelofibrosis. Clinicians should account for patient age, as there are limited outcomes data regarding HSCT in patients with myelofibrosis who are aged 70 years or older.

Managing Complications

The review offered information about approaches to managing splenomegaly and pretransplant treatment, recommended conditioning regimens, post-transplant outcome prediction models, recommendations for sourcing stem cells (eg, bone marrow, peripheral blood, cord blood), and criteria for selecting stem cell donors.

The authors provided protocol recommendations for preventing GVHD, managing patients with blast and accelerated phase myelofibrosis, and monitoring for disease markers. They also recommended monitoring driver mutations and early clinical intervention with cellular therapy to treat relapse. They also provided guidance for cases of hematologic reconstitution and graft failure.

“The treatment is different according to the degree of donor chimerism: in patients who show mixed donor or only host-derived cells, the graft has failed completely, and the only solution is an early second transplant. On the other hand, if complete donor chimerism is present, then a boost of CD34 positive cells from the same donor, without conditioning regimen, can rescue over 70% of patients,” Dr. Ali and Dr. Bacigalupo explained.

Myelofibrosis is a nuanced disease that often bears a significant transfusion burden and an unfavorable marrow environment, and early selection of patients for HSCT is critical to enhancing transplant outcomes.

“HSCT in myelofibrosis is becoming safer due to new transplant strategies and is even offered in older patients. Early consideration of HSCT in patients with myelofibrosis is the key to the success of the transplant,” Dr. Ali and Dr. Bacigalupo concluded.