Reduced-intensity conditioning versus myeloablative conditioning allogeneic stem cell transplantation for patients with myelofibrosis

Optimization of allogeneic hematopoietic cell transplantation for patients with myelofibrosis treated with ruxolitinib: eligibility, best practices, and improving transplant outcomes

Allogeneic hematopoietic cell transplantation (HCT) is the only curative treatment for myelofibrosis (MF), and current guidelines recommend assessing all patients with MF for eligibility. Several patient- and disease-specific factors impact transplantation outcomes, and timely assessment of potential transplant candidates is key to optimizing post-HCT outcomes. The role of HCT in the treatment of MF continues to evolve, with the adoption of newer and safer approaches, enhanced donor availability, use of reduced-intensity conditioning, improvements in graft-versus-host disease (GVHD) prophylaxis and treatment, and greater understanding of high-risk clinical and molecular features of the disease. These developments highlight the importance of early and ongoing assessment throughout the MF disease course to optimize eligibility and consideration for HCT. Ruxolitinib is approved for first-line treatment of intermediate- or high-risk MF, and emerging data have clarified the important role of ruxolitinib in not only optimizing clinical status before HCT but also mitigating and treating post-HCT complications in patients with MF, notably acute and chronic GVHD and relapse. Here we review strategies for optimizing clinical outcomes in patients considered for and undergoing HCT for MF treated with ruxolitinib. We discuss strategies for appropriate patient and donor selection, optimization of ruxolitinib therapy in the pre- and peri-HCT periods, choice of conditioning regimen, GVHD prophylaxis, post-HCT management of GVHD, continued monitoring for MF relapse, and the role of post-HCT ruxolitinib maintenance to reduce risks of GVHD and disease relapse.

Reduced intensity versus myeloablative conditioning for MDS: long-term results of an EBMT phase III study (RICMAC)

Short-term outcome of myeloablative (MAC) and reduced intensity (RIC) conditioning in the prospective randomized international EBMT RICMAC study in patients with myelodyplastic syndrome (MDS) was comparable but longer follow up is lacking. Patients with MDS aged 18-65 years were randomized to receive MAC (N = 64) with busulfan/cyclophosphamide or RIC (n = 65) with busulfan/fludarabine followed by stem cell transplantation -(HCT) from HLA matched or mismatched donor. After a median follow-up of 6.2 (0.4-12.5) years, 10-year OS and RFS were 54.0% and 43.9% for RIC and 44.4% and 44.2% for MAC (p = 0.15 and p = 0.78), respectively. Since the first report, 6 patients died on NRM, 4 after RIC, and 2 after MAC. Similarly, 8 patients relapsed (4 in each arm), increasing the number of relapsed patients to 28. The second HCT was performed in 18 pts, 8 in the MAC, and 10 in the RIC arm. In a multivariate analysis, ECOG status and chemotherapy prior to HCT were independent risk factors for OS and RFS, ECOG and low cytogenetic risk for NRM and chemotherapy prior to HCT for RI. Patients with low cytogenetic risk had better OS [p = 0.002], RFS [p = 0.02], and NRM (p = 0.015) after RIC as compared to MAC.

Janus kinase inhibition in the treatment and prevention of graft-versus-host disease

Graft-versus-host disease (GVHD) is a significant cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). For many years, corticosteroids have been the mainstay treatment for GVHD, but cases of steroid-refractory GVHD and the severe adverse effects of high-dose corticosteroids have increased the need for preventative and therapeutic strategies for GVHD. Due to the nature of alloreactive T cells, GVHD is inherently linked to the graft-versus-leukemia (GVL) effect, the therapeutic driving force behind stem cell transplantation. A considerable clinical challenge is to preserve GVL while suppressing GVHD. The field of GVHD research has greatly expanded over the past decades, including advancements in T cell modulation and depletion, antibody therapies, chemotherapeutics, cellular therapies, and Janus kinase inhibition. In this review, we discuss current approaches and advances in the prophylaxis and treatment of GVHD with a focus on new emerging advancements in Janus kinase inhibitor therapy.