The impact of tyrosine kinase inhibitors on allogeneic hematopoietic stem cell transplantation for adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

Knockdown of HCK promotes HREC cell viability and inner blood-retinal barrier integrity by regulating the AMPK signaling pathway

Diabetic retinopathy (DR), a major complication of diabetes causing blindness, is characterized by retinal damage due to capillary degeneration and vascular leakage. Current treatments are not fully effective, highlighting the need for searching new therapeutic targets. Hematopoietic cell kinase (HCK), a protein involved in various diseases, has been identified as a potential biomarker in DR, but its role in disease progression requires further investigation. Here we investigated the role of HCK in DR and its potential mechanism. We found the expression of HCK increased under the stimulation of high glucose (HG) in human retinal capillary endothelial cells (HRECs). Knockdown of HCK can improve HREC cell viability and the integrity of the internal blood-retinal barrier. HCK depletion suppressed the AMPK pathway in HG-induced HRECs. In summary, HCK may be a potential target for the treatment of DR, which provides a theoretical basis for the development of new treatment strategies.

Prophylactic or preemptive tyrosine kinase inhibitor therapy after allogeneic hematopoietic cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia

Prevention of disease relapse after allogeneic hematopoietic cell transplantation (allo-HCT) in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia remains a major concern. Maintenance therapy with tyrosine kinase inhibitors (TKIs) after allo-HCT has been used to reduce the incidence of relapse. Two main strategies are employed for using TKIs after allo-HCT: prophylactic TKI therapy, which is given before measurable residual disease (MRD) detection, and preemptive TKI therapy, which is given after MRD detection. These strategies both have advantages and disadvantages in terms of treatment efficacy, adverse events, adherence, and socioeconomic factors. In addition, many issues remain to be resolved because of the lack of large prospective studies on how to use TKIs after allo-HCT. These include indications for prophylactic and preemptive TKI therapy, timing of initiation, frequency of MRD monitoring, TKI selection, dose, and treatment duration. While the current available evidence is extremely limited, this article will discuss these issues after summarizing some representative and recent studies. It will also share a novel indicator that can be used to visualize the reversible transition between molecular relapse and remission by TKI therapy.

Treatment of Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia in Adults

Simple Summary

Outcome of patients with Philadelphia-chromosome positive acute lymphoblastic leukemia (Ph+ ALL) dramatically improved during the past 20 years with the advent of tyrosine kinase inhibitors and monoclonal antibodies. Their great efficacy in young and fit patients led to question our reliance on chemotherapy and allogeneic hematopoietic stem cell transplantation. Moreover, these well-tolerated treatments can be safely administrated even in the elderly that represent the majority of Ph+ ALL patient. This review will focus on the recent changes of paradigm in the management of Ph+ ALL patients and the development of novel therapeutic strategies.

Abstract

Philadelphia-chromosome positive acute lymphoblastic leukemia (Ph+ ALL) is the most common subtype of B-ALL in adults and its incidence increases with age. It is characterized by the presence of BCR-ABL oncoprotein that plays a central role in the leukemogenesis of Ph+ ALL. Ph+ ALL patients traditionally had dismal prognosis and long-term survivors were only observed among patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first complete remission (CR1). However, feasibility of allo-HSCT is limited in this elderly population. Fortunately, development of increasingly powerful tyrosine kinase inhibitors (TKIs) from the beginning of the 2000′s dramatically improved the prognosis of Ph+ ALL patients with complete response rates above 90%, deep molecular responses and prolonged survival, altogether with good tolerance. TKIs became the keystone of Ph+ ALL management and their great efficacy led to develop reduced-intensity chemotherapy backbones. Subsequent introduction of blinatumomab allowed going further with development of chemo free strategies. This review will focus on these amazing recent advances as well as novel therapeutic strategies in adult Ph+ ALL.