Ruxolitinib for steroid-refractory graft versus host disease in pediatric HSCT: high response rate and manageable toxicity.

Ruxolitinib, a selective Janus Kinase (JAK) 1/2 inhibitor, is a promising treatment for the steroid-refractory graft-vs-host disease (GvHD) after hematopoietic stem cell transplantation (HSCT). Most studies have been performed in the adult population showing efficacy against GvHD. In this retrospective study, we evaluated the outcomes of 19 children who received ruxolitinib for refractory acute or chronic GvHD (cGvHD) after HSCT from two Pediatric Hemato-Oncology Departments in Spain between March 2017 and December 2018. Patients received a median number of 4 (IQR 2) previous lines of treatment before starting ruxolitinib. The overall response rate in acute GvHD (aGvHD) and cGvHD was 87% and 91%, respectively. Complete response (CR) was observed in 37% of aGvHD and 8.3% of cGvHD. Remarkably, 43% and 40% of patients with steroid-refractory gastrointestinal aGvHD and lung cGvHD achieved CR. During ruxolitinib treatment, there were 36%, 31%, and 10% infections caused by viruses, bacteria, and fungi, respectively. Overall, four patients interrupted ruxolitinib due to infectious complications, hematological, and liver toxicity. The 2-year overall survival was 71.9% (CI 95% 58.6-85.2). Our experience supports the use of ruxolitinib as an effective treatment for steroid-refractory acute and cGvHD in children with a moderate toxicity profile.

Lessons Learned from Two Decades of Clinical Trial Experience in Gene Therapy for Fanconi Anemia.

Allogeneic hematopoietic stem cell transplantation is the only curative treatment for patients with the non-malignant bone marrow failure syndrome called Fanconi anemia (FA). However, early and late complications associated with this approach underscore the need for alternative treatments. Gene therapy approaches aiming to correct the genetic defect in the patient's own hematopoietic stem cells remain the most promising strategy to overcome FA-associated bone marrow failure. Yet, despite more than two decades of clinical research, a therapeutic "success" has not yet been achieved. Here we review the clinical trials conducted to date and highlight the unique features of FA revealed by these studies. These features render FA the "holy grail" of hematopoietic stem cell gene therapy approaches, and identify the future steps required to achieve clinical success in this rare disease.