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.