busulfan conditioning

A chemotherapy regimen used to clear out a patient's existing bone marrow to make room for newly transplanted or edited gene-therapy cells.

Busulfan conditioning is a medical preparation process where a patient receives the chemotherapy drug busulfan prior to undergoing a stem cell transplant or receiving an autologous gene therapy. The goal is to destroy the patient's diseased or existing bone marrow stem cells, creating physical space for the newly edited or healthy cells to engraft. For investors in the genetic medicine space, conditioning regimens represent a major safety and commercial bottleneck. Busulfan is highly toxic and associated with severe side effects, including organ damage and infertility. Therapies requiring harsh conditioning may face lower patient adoption and higher clinical trial safety risks compared to emerging platforms trying to develop non-toxic, targeted conditioning methods.