Orphan drug designation is a special status given by the Food and Drug Administration (FDA) for potential treatments of rare diseases that affect fewer than 200,000 in the U.S. This type of status can significantly help advance treatments for rare diseases by providing financial incentives in the form of tax credits towards the cost of clinical trials and prescription drug user fee waivers.

Fortunately for us, a stem cell-gene therapy approach used in a CIRM-funded clinical trial for Cystinosis has just received orphan drug designation. The trial is being conducted by Dr. Stephanie Cherqui at UC San Diego, which is an academic collaborator for AVROBIO, Inc.

Cystinosis is a rare disease that primarily affects children and young adults, and leads to premature death, usually in early adulthood.  Patients inherit defective copies of a gene called CTNS, which results in abnormal accumulation of an amino acid called cystine in all cells of the body.  This buildup of cystine can lead to multi-organ failure, with some of earliest and most pronounced effects on the kidneys, eyes, thyroid, muscle, and pancreas.  Many patients suffer end-stage kidney failure and severe vision defects in childhood, and as they get older, they are at increased risk for heart disease, diabetes, bone defects, and neuromuscular defects. 

Dr. Cherqui’s clinical trial uses a gene therapy approach to modify a patient’s own blood stem cells with a functional version of the defective CTNS gene. The goal of this treatment is to reintroduce the corrected stem cells into the patient to give rise to blood cells that will reduce cystine buildup in affected tissues.  

In an earlier blog, we shared a story by UCSD news that featured Jordan Janz, the first patient to participate in this trial, as well as the challenges promising approaches like this one face in terms of getting financial support. Our hope is that in addition to the funding we have provided, this special designation gives additional support to what appears to be a very promising treatment for a very rare disease.

You can read the official press release from AVROBIO, Inc. related to the orphan drug designation status here.