FDA Grants Rare Pediatric Disease Status to Investigational Gene Therapy ARU-1801 for Sickle Cell

The U.S. Food and Drug Administration (FDA) granted rare pediatric disease designation to ARU-1801, Aruvant’s experimental gene therapy for the treatment of sickle cell disease (SCD) and beta-thalassemia.

This designation means the company will be eligible to receive a priority review voucher once the FDA approves a biologics license application for ARU-1801.

ARU-1801 uses a proprietary technology that is intended to increase the number of functional red blood cells by inserting a modified version of the gene that provides instructions to make a protein called fetal hemoglobin directly into the patients’ own stem cells.

The process of inserting the fetal hemoglobin gene into patients’ stem cells is mediated through a special viral vector called a lentivirus.

Production of fetal hemoglobin, the main form of hemoglobin found in fetuses, is normally “switched off” in adults. Because fetal hemoglobin is more effective transporting oxygen than the normal version of the protein found in adults, some therapies are now focusing on boosting the production of this protein to reduce the frequency of painful vaso-occlusive crises and hospitalizations, and to improve the overall health of those with SCD.

ARU-1801 is currently the only form of gene therapy based on delivering a modified version of the fetal hemoglobin gene — optimized to enhance the protein’s natural oxygen carrying ability and anti-sickling properties — that is being tested in the clinic.

“The FDA’s Rare Pediatric Disease designation for ARU-1801 highlights the large and unmet need currently experienced by patients suffering from sickle cell disease,” Will Chou, MD, CEO of Aruvant, said in a press release.

“Other investigational gene therapies for sickle cell disease require the use of high-intensity myeloablative conditioning regimens, which are associated with lengthy hospital stays and a host of possibly serious complications,” Chou said. “Our Reduced Intensity Conditioning (RIC) approach aims to provide patients a cure with an improved risk-benefit profile, including a lower risk of infertility and fewer days in the hospital.”

As defined by the FDA, a rare pediatric disease is a serious or life-threatening disorder that affects fewer than 200,000 people in the U.S., mainly those under 18.