Throughout the PoC study, treatment with OTL-203 has been generally well-tolerated with a safety profile consistent with the selected conditioning regimen. The viral vector integration profile was consistent with other lentiviral-based HSC gene therapy studies, and all participants had a stable and highly polyclonal repertoire. Anti-alpha-L-iduronidase (IDUA) antibodies present prior to gene therapy as a result of ERT were not seen in any patient within two months following treatment. In addition, ERT was discontinued at least three weeks prior to any patient receiving gene therapy treatment, and no patients have re-started ERT post-treatment.
Global Registrational Trial Expected to Commence by Year-end
Following the promising results observed in the PoC study, Orchard Therapeutics is initiating a multi-center, randomized, active controlled clinical trial designed to evaluate the efficacy and safety of OTL-203 in patients with MPS-IH compared to standard of care with allogeneic HSCT. A total of 40 patients with a confirmed diagnosis of MPS-IH who meet the study inclusion criteria will be randomized 1:1 to receive either OTL-203 or allogeneic HSCT. The study is powered to demonstrate superiority of OTL-203 over HSCT.
The primary endpoint, which will be measured at two years post-treatment, comprises a composite of clinically meaningful outcomes, including death, the need for rescue transplant, treatment failure, immunological complications, as well as severe cognitive and/or growth impairment. Secondary endpoints include biochemical markers, additional clinical assessments, as well as safety and tolerability. The company expects to activate up to six sites in the United States and Europe. For more information, please visit www.clinicaltrials.gov (NCT06149403).
About MPS-I
Mucopolysaccharidosis type I (MPS-I) is a rare, inherited neurometabolic disease caused by a deficiency of the alpha-L-iduronidase (IDUA) lysosomal enzyme, which is required to break down sugar molecules called glycosaminoglycans (GAGs). The accumulation of GAGs across multiple organ systems results in multiple symptomatic manifestations of the disease including severe neurocognitive impairment, skeletal deformities, cardiovascular and pulmonary complications, impaired motor function, loss of hearing and corneal clouding. MPS-I occurs at an overall estimated frequency of one in every 100,000 live births. There are three subtypes of MPS-I. Approximately 60 percent of children born with MPS-I have the most severe subtype, called Hurler syndrome (MPS-IH), and rarely live past the age of 10 when untreated.
Treatment options for MPS-I include hematopoietic stem cell transplant and chronic enzyme replacement therapy, both of which have limitations, such as inadequate impact on some of the more severe manifestations of disease, as well as significant morbidity and mortality. At present, Newborn Screening (NBS) for MPS-I has been established in multiple geographies, including the United States and Europe.
About OTL-203
OTL-203 is an investigational hematopoietic stem cell gene therapy being developed for the treatment of MPS-IH. It uses a modified virus to insert a functional copy of the IDUA gene into a patient’s cells. OTL-203 is being developed in partnership with the San Raffaele Telethon Institute for Gene Therapy in Milan, Italy. OTL-203 has received Rare Pediatric Disease (RPD) and Fast Track designations from the U.S. FDA, as well as priority medicines (PRIME) status from the European Medicines Agency.
About Orchard Therapeutics
At Orchard Therapeutics, our vision is to end the devastation caused by genetic and other severe diseases. We aim to do this by discovering, developing and commercializing new treatments that tap into the curative potential of hematopoietic stem cell (HSC) gene therapy. In this approach, a patient’s own blood stem cells are genetically modified outside of the body and then reinserted, with the goal of correcting the underlying cause of disease in a single treatment.
In 2018, the company acquired GSK’s rare disease gene therapy portfolio, which originated from a pioneering collaboration between GSK and the San Raffaele Telethon Institute for Gene Therapy in Milan, Italy. Today, Orchard is advancing a pipeline spanning pre-clinical, clinical and commercial stage HSC gene therapies designed to address serious diseases where the burden is immense for patients, families and society and current treatment options are limited or do not exist.