Orchard Therapeutics announces presentation of study of OTL-203 at ESGCT

Orchard Therapeutics announced a range of interim clinical outcomes, in addition to the previously reported neurological and skeletal results, from the company’s ongoing proof-of-concept study of OTL-203, a hematopoietic stem cell gene therapy in development for the treatment of the Hurler subtype of mucopolysaccharidosis type I. In the single-center PoC study, eight patients diagnosed with MPS-IH were treated at Ospedale San Raffaele in Milan, Italy with investigational OTL-203 between July 2018 and December 2019. Interim results published in The New England Journal of Medicine showed all patients had stable cognitive performance post-treatment. Additional Ocular and Auditory Clinical Data Presented at ESGCT 2023: Results showed: Treatment with OTL-203 resulted in improvement or stabilization of corneal clouding at the time of last follow-up compared to baseline measured prior to administration with OTL-203. Importantly, following treatment with OTL-203, no patients reported photophobia, or any other ophthalmological symptoms typically associated with MPS-IH. At last follow-up, 50.0% of patients showed normal hearing function, and none developed severe hearing loss. In addition, no treated patients have required a hearing aid or any intervention for hearing loss following administration with OTL-203 as of last follow-up. Follow-up to fully assess and characterize the potential impact of HSC gene therapy on ocular and auditory manifestations of MPS-IH is ongoing. Summary of Previously Reported Safety Results: Treatment with OTL-203 has been generally well-tolerated with a safety profile consistent with the selected conditioning regimen. Anti-alpha-L-iduronidase antibodies present prior to gene therapy as a result of ERT were not seen in any patient within two months following treatment. Global Registrational Trial Expected to Commence by Year-end: Following the promising results observed in the proof-of-concept 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. 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 treatment, treatment failure, immunological complications, as well as severe cognitive and growth impairment.