Orchard Therapeutics Begins Early Trials for Genetic Treatments of Wiskott-Aldrich Syndrome and Beta-Thalassemia


Orchard Therapeutics has begin proof of concept trials for two separate rare diseases for which the current standard of care is quite poor.

The first therapy is called OTL-103, and it is an autologous hematopoietic stem cell gene therapy for Wiskott-Aldrich Syndrome (WAS). WAS is a life threatening immune disorder and the current standard of care is a bone marrow transplant, which carries a high risk for mortality.

Orchard Therapeutics seeks to enroll 6 patients for an early trial of it’s WAS treatment. At this time, they have only dosed one patient. Prospective patients can find more information at clinicaltrials.gov. More information about OTL-103 can be found in Orchard Therapeutic’s press release.

The second therapy is called OTL-300, and is a treatment aimed at blood transfusion-dependent Beta Thalassemia (BA) patients. Like OTL-103, it is a stem cell based gene therapy that seeks to target the underlying disorder.

In an early clinical proof-of-concept trial involving 9 patients, the results were extremely promising:

Safety Data

  • All nine patients met the safety endpoint of survival with follow-up ranging from 16 to 43 months (3.6 years). No adverse events related to the product were reported. 
  • Vector integration profiles had the expected polyclonal genomic distribution seen with other lentiviral vector mediated HSC gene therapy studies, and no evidence of abnormal proliferation or clonal dominance was observed.

Efficacy Results

  • The primary efficacy endpoint of transfusion reduction at 12 months following treatment was achieved in eight of nine TDT patients treated with OTL-300.
       –   Of the six pediatric patients treated, four achieved transfusion independence and one showed a reduction in transfusion requirement.
       –   All three adult patients had a reduction in their transfusion requirements.
       –   As published previously in Nature Medicine, one pediatric patient did not have a reduced transfusion requirement compared to pre-treatment levels at 12 months, which was attributed to poor engraftment of the gene-modified cells.

For more information about OTL-300, please see Orchard Therapeutics’ press release.


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