DMD Patient Dies in CRISPR Gene Therapy Trial Led By Nonprofit Biotech Cure Rare Disease
The trial was launched through a partnership between Cure Rare Disease and UMass Chan Medical School.
Terry Horgan, the primary patient in an N-of-1 clinical trial evaluating a CRISPR-based gene therapy for the treatment of Duchenne muscular dystrophy (DMD), has died, according to an announcement from Cure Rare Disease, the nonprofit biotech sponsoring the trial.1
Horgan is the brother of Cure Rare Disease founder Rich Horgan, who started the nonprofit to help identify a potential treatment for his brother, who was diagnosed with the degenerative neuromuscular disorder in 1999.
Back in August, the FDA gave the nonprofit the go-ahead to proceed with the trial (NCT05514249),2 which involved the intravenous administration of a CRISPR-based gene therapy intended to treat muscle promotor and exon 1 mutations on the dystrophin gene that would upregulate an isoform of the dystrophin protein in hopes of stabilizing an potentially reversing symptom progression in DMD. It has not been made abundantly clear whether or not Horgan actually received the therapy before his death.
"We know the CRD-TMH-001 trial and the outcome have been closely followed by the rare disease community and many are eager for more details. While these details are currently being studied by multiple teams across the country, this is a complex undertaking and could take up to four months," Cure Rare Disease said in a statement. "The comprehensive work these teams are doing is critical to gaining a clear understanding of the outcome of the CRD-TMH-001 trial and to shedding additional light on the challenges of gene therapy broadly."
The investigational therapy, CRD-TMH-001, is 1 of several therapeautic pursuits being supported by Cure Rare Disease, although it is the only one to have reached the clinical trial stage so far. The nonprofit is currently exploring 19 different mutations associated with Duchenne and Becker muscular dystrophies, as well as several other pipeline candidates in limb girdle muscular dystrophy, adenylosuccinate synthase 1, and spinocerebellar ataxia.
The news is yet another bump in the road for the close-knit DMD community, who have become increasingly vocal proponents of investigational therapies coming before regulators. Several companies are working on therapeutics with DMD-related targets, but few have hedged big successes.
Most recently, Solid Biosciences presented new data on its gene therapy candidate SGT-001,3 which showed that treatment with the microdystrophin gene therapy was associated with improvements in stride velocity 95th centile at 1-year post-dose compared with baseline. Patients treated demonstrated an average improvement of 8.8%-9.5% from baseline, 23.9%-24.6% compared to natural history, and 26.0%-26.7% compared to the control patient. Solid plans to initiate clinical trial evaluation of another gene therapy candidate, SGT-003, in late 2023.
Further along in the process is Sarepta Therapeutics, who recently submitted a biologics license application to the FDA for the accelerated approval of SRP-001 (delandistrogene moxeparvovec), its gene therapy candidate for the treatment of ambulatory patients with DMD.4 The application is based on the expression of a shortened, functional version of the dystrophin protein as a surrogate end point that will likely result in clinical benefit. If accepted, Sarepta could expect a decision in May 2023.
