NEW YORK – Sangamo Therapeutics is having "productive discussions" with the US Food and Drug Administration and other regulators about pathways to registrational trials for its gene therapy candidate for Fabry disease, the firm said Monday.
However, the Richmond, California-based company also reaffirmed that it is pausing investments into planning for such a trial of the investigational treatment, ST-920 (isaralgagene civaparvovec), until it secures a partnership or financing for the program. Sangamo announced that it would pause investment into the Fabry disease gene therapy program in November.
Early safety and tolerability results from the open-label, global, dose-ranging Phase I/II trial of ST-920, which is called STAAR, have been promising, according to updated results on 24 patients the firm released Monday.
Patients in the STAAR study receive a single dose of the gene therapy, delivered through an IV infusion, which delivers a functional copy of the GLA gene to the liver to increase production of functional alpha-Gal A, an enzyme needed to metabolize globotriaosylceramide. Fabry disease, a rare lysosomal storage disorder, is caused due to a deficiency of the enzyme.
Investigators have observed sustained elevated expression of alpha-Gal A activity for up to three years for the longest-treated patient, as of the Sept. 19 data cutoff. In 13 patients followed for at least a year, renal function remained stable, and patients experienced a significant improvement in overall disease severity, quality of life, and gastrointestinal symptoms.
All 12 patients who had withdrawn from enzyme replacement therapy remain off of the therapy, with sustained alpha-Gal A activity for up to 19 months.
The gene therapy has been well tolerated, and the most common adverse events observed are pyrexia, headache, COVID-19, fatigue, and nasopharyngitis. There were no liver function test elevations that required steroids after treatment.
Enrollment in the Phase I/II trial is complete, and "we expect to complete dosing of the remaining patients in the first half of this year as we continue to explore potential partnerships and other financing options to support the initiation of a registrational trial," Sangamo Chief Medical Officer Lisa Rojkjaer said in a statement.