The Food and Drug Administration (FDA) has granted Breakthrough Therapy designation to DCR-PHXC (Dicerna Pharmaceuticals) for the treatment of patients with primary hyperoxaluria type 1 (caused by a mutation in the AGXT gene).

DCR-PHXC is a ribonucleic acid interference (RNAi) investigational treatment that works by inhibiting the lactate dehydrogenase A enzyme (LDHA) in the liver to reduce excess production of oxalate. The Breakthrough Therapy designation is supported by data from the PHYOX1 phase 1 trial which was recently presented at the Oxalosis and Hyperoxaluria Foundations’s International Workshop.

Results demonstrated significant post-dose reductions in 24 hour urinary oxalate levels in adults and adolescent patients with primary hyperoxaluria type 1 and type 2 (caused by a mutation in the GRHPR gene); additionally, urinary oxalate levels in a majority of patients were normalized or near-normal after a single dose of DCR-PHXC. Regarding safety, DCR-PHXC was generally well-tolerated.

“By granting Breakthrough Therapy designation, the FDA recognizes both the urgent need to develop a therapy for primary hyperoxaluria type 1 and the encouraging preliminary data from the PHYOX1 clinical trial of DCR-PHXC in these patients,” said Ralf Rosskamp, MD, Dicerna’s chief medical officer. “We look forward to continuing our dialogue with the FDA as we advance DCR-PHXC as quickly as possible as a potential therapeutic option for all persons living with primary hyperoxaluria.”

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The Company is currently enrolling patients in the PHYOX2 phase 2 trial and will continue discussions with the FDA to investigate end points for future DCR-PHXC studies in patients with primary hyperoxaluria type 2 and 3 (caused by a mutation in the HOGA1 gene).

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