Ultragenyx Pharmaceutical (RARE) said Friday it has resubmitted its biologics license application for accelerated approval of gene therapy UX111 to treat Sanfilippo syndrome type A to the US Food and Drug Administration.

The resubmission follows a complete response letter issued by the FDA in July and includes longer-term data on treatment benefits to back up a clinical endpoint for accelerated approval, the company said.

The updated data shows "a durable treatment effect" across multiple biomarkers and an "acceptable" safety profile, Ultragenyx said.

The company said it anticipates up to a six-month review period.