In January 2018, we entered into a strategic collaboration with Censa Pharmaceuticals, a privately-held company focused on developing therapies in metabolic disorders, to advance CNSA-001 for the treatment of phenylketonuria (PKU).

PKU is a rare, genetic metabolic condition in which the body can't break down phenylalanine due to a missing or defective phenylalanine hydroxylase enzyme. High levels of phenylalanine caused by PKU can lead to neurological and behavioral impairment. PKU has an estimated addressable prevalence of 1 in 10,000 births in the U.S. and 1 in 20,000 births depending on the country of origin.1

CNSA-001 is an orally available proprietary form of sepiapterin, a natural precursor of tetrahydrobiopterin (BH4) that is converted by an endogenous enzymatic pathway to BH4. Preclinical data suggests that CNSA-001 may be more effective at increasing intracellular BH4, including in the liver and brain, and therefore induce greater reduction of phenylalanine compared to the current standard of care. The data also suggest that CNSA-001 crosses the blood brain barrier, which could offer greater potential given the cognitive decline patients experience.

These early data, combined with a well-defined regulatory pathway that should enable us to advance CNSA-001 quickly, fuel our excitement about the opportunity to make a difference for PKU patients in the not-too-distant future. Censa is currently conducting single and multiple ascending dose studies with a Phase 2 proof-of-concept study in PKU patients expected to begin mid-year 2018.

As part of our agreement with Censa, we will provide funding for the development of CNSA-001 in PKU, and Censa will run the development program which will be conducted under the oversight of a joint steering committee. Retrophin will pay certain milestone payments and holds the exclusive option to acquire Censa upon conclusion of a specified option period, pending clinical proof-of-concept of CNSA-001 in PKU.

Request more information about CNSA-001.

  1. National PKU Alliance.