Clinical Trials

We partner with researchers from around the world to conduct clinical trials studying our investigational therapies.

Fosmetpantotenate (RE-024)

In July 2017, the first patient was dosed in the FORT (FOsmetpantotenate Replacement Therapy) Study, an international, registrational Phase 3 clinical trial assessing the safety and efficacy of fosmetpantotenate for the treatment of pantothenate kinase-associated neurodegeneration (PKAN), a rare, genetic neurological disorder. 1 Approximately 82 patients with PKAN aged 6 to 65 years are participating in this randomized, double-blind, placebo-controlled study.

The primary endpoint will be the change in score on the Pantothenate Kinase-Associated Neurodegeneration Activities of Daily Living (PKAN-ADL) scale, from baseline through 24 weeks of treatment. After completing the 24-week treatment period, all patients will be eligible to receive RE-024 as part of an open-label extension. The PKAN-ADL is a novel, PKAN-specific, patient-reported outcome scale measuring motor abilities to function in daily living for patients with PKAN. The scale is an adaptation of Part II of the comprehensive and widely-referenced Unified Parkinson's Disease Rating Scale (UPDRS). For the purposes of this trial, the UPDRS was adapted to be optimally relevant to PKAN through a systematic revision involving experts, patient advocacy leaders and regulatory interaction.

The FORT Study is being conducted under a Special Protocol Assessment (SPA) agreement, which indicates concurrence by the U.S. Food and Drug Administration (FDA) that the design of the pivotal trial can adequately support a New Drug Application (NDA) seeking U.S. approval of RE-024 for the treatment of PKAN. Fosmetpantotenate was also granted fast track status in the U.S., which is designed to facilitate the development and expedite the regulatory review of medicines intended to treat serious conditions with unmet medical needs, in order to reach patients earlier.

For additional information about the FORT Study and to learn more about eligibility, patients can visit and


We are also planning to initiate a pivotal Phase 3 trial evaluating sparsentan for the treatment of focal segmental glomerulosclerosis (FSGS) after receiving regulatory feedback during the second half of 2017. Sparsentan could be the first FDA-approved pharmacologic treatment option for patients with this rare kidney disorder that often leads to end-stage renal disease. 2

The trial is expected to include an interim assessment of proteinuria that could serve as the basis for a New Drug Application seeking Subpart H accelerated approval of sparsentan. The confirmatory endpoint of the study is expected to subsequently compare changes from baseline in estimated glomerular filtration rate, or eGFR. In the Phase 2 DUET study, which is currently in its open-label phase, the overall sparsentan treatment group experienced statistically significant reductions in proteinuria, andSresults showed parsentan was generally safe and well tolerated in the study.3

To learn more about our clinical trials, including enrollment and study centers, contact Retrophin at or visit

To learn more about our clinical trials, including enrollment and study centers, contact Retrophin at or visit Clinical

  1. Gregory, et al. GeneReviews. 2002.
  2. Middleton, et al. Nephrology Rounds 2007; 5(4).
  3. Trachtman H, Nelson P, Radko K on behalf of the DUET Investigators. Efficacy and Safety of Sparsentan, a Dual Angiotensin II and Endothelin Type A Receptor Antagonist, in Patients with Focal Segmental Glomerulosclerosis: A Phase 2 Trial (DUET).  Presented at the American Society of Nephrology Kidney Week Meeting; November 15-20 2016, Chicago, IL.