Retrophin has reached an agreement with the U.S. Food and Drug Administration (FDA) under the Special Protocol Assessment (SPA) process for a Phase 3 clinical trial evaluating RE-024, the company’s novel investigational replacement therapy, for the treatment of pantothenate kinase-associated neurodegeneration (PKAN). The SPA indicates concurrence by the 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. The company plans to initiate this trial before year-end 2016.
“This SPA agreement marks a major milestone for the RE-024 program, as we now have a single pivotal trial design that clarifies our regulatory pathway and positions us to deliver the first approved treatment for PKAN,” said Stephen Aselage, chief executive officer of Retrophin. “We look forward to initiating the trial before year-end and enrolling patients as quickly as possible, with the hope of filling this significant unmet medical need.”
As outlined in the agreement, the Phase 3 clinical trial will be an international, randomized, double-blind, placebo-controlled study evaluating RE-024 for the treatment of PKAN. This pivotal trial will evaluate the safety and efficacy of RE-024 in approximately 82 patients with PKAN aged 6 to 65 years. 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.
About Special Protocol Assessment (SPA)
SPA is a process in which sponsors engage the U.S. Food and Drug Administration (FDA) to reach agreement on key study design features, such as size, entry criteria, dose, endpoints and planned analyses. This agreement ensures that a trial has the potential to support a New Drug Application (NDA) that meets regulatory requirements for an FDA approval. An SPA agreement does not guarantee that the agency will accept an NDA, or that the trial results will be adequate to support approval.