Polaryx Therapeutics Receives FDA Fast Track Designation for PLX-200 in CLN2 Disease
Polaryx Therapeutics, Inc. (Nasdaq: PLYX), a clinical-stage biotechnology company headquartered in Paramus, New Jersey, announced that the U.S. Food and Drug Administration has granted Fast Track Designation to PLX-200, an oral small molecule peroxisome proliferator-activated receptor alpha (PPARα) agonist comprised of gemfibrozil, for the treatment of Late-Infantile Neuronal Ceroid Lipofuscinosis (LINCL/CLN2 disease). The PLX-200 Fast Track designation enables more frequent FDA interactions and eligibility for rolling review of a future marketing application. PLX-200 has also received Rare Pediatric Disease Designation for CLN2 disease and Orphan Drug Designation for Neuronal Ceroid Lipofuscinosis from the FDA.
PLX-200 is being advanced through SOTERIA, a Phase II, open-label, single-arm basket trial designed to evaluate safety, tolerability, and clinical activity across four lysosomal storage disorders: CLN2, CLN3, Krabbe disease, and Sandhoff disease. Polaryx received a safe-to-proceed letter from the FDA in October 2025 and plans to initiate SOTERIA in Q3 2026 at sites in the United States, Europe, and Asia. For the CLN2 and CLN3 cohorts, the trial will incorporate analyses comparing treated patients against natural history data as a control arm. No NCT identifier for SOTERIA was disclosed in the company's announcement. Gemfibrozil itself holds longstanding FDA approval as a lipid-regulating agent for adults with hypertriglyceridemia, marketed as Lopid since 1981, but has not previously been approved for pediatric or neurological indications.
Research context
CLN2 disease is a rare, autosomal recessive neurodegenerative disorder caused by deficiency of the lysosomal enzyme tripeptidyl peptidase 1. Onset typically occurs between ages two and four, with rapid progression of seizures, language loss, motor decline, and vision impairment, leading to death in adolescence. The only approved disease-modifying therapy is cerliponase alfa (Brineura), a recombinant enzyme replacement therapy administered via intracerebroventricular infusion every two weeks. While cerliponase alfa has been shown to slow functional decline and improve survival, it does not halt disease progression and requires invasive delivery through a surgically implanted reservoir. Delayed diagnosis remains a documented barrier to treatment effectiveness, as neurodegeneration is already advanced by the time many patients begin therapy.