PARAMUS, N.J. — Polaryx Therapeutics, Inc. (Nasdaq: PLYX), a clinical-stage biotechnology company developing disease-modifying therapies for rare pediatric LSDs, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation (FTD) to PLX-200 for the treatment of Juvenile Neuronal Ceroid Lipofuscinosis (JNCL/CLN3 disease), Krabbe disease (globoid cell leukodystrophy), and Sandhoff disease (GM2 gangliosidosis Type II).
Following the March 2026 grant of FTD to PLX-200 in treatment of Late-Infantile Neuronal Ceroid Lipofuscinosis (LINCL/CLN2 disease), PLX-200 now holds FTD for all four prospective indications to be studied in the SOTERIA Phase 2 basket trial.
The Fast Track program is designed to facilitate and expedite the review of therapies intended to treat serious or life-threatening conditions with unmet medical need. Companies receiving Fast Track Designation may benefit from more frequent interactions with the FDA and the potential for rolling review of a future marketing application.
“We are delighted by the FDA’s decision to further extend Fast Track Designation to CLN3, Krabbe disease, and Sandhoff disease,” said Alex Yang, Chair and Chief Executive Officer of Polaryx Therapeutics. “As we prepare to advance the SOTERIA Phase 2 basket trial, receiving this designation across all four indications underscores the enormous need that exists in the current LSD landscape while also recognizing PLX-200’s potential to meaningfully address treatment gaps across multiple LSDs.”
“CLN2 disease, CLN3 disease, Krabbe disease, and Sandhoff disease are devastating neurodegenerative conditions with limited or no disease‑modifying treatment options. The regulatory alignment received from the FDA’s Fast Track Designations highlight the seriousness of these disorders and the need for new therapeutic options like PLX-200,” said Lisa L. Bollinger, M.D., Chief Medical Officer of Polaryx Therapeutics. “We remain focused on preparing the SOTERIA trial to advance PLX‑200 into the clinic in the second half of 2026.”
About PLX-200
Polaryx’s lead drug candidate, PLX-200, is an orally available compound comprised of gemfibrozil. Gemfibrozil is an FDA-approved lipid regulating agent in the fibrate family which has only been approved in a capsule form for adult patients with very high elevations of serum triglyceride levels to decrease serum triglycerides and very low-density lipoprotein cholesterol and increase high density lipoprotein cholesterol. The ability of gemfibrozil to cross the blood-brain barrier (BBB) has also been documented in third-party preclinical trials and safe use of gemfibrozil in adults has also been well-established over several decades of clinical investigation and commercial use, which we believe accelerates clinical development and reduces associated costs. We believe the unique ability of PLX-200 to cross the BBB, along with its widely applicable mechanism of action, positions PLX-200 to potentially address the immense unmet need in multiple rare, catastrophic LSD indications.
About the SOTERIA Trial
SOTERIA is a Phase 2, open-label, single arm trial intended to assess the safety, tolerability, and clinical activity of Polaryx’s lead drug candidate, PLX-200, in CLN2, CLN3, Krabbe disease, and Sandhoff disease, four different LSDs whose patient populations Polaryx believes represent approximately one quarter of the LSD population. SOTERIA is designed to be flexible, resource-efficient, and provide important data and information important to PLX-200’s future clinical development. Polaryx received a safe to proceed letter in October 2025 from the FDA and plans to initiate SOTERIA in the second half of 2026 in trial sites in the United States as well as in Europe and Asia or other foreign jurisdictions. Designed with a high degree of flexibility, SOTERIA represents a resource-efficient opportunity to validate PLX-200’s preclinical science across multiple LSDs while gathering data that will be invaluable in planning PLX-200’s future development pathway, including the initiation of potentially pivotal trials. For the CLN2 and CLN3 cohorts, although the entire trial is open label, these cohorts will incorporate analyses comparing natural history data as a control arm to PLX-200’s treated arm. A natural history study is a preplanned observational study intended to track the course of the disease. Should the data demonstrate compelling clinical activity, Polaryx may seek conditional marketing authorization.
About CLN3 Disease
CLN3 disease, also known as juvenile neuronal ceroid lipofuscinosis (JNCL) or juvenile Batten disease, is a rare inherited LSD that primarily affects the nervous system in childhood. With a prevalence of one in 100,000 births worldwide, CLN3 disease is caused by mutations in the CLN3 gene which encodes a lysosomal transmembrane protein, Battenin. The most common genetic defect is a ~1-kb deletion in CLN3, leading to a loss of protein function. The disorder follows an autosomal recessive inheritance pattern, requiring two defective copies of CLN3 for disease manifestation. Due to impaired lysosomal function, neurons accumulate waste material and progressively deteriorate, resulting in a neurodegenerative disease course.
About Krabbe Disease
Krabbe disease, also known as globoid cell leukodystrophy, is caused by mutations in the galactosylceramidase (GALC) gene, leading to GALC deficiency and an inability to break down certain lipids in the body. This results in accumulation of toxic substances in the brain and other areas of the nervous system leading to demyelination and severe neurological decline. The incidence rate of Krabbe disease varies significantly, affecting 0.3 to 2.6 per 100,000 live births. We believe that there are approximately 6,700 Krabbe disease patients in the United States, Europe and select regions of the ROW. Hematopoietic stem cell transplantation (HSCT) is considered the current standard of care.
About Sandhoff Disease
Sandhoff disease, a more severe form of Tay-Sachs disease, is caused by mutations in the HEXB gene, which impair the function of β-hexosaminidase enzymes. This deficiency causes the accumulation of GM2 gangliosides in neurons, resulting in progressive neurodegeneration. Several subtypes of Sandhoff disease exist, varying depending on the age of onset. The infantile form typically manifests between three and six months of age and is the most severe. The first symptom is often hypotonia, accompanied by an exaggerated startle response to auditory stimuli, followed by developmental regression. Acute infantile and sub-acute juvenile Sandhoff disease patients begin regressing significantly after the onset of symptoms, with death usually occurring between two and three years for the infantile cohort and early to late teens for the juvenile cohort. Life expectancy for late-onset Sandhoff patients is not significantly impacted. We believe that there are approximately 1,200 Sandhoff disease patients in the United States, Europe and select regions of the ROW.
About Polaryx Therapeutics, Inc.
With a patient-first approach in our R&D process, Polaryx is committed to developing non-invasive therapeutic alternatives to treat lysosomal storage disorders. Our orally-available small molecule therapies aim to promote lysosome biogenesis via PPARα-dependent TFEB upregulation, attenuate inflammation in the brain, and enhance neuronal survival.
In collaboration with Rush University Medical Center, we have confirmed the in-vivo efficacy of our drug candidates using human astrocytes and various murine models of lysosomal storage disorders. Importantly, all of our preclinical studies improved motor and cognitive functions and increased life expectancy. To learn more visit https://polaryx.com/ or follow the company on X.
Media Contact
CORE IR
(212) 655-0924
[email protected]
Investor Contact
CORE IR
(212) 655-0924
[email protected]