Polaryx Therapeutics Marks Rare Disease Day, Reaffirming Commitment to Patients with Rare Pediatric Lysosomal Storage Disorders

Rhea-AI Summary

Polaryx Therapeutics (Nasdaq: PLYX) marked Rare Disease Day and reaffirmed its commitment to patients with rare pediatric lysosomal storage disorders by advancing the SOTERIA Phase 2 trial of lead candidate PLX-200.

The open-label, single-arm SOTERIA study will evaluate safety, tolerability, and clinical activity across four LSDs: CLN2, CLN3, Krabbe, and Sandhoff disease.

Positive

• Initiated SOTERIA Phase 2 trial evaluating PLX-200 across 4 LSDs
• Targets rare pediatric diseases affecting about 1 in 5,000 births
• PLX-200 positioned as a disease-modifying, family-friendly therapy

Negative

• SOTERIA is open-label, single-arm, limiting randomized control comparisons
• No efficacy readouts reported yet for PLX-200

Key Figures

Insider purchase: 2,867 shares Purchase price: $2.7871 per share CFO holdings: 228,225 shares +5 more

8 metrics

Insider purchase 2,867 shares CFO open-market buy on Feb 18, 2026

Purchase price $2.7871 per share CFO Form 4 transaction

CFO holdings 228,225 shares Directly held after Feb 18, 2026 purchase

Group ownership 22,744,796 shares (48.0%) Schedule 13D group led by Mstone and Alex Yang

Shares outstanding 47,343,297 shares As of Jan 12, 2026 in Schedule 13D

Aggregate purchase price $3,000,513 Cost basis of shares held by 13D group

SOTERIA indications 4 lysosomal storage disorders CLN2, CLN3, Krabbe disease, Sandhoff disease

People with rare diseases More than 300 million Global prevalence cited from NORD

Market Reality Check

Price: $3.19 Vol: Volume 486K is 0.14x the ...

low vol

$3.19 Last Close

Volume Volume 486K is 0.14x the 20-day average 3.41M, indicating light trading relative to recent norms. low

Technical Price $3.19 is trading below the 200-day MA at $8.17, reflecting a longer-term downtrend despite the bounce.

Historical Context

4 past events · Latest: Feb 17 (Positive)

Pattern 4 events

Date	Event	Sentiment	Move	Catalyst
Feb 17	Trial operations	Positive	+64.3%	CRO selected to run Phase 2 SOTERIA basket trial for PLX-200.
Feb 10	Preclinical data	Positive	-24.1%	Preclinical PLX-200 data for Krabbe disease presented at WORLDSymposium.
Feb 05	Board changes	Positive	-28.9%	Three new board members appointed as PLX-200 advances to Phase 2.
Feb 03	Conference preview	Positive	-37.3%	Announcement of late-breaking PLX-200 data presentation and SOTERIA plans.

Pattern Detected

Recent positive clinical and corporate updates often saw negative next-day moves, with only one of four prior events aligning positively with sentiment.

Recent Company History

Over recent months, Polaryx has focused on advancing PLX-200 and the Phase 2 SOTERIA basket trial. The company announced late-breaking preclinical data, CRO selection, and new board members as it prepared for an IND-approved Phase 2 launch across multiple lysosomal storage disorders. Market reactions were mixed, with several clinically positive updates followed by sharp declines. Today’s Rare Disease Day announcement reinforces the same strategic focus on SOTERIA and rare pediatric LSDs, but centers more on awareness and patient commitment than new clinical data.

Market Pulse Summary

This announcement underscores Polaryx’s commitment to rare pediatric lysosomal storage disorders and...

Analysis

This announcement underscores Polaryx’s commitment to rare pediatric lysosomal storage disorders and highlights the planned Phase 2 SOTERIA basket trial of PLX-200 across four LSDs. It places the program within the broader backdrop of more than 6,000 rare diseases and over 300 million affected people worldwide. Recent history shows multiple SOTERIA-focused updates, board strengthening, and insider buying. Investors may watch for concrete milestones such as trial initiation timing and future clinical readouts.

Key Terms

lysosomal storage disorders, phase 2, open-label, single-arm, +1 more

5 terms

lysosomal storage disorders medical

"developing novel, disease-modifying therapies for rare, pediatric lysosomal storage disorders"

A group of inherited conditions where cells cannot break down and clear certain molecules, like a clogged recycling center inside cells causing harmful buildup that damages organs and the nervous system. Investors care because these disorders create clear targets for specialized treatments, often qualify for orphan-drug incentives and accelerated review, and can drive focused clinical programs and high-value niche markets if therapies prove safe and effective.

phase 2 medical

"launch of SOTERIA, a phase 2, open-label, single-arm trial designed to evaluate"

Phase 2 is the mid-stage clinical trial where a new drug or treatment is tested in a larger group of patients to see if it works and to keep checking safety after initial human testing. Think of it as a field test that proves whether a product actually delivers its promised benefit. Investors watch Phase 2 closely because its results strongly influence a medicine’s chances of reaching the market, the size of its potential sales, and the company’s valuation.

open-label medical

"SOTERIA, a phase 2, open-label, single-arm trial designed to evaluate"

Open-label describes a situation where everyone involved in a study or process knows the full details, such as who is receiving a treatment or intervention. For investors, understanding whether a project or product is open-label helps gauge the level of transparency and potential biases, influencing trust and decision-making. It’s like knowing whether a test or experiment is conducted openly or behind closed doors.

single-arm medical

"SOTERIA, a phase 2, open-label, single-arm trial designed to evaluate"

A single-arm study is a clinical trial that gives all participants the same treatment and does not include a separate comparison group or placebo. Think of it like testing a new recipe by serving it to diners without offering a control dish — you can see how people respond, but you can’t directly compare results to another option. For investors, single-arm trials can speed development and reduce cost but leave more uncertainty about how a treatment stacks up against existing therapies and how regulators will view the evidence.

hematopoietic stem cell transplantation medical

"Hematopoietic stem cell transplantation (“HSCT”) is considered the current standard of care"

A procedure that replaces a person’s damaged or diseased blood-forming cells with healthy stem cells so the body can rebuild its blood and immune system; think of it as replanting seeds in a damaged garden so new plants can grow. It matters to investors because the success, supply, cost and regulation of these transplants and related products (donor cells, lab-grown or engineered alternatives, hospital services) can significantly affect the revenues, trial outcomes and valuation of biotech, medical device and healthcare companies.

AI-generated analysis. Not financial advice.

PARAMUS, NJ, Feb. 27, 2026 (GLOBE NEWSWIRE) -- Polaryx Therapeutics (Nasdaq: PLYX), a clinical-stage biotechnology company developing novel, disease-modifying therapies for rare, pediatric lysosomal storage disorders (“LSDs”), joins the global rare disease community in raising awareness and supporting patients, families, caregivers, and healthcare providers.

“On Rare Disease Day, Polaryx proudly stands alongside the rare disease community - patients, families, caregivers, researchers, and advocacy partners to underscore the urgent need for new and transformative treatments,” said Alex Yang, Chairman and Chief Executive Officer of Polaryx Therapeutics, Inc. “We are deeply committed to raising awareness of rare pediatric lysosomal storage disorders and developing disease-modifying, family-friendly therapies across multiple LSDs.”

Polaryx continues to pursue its mission of addressing significant unmet medical needs in rare pediatric disorders by advancing the launch of SOTERIA, a phase 2, open-label, single-arm trial designed to evaluate the safety, tolerability, and clinical activity of Polaryx’s lead candidate, PLX-200, across four rare LSDs, including CLN2, CLN3, Krabbe disease and Sandhoff disease.

LSDs are a heterogeneous group of more than 50 inherited rare metabolic diseases caused by mutations in genes encoding lysosomal enzymes or associated proteins. These mutations result in the accumulation of undegraded substrates within lysosomes, leading to cellular dysfunction, chronic inflammation, and cell apoptosis. LSDs often manifest in infancy or early childhood and are associated with severe clinical outcomes, including developmental regression, seizures, blindness, motor impairment, and premature death. LSDs affect approximately 1 in 5,000 births. Among the indications, the SOTERIA trial specifically targets rare subtypes, including:

• CLN2 disease, also known as late infantile neuronal ceroid lipofuscinosis (“LINCL”), is associated with mutations in the CLN2 gene, which encodes lysosomal tripeptidyl-tripeptidase I (“TPP1”). This mutation in the CLN2 gene results in a deficiency and/or loss of function of the TPP1 protein that leads to intralysosomal accumulation of auto-fluorescent lipopigments known as ceroid-lipofuscin. Globally, the classical form of CLN2 disease has a prevalence of 0.6 to 0.7 per million inhabitants. CLN2 is a rare neurodegenerative genetic disease that affects children in early life

• 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. Due to impaired lysosomal function, neurons accumulate waste material and progressively deteriorate, resulting in a neurodegenerative disease course

• Krabbe disease, also known as globoid cell leukodystrophy, is caused by mutations in the galactosylceramidase (“GALC”) gene, leading to galactocerebrosidase 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. Hematopoietic stem cell transplantation (“HSCT”) is considered the current standard of care

• Sandhoff disease, is part of a group of inherited disorders called GM2 gangliosidoses, resulting from deficiencies in the hexosaminidase enzyme. This mutation leads to an accumulation of GM2 ganglioside in nerve cells, resulting in rapid neurodegeneration. Sandhoff Disease has a prevalence of approximately 0.67 per 100,000 births. There is currently no established standard of care for these diseases

The National Organization for Rare Diseases (NORD), a rare disease patient advocacy organization, notes that a disease is considered rare when it affects fewer than 1 in 2,000 people globally, with approximately 70% of these diseases starting in childhood. There are more than 6,000 rare diseases identified, 72% of which are genetically inherited. More than 300 million people worldwide live with rare diseases, representing about 3.5% to 5.9% of the global population. Many of these diseases currently have limited treatment options, highlighting the urgent need for ongoing research and support for affected individuals and families.

Rare Disease Day, observed annually on the last day of February, serves as an international campaign to raise awareness about the challenges faced by individuals and families living with rare diseases. For more information about Rare Disease Day, please visit www.rarediseaseday.org.

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 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 first 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 Polaryx Therapeutics

Polaryx Therapeutics, Inc. is a clinical-stage biotechnology company focused on developing patient-friendly small molecule and gene therapy treatments for rare orphan lysosomal storage disorders (LSDs). Founded in 2014, Polaryx seeks to deliver safe, effective, and patient-friendly treatments that address the underlying pathophysiology of these catastrophic diseases and their significant unmet need. Our approach integrates small molecule therapies, including a combination therapy, and a gene therapy, positioning us to potentially address both the genetic and downstream pathological features of LSDs. Our small molecule drug candidates share similar modes of action that have been demonstrated to address lysosomal dysfunction, neuroinflammation, and neuronal loss in our validated animal models that closely mimic human clinical phenotypes. Our most advanced product candidate, PLX-200, targets several LSDs and we intend to launch SOTERIA, a Phase 2 basket trial, to evaluate PLX-200’s safety and efficacy. For more information, please visit www.polaryx.com.

Forward-Looking Statements

Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including, but not limited to, statements regarding: Polaryx’s clinical development plans for PLX-200, including the timing for initiation of the SOTERIA trial. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. While Polaryx believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to the company on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in Polaryx’s filings with the U.S. Securities and Exchange Commission (the SEC), many of which are beyond the company’s control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility, expectations regarding the initiation, progress, and expected results of Polaryx’s clinical trials; expectations regarding the timing, completion and outcome of Polaryx’s clinical trials; the timing or likelihood of regulatory filings and approvals; liquidity and capital resources; and other risks and uncertainties identified in Polaryx’s Registration Statement on Form S-1, as amended, filed with the SEC on January 27, 2026 and subsequent disclosure documents Polaryx may file with the SEC. Polaryx claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. Polaryx expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law.

Media Contact:
Jules Abraham
Managing Director, Communications
CORE IR
(212) 655-0924
Julesa@coreir.com

Investor Contacts:
CORE IR
(212) 655-0924
investor@polaryx.com 

FAQ

What did Polaryx (PLYX) announce on February 27, 2026 about PLX-200?

Polaryx announced advancement of the SOTERIA Phase 2 trial for PLX-200 across four rare LSDs. According to Polaryx, the open-label, single-arm study will assess safety, tolerability, and clinical activity in CLN2, CLN3, Krabbe, and Sandhoff disease.

Which lysosomal storage disorders will PLYX’s SOTERIA trial target in 2026?

The SOTERIA trial will target CLN2, CLN3, Krabbe, and Sandhoff disease. According to Polaryx, the study is designed to evaluate safety, tolerability, and clinical activity of PLX-200 in these four pediatric LSD subtypes.

How is the SOTERIA Phase 2 trial of PLX-200 designed and what are implications for investors?

SOTERIA is an open-label, single-arm Phase 2 study, limiting controlled efficacy comparisons. According to Polaryx, the design focuses on safety, tolerability, and clinical activity signals rather than randomized efficacy proof.

What unmet needs does Polaryx (PLYX) aim to address with PLX-200?

Polaryx aims to address rare pediatric LSDs that often lack effective treatments, including diseases with no established standard of care. According to Polaryx, PLX-200 is intended as a disease-modifying, family-friendly therapy across multiple LSDs.

Does Polaryx provide prevalence context for the lysosomal storage disorders targeted by PLYX?

Yes; the company notes LSDs affect about 1 in 5,000 births, with specific prevalences cited for CLN2, CLN3, Krabbe, and Sandhoff. According to Polaryx, these numbers illustrate the rare, pediatric nature of the target indications.