Protalix Bets on Gout and Rare Kidney Diseases as It Eyes New Drug Launches in 2026

Protalix BioTherapeutics, Inc. (NYSE:PLX), a biopharmaceutical company focused on the discovery, development, production and commercialization of innovative therapeutics for rare diseases with significant unmet needs, today announced the following update from President and Chief Executive Officer, Dror Bashan, to its stockholders.

 

Dear Protalix Stockholders,

As we look forward to 2026, we remain focused on building with our partners a growing, profitable business and an innovative pipeline for patients with high-need rare diseases.

A core element of this plan is our advancement of PRX-115 for patients with uncontrolled gout. Clinical data from our Phase 1 trial demonstrate that PRX-115 provides a rapid and durable urate-lowering effect with a favorable tolerability profile, supporting its potential as a meaningful differentiated treatment option. Epidemiologic analyses confirm gout prevalence continues to rise worldwide, with U.S. rates increasing significantly over the last two decades.1,2 Despite available therapies, a large proportion of patients remain uncontrolled due to treatment limitations and poor adherence.3,4 Uncontrolled gout is a high–need, high–value indication and PRX-115 has the potential to deliver a differentiated clinical profile with rapid onset and durable urate control. PRX-115 emerges from our internal pipeline as a possible third molecule for commercialization.

In parallel, we are sharpening our strategic focus on rare kidney diseases to build a renal pipeline through innovation and partnerships — starting with PRX-119 as a long–acting DNase I for the treatment of inflammation and fibrosis.

This initiative reflects our conviction to continue delivering meaningful therapies for patients facing complex diseases with high unmet need while building durable, long–term value. Commercial execution through our partners remains a core driver of our near–term value and long-term growth.

Commercial Execution and Market Positioning

Throughout last year, we had consistent performance with our partner, Chiesi Global Rare Diseases, across the United States and key ex-U.S. markets, achieving solid Elfabrio® launch execution for the treatment of Fabry disease. Core indicators, including treated patient counts and market share across the United States, EU, and additional geographies, continue to track to plan.

Our future sales will continue to be anchored by Elfabrio through our partner, Chiesi, across the United States and key ex-U.S. markets. Our confidence in the Fabry market has been further validated by the recent acquisition,5 and the global Fabry market is projected to reach approximately $3.4°billion by 2030. We believe Elfabrio is positioned to capture 15% to 20% of this market over the same period.

A re-examination of the negative opinion issued in November 2025 by the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) regarding the proposed 2 mg/kg every-four-weeks (E4W) dosing regimen for Elfabrio is underway, with an appeal outcome expected in the first quarter of 2026. This effort reflects Chiesi's and Protalix's mutual commitment to expanding patient access by offering a more flexible dosing option. Importantly, this process does not affect the existing bi-weekly label, which remains intact.

We also expect steady and durable contributions from Elelyso®, supported by our longstanding collaboration with Pfizer Inc. and continued support through our partnership with Fundação Oswaldo Cruz (Fiocruz), an arm of the Brazilian Ministry of Health. These established revenue streams help underpin our operating resilience.

Pipeline Strategy and Progress

With a commercial foundation complemented by well-established partners, we are advancing a purpose-built R&D pipeline to address significant market opportunities with high unmet medical need. Our uncontrolled gout and rare renal disease programs align with areas of growing investments, increasing disease prevalence, and meaningful therapeutic gaps, allowing us to deploy capital toward initiatives that we believe have the potential to deliver substantial long-term returns.

PRX-115 for Uncontrolled Gout

• In October 2025, we submitted an Investigational New Drug (IND) application to the U.S. Food and Drug Administration (FDA) in connection with our planned Phase 2 clinical trial of PRX-115, which became effective following the FDA's standard 30–day review period (NCT05745727), and the first clinical sites have been fully activated.
• Phase 1 data demonstrate that PRX-115 was generally well–tolerated, with mainly mild and transient events. Data also showed that a single dose reduced urate below the target levels (<6 mg/dL) across all cohorts and that the effect lasted for 12 weeks at higher doses.
• PRX–115 is engineered for high specific activity, enhanced stability, and reduced immunogenicity. We believe it has the potential to be a best–in–class therapy for uncontrolled gout, with once–every–four–weeks dosing without an immunomodulator or longer dosing intervals when used with methotrexate.

Focus on Rare Renal Indications (Preclinical Programs)

As we expand our portfolio, we are executing a focused strategy centered on rare kidney diseases, leveraging our platform strengths and a diversified modality mix to address high unmet needs.

• PRX–119: Our PEGylated, long–acting DNase I is designed to degrade neutrophil extracellular traps (NETs) and reduce downstream inflammation and fibrosis. PRX–119 has the potential to be a key pipeline asset.
• Secarna Collaboration: We recently announced an RNA–based collaboration with Secarna Pharmaceuticals utilizing Secarna's AI–powered OligoCreator® platform. This partnership combines our rare disease and biologics expertise with Secarna's AI–driven platform to jointly develop novel therapeutic candidates for rare renal indications.

Outlook: Building Durable Growth and Long–Term Value

Protalix enters 2026 with a profitable commercial business through our partners and a focused pipeline aligned to areas of high unmet need. We believe this foundation limits downside risk while preserving significant upside potential as we execute our clinical programs, expand our commercial footprint, and pursue strategic partnerships that can accelerate impact and scale.

Our priorities remain consistent:

1. Facilitate Chiesi's commercial performance with Elfabrio
2. Advance PRX–115 as a potential best–in–class therapy for uncontrolled gout
3. Advance rare renal programs leveraging our R&D strengths

We move forward with confidence, commitment, and an unwavering focus on creating long–term value for patients, partners, and shareholders alike.

On behalf of the entire Protalix team, thank you for your continued trust and support.

Truly yours,

Dror Bashan

President & Chief Executive Officer