Protalix BioTherapeutics, Inc. (NYSE-American: PLX) has announced positive preliminary results from its Phase 1 first-in-human study of PRX-115, a recombinant uricase candidate for the treatment of uncontrolled gout. The study, a double-blind, placebo-controlled, single ascending dose trial, evaluated the safety, pharmacokinetics, and pharmacodynamics of PRX-115 in subjects with elevated uric acid levels.
The Phase 1 trial enrolled 64 randomized subjects across eight cohorts, each consisting of eight subjects (six active and two placebo). All subjects completed the study, and the data is currently being analyzed. The preliminary results were presented in a late-breaking poster at the American College of Rheumatology (ACR) Convergence 2024.
Key Findings from the Phase 1 Trial
- Dose-Dependent Exposure: Exposure to PRX-115 increased in a dose-dependent manner. PRX-115 levels were observed in plasma for up to 12 weeks in subjects from the highest dose cohorts (6, 7, and 8).
- Rapid Uric Acid Reduction: A single dose of PRX-115 rapidly reduced plasma uric acid levels across all tested doses. The effect and duration of response were dose-dependent. At the highest dose levels, mean plasma uric acid levels remained below 6.0 mg/dL for up to 12 weeks following a single dose.
- Tolerability: PRX-115 was generally well-tolerated. Only 25% of subjects treated with PRX-115 (12/48) reported study drug-related adverse events, the majority of which were mild to moderate and transient. One subject experienced an anaphylactic reaction immediately following the start of infusion, which was resolved completely. No other serious adverse events were reported.
Dror Bashan, Protalix's President and Chief Executive Officer, stated, "Preliminary results from this study are encouraging and demonstrate the potential of PRX-115 to be a promising uric-acid lowering treatment option for individuals with gout. We are actively planning a phase II clinical trial of PRX-115 in gout patients and expect to initiate the study in the second half of 2025."
Potential Clinical Impact
The preliminary results suggest that PRX-115 may offer an effective uric acid-lowering treatment with a potentially wide dosing interval, which could enhance patient compliance and treatment flexibility. Gout affects millions worldwide, and uncontrolled gout can lead to significant morbidity, including joint damage and kidney disease. Current treatments often require frequent dosing and may have limitations in certain patient populations.
Further studies are needed to confirm the long-term safety and efficacy of PRX-115 in the gout patient population. Protalix is planning to initiate a Phase 2 clinical trial in gout patients in the second half of 2025 to further evaluate the potential of PRX-115.
Third Quarter 2024 Financial Results
Protalix also reported its financial results for the third quarter of 2024:
- Revenue: Total revenue for the three months ended September 30, 2024, was $17.9 million, an increase of 73% compared to $10.3 million for the three months ended September 30, 2023. Revenues from selling goods increased by $7.6 million, primarily due to increased sales to Chiesi Farmaceutici S.p.A. and Pfizer Inc.
- Net Income: Net income for the three months ended September 30, 2024, was $3.2 million, or $0.04 per share, basic, compared to a net loss of $1.9 million, or $0.03 per share, basic, for the same period in 2023.
- Cash Position: Cash and cash equivalents were approximately $27.4 million at September 30, 2024.
