Arcturus Therapeutics (ARCT) Guggenheim Securities Emerging Outlook: Biotech Summit 2026 summary

Pipeline and clinical progress

• Advanced mRNA therapeutics for rare diseases are in phase II, with key milestones and data readouts expected this year.

• Inhaled mRNA program for cystic fibrosis (CF) is progressing, with phase IIb (fourth cohort) set to start in the first half of the year, expanding to 20 subjects and extending treatment to 12 weeks.

• Dose escalation in CF trials reached 15 mg daily, showing dose-responsive reduction in mucus plugs, with safety and tolerability at this dose under evaluation.

• Phase IIb will use improved baseline measurements, historical data, and both FEV and LCI as endpoints, aiming for more definitive results.

• The study targets CF patients unresponsive to modulators, representing 15%-18% of the CF population with significant unmet need.

Clinical endpoints and regulatory strategy

• Success in phase IIb is defined by measurable improvements in FEV (3%-4%) and/or LCI, with high-res CT scans as supportive evidence.

• LCI is highlighted as a more sensitive and accurate lung function measure, especially for micro changes in mucus reduction.

• The FDA is supportive, encouraging collection of CT scan data and open to various endpoints for this high-need population.

• Recruitment for phase IIb is expected to be rapid due to multiple sites and motivated patients, with interim data possible but timing guidance pending.

Competitive landscape and technology

• The inhaled mRNA program is positioned as a leader in the field, attributed to optimized delivery technology for bronchial epithelial cells.

• Delivery system is designed for nebulizability, sputum survival, and effective cell entry, overcoming historical safety and tolerability issues.

• Transient mRNA therapeutics are considered ideal for regenerating organs like the lung and liver, differentiating from gene therapy approaches.