Sionna Therapeutics Inc (NASDAQ: SION) is a clinical-stage biopharmaceutical company developing small molecule therapies for cystic fibrosis. The company generates no product revenue and funds operations through capital raises, reporting a net loss of $75.3 million for the year ended December 31, 2025, compared to a net loss of $61.7 million for the year ended December 31, 2024. Research and development expenses totaled $60.3 million in FY2025, with the NBD1 and combination development programs accounting for $32.9 million of that total. General and administrative expenses were $28.7 million in FY2025. Interest income of $13.3 million in FY2025 partially offset operating losses, indicating a cash-rich balance sheet from prior financings. Lead candidates include SION-109, SION-451, and SION-719, with SION-109 having completed Phase 1 trials as of the 10-K filed March 2, 2026. CEO is Michael Cloonan; CFO is Elena Ridloff.

Revenue model

Sionna Therapeutics has no approved products and generates no product revenue as of the 10-K filed March 2, 2026. Operations are funded through equity financing. Interest income of $13.3 million (FY2025) is the only income line reported.

Products and services

Pipeline includes SION-109 (completed Phase 1, evaluated in single ascending dose, multiple ascending dose, and combination cohorts), SION-451, and SION-719, all targeting cystic fibrosis. The company is pursuing dual and combination modulator regimens. NBD1 and combination development programs represented $32.9 million in direct R&D spend in FY2025. Complementary modulator programs represented $5.8 million in FY2025.

Customers and end markets

No commercial customers as of the filing date. End market is cystic fibrosis patients. The company anticipates potential future clinical trials in Europe if product candidates advance to later development stages.

Value-chain role

Drug discovery and clinical development organization. Relies on third-party contract research organizations and service providers for clinical trial execution. Tracks R&D expenses on a program-by-program basis.

Geographic exposure

Headquartered in the United States. Clinical activity to date conducted in the U.S. European clinical trials anticipated in later development stages, which would subject the company to GDPR obligations.

Source: SEC 10-K, filed 2026-03-02

Industry: Pharmaceutical Preparations