Sionna Therapeutics

What Sionna Therapeutics does

Sionna Therapeutics is a clinical-stage biopharmaceutical company developing small molecule therapies intended to normalize CFTR protein function in people living with cystic fibrosis. The company's pipeline is anchored by first-in-class NBD1 (Nucleotide-Binding Domain 1) stabilizers — SION-719 (Phase 2a) and SION-451 (Phase 1) — designed to directly correct the molecular defect caused by the F508del mutation, which is present in approximately 90% of CF patients and is not addressed by any currently approved CF therapy. The portfolio is complemented by additional CFTR modulators (SION-109 and SION-2222/Galicaftor) intended to work synergistically with NBD1 stabilizers. Discovery is grounded in more than a decade of co-founder research from Sanofi Genzyme, biophysical and cell-based screening campaigns, structural biology, and a clinically predictive CFHBE preclinical model; lead assets are progressing through Phase 1/2 trials supported by the Cystic Fibrosis Foundation's Therapeutics Development Network.

The company was co-founded in 2019 by Greg Hurlbut, Ph.D. and Mark Munson, Ph.D., and is headquartered in Waltham, Massachusetts. Following a $111M Series B in April 2022 (led by OrbiMed), a $182M Series C in March 2024 (co-led by Enavate Sciences, Viking Global Investors, and Perceptive Advisors), and a ~$220M upsized IPO on NASDAQ in February 2024, Sionna held approximately $310.3 million in cash at year-end 2025 and trades under ticker SION with a market capitalization of approximately $1.94 billion as of April 2026. As a pre-commercial company, Sionna generates no product revenue (FY 2025 net loss of $75.3 million) and will, upon potential approval, distribute therapies through specialty pharmacy networks and CF Foundation-accredited care centers following the established CFTR modulator commercialization model.

Name

Sionna Therapeutics

Legal name

Sionna Therapeutics, Inc.

Website

https://sionnatx.com

Company type

Public

Founded year

2019

Operating status

Operating

Headcount range

11–50 employees

Short description

Sionna Therapeutics is a clinical-stage biopharmaceutical company developing first-in-class small molecule NBD1 stabilizers and complementary CFTR modulators to normalize CFTR function in cystic fibrosis patients carrying the F508del mutation.

Ownership category

akta.pro rank

Product category

Cystic Fibrosis Therapeutics

akta.pro primary industry

siRNA Therapeutics (gene silencing) (HLAAADAB)

akta.pro secondary industries

RNA Chemistry & Oligonucleotide Engineering (backbones, modifications, stereochemistry) (HLAAADAE), RNA Manufacturing & CMC (oligo synthesis, IVT, purification, formulation, QC) (HLAAADAF)

Keywords

• Cystic fibrosis treatment
• Small molecule therapeutics
• CFTR modulators
• NBD1 stabilizers
• Rare disease biopharmaceuticals

Headquarters

HQ city

Natick

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales, Infrastructure, Others

Revenue model

1. Pharmaceutical product revenue: As a clinical-stage biopharmaceutical company, Sionna does not currently generate product revenue. Future revenue is expected to come from the commercialization of NBD1 stabilizers and complementary CFTR modulators for cystic fibrosis treatment, delivered through standard pharmaceutical distribution channels upon regulatory approval.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels7 records

Core offering

Sionna Therapeutics develops a proprietary pipeline of first-in-class small molecule NBD1 (Nucleotide-Binding Domain 1) stabilizers and complementary CFTR modulators intended to normalize CFTR protein function in cystic fibrosis patients carrying the F508del mutation. The company advances clinical-stage drug candidates (SION-719 in Phase 2a, SION-451 in Phase 1) designed to work synergistically with complementary modulators (SION-109, SION-2222/Galicaftor) to restore CFTR function to as close to normal as possible.

Product overview

Sionna Therapeutics is a clinical-stage biopharmaceutical company developing a proprietary portfolio of NBD1 stabilizers and complementary CFTR modulators as small molecule drugs for cystic fibrosis treatment. The company's pipeline includes lead candidates SION-719 (Phase 2a) and SION-451 (Phase 1), which directly stabilize the NBD1 domain of the CFTR protein to correct defects caused by the ΔF508 mutation. These NBD1 stabilizers are designed to work synergistically with complementary modulators including SION-109 and SION-2222 (Galicaftor) to achieve the highest probability of normalizing CFTR function. The company also previously advanced SION-638 and SION-109 through IND-enabling studies.

Differentiator

Problem solved

Functional benefit

Products and services

• SION-719 A first-in-class NBD1 stabilizer in Phase 2a clinical development for cystic fibrosis, designed to be added to standard-of-care treatment Trikafta. It directly stabilizes the NBD1 domain of CFTR to restore protein function in patients with the F508del mutation. In preclinical CFHBE studies, SION-719 increased F508del-CFTR protein half-life to the wild-type range.
• SION-451 An NBD1 stabilizer in Phase 1 clinical development, being studied in a healthy volunteer dual-combination study. Works synergistically with other CFTR modulators to improve CFTR function in patients carrying the F508del mutation.
• SION-638 An NBD1 stabilizer program targeting the NBD1 domain of CFTR for the treatment of cystic fibrosis. The company previously advanced SION-638 through IND-enabling studies following the company's launch in 2022.
• SION-109 A complementary CFTR modulator program targeting the NBD1 domain of CFTR, designed to work synergistically with Sionna's NBD1 stabilizers to improve CFTR function. Previously advanced through IND-enabling studies.
• SION-2222 (Galicaftor) A complementary CFTR corrector/modulator that synergizes with Sionna's NBD1 stabilizers (SION-719 and SION-451) to enable full correction of ΔF508-CFTR function in preclinical studies.

Quantifiable outcome

• SION-719 NBD1 stabilizer increased F508del-CFTR protein half-life to wild-type range in preclinical CFHBE model
• +2 more outcomes

Segments1 record

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Seven partnerships are on record, tiered minor and core.

• Goldman SachsminorGTM or Marketing Partner · 10 June 2026Sionna presented at Goldman Sachs' 47th Annual Global Healthcare Conference 2026, with President and CEO Mike Cloonan and CMO Charlotte McKee in attendance, moderated by Goldman Sachs Research Division.
• RBC Capital MarketsminorGTM or Marketing Partner · 13 May 2026Sionna participated in a fireside chat at the 2026 RBC Capital Markets Global Healthcare Conference in May 2026, with a live webcast accessible through its investor relations website.
• Raymond JamesminorGTM or Marketing Partner · 7 April 2026Sionna participated in one-on-one investor meetings at the Raymond James 2026 Biotech Innovation Symposium on April 14, 2026.
• Guggenheim Securities / Guggenheim Emerging Outlook Biotech SummitminorGTM or Marketing Partner · 15 February 2026Sionna presented at the Guggenheim Emerging Outlook Biotech Summit 2026 outlining its clinical strategy and NBD1 stabilizer development programs.
• Cystic Fibrosis FoundationcoreStrategic or Co-development Partner · 19 April 2022The CF Foundation provided grant funding of $32 million to support CF drug discovery and preclinical development (through CFFT Development Initiative), and its Therapeutics Development Network supports clinical trial sites. The CF Foundation has long supported CF research and provided $32M in grant funding through its CFFT Development Initiative for NBD1 research.
• University of Massachusetts Medical SchoolminorStrategic or Co-development Partner · 19 April 2022Greg Hurlbut, Ph.D., co-founder and SVP of Discovery Research, served as an adjunct faculty member in the Department of Biochemistry and Molecular Pharmacology at UMMS, where early NBD1 research was conducted.
• CF Foundation Therapeutics Development NetworkcoreStrategic or Co-development PartnerThe Phase 2a PreciSION CF trial is being conducted at multiple sites including those in the CF Foundation-supported Therapeutics Development Network, providing clinical trial infrastructure and patient access.

Scale indicators10 records

Recent moves7 records

Expansion highlights5 records

Direct peers

• Vertex Pharmaceuticals: Vertex dominates the CF market with Trikafta/Kaftrio (elexacaftor/tezacaftor/ivacaftor), the current standard-of-care CFTR modulator therapy. It is the most directly comparable peer because Sionna's NBD1 stabilizers are explicitly designed to be added to or replace Vertex's modulators for the same F508del patient population.
• Galapagos NV: Galapagos historically developed CFTR modulators through its alliance with AbbVie (including potentiator GLPG1837) and remains a relevant comparator in CF small-molecule drug development, even after restructuring its CF program. Comparable to Sionna as a small-molecule CF pipeline peer.

Broad incumbents

• AbbVie: AbbVie is a large diversified biopharmaceutical company that has invested in CF assets and competes broadly in the pulmonology and rare-disease space. It is comparable to Sionna as a broad incumbent with overlapping therapeutic-area interest and capital deployment capacity for respiratory indications.
• Translate Bio (Sanofi): Translate Bio was acquired by Sanofi to advance mRNA therapeutics for CF, including MRT5005. As a broad incumbent (Sanofi) with a dedicated CF mRNA program, it represents a larger competitor pursuing a parallel CF mechanism to Sionna's small-molecule approach.
• Insmed Incorporated: Insmed is a late-stage rare-disease biopharmaceutical company that has developed brensocatib for bronchiectasis and pursued CF-relevant respiratory indications. Comparable as a rare respiratory-disease biopharma with infrastructure and commercial experience adjacent to CF.

Emerging players

• ProQR Therapeutics: ProQR is developing RNA-editing therapies for CF, including eluforsen for F508del class I/II mutations. It targets the same F508del population as Sionna via a different modality (RNA editing), making it a relevant emerging peer in the next-generation CF therapy landscape.
• Arcturus Therapeutics: Arcturus is developing ARCT-032, an inhaled mRNA therapeutic for cystic fibrosis. It targets the same underlying CFTR deficiency as Sionna through a fundamentally different modality, making it a key emerging competitor in the next-generation CF treatment space.
• Eloxx Pharmaceuticals: Eloxx is developing small-molecule readthrough agents (e.g., ELX-02) for nonsense-mutation CF and other rare diseases. It is comparable to Sionna as a clinical-stage small-molecule CF developer using a differentiated mechanistic approach.
• ReCode Therapeutics: ReCode is developing SORT lipid nanoparticle-delivered mRNA and gene correction therapies for CF, including RCT1100. It targets the same F508del population as Sionna via a different modality and is a relevant emerging peer in next-generation CF therapeutics.
• Spirovant Sciences: Spirovant is developing gene therapy approaches (both AAV and lentiviral) for cystic fibrosis. It targets the same underlying CFTR defect as Sionna via a curative-intent modality and is a relevant emerging peer in the next-generation CF treatment landscape.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/sionna_tx
• LinkedInlinkedin.com/company/sionna-therapeutics

Revenue estimate

Valuation estimate

Number of profiles

Profiles15 records

Funding overview

Funding rounds2 records

Investors10 records

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M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Sionna Therapeutics