Sionna Therapeutics Files IPO Prospectus to Challenge Vertex's Dominance in Cystic Fibrosis with First-in-Class CFTR Restoring Therapy

In 2019, the film *Five Feet Apart*》Let cystic fibrosis (CF) Entering the Public Eye，Co-morbidityThe male and female protagonists with CF must always maintain a social distance of “five feet” (approximately 1.5 meters). A simple hug is as difficult as crossing a chasm, while the clinical manifestations of recurrent bronchial infections and airway obstruction impose an unattainable longing and restraint upon them.

CurrentCF Treatment OnlyCan help alleviate or maintain the condition，Andcannot fully resolve the cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction issues.However,Biopharmaceutical CompanySionna Therapeutics (hereinafter referred to as “Sionna”)Poised to break the status quo and developFull RecoveryPotential "first-in-class" small-molecule drugs for CFTR function.

SionnaYu2019InBostonFounding。TodayYearMarch,SionnaCompletele$182 Million Series C Financing。As ofCurrently，SionnaObtained2RoundRecent3$100 millionofFinancingUh。

Sionna atFinancingTimelineof“Smooth sailing” is inseparable from the efforts of Mike Cloonan, President and Chief Executive Officer of the company."Spare no effort"”。

Mike has accumulated over 20 years of experience in the biopharmaceutical industry. He previously served as Chief Operating Officer at Sage Therapeutics (hereinafter referred to as “Sage”), where he oversaw all business units—including commercial and government affairs—as well as finance and administrative functions. During his four-year tenure at Sage, he led the company through multiple financing rounds totaling nearly $1 billion and launched Zulresso, the world’s first medication for postpartum depression.®。

Upon joiningPrior to joining Sage, Mike spent 14 years at Biogen, where he served as Senior Vice President of U.S. Commercial, overseeing a multi-billion-dollar franchise encompassing multiple sclerosis, hemophilia, and progressive spinal muscular atrophy.

AtDuring his tenure at Sage, Mike also facilitated a $1.52 billion transformative collaboration between Sage and his former employer, Biogen.Both parties have reached an agreement to jointly develop and commercialize treatments for major depressive disorder (MDD), postpartum depression (PPD), and other psychiatric disorders, as well as SAGE-324 for the treatment of essential tremor and other neurological disorders. Meanwhile, Biogen has also obtained exclusive licenses to develop and commercialize the antidepressant zuranolone and SAGE-324 in certain regions outside the United States.

Mike Cloonan (Image source: Sionna official website)

Cystic fibrosis (CF) is a hereditary exocrine gland disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. It was included in China’s first batch of the Rare Disease Catalogue in 2018. The CFTR gene encodes an ion channel protein that helps regulate the movement of chloride ions and water across the epithelial cells of the lungs, pancreas, and other organs.andCFTR Gene Mutationthenwill inhibit ion channel proteinsnormal function，GeneratePulmonary and Airway Mucus AccumulationandImpaired Pancreatic Secretory FunctionWaitPathological changes.

Most CommonThe CFTR mutation is known as ΔF508, which is located within the NBD1 (nucleotide-binding domain 1) of CFTR.。The NBD1 domain affects CFTR folding andSynthesis, inTransporting ions to the cell surface and regulating water flowprocess ofplays a key role in.

ΔF508DestructionleInstability of NBD1 prevents CFTR from being properly transported to the cell surface and functioning., leading to mucus accumulation in the lungs and other organs。ExistingTherapy cannot be fully correctedInstability of ΔF508-CFTR and Other Similar Mutations，UnableSolutionNBD1 Defect，CF patientsRegardingremain subject toThe Impact of Reduced CFTR Function.

ForΔF508，SionnaPioneeringOutNovelSmall-molecule therapies, planned to advance targetingDevelopment of a small-molecule series targeting NBD1 and complementary modulators, including the interface where NBD1 binds to the intracellular loop 4 (ICL4) region and transmembrane domain 1 (TMD1) of CFTR, by maximizing stabilitythe structure of the CFTR protein to restore its normal function.

 (Image source: Sionna official website)

Leveraging mature, clinically predictiveCF model, combining Sionna’s NBD1-targeting small molecules with other complementary modulators,According toSionna，CurrentlyIt has been demonstrated that stable in vitro realization of the receptor is feasibleΔF508 gene mutation affects the folding and synthesis of the CFTR protein, among other processes.

SionnaYesPlaceStable Transport of CFTR to the Cell Surface，NormalRegulating the flow of ions and water，ThereforepossessCompleteRecoveryCFTR Function in Patients with the ΔF508 Gene MutationPre-diseasePotential。

 (Image source: Sionna official website)

ForSionna has developed nearly 10 drug candidates targeting the NBD1, ICL4, and TMD1 domains of CFTR. The most advanced candidate, SION-638, has progressed to Phase I clinical trials.SION-638AsCorrectionInnovative Drugs for CFTR NBD1 Domain Defects，HopefulBecome“Best-in-class,” providing a robust solution to the core functional deficiencies of CF.

 Drug Pipeline (Source: Sionna Official Website)

In November 2022, Sionna disclosed preclinical data demonstrating that stabilizing NBD1 in cystic fibrosis with SION-638 could restore CFTR function impaired by the ΔF508 mutation. In December of the same year, Sionna announced SION-638 for the treatment of cystic fibrosisCompletedApprovedINDandStartPhase I Clinical Trial.

In January 2023, Sionna announced the nomination of three compounds as development candidates (DCs). Two of these compounds (SION-719 and SION-451) target the NBD1 domain, while one compound (SION-676) targets the TMD1 domain.

These two types of targetedCompounds targeting NBD1 are derived from the company’s second series of NBD1-directed modulators and have demonstrated high potency; when combined with complementary modulators targeting ICL4 or TMD1, they hold the potential to achieve comprehensive CFTR correction. In the same year, preclinical data presented by Sionna at the North American Cystic Fibrosis Conference further demonstrated that this second series of NBD1-directed modulators can normalize CFTR function affected by the ΔF508 genetic mutation.

Furthermore,Sionna also announced plans to advance four drug candidates into clinical trials in 2024, including three NBD1 stabilizers and one ICL4 modulator. In January 2024, Sionna announced the initiation of a Phase 1 clinical study of SION-109, an ICL4 modulator, for the treatment of cystic fibrosis.

When it comes to cystic fibrosis, one cannot help but mention the also Boston-basedVertex Pharmaceuticals (hereinafter referred to as “Vertex”). Vertex holds an absolute advantage in the field of cystic fibrosis, and the companyof theFour Cystic Fibrosis Drugs: Trikafta/Kaftrio®sales revenue, inThe First Full Year After Listing2020reachedUSD 3.9 billion, with fourth-quarter sales reachingle$1.1 billion.

In August 2023, Vertex announcedof2023 First-Half Performance ReportDisplay, total product revenue was$4.868 billion, of which the triple therapy for cystic fibrosis (CF), Trikafta/Kaftrio®, accounted for $4.337 billion, a year-on-year increase of 19%,OtherCF drug revenue continued to shrink to $531 million, based on Trikafta/Kaftrio®Robust sales performance,Vertex has raised its full-year 2023 revenue forecast for CF products from the previous $9.55 billion to $9.7 billion to $9.7 billion to $9.8 billion.

Charlotte McKee, Chief Medical Officer of SionnaAlsoPreviously atVertex serves as Vice President of Clinical Development for CF and Alpha-1 Antitrypsin Deficiency, providing the CFTR modulator Trikafta/Kaftrio to patients with CF®、Symdeko/Symkevi®andOrkambi®and expand the entireplayed a significant role in the indications for the CF product portfolio.

AlthoughVertex is gaining strong momentum, but Sionna also possesses its own differentiated advantages.Vertex's TherapiesYesPartially Restoring the Core Pathogenic Mechanism of Cystic FibrosisFunction of the CFTR Protein, andSionna’s small-molecule drug candidate holds promise for fully restoring CFTR function, far surpassing the current standard of care.

Mike Cloonan, President and Chief Executive Officer of Sionna Therapeutics, stated, “NBD1 is a well-known and extensively studied target, butPreviouslyyet are considered undruggable. Based onSionna’s continued progress in NBD1 demonstrates the potential to normalize CFTR function in the vast majority of cystic fibrosis patients.“Cure and treatment, though seemingly similar, differ significantly. Treatment is the process and pathway to a cure, whereas a cure represents the ultimate goal and patient expectation.”