Aptar Pharma and Aceso Therapeutics Partner to Advance Inhaled Antisense Oligonucleotide for Cystic Fibrosis

Aptar Pharma announced a collaboration with Aceso Therapeutics, a Montpellier, France-based biotech, to advance ACT-101, an antisense oligonucleotide (ASO) candidate designed to target the underlying disease mechanisms of cystic fibrosis (CF).¹ The program will be supported by Nanopharm, Aptar Pharma's specialist inhalation development services business, which will lead formulation development and device assessment activities for Aceso's clinical development roadmap.¹ The work complements Aptar Pharma's broader biologics compatibility program, which systematically evaluates how complex biologic molecules — including nucleic acids, peptides, proteins, and their associated nanoparticle-based delivery systems — interact with the company's pulmonary and nasal delivery platforms.¹

Gemma Budd, general manager of Nanopharm, said, "Cystic fibrosis remains a devastating disease with significant unmet need. Partnering with Aceso Therapeutics enables us to apply our formulation and inhalation science expertise to an innovative oligonucleotide asset. We are proud to contribute our expertise to this early-stage development program."¹ Thomas Tran, CEO and co-founder of Aceso Therapeutics, said, "By partnering with Nanopharm, Aceso Therapeutics aims to accelerate the development of ACT-101 towards clinical evaluation, exploring its potential through direct delivery to the lung. Nanopharm's proven track record in inhaled and nasal drug product development, combined with the wider scientific depth within Aptar Pharma, gives us confidence as we continue to advance our ASO platform."¹

How does ACT-101 work, and who is it designed for?

ACT-101 is built on Aceso's proprietary PTGR platform, which the company describes as designed to restore gene expression in genetic diseases, developed over more than a decade of academic research in collaboration with the PhyMedExp laboratory.¹ ACT-101 is designed to act on CFTR pre-mRNA processing rather than the DNA sequence itself, aiming to correct or improve CFTR protein output in CF patients who carry the F508del mutation — the disease's most common genetic driver.² F508del is by far the most common disease-causing CFTR mutation, found in roughly 70% of CF alleles in Caucasian populations, though its frequency varies substantially by geography and population.³

Why is inhaled delivery significant for this class of therapy?

Delivering nucleic acid-based therapeutics directly to the lung carries formulation challenges distinct from systemic or injectable administration. As quoted in BioPharm International in the context of a different inhaled RNA therapeutic program, Christian Dohmen, executive director, technology development and CMC at Ethris said that “delivery to the respiratory tract via an inhaled route of administration presents added challenges because it involves nebulization of the product, which induces additional stress to the formulation and can lead to LNP aggregation."⁴ While ACT-101 is an antisense oligonucleotide rather than an mRNA-lipid nanoparticle formulation, the underlying formulation and device-engineering challenges of getting a nucleic acid therapeutic intact and functional into lung tissue are broadly shared across inhaled RNA-based modalities — the specific reason Aceso is working with a specialist inhalation development partner rather than pursuing formulation work independently.

How does this fit into the broader oligonucleotide therapeutics landscape?

Investment in oligonucleotide-based therapeutics has accelerated across the industry. Novartis completed its $1.7 billion acquisition of Regulus Therapeutics for farabursen, an oligonucleotide targeting miR-17 for autosomal dominant polycystic kidney disease, adding to a growing list of large pharmaceutical companies building out oligonucleotide and RNA therapeutic capabilities and delivery infrastructure.⁵ ACT-101 remains an early-stage, investigational candidate that has not been approved by any regulatory authority, and no conclusions regarding its safety or efficacy can be drawn at this stage.¹

Why does cystic fibrosis represent a significant unmet need?

CF is a rare, inherited disease that causes severe damage to the lungs, digestive system, and other organs, affecting approximately 100,000 people worldwide, according to the American Lung Association.¹ CF results from mutations in the CFTR gene, which normally regulates chloride transport across epithelial tissue in the lungs, pancreas, and other organs; when CFTR is reduced or dysfunctional, the resulting disruption in ion transport drives the multisystem disease pathology seen in CF.³ CFTR modulator therapies have improved outcomes for many CF patients with specific mutations over the past decade, though gaps in available treatment options remain across the range of CFTR mutations — the space Aceso's ASO platform is positioned to address.

What happens next?

Nanopharm will lead formulation development and device assessment for ACT-101 to support Aceso's clinical development roadmap.¹ As an early-stage program, no timeline for clinical trial initiation was disclosed.

References

1. Aptar Pharma. Aptar and Aceso Therapeutics Announce Collaboration to Advance Inhaled Antisense Oligonucleotide Therapy for Cystic Fibrosis. Press release. Published September 7, 2026. Accessed September 8, 2026.
2. Law R. Aptar Pharma to Support Aceso's Inhaled Cystic Fibrosis Candidate's Advance. Pharmaceutical Technology. Published September 7, 2026. Accessed September 8, 2026.
3. Ferec C, Cutting GR. Assessing the Disease-Liability of Mutations in CFTR. Cold Spring Harb Perspect Med. 2012;2(12):a009480. doi:10.1101/cshperspect.a009480.
4. Challener C. Increasing mRNA Product Stability with Lyophilization. BioPharm International. Published February 1, 2024. Accessed September 8, 2026.
5. Lavery P. Novartis Acquisition of Regulus Therapeutics is Complete. BioPharm International. Published June 25, 2025. Accessed September 8, 2026.