Press Release
Fair Therapeutics to Cease Operations
28 May 2026, Utrecht, the Netherlands - Fair Therapeutics will be winding down its operations.
Fair Therapeutics originates from the European HIT-CF consortium which aims to find suitable treatment for those people with Cystic Fibrosis that currently do not have access to treatment.
Fair Therapeutics took up the triple modulators originally developed by Proteostasis Therapeutics, inc. Fair Therapeutics, together with its partners in the HIT-CF consortium and support from the EU HORIZON 2020 program, has successfully completed the CHOICES Phase 2b study which was led by University Medical Center Utrecht. The CHOICES study has generated valuable insights into CF treatment and marks a significant milestone in advancing scientific understanding in this field.
Importantly, the trial provides meaningful insights into the use of organoid models for patient selection. The study was conducted in a particularly challenging patient population with rare CFTR variants, where treatment options remain limited. While no consistent overall improvement was observed across the full study population, clinical benefit was significantly higher in those patients whose organoids showed a strong response. This demonstrated that organoid-based stratification in placebo-controlled, double blinded early phase clinical trials leads to improved efficacy outcomes. This represents a significant step forward and support the further use of organoid technology for CF patient stratification for drugs in development or on the market, and support similar studies with organoids in other disease and therapeutic indications.
The treatment demonstrated an acceptable safety profile, with no unexpected safety findings observed during the study. The most notable side effect was increased sensitivity of the skin to sunlight or UV exposure in a subset of patients. Overall, the safety observations support continued scientific interest in further exploring this therapeutic approach.
We hope that others will build on these findings.
The clinical study results can also be found on the CTIS website.
Despite these important findings and encouraging results, we have unfortunately not been able to secure the financing required to continue the development of the modulators and are therefore winding down our operations. As part of this process, the license to the modulators has been returned to HealthCare Royalty Partners. While these assets are no longer under our control, we remain encouraged by their potential and would be welcome to support parties that wish to further develop these modulators.
Our mission — to contribute to the development of accessible therapies for all — remains as relevant as ever. We sincerely hope that this mission, and the knowledge generated through our work, will be carried forward by others in the field.
We would like to thank all patients, investigators, partners, and supporters for their trust and contributions throughout this journey.
For further information or to explore opportunities to build on this work, please use the contact form on our website.
Press Release
Fair Therapeutics B.V. Announces Final Results Choices HIT-CF Trial: Clinical Effect Proportional To In-Vitro Effect
Utrecht, The Netherlands, 20 October 2025 – The HIT-CF Consortium (www.hitcf.org) presented its final results on the evaluation of new CFTR-modulator drugs to the European Commission which funded the project under the European Union’s Horizon 2020 research and innovation program (755021).
The clinical effect of the CFTR modulator combination Dirocaftor-Posenacaftor-Nesolicaftor, as licensed by Fair Therapeutics (www.fairtherapeutics.com) was proportional to the in vitro effects in people with cystic fibrosis (PwCF) with all classes of CFTR gene (and ultra rare) variants. In a placebo-controlled double blinded study, changes in percentages predicted FEV1 ranged from -12% up to +22% percentage points with concordant changes in sweat chloride levels and patient reported outcomes (CFQ-R). In vitro responses were measured in organoids of over 500 pwCF from 16 different European countries using the forskolin induced swelling (FIS) assay.
The results strongly underline the earlier supporting statement of the European Medicines Agency that the FIS assay is a reproducible ex vivo biomarker with strong biological rationale. They also support the use of FIS to: 1) pre-select individuals for clinical trials; and 2) select responders in vitro among PwCF with rare variants not considered in commercial clinical trials with CFTR modulators.
The study also shows promising clinical effects of the new CFTR modulator combination Dirocaftor-Posenacaftor-Nesolicaftor of Fair Therapeutics as first-line treatment in PwCF who show responsiveness in the FIS assay, with a favorable safety profile.
The European Commission strongly supports the further development of both biomarker-driven (individualized) prescription of disease-modifying drugs in chronic diseases in general through cost-effective precision medicine approaches, as well as the further development of the new CFTR modulator combination for PwCF worldwide.
Professor Dr Kors van der Ent, coordinator of the HIT-CF project said: ‘We are really thrilled about the results of our project. Despite all hurdles during the pandemic and changing industry partners, the entire European CF community showed perseverance and dedication to realize new treatments for PwCF.
Mrs Anne van Loon, CEO of Fair Therapeutics stated: ‘FAIR Therapeutics is proud to show the results of their new modulator combination. Around 45,000 diagnosed people with CF do not have access to a potentially life-changing treatment. We are determined to set next steps in the development of this combination and complete our mission to transform CF treatment.’
Mrs Hilde De Keyser, CEO of CF Europe, the federation of national and regional patient associations of PwCF in Europe mentioned: ‘The patient community was actively involved in the HIT-CF project and we strongly support the goal to realize treatment for patients with ultra-rare mutations and in underserved areas.’
The HIT-CF Consortium consists of the University Medical Center Utrecht (The Netherlands) (coordinator); the KU Leuven, Belgium; Faculdade de Ciências da Universidade de Lisboa, Portugal; The European Cystic Fibrosis Society, Aarhus (Denmark), CF Europe, Fair Therapeutics B.V., Utrecht (The Netherlands), HUB Organoids, Utrecht (The Netherlands), Julius Clinical, Utrecht (The Netherlands), and Patergus – Biotechsubsidy, Aalter, Belgium.
Fair Therapeutics (Fair TX) is a privately held, clinical-stage biopharmaceutical company developing accessible, personalized treatments for Cystic Fibrosis.
Cystic Fibrosis is a genetic life-shortening disorder affecting the lungs, digestive system, and other organs. It is caused by variants in the CFTR gene, leading to thick, sticky mucus buildup. This clogs airways, traps bacteria, leading to progressive loss of lung function and also disrupts digestion. Without CFTR modulator therapies median survival is limited to early adulthood.
Media Contact:
Anne van Loon
CEO
info@fairtherapeutics.com
Press Release
Fair Therapeutics B.V. Announces Full Enrollment in Phase IIb CHOICES Trial Evaluating Novel CFTR Modulator Therapy for People with Cystic Fibrosis with Ultra-Rare Variants
Utrecht, The Netherlands, 8 January 2025 – Fair Therapeutics B.V. (Fair TX), a clinical-stage biopharmaceutical company focused on personalized treatments for cystic fibrosis (CF), today announced the full enrollment of its Phase IIb clinical trial, CHOICES (NCT06468527). The trial aims to assess the efficacy and safety of Fair TX’s novel Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) triple modulator therapy—Diponecaftor (Dirocaftor/Posenacaftor/Nesolicaftor)—in adults with ultra-rare CF variants who currently cannot benefit from any disease-modifying treatment. The CHOICES trial is a pivotal step in the company’s mission to address the high unmet needs of people with cystic fibrosis (PwCF). Results of the trial are expected mid-2025.
The trial, a double-blinded cross-over trial, began in June 2024, and has enrolled 40 adult patients (18+) from 9 European countries. All participants were pre-selected using the innovative organoid test, which uses laboratory-grown organoids from patients’ own cells to predict clinical response to the therapy in the lab.
Key objectives of the CHOICES trial include:
Evaluating efficacy: The trial will assess the predicted clinical impact of Fair TX’s CFTR modulators in PwCF identified through their organoid response.
Focusing on ultra-rare variants: The trial aims to demonstrate that Diponecaftor is effective in treating ultra-rare CF variants, a patient population with limited treatment options.
Validating the organoid model: Data from the trial will be compared with results from the earlier Human Individualized Therapy of CF (HIT-CF) Organoid Study (NTR7520), which tested CFTR modulators on organoids from over 500 European PwCF with rare variants. This comparison will further validate the use of organoids as a reliable predictive tool to preselect PwCF for the treatment.
The CHOICES trial is being executed by the HIT-CF Europe consortium, a collaborative effort supported by the EU Horizon 2020 initiative. The consortium includes academic research institutions, not-for-profit organizations, contract research organizations (CROs), biopharma companies developing CF therapies, and supporting service providers (click here for the full list of consortium partners). Fair TX’s Co-Founder, Dr. Kors van der Ent, chairs the HIT-CF Europe consortium, playing a pivotal role in leading the trial.
Dr. Kors van der Ent, Co-Founder of Fair TX, commented:
“We are thrilled to have completed enrollment for the CHOICES trial, which represents a significant milestone for Fair TX and the cystic fibrosis community. By focusing on ultra-rare CF variants and using organoid-based diagnostics, we are advancing personalized medicine and bringing much-needed hope to PwCF who have had limited or no treatment options. We look forward to sharing the results of this groundbreaking trial.”
Anne van Loon, Acting CEO of Fair TX, added:
“Completing enrollment in the CHOICES trial highlights our commitment to addressing the unmet needs of people with ultra-rare CF variants. This is an exciting time for Fair TX as we continue to demonstrate the potential of our personalized approach to treatment. We are deeply grateful to the patients, families, and clinical teams who have made this milestone possible.”
The Phase IIb CHOICES trial is being conducted at 15 clinical centers across Europe. The final patient has now been enrolled, and all 40 participants have commenced treatment.
For more information on the HIT-CF project, please visit https://www.hitcf.org.
About Fair Therapeutics
Fair Therapeutics (Fair TX) is a privately held, clinical-stage biopharmaceutical company developing personalized treatments for cystic fibrosis (CF). Diponecaftor, the company’s innovative CFTR triple modulator therapy, combined with its companion diagnostic based on laboratory-grown organoids, aims to address the unmet needs of PwCF with rare and ultra-rare variants. Committed to fair medicine principles, Fair TX strives to ensure fair value and equal access to treatment. Founded in 2021, the company collaborates with industry, academic research institutions, healthcare professionals, and patient advocacy groups to advance its mission.
For more information, visit www.fairtherapeutics.com or contact:
Media Contact:
Anne van Loon
Acting CEO
+31 683 087 289
info@fairtherapeutics.com
Press Release
Fair Therapeutics B.V. Announces Final Results Choices HIT-CF Trial: Clinical Effect Proportional To In-Vitro Effect
Utrecht, The Netherlands, 20 October 2025 – The HIT-CF Consortium (www.hitcf.org) presented its final results on the evaluation of new CFTR-modulator drugs to the European Commission which funded the project under the European Union’s Horizon 2020 research and innovation program (755021).
The clinical effect of the CFTR modulator combination Dirocaftor-Posenacaftor-Nesolicaftor, as licensed by Fair Therapeutics (www.fairtherapeutics.com) was proportional to the in vitro effects in people with cystic fibrosis (PwCF) with all classes of CFTR gene (and ultra rare) variants. In a placebo-controlled double blinded study, changes in percentages predicted FEV1 ranged from -12% up to +22% percentage points with concordant changes in sweat chloride levels and patient reported outcomes (CFQ-R). In vitro responses were measured in organoids of over 500 pwCF from 16 different European countries using the forskolin induced swelling (FIS) assay.
The results strongly underline the earlier supporting statement of the European Medicines Agency that the FIS assay is a reproducible ex vivo biomarker with strong biological rationale. They also support the use of FIS to: 1) pre-select individuals for clinical trials; and 2) select responders in vitro among PwCF with rare variants not considered in commercial clinical trials with CFTR modulators.
The study also shows promising clinical effects of the new CFTR modulator combination Dirocaftor-Posenacaftor-Nesolicaftor of Fair Therapeutics as first-line treatment in PwCF who show responsiveness in the FIS assay, with a favorable safety profile.
The European Commission strongly supports the further development of both biomarker-driven (individualized) prescription of disease-modifying drugs in chronic diseases in general through cost-effective precision medicine approaches, as well as the further development of the new CFTR modulator combination for PwCF worldwide.
Professor Dr Kors van der Ent, coordinator of the HIT-CF project said: ‘We are really thrilled about the results of our project. Despite all hurdles during the pandemic and changing industry partners, the entire European CF community showed perseverance and dedication to realize new treatments for PwCF.
Mrs Anne van Loon, CEO of Fair Therapeutics stated: ‘FAIR Therapeutics is proud to show the results of their new modulator combination. Around 45,000 diagnosed people with CF do not have access to a potentially life-changing treatment. We are determined to set next steps in the development of this combination and complete our mission to transform CF treatment.’
Mrs Hilde De Keyser, CEO of CF Europe, the federation of national and regional patient associations of PwCF in Europe mentioned: ‘The patient community was actively involved in the HIT-CF project and we strongly support the goal to realize treatment for patients with ultra-rare mutations and in underserved areas.’
The HIT-CF Consortium consists of the University Medical Center Utrecht (The Netherlands) (coordinator); the KU Leuven, Belgium; Faculdade de Ciências da Universidade de Lisboa, Portugal; The European Cystic Fibrosis Society, Aarhus (Denmark), CF Europe, Fair Therapeutics B.V., Utrecht (The Netherlands), HUB Organoids, Utrecht (The Netherlands), Julius Clinical, Utrecht (The Netherlands), and Patergus – Biotechsubsidy, Aalter, Belgium.
Fair Therapeutics (Fair TX) is a privately held, clinical-stage biopharmaceutical company developing accessible, personalized treatments for Cystic Fibrosis.
Cystic Fibrosis is a genetic life-shortening disorder affecting the lungs, digestive system, and other organs. It is caused by variants in the CFTR gene, leading to thick, sticky mucus buildup. This clogs airways, traps bacteria, leading to progressive loss of lung function and also disrupts digestion. Without CFTR modulator therapies median survival is limited to early adulthood.
Media Contact:
Anne van Loon
CEO
info@fairtherapeutics.com
Press Release
Fair Therapeutics B.V. Announces Full Enrollment in Phase IIb CHOICES Trial Evaluating Novel CFTR Modulator Therapy for People with Cystic Fibrosis with Ultra-Rare Variants
Utrecht, The Netherlands, 8 January 2025 – Fair Therapeutics B.V. (Fair TX), a clinical-stage biopharmaceutical company focused on personalized treatments for cystic fibrosis (CF), today announced the full enrollment of its Phase IIb clinical trial, CHOICES (NCT06468527). The trial aims to assess the efficacy and safety of Fair TX’s novel Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) triple modulator therapy—Diponecaftor (Dirocaftor/Posenacaftor/Nesolicaftor)—in adults with ultra-rare CF variants who currently cannot benefit from any disease-modifying treatment. The CHOICES trial is a pivotal step in the company’s mission to address the high unmet needs of people with cystic fibrosis (PwCF). Results of the trial are expected mid-2025.
The trial, a double-blinded cross-over trial, began in June 2024, and has enrolled 40 adult patients (18+) from 9 European countries. All participants were pre-selected using the innovative organoid test, which uses laboratory-grown organoids from patients’ own cells to predict clinical response to the therapy in the lab.
Key objectives of the CHOICES trial include:
Evaluating efficacy: The trial will assess the predicted clinical impact of Fair TX’s CFTR modulators in PwCF identified through their organoid response.
Focusing on ultra-rare variants: The trial aims to demonstrate that Diponecaftor is effective in treating ultra-rare CF variants, a patient population with limited treatment options.
Validating the organoid model: Data from the trial will be compared with results from the earlier Human Individualized Therapy of CF (HIT-CF) Organoid Study (NTR7520), which tested CFTR modulators on organoids from over 500 European PwCF with rare variants. This comparison will further validate the use of organoids as a reliable predictive tool to preselect PwCF for the treatment.
The CHOICES trial is being executed by the HIT-CF Europe consortium, a collaborative effort supported by the EU Horizon 2020 initiative. The consortium includes academic research institutions, not-for-profit organizations, contract research organizations (CROs), biopharma companies developing CF therapies, and supporting service providers (click here for the full list of consortium partners). Fair TX’s Co-Founder, Dr. Kors van der Ent, chairs the HIT-CF Europe consortium, playing a pivotal role in leading the trial.
Dr. Kors van der Ent, Co-Founder of Fair TX, commented:
“We are thrilled to have completed enrollment for the CHOICES trial, which represents a significant milestone for Fair TX and the cystic fibrosis community. By focusing on ultra-rare CF variants and using organoid-based diagnostics, we are advancing personalized medicine and bringing much-needed hope to PwCF who have had limited or no treatment options. We look forward to sharing the results of this groundbreaking trial.”
Anne van Loon, Acting CEO of Fair TX, added:
“Completing enrollment in the CHOICES trial highlights our commitment to addressing the unmet needs of people with ultra-rare CF variants. This is an exciting time for Fair TX as we continue to demonstrate the potential of our personalized approach to treatment. We are deeply grateful to the patients, families, and clinical teams who have made this milestone possible.”
The Phase IIb CHOICES trial is being conducted at 15 clinical centers across Europe. The final patient has now been enrolled, and all 40 participants have commenced treatment.
For more information on the HIT-CF project, please visit https://www.hitcf.org.
About Fair Therapeutics
Fair Therapeutics (Fair TX) is a privately held, clinical-stage biopharmaceutical company developing personalized treatments for cystic fibrosis (CF). Diponecaftor, the company’s innovative CFTR triple modulator therapy, combined with its companion diagnostic based on laboratory-grown organoids, aims to address the unmet needs of PwCF with rare and ultra-rare variants. Committed to fair medicine principles, Fair TX strives to ensure fair value and equal access to treatment. Founded in 2021, the company collaborates with industry, academic research institutions, healthcare professionals, and patient advocacy groups to advance its mission.
For more information, visit www.fairtherapeutics.com or contact:
Media Contact:
Anne van Loon
Acting CEO
+31 683 087 289
info@fairtherapeutics.com