Our Science

Approach

We have entered a new age in our understanding of the interaction between cells and their surrounding tissue, enabling the discovery of new therapeutic targets for inflammation and fibrosis.

Halo's approach focuses on the inhibition of a critical cell-tissue mediator that is dysregulated in the context of inflammatory and fibrotic disease - Hyaluronan (HA). Our work has shown that inhibiting the synthesis of HA has the potential to safely down-regulate various inflammatory and fibrotic cell-signaling pathways and to drive clinical outcomes in diseases like pulmonary hypertension and pulmonary fibrosis.

Clinical Translation

Leveraging our unique insights into HA and extracellular matrix (ECM) biology, we are developing a new class of hyaluronan-synthesis inhibitors. Our lead program, H1614, is a reformulation of the HA-inhibitor 4-methylumbelliferone or 4-MU.

Together with our collaborators at Stanford University, we recently completed a Phase 2a clinical study of 4-MU in patients with pulmonary hypertension (The SATURN Study - NCT05128929). In addition to confirming safety and tolerability of 4-MU, this study highlighted the potential to drive functional improvements in patients with Group 3 PH. Insights from this study are reinforcing the basis for our proprietary formulation of 4-MU and were presented at ATS in May 2024. The full study results have been accepted for publication in the journal Thorax.

Our team's significant investment in translational research to establish the clinical potential of 4-MU include four investigator-sponsored studies conducted in partnership with Stanford University and the National Institutes of Health.

Phase 1 - Healthy Volunteers https://clinicaltrials.gov/study/NCT02780752

Phase 2 - Pulmonary Hypertension https://clinicaltrials.gov/study/NCT05128929

Phase 2 - Pulmonary Fibrosis https://clinicaltrials.gov/study/NCT06325696

Phase 2 - Primary Sclerosing Cholangitis

https://clinicaltrials.gov/study/NCT05295680

Our Pipeline

About Pulmonary Hypertension

Pulmonary hypertension (PH) is a progressive condition caused by elevated blood pressure in the arteries of the lungs, leading to reduced oxygen exchange, right heart strain and eventual heart failure.[i] Symptoms include breathlessness, fatigue, and dizziness[ii]. PH diagnosis is often delayed and accompanied by comorbidities, with most patients diagnosed between the ages of 60 and 70[iii]. When PH is associated with interstitial lung disease (PH-ILD), the course of disease is often more accelerated, with these patients facing a median survival of just 2 to 5 years.[iv]

Currently, there is only one FDA-approved therapy for PH-ILD,{iv} leaving a significant unmet need for therapies that target the underlying mechanisms of disease progression. New approaches are urgently needed to improve outcomes and quality of life for this vulnerable patient population.

[i] Pulmonary Fibrosis Foundation. Pulmonary Hypertension Related to Interstitial Lung Disease (for Patients). Retrieved from https://www.pulmonaryfibrosis.org/researchers-healthcare-providers/clinical-resources/position-statements/pulmonary-hypertension-related-to-ild-for-patients

[ii] Pulmonary Hypertension Association. Diagnosing Pulmonary Hypertension. Accessed on June 3, 2025 from https://phassociation.org/patients/diagnosis/

[iii] Mount Sinai Health System. (n.d.). Idiopathic pulmonary fibrosis. Mount Sinai Health Library. Retrieved June 3, 2025, from https://www.mountsinai.org/health-library/diseases-conditions/idiopathic-pulmonary-fibrosis

[iv] Nathan, S. D., Stinchon, M. R., Atcheson, S., Simone, L., & Nelson, M. (2025). Shining a spotlight on pulmonary hypertension associated with interstitial lung disease care: The latest advances in diagnosis and treatment. Journal of Managed Care & Specialty Pharmacy, 31(1-a Suppl), S2–S29. https://doi.org/10.18553/jmcp.2025.31.1-a.s2

Relevant Publications

Czepiel K, Nagy N, Panjalingam T, et al. Randomised, placebo-controlled trial of oral hymecromone in adults with pulmonary hypertension Thorax Published Online First: 01 June 2025. doi: 10.1136/thorax-2024-222725

Nagy N, et al. Hymecromone Promotes Longevity and Insulin Sensitivity in Mice. Cells. 2024; 13(20):1727. https://doi.org/10.3390/cells13201727

Rosser, JI, et al. Oral hymecromone decreases hyaluronan in human study participants. J Clin Invest. 2022; 132(9):e157983. https://doi.org/10.1172/JCI157983

Collum SD, et al. Adenosine and hyaluronan promote lung fibrosis and pulmonary hypertension in combined pulmonary fibrosis and emphysema. Dis Model Mech. 2019 May 1;12(5):dmm038711.

Nagy N, et al. Hyaluronan in immune dysregulation and autoimmune diseases. Matrix Biol. 2019;78-79:292-313. doi:10.1016/j.matbio.2018.03.022

Collum SD, et al. Inhibition of hyaluronan synthesis attenuates pulmonary hypertension associated with lung fibrosis. British Journal of Pharmacology. 2017;174(19):3284–301.

Collum SD, et al. Pulmonary Hypertension Associated with Idiopathic Pulmonary Fibrosis: Current and Future Perspectives. Can Respir J. 2017;2017:1430350.

Nagy N, et al. 4-methylumbelliferone treatment and hyaluronan inhibition as a therapeutic strategy in inflammation, autoimmunity, and cancer. Front Immunol. 2015;6:123.

Our Science

Approach

Clinical Translation

About Pulmonary Hypertension

Relevant Publications

Our research adheres to industry standards and regulations