Monopar Therapeutics presented compelling long-term neurological efficacy and safety data for its investigational therapy ALXN1840 (tiomolybdate choline) in Wilson disease at the 150th American Neurological Association Annual Meeting on September 14-15, 2025. The data, delivered by Matthew Lorincz, M.D., Ph.D., Professor of Neurology and Co-Director of the Wilson Disease Center of Excellence at the University of Michigan, demonstrated sustained neurological benefits over an extended treatment period.
Comprehensive Clinical Analysis
The analysis pooled efficacy outcomes from three independent clinical trials involving 255 patients, while safety data included a fourth independent clinical trial with 266 patients. The median treatment duration with ALXN1840 was approximately 2.6 years for both efficacy and safety analyses, providing substantial long-term follow-up data.
The findings build upon recent hepatic and systemic efficacy data presented at the European Association for the Study of the Liver International Liver Congress 2025, collectively demonstrating ALXN1840's potential to address both neurological and hepatic manifestations of Wilson disease.
Sustained Neurological Improvements
The study revealed statistically significant neurologic improvement from baseline on the Unified Wilson Disease Rating Scale Part II (patient-reported symptoms) and Part III (clinician-reported symptoms) that was sustained over 6 years. This sustained benefit represents a significant advancement for Wilson disease patients, who often experience progressive neurological deterioration without effective treatment.
Particularly noteworthy were the crossover benefits observed in patients who transitioned from standard of care to ALXN1840. These patients demonstrated additional neurological improvement, with a majority of patients who had worsened on standard of care showing a reversal of symptoms when treated with ALXN1840.
Psychiatric and Safety Outcomes
Beyond neurological improvements, ALXN1840 demonstrated statistically significant psychiatric improvement from baseline that was sustained over multiple years, as measured by the Brief Psychiatric Rating Scale. This finding is particularly relevant given the psychiatric manifestations commonly associated with Wilson disease.
The therapy's neurological benefits were observed consistently across multiple independent studies, reinforcing the reliability of the treatment effects. From a safety perspective, across more than 645 patient-years of ALXN1840 treatment, less than 1% of patients experienced a drug-related neurological serious adverse event.
Clinical Significance
"These results are very encouraging for Wilson disease patients, including for those already on standard of care treatment," said Dr. Matthew Lorincz, highlighting the potential benefit for patients currently receiving existing therapies who may still experience disease progression.
Monopar Therapeutics, a clinical-stage biopharmaceutical company, is developing ALXN1840 as part of its late-stage Wilson disease program. The company also maintains radiopharmaceutical programs including Phase 1-stage MNPR-101-Zr for imaging advanced cancers, and Phase 1a-stage MNPR-101-Lu and late preclinical-stage MNPR-101-Ac225 for treating advanced cancers.
