Monopar Publishes Phase 2 Data Showing ALXN1840 Improves Copper Balance in Wilson Disease Patients

Peer-reviewed data published in Hepatology Communications positions Monopar Therapeutics to advance ALXN1840 (tiomolibdate choline) with a clinical evidence base that directly challenges the adequacy of long-established Wilson disease standard of care, a signal regulatory and clinical development teams at rare-disease manufacturers should read carefully against their own pipeline timelines.

The open-label, single-arm Phase 2 ALXN1840-WD-204 study (NCT04573309) enrolled nine patients across two centres in the United Kingdom and New Zealand. Participants were admitted to a clinical research unit, placed on a copper-controlled diet, and monitored through a pre-treatment baseline period before daily ALXN1840 dosing commenced. The controlled-intake design allowed precise measurement of fecal copper excretion as the primary driver of copper balance change, a methodological point Monopar had previously flagged in a Journal of Hepatology letter addressing baseline-comparison standards in Wilson disease trials.

Key efficacy findings from the publication include a cumulative mean decrease in copper balance of -6.08 mg over 21 days (95% CI: -10.18 mg to -1.98 mg), a mean daily copper balance change of -0.37 mg (p=0.005) during the 15 mg/day treatment period, and approximately a 50% increase in the daily fecal copper output-to-intake ratio versus baseline (p=0.041). Immediate increases in plasma total copper and directly measured non-ceruloplasmin-bound copper were consistent with copper mobilisation and formation of stable albumin tripartite complexes. No serious adverse events were reported.

The patient population carried a mean prior standard-of-care treatment duration of 16 years, yet still presented with mobilisable residual copper, a finding that aligns with data from the completed 48-week Phase 3 trial, where ALXN1840 demonstrated superior copper mobilisation versus standard of care in patients averaging 11 years on existing therapy. For regulatory strategy leads, that cross-study consistency strengthens the benefit-risk narrative ahead of any submission package, particularly given Wilson disease's orphan designation status and the accelerated pathway considerations that accompany it.

Manufacturing and CMC teams supporting rare-disease programmes should note that the fecal-excretion mechanism and albumin tripartite complex formation introduce specific analytical characterisation requirements that will need to be addressed within process validation and release-testing frameworks aligned with ICH Q10 quality system expectations.

The Phase 3 dataset, now reinforced by this Phase 2 publication, will form the evidentiary core of Monopar's regulatory submission package, making the completeness and traceability of that clinical manufacturing record a near-term operational checkpoint.

Source: Monopar Therapeutics Inc. via GlobeNewswire, 19 May 2026.