Maze’s MZE829 Cuts Proteinuria by Up to 61.8%, Challenges Vertex’s Inaxaplin
Oral APOL1 inhibitor MZE829 achieved a mean 35.6% reduction in urinary albumin-to-creatinine ratio at week 12 and up to 61.8% reduction in focal segmental glomerulosclerosis patients without serious adverse events. These Phase II results pit Maze’s candidate directly against Vertex’s inaxaplin, which yielded a 47.6% proteinuria drop at 13 weeks.
1. Phase II Trial Results for MZE829
In the open-label HORIZON basket trial, oral APOL1 inhibitor MZE829 delivered a mean 35.6% reduction in uACR at week 12 across broad APOL1-mediated kidney disease patients. Subgroup analysis showed a 61.8% mean uACR drop in focal segmental glomerulosclerosis patients and a 48.6% reduction in non-diabetic APOL1-mediated kidney disease patients. No serious or severe treatment-related adverse events were reported.
2. Comparison with Vertex’s Inaxaplin
Vertex’s Phase IIa candidate inaxaplin achieved a 47.6% proteinuria reduction at 13 weeks in APOL1-mediated kidney disease with FSGS, placing it between MZE829’s overall and FSGS subgroup outcomes. Both drugs target the APOL1 pathway, intensifying competition in precision therapies addressing podocyte function and channel inhibition.
3. Market and Stock Impact
Maze’s stock plunged 18.3% on March 25 following its annual financial report and trial data release, closing at $29.77 intraday. The strong efficacy data for MZE829 raises questions about Vertex’s market share in its kidney disease franchise and may prompt strategic adjustments in its ongoing Phase II/III program.