---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-25-056215"
form_type: "8-K"
ticker: "ZBIO"
cik: "0001953926"
company_name: "Zenas BioPharma, Inc."
filed_at: "2025-06-04T23:59:59+00:00"
generated_at: "2026-05-20T00:23:25.153489+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Zenas BioPharma updates pipeline timelines; obexelimab Phase 3 IgG4-RD data due year-end 2025

## Summary
- Phase 3 INDIGO trial (IgG4-RD) topline results expected year-end 2025; over 190 patients enrolled.
- Phase 2 MoonStone (RMS) primary endpoint (12-week new T1 Gd+ lesions) data expected early Q4 2025.
- Phase 2 SunStone (SLE) primary endpoint (24-week BICLA) data expected mid-2026.
- Q1 2025 cash of ~$314M; management expects cash runway into Q4 2026.
- Prior Phase 2 IgG4-RD showed 93% ongoing response; SLE optimized exposure effect size 35% vs placebo.

## SEC filing metadata
- accession: 0001104659-25-056215
- form_type: 8-K
- ticker: ZBIO
- cik: 0001953926
- company_name: Zenas BioPharma, Inc.
- filed_at: 2025-06-04T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1953926/000110465925056215/0001104659-25-056215-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1953926/000110465925056215/tm2517068d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-25-056215
- JSON: https://secwatch.observer/filing/0001104659-25-056215.json
- Plain text: https://secwatch.observer/filing/0001104659-25-056215.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.