Exhibit 99.1 Hosted key opinion leader event highlighting the important role of the Aryl Hydrocarbon Receptor (AhR) in intestinal inflammation, the unmet medical need in ulcerative colitis, and the potential clinical utility of EQ504, a novel oral AhR modulator EQ504 Phase 1 clinical study initiation planned for mid-2026 LA JOLLA, California, November 13, 2025 – Equillium, Inc. (Nasdaq: EQ), a clinical-stage biotechnology company leveraging a deep understanding of immunobiology to develop novel therapeutics ...