MGC026

July 23, 2026: MacroGenics, Inc. (NASDAQ: MGNX) said interim Phase 1 results from its ongoing first-in-human study of MGC026, a B7-H3–directed antibody-drug conjugate in advanced solid tumors, were accepted for poster presentation at the ESMO 2026 Congress (Oct. 23–27, 2026; Madrid). The dose-escalation portion (1–9 mg/kg q3W) was completed in 4Q 2025, and 7.5 mg/kg q3W is being evaluated in four expansion cohorts: recurrent/metastatic squamous cell carcinoma of the head and neck (SCCHN), endometrial cancer, melanoma, and soft tissue sarcoma.

In the SCCHN cohort (Simon’s two-stage design; planned n=40), the study met the pre-specified Stage 1 response threshold and is now enrolling Stage 2. As of July 8, 2026, 74 patients had been enrolled across escalation and expansion; no interstitial lung disease or ocular toxicity had been reported, and evidence of anti-tumor activity was observed across several indications.

Upcoming catalysts at ESMO 2026: MGC026 Phase 1 poster (1020P) on Oct. 23, 2026, and a Phase 2 LINNET poster (1278P) evaluating lorigerlimab (PD-1 × CTLA-4 DART molecule) in advanced gynecologic cancers on Oct. 26, 2026.