Aakash Desai, Associate Director, Phase 1 and Precision Oncology Program at UAB O’Neal Comprehensive Cancer Center, shared on LinkedIn:
“Phase 1 dose selection, in real time: MGC026 (B7-H3 ADC) at ESMO 2026
MacroGenics, Inc. presented first-in-human data for MGC026 (poster 1020P, Sanborn et al.), a B7-H3-directed ADC with an exatecan-based TOP1 inhibitor payload (Synaffix linker-payload, DAR 4).
What was reported (data cutoff Sept 1, 2026):
- Dose escalation (n=32, 1–9 mg/kg Q3W, median 4 prior lines): among 17 response-evaluable patients at ≥6 mg/kg, confirmed ORR 29% (5/17), DCR 65%, median DoR 10.2 months
- Expansion dose: 7.5 mg/kg Q3W, chosen because PK showed dose-dependent exposure of the ADC and the unconjugated payload
- R/M head and neck SCC expansion (n=22 evaluable): best ORR 27% (6/22; 4 confirmed + 2 unconfirmed PRs), DCR 64%; 5 of the 6 responses were in HPV-positive disease (5/16)
- Safety across all 85 treated: grade ≥3 TRAEs 51% (neutropenia 27%, anemia 25%), TRAE discontinuation 5%, no grade 5 TRAEs
- No ILD, pneumonitis or ocular toxicity observed
- Next: a front-line MGC026 + pembrolizumab cohort in PD-L1 CPS ≥1 R/M SCCHN planned for early 2027
Interesting to see whether development plans include SCLC, with recent withdrawal of IDXd, a gap needs to be filled?
Source: MacroGenics press release, Oct 23, 2026 (ESMO 2026 poster 1020P).”
Other articles about MGC026 on OncoDaily.