Lucicebtide/ST101 (C/EBPβ Antagonist) Shows Early Survival Signal in GBM

Lucicebtide (ST101) is a first-in-class peptide antagonist of C/EBPβ designed to suppress the mesenchymal GBM program and reprogram immunosuppressive tumor-associated myeloid cells. In a Phase 2 window-of-opportunity study (NCT04478279), newly diagnosed GBM patients received perioperative lucicebtide then continued lucicebtide with standard chemoradiation (n=9), while recurrent GBM patients received perioperative lucicebtide then monotherapy to progression (n=9). Safety was described as well tolerated without detailed grade ≥3 rates; pharmacodynamic data showed BBB penetration and target engagement, while efficacy signals included ndGBM 18- and 24-month OS of 67% and 44% versus historical Stupp-style 18- and 24-month OS around 39–45% and 26–31%, and rGBM mPFS 4.0 months/mOS 12.3 months versus common salvage benchmarks often near mPFS 2–4 months and mOS 8–9 months.