Lucicebtide, also known as ST101, is Sapience Therapeutics' first-in-class peptide antagonist of CCAAT/enhancer-binding protein beta (C/EBPβ), a transcription factor that drives tumor aggressiveness, immune evasion, and therapy resistance in glioblastoma. The drug is designed to cross the blood-brain barrier and shut down the C/EBPβ-driven mesenchymal program that makes GBM so resistant to standard chemoradiation.
At ASCO 2026, Sapience reported updated Phase 2 data from a 125-patient program. In newly diagnosed GBM patients treated with lucicebtide plus standard of care, projected median progression-free survival reached 28.4 months versus a 4.0-to-6.9-month historic benchmark, and median overall survival was not yet reached, with six of nine patients alive past 22.3 months. Spatial transcriptomics confirmed on-target activity through negative enrichment of the C/EBPβ regulon and suppression of the mesenchymal GBM transformation; no dose-limiting toxicities or related serious adverse events were reported.
Stories here cover lucicebtide trial readouts and the broader C/EBPβ and brain-penetrant peptide landscape. See #st101, #c-ebp-beta, and #sapience-therapeutics for adjacent threads.
At ASCO 2026, Sapience Therapeutics presented updated Phase 2 data for lucicebtide (ST101), a first-in-class peptide antagonist of the transcription factor C/EBPβ, now studied in 125 patients. In newly diagnosed glioblastoma plus standard of care, projected median PFS reached 28.4 months and median OS was not yet reached, with 6 of 9 patients alive beyond 22.3 months. Spatial transcriptomics confirmed on-target activity through negative enrichment of the C/EBPβ regulon and suppression of mesenchymal transformation, with no dose-limiting toxicities or related serious adverse events.
Sapience Therapeutics' May 21 ASCO 2026 data update on lucicebtide (ST101) — a first-in-class C/EBPβ peptide antagonist — included a specific data point worth surfacing for the Tuesday cycle. In the Phase 2 Window-of-Opportunity study (n=9 evaluable as of April 27 data cutoff), patients with newly diagnosed glioblastoma (ndGBM) treated with lucicebtide plus standard-of-care chemoradiation achieved a projected median progression-free survival of 28.4 months — meaningfully exceeding the 4.0-6.9 month historic benchmark range. Six of nine patients remain alive past 22.3 months against a historical median OS range of 14.6-17.0 months. Median overall survival has not yet been reached. Lucicebtide crossed the blood-brain barrier with confirmed tumor uptake and target engagement via negative enrichment of the C/EBPβ regulon in tumor and myeloid cells. The poster session is scheduled for Monday June 1.
Sapience Therapeutics announced May 22 positive Phase 2 clinical and pharmacodynamic data update from its lucicebtide (ST101) trial in glioblastoma ahead of the ASCO 2026 Annual Meeting (May 29-June 2 Chicago). The Phase 2 Window-of-Opportunity study evaluates lucicebtide alone and in combination with standard-of-care chemoradiation, with dosing both before and after surgical resection. Nine patients were evaluable for analysis; the maturing data show durable progression-free and overall-survival improvements with a well-tolerated safety profile. Lucicebtide is a first-in-class peptide antagonist of CCAAT/enhancer-binding protein β (C/EBPβ) — a transcription factor that drives tumor aggressiveness, immune evasion, and stemness in glioblastoma. The 125-patient program across recurrent GBM monotherapy and newly diagnosed combination cohorts is the largest peptide-mechanism dataset in GBM to date. The Monday June 1 poster session details the efficacy, pharmacodynamics, and safety in newly-diagnosed patients.