MBS309 / Beijing Mabworks Biotech - LARVOL DELTA

Preclinical characterization of MBS309, a conditionally active PD-1-dependent IL-2 mutation with significantly superior anti-tumor efficacy with safety (AACR 2024) - "In our in vivo tumor murine models, 1mg/kg MBS309 showed much better suppression effect in MC38/hPD-L1 tumor than 1mg/kg RG6279 analog and Pembrolizumab (1mg/kg) combination with wild type IL-2 (0.1mg/kg); And MBS309 at the dosage of 5mg/kg can significantly inhibit tumor growth in PD-1 resistant Pan-02 xenograft models without any side-effects observed, while RG6279 analog at the dosage of 5mg/kg induced severe body reduction of the mice and resulted in 80% (4/5) mice death after two dosages...20mg/kg of MBS309 was well tolerated in mouse, while 10mg/kg of RG6279 analog or PF-07209960 analog show severe toxicity and resulted in death of all the mice...And it shows much higher anti-tumor effect compared to anti-PD-1/-L1 antibodies alone in both PD-1 sensitive and resistant tumor models. MBS309 has demonstrated a favorable safety profile and highly anti-tumor activities in vivo, which has the potential to supporting its clinical development for the treatment of cancer."

IO biomarker • Preclinical • Oncology • CD8 • IL2 • PD-1

Preclinical characterization of MBS309, a PD-1-targeted and α-biased IL-2, demonstrating robust anti-tumor activity and a favorable safety profile (AACR 2026) - "It consists of an α-biased IL-2 variant fused to theC-terminus of pembrolizumab (Keytruda). Pharmacodynamicinvestigations revealed the mechanistic basis for this improved therapeutic window:MBS309 induced dampened T cell activation in normal tissues while achieving potentintra-tumoral CD8+ T cell expansion comparable to the benchmark.The compelling preclinical profile of MBS309, characterized by robustanti-tumor efficacy and a favorable safety window, warrants its further clinicalinvestigation as a promising therapeutic candidate for oncology.Disclosures: All the authors are employees from Beijing Mabworks Biotech Co. Ltd"

Preclinical • Oncology • CD8 • IL2