In vivo efficacy of M3258 in a scaffold-based model of the human bone marrow niche. A, Representation of the establishment of the in vivo ceramic scaffold model of the human multiple myeloma bone marrow niche. Overall survival (B) and tumor volume (C) in mice bearing the MM.1S-containing scaffolds that were treated with vehicle or M3258 (10 mg/kg, once daily orally). The P value for the statistical comparison of survival curves of the vehicle and M3258 groups is indicated. Abbreviations: BCP, biphasic calcium phosphate; BMSC, bone marrow–derived stem cells; s.c., subcutaneous.