Supplementary Figure S7 from Palazestrant (OP-1250), A Complete Estrogen Receptor Antagonist, Inhibits Wild-type and Mutant ER-positive Breast Cancer Models as Monotherapy and in Combination

OP-1250 demonstrates potent activity in an ER+ breast cancer intracranial xenograft and outperforms ribociclib. A, Schematic of intracranial xenograft experiment with data shown in B–D. B, Mean and SEM intracranial tumor volume over time with listed treatments as assessed by MRI in an ESR1Y537S ST941 PDX intracranial xenograft model. C, Percent change in intracranial tumor volume of individual animals in listed treatment groups at day 101 or at the last recorded timepoint in the ST941 intracranial xenograft study, normalized to day 1 tumor volume. D, Kaplan–Meier graphs of animal survival over time in listed treatment groups of mice implanted intracranially with the ST941 PDX xenograft. Dosing ended on day 100 of the study in the OP-1250 10 mg/kg group, as indicated by the shaded area. E, Representative intracranial MRIs from ST941-implanted mice with data shown in Figure 6 (see main article) at indicated timepoints and treatment groups. PO=orally.