[CAS NO. 1448867-41-1]  Siremadlin

Siremadlin (NVP-HDM201) is an imidazolopyrrolidinone analogue, showing a very advantageous in vivo profile. NVP-HDM201 has recently entered Phase 1 clinical trials in cancer patients ^[2] . Constitutive PB mutagenesis in Arf ^−/− mice provides a collection of spontaneous tumors with characterized insertional genetic landscapes. Tumors are allografted in large cohorts of mice to assess the pharmacologic effects of Siremadlin (NVP-HDM201). Sixteen out of 21 allograft models are sensitive to Siremadlin (NVP-HDM201) but ultimately relapse under treatment. A comparison of tumors with acquired resistance to Siremadlin (NVP-HDM201) and untreated tumors identified 87 genes that are differentially and significantly targeted by the PB transposon ^[1] . Siremadlin (NVP-HDM201) administered either daily at a low dose or once at a high dose revealed a differentiated engagement of the p53 molecular response. In contrast to the daily low dose treatment regimen, the single high dose Siremadlin (NVP-HDM201) regimen results in a rapid and dramatic induction of p53-dependent PUMA expression and apoptosis. This is consistent with the finding that a single high dose Siremadlin (NVP-HDM201) treatment, administered orally or intravenously, results in a robust and sustained tumor regression. Overall, both daily and once every 3 weeks dosing regimen shows comparable long term efficacy in preclinical studies. The ongoing clinical trial is currently designed to compare both dosing regimens with regard to efficacy and tolerability ^[3] .

MCE has not independently confirmed the accuracy of these methods. They are for reference only.