Description: Encequidar mesylate (HM30181; HM-30181A; Oraxol), the mesylate salt of encequidar, is a novel, highly specific, and orally bioavailable inhibitor of P-glycoprotein (P-gp), which is an adenosine triphosphate (ATP)-binding cassette (ABC) transporter. It was designed to improve the oral bioavailability of drugs that are
P-gp substrates that can be pumped out of cells by P-gp,
resulting in drug resistance. The combination of oral paclitaxel and encequidar is being developed for cancer treatment. Paclitaxel cannot be administered orally, because it is a substrate of the P-glycoprotein (P-gp), and the bioavailability of paclitaxel is improved when oral paclitaxel is
administered with the highly specific, potent P-gp inhibitor encequidar. Oral paclitaxel and encequidar is the first world taxane to demonstrate superiority in radiologically confirmed tumor response rate, with reduced neuropathy and alopecia compared to IV paclitaxel in women with metastatic breast cancer. Encequidar was supported by FDA in March
2021 for the new drug application for combination with oral paclitaxel
in the treatment of patients with metastatic breast cancer. Encequidar showed the highest potency
(IC(50)=0.63nM) among several MDR1 inhibitors, including cycloporin A,
XR9576, and GF120918, and effectively blocked transepithelial transport
of paclitaxel in MDCK monolayers (IC(50)=35.4nM). Encequidar is
currently under clinical trials.
References:
[1]. Bauer F, et al. Interaction of HM30181 with P-glycoprotein at the murine blood-brain barrier assessed with positron emission tomography. Eur J Pharmacol. 2012 Dec 5;696(1-3):18-27.
[2]. Kim TE, et al. Effects of HM30181, a P-glycoprotein inhibitor, on the pharmacokinetics and pharmacodynamics of loperamide in healthy volunteers. Br J Clin Pharmacol. 2014 Sep;78(3):556-64.
[3]. Sustained Increase in the Oral Bioavailability of Loperamide after a Single Oral Dose of HM30181, a P-glycoprotein Inhibitor, in Healthy Male Participants. Basic Clin Pharmacol Toxicol. 2013 Jul 6. doi: 10.1111/bcpt.12108.
Related CAS #: 849675-66-7 (free base) 849675-88-3 (HCl) 849675-87-2 (mesylate)