Levosimendan is a vasodilator used in the treatment of acute heart failure. In the present study, the effect of hepatic impairment on the pharmacokinetics of levosimendan and its 2 metabolites, OR-1855 and OR-1896 (pharmacologically active), was investigated in 12 healthy subjects and 12 subjects with moderate hepatic impairment due to alcoholic cirrhosis of the liver but with no heart failure. In addition, the effect of acetylator status on the pharmacokinetics of levosimendan, OR-1855, and OR-1896 was evaluated. Safety and tolerability of levosimendan were also assessed. Levosimendan was given as an intravenous infusion of 0.1 microg/kg/min for 24 hours. Levosimendan showed similar C(max), AUC, and elimination half-life (t(1/2)), with a mean (+/-SEM) t(1/2) of 0.9 +/- 0.0 hours in healthy subjects and 0.8 +/- 0.1 hours in hepatically impaired subjects, respectively (not significant). The t(1/2) of OR-1855 was 61 +/- 5 hours in healthy subjects and 82 +/- 3 hours (P < .01) in subjects with hepatic impairment. The t(1/2) of OR-1896 was 62 +/- 5 hours and 91 +/- 5 hours (P < .01), respectively. However, the AUCs of OR-1855 and OR-1896 were similar in healthy volunteers and hepatically impaired subjects. The effect of acetylator status was seen as higher C(max) and AUC of OR-1855 in slow acetylators. Correspondingly, higher C(max) and AUC of OR-1896 were observed in rapid acetylators. Levosimendan was well tolerated in both study groups. In conclusion, the pharmacokinetics of the parent drug levosimendan was unaltered in subjects with moderate hepatic impairment, whereas the elimination of the metabolites was prolonged. However, because the maximum duration of levosimendan infusion is 24 hours, dosing adjustments of levosimendan may not be required in subjects with impaired hepatic function.
We report the discovery of a novel nonsteroidal dual-action compound, ODM-204, that holds promise for treating patients with castration-resistant prostate cancer (CRPC), an advanced form of prostate cancer characterised by high androgen receptor (AR) expression and persistent activation of the AR signaling axis by residual tissue androgens. For ODM-204, has a dual mechanism of action. The compound is anticipated to efficiently dampen androgenic stimuli in the body by inhibiting CYP17A1, the prerequisite enzyme for the formation of dihydrotestosterone (DHT) and testosterone (T), and by blocking AR with high affinity and specificity. In our study, ODM-204 inhibited the proliferation of androgen-dependent VCaP and LNCaP cells in vitro and reduced significantly tumour growth in a murine VCaP xenograft model in vivo. Intriguingly, after a single oral dose of 10-30 mg/kg, ODM-204 dose-dependently inhibited adrenal and testicular steroid production in sexually mature male cynomolgus monkeys. Similar results were obtained in human chorionic gonadotropin-treated male rats. In rats, leuprolide acetate-mediated (LHRH agonist) suppression of the circulating testosterone levels and decrease in weights of androgen-sensitive organs was significantly and dose-dependently potentiated by the co-administration of ODM-204. ODM-204 was well tolerated in both rodents and primates. Based on our data, ODM-204 could provide an effective therapeutic option for men with CRPC.
Binding of steroid hormones to their cognate receptors regulates the growth of most prostate and breast cancers. We hypothesized that CYP11A inhibition might halt the synthesis of all steroid hormones, since CYP11A is the only enzyme that catalyses the first step of steroid hormone biosynthesis. We speculated that a CYP11A inhibitor could be administered safely provided that the steroids essential for life are replaced. Virtual screening and systematic structure-activity relationship optimization were used to develop ODM-208, the first-in-class, selective, non-steroidal, oral CYP11A1 inhibitor. Safety of ODM-208 was assessed in rats and Beagle dogs, and efficacy in a VCaP castration-resistant prostate cancer (CRPC) xenograft mouse model, in mice and dogs, and in six patients with metastatic CRPC. Blood steroid hormone concentrations were measured using liquid chromatography-mass spectrometry. ODM-208 binds to CYP11A1 and inhibited its enzymatic activity. ODM-208 administration led to rapid, complete, durable, and reversible inhibition of the steroid hormone biosynthesis in an adrenocortical carcinoma cell model in vitro, in adult non-castrated male mice and dogs, and in patients with CRPC. All measured serum steroid hormone concentrations reached undetectable levels within a few weeks from the start of ODM-208 administration. ODM-208 was well-tolerated with steroid hormone replacement. The toxicity findings were considered related to CYP11A1 inhibition and were reversed after stopping of the compound administration. Steroid hormone biosynthesis can be effectively inhibited with a small-molecule inhibitor of CYP11A1. The findings suggest that administration of ODM-208 is feasible with concomitant corticosteroid replacement therapy.
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