Design and optimization of highly-selective fungal CYP51 inhibitors.

While the orally-active azoles such as voriconazole and itraconazole are effective antifungal agents, they potently inhibit a broad range of off-target human cytochrome P450 enzymes (CYPs) leading to various safety issues (e.g., drug-drug interactions, liver toxicity). Herein, we describe rationally-designed, broad-spectrum antifungal agents that are more selective for the target fungal enzyme, CYP51, than related human CYP enzymes such as CYP3A4. Using proprietary methodology, the triazole metal-binding group found in current clinical agents was replaced with novel, less avid metal-binding groups in concert with potency-enhancing molecular scaffold modifications. This process produced a unique series of fungal CYP51-selective inhibitors that included the oral antifungal 7d (VT-1161), now in Phase 2 clinical trials. This series exhibits excellent potency against key yeast and dermatophyte strains. The chemical methodology described is potentially applicable to the design of new and more effective metalloenzyme inhibitor treatments for a broad array of diseases.

Highly-selective 4-(1,2,3-triazole)-based P450c17a 17,20-lyase inhibitors.

The orally-active CYP17A1 inhibitor abiraterone acetate (AA) decreases adrenal and intratumoral androgen biosynthesis and is an effective agent for the treatment of prostate cancer. Abiraterone potently inhibits both reactions catalyzed by CYP17, the 17α-hydroxylase (hydroxylase) reaction as well as the 17,20-lyase (lyase) transformation. CYP17 hydroxylase inhibition prevents the synthesis of adrenal glucocorticoids and causes an accumulation of circulating mineralocorticoids. As a consequence of potent CYP17 hydroxylase inhibition (i.e., lack of lyase selectivity), AA must be co-administered with the cortisol replacement prednisone and patients may experience the effects of mineralocorticoid excess syndrome (MES). Herein, we describe rationally-designed, CYP17 lyase-selective inhibitors that could prove safer and more effective than abiraterone. Using proprietary methodology, the high-affinity pyridine or imidazole metal-binding group found in current clinical CYP17 inhibitors was replaced with novel, less avid, metal-binding groups in concert with potency-enhancing molecular scaffold modifications. This process produced a unique series of CYP17 lyase-selective inhibitors that included the oral agent 6 (VT-464), now in Phase 2 prostate cancer clinical trials. The chemical methodology described is potentially applicable to the design of new and more effective metalloenzyme inhibitor treatments for a broad array of diseases.

An efficient synthesis of a potent PPARpan agonist.

An efficient synthesis of 2-{4-[({4-{[4-(4-methoxyphenyl)piperazin-1-yl]methyl}-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)thio]phenoxy}-2-methylpropanoic acid (1), a potent PPARpan agonist, is described. The seven-step synthesis, which afforded 1 in 30% overall yield, includes a highly regioselective carbon-sulfur bond formation via coupling of a bishydroxymethylthiazole (3) with 4-hydroxythiophenol, displacement of the remaining alcohol through a three-step telescoped sequence involving an efficient cleavage of an aryl mesylate, and an efficient and practical method of introducing an isobutyric acid fragment.