HET0016 (Synonyms: N-hydroxy-N'-(4-n-butyl-2-methylphenyl)Formamidine)

IC50: 35 nM for 20-HETE formation in rat renal microsomes

HET0016 is an inhibitor of 20-HETE formation.

20-HETE, a major biologically active cytochrome P450 metabolite of arachidonic acid in the kidney and liver, regulates renal vascular and tubular functions as well as vascular tone in the cerebral circulation.

In vitro: HET0016 showed a high degree of selectivity in inhibiting the formation of 20-HETE in rat renal microsomes. The IC(50) value averaged 35 nM, whereas the IC(50) value for inhibition of the formation of epoxyeicosatrienoic acids averaged 2800 nM. Moreover, in human renal microsomes, HET0016 could potently inhibit the formation of 20-HETE with an IC(50) value of 8.9 nM. In addition, higher HET0016 concentrations could also inhibit the CYP2C9, CYP2D6 and CYP3A4-catalysed substrates oxidation [1].

In vivo: A previous study generated an improved IV formulation of HET0016 with HPβCD. Administration of a single IV dose led to 7-fold higher levels of HET0016 in plasma and 3.6-fold higher levels in tumor than that in IP route. IV treatment with HPβCD-HET0016 decreased tumor growth, and altered vascular kinetics in early and late treatment groups. Moreover, similar growth inhibition was observed in syngeneic GL261 GBM. In addition, survival studies using patient derived xenografts of GBM811, showed prolonged survival to 26 weeks in animals treated with focal radiation, in combination with HET0016 and TMZ [2].

Clinical trial: So far, no clinical study has been conducted.

References:
[1] Miyata, N. ,Taniguchi, K.,Seki, T., et al. HET0016, a potent and selective inhibitor of 20-HETE synthesizing enzyme. British Journal of Pharmacology 133, 325-329 (2001).
[2] Jain M et al.  Intravenous Formulation of HET0016 Decreased Human Glioblastoma Growth and Implicated Survival Benefit in Rat Xenograft Models. Sci Rep. 2017 Jan 31;7:41809.