ME3183, a novel phosphodiesterase-4 inhibitor, exhibits potent anti-inflammatory effects and is well tolerated in a non-clinical study.

Phosphodiesterase 4 (PDE4) inhibitors are expected to exhibit efficacy against inflammatory diseases due to their broad pharmacological activity. The launched PDE4 inhibitors apremilast, crisaborole, and roflumilast have not exhibited sufficient inhibitory potential due to poor margins of effectiveness and tolerability. In this report, we describe the non-clinical efficacy, brain translocation, and vomit-inducing effects of ME3183 compared with apremilast. ME3183 showed extensive cytokine suppression in vitro studies using human peripheral blood mononuclear cells and T cells. ME3183 also significantly suppressed skin inflammation in a chronic oxazolone-induced dermatitis model and showed antipruritic effects in a substance P-induced mouse pruritus model. In these in vitro and in vivo studies, ME3183 also significantly suppressed cytokines, and focusing on tumor necrosis factor-α as a psoriasis-related cytokine and interleukin-4 as an atopic dermatitis-related cytokine, ME3183 potently inhibited both cytokines. ME3183 showed in vivo efficacy at lower doses than apremilast. The brain distribution of ME3183 was sufficiently low in mice and rats. The effective dose of ME3183 for emesis was similar to that of apremilast in ferrets. Given its high-potency inhibitory effects, ME3183 would have a wide margin of efficacy and tolerability. These wide margins demonstrate the effectiveness of ME3183 in treating many inflammatory diseases, such as psoriasis and atopic dermatitis. An on-going phase 2 trial is expected to further demonstrate the efficacy and safety of ME3183.

The phosphodiesterase 4 inhibitor AA6216 suppresses activity of fibrosis-specific macrophages.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a form of chronic, progressive fibrosing interstitial pneumonia of unknown cause, with a poor prognosis. We previously showed the antifibrotic effects of a novel phosphodiesterase 4 (PDE4) inhibitor, AA6216. In this study, we examined the effect of AA6216 on the pulmonary accumulation of segregated-nucleus-containing atypical monocytes (SatMs), which produce tumor necrosis factor (TNF)-α and are involved in murine lung fibrosis. METHODS: Mice were treated with bleomycin intratracheally at day 0 and either 10 mg/kg AA6216, 100 mg/kg nintedanib, or vehicle orally once daily from day 0 to 8. On day 9, we isolated the bronchoalveolar lavage fluid and analyzed the SatM ratio. In addition, we evaluated the effect of AA6216 on TNF-α production from SatMs isolated from murine bone marrow. RESULTS: AA6216, and not the antifibrotic agent nintedanib, significantly suppressed the pulmonary accumulation of SatMs (AA6216: 68.3 ± 5.4%, Nintedanib: 129.8 ± 19.7%). Furthermore, AA6216 dose-dependently inhibited the production of TNF-α by SatMs. CONCLUSIONS: AA6216 suppresses pathogenic SatMs in the lung, which contributes to its antifibrotic effects.

A novel phosphodiesterase 4 inhibitor, AA6216, reduces macrophage activity and fibrosis in the lung.

Idiopathic pulmonary fibrosis (IPF) is an intractable disease with poor prognosis, and therapeutic options are limited. While the pathogenic mechanism is unknown, cytokines, such as transforming growth factor (TGF)-ß, and immune cells, such as monocytes and macrophages, that produce them, seem to be involved in fibrosis. Some phosphodiesterase 4 (PDE4) inhibitors reportedly have anti-fibrotic potential by acting on these disease-related factors. Therefore, we evaluated the effect of a novel PDE4 inhibitor, AA6216, on nonclinical IPF-related models and samples from IPF patients. First, we examined the inhibitory effect of AA6216 on the production of TGF-ß1 from a human monocytic cell line, THP-1. Second, we analyzed the impact of AA6216 on TNF-α production by human alveolar macrophages collected from patients with IPF. Finally, we investigated the anti-fibrotic potency of AA6216 on bleomycin-induced lung fibrosis in mice. We found that AA6216 significantly inhibited TGF-ß1 production by THP-1 cells. It also significantly suppressed TNF-α production by alveolar macrophages from patients with IPF. In the mouse model of bleomycin-induced pulmonary fibrosis, therapeutic administration of AA6216 significantly reduced fibrosis scores, collagen-stained areas, and TGF-ß1 in bronchoalveolar lavage fluid. AA6216 may represent a new agent for the treatment of IPF with a distinct mechanism of action from that of conventional anti-fibrotic agents.

NBRI17671, a new antitumor compound, produced by Acremonium sp. CR17671.

The interaction between the receptor for advanced glycation end-product (RAGE) and amphoterin has an important role in tumor growth and metastasis. Because the abrogation of the interaction results in the inhibition of the tumor growth and metastasis, we designed a screening system for an inhibitor of the interaction between RAGE and amphoterin. In the course of our screening of the inhibitor, we isolated a novel natural compound NBRI17671 (1) from the fermentation broth of Acremonium sp. CR17671. We also modified 1 into a more active NBRI17671al (2). Although 1 at 50 g ml(-1) weakly inhibited binding of various cells to amphoterin, 2 at 50 g ml(-1) inhibited it by >50% of control. Compound 2 effectively inhibited the tumor growth of glioma and lung tumor xenografts in mice at 25 mg kg(-1). Furthermore, 2 was found to downregulate mitogen-activated protein kinase (MAPK) activity in the tumor cells.

Pharmacological characterization and feeding-suppressive property of FMS586 [3-(5,6,7,8-tetrahydro-9-isopropyl-carbazol-3-yl)-1-methyl-1-(2-pyridin-4-yl-ethyl)-urea hydrochloride], a novel, selective, and orally active antagonist for neuropeptide Y Y5 receptor.

We evaluated the pharmacological profiles of FMS586 [3-(5,6,7,8-tetrahydro-9-isopropyl-carbazol-3-yl)-1-methyl-1-(2-pyridin-4-yl-ethyl)-urea hydrochloride], a novel tetrahydrocarbazole derivative as a neuropeptide Y (NPY) Y5 receptor antagonist. This compound showed a highly selective in vitro affinity for Y5 (IC(50) = 4.3 +/- 0.4 nM) relative to other NPY receptor subtypes like Y1 or Y2. Its binding to Y5 was found to be fully antagonistic from cyclic AMP accumulation assays in human embryonic kidney 293 cells. Pharmacokinetic analysis revealed sufficient oral availability and brain permeability of this compound accompanied with clear dose relation. We attempted to assess the selectivity of FMS586 and, thereby, to infer the physiological role of Y5 in the following feeding experiments in normal rats. An intracerebroventricular injection of NPY and Y5-selective agonist peptide induced acute and robust feeding responses in satiated rats, and prior administration of FMS586 at the doses from 25 to 100 mg/kg clearly inhibited these responses by approximately 55 and 90%, respectively. This compound also showed dose-dependent but transient suppression in natural feeding models of both overnight fasting-induced hyperphagia and spontaneous daily intake. FMS586 did not modulate food intake induced by the topical injection of norepinephrine, galanin, or gamma-aminobutyric acid receptor agonist muscimol to the paraventricular nucleus. In addition, we confirmed the Y5-specific activity profile of FMS586 by immunohistochemical analysis. Taken together, we propose not only that our compound potentially expresses specific blockade of central Y5 signals but also that Y5 receptor would certainly contribute to physiological regulation of food intake in normal rats, as suggested from its origin.

Endocrinological properties of two novel nonsteroidal progesterone receptor modulators, CP8816 and CP8863.

We have isolated PF1092A, B, and C, novel nonsteroidal progesterone ligands with preferential affinity for the progesterone receptor, from fermentation broth of a fungus [Tabata Y, Miike N, Hatsu M, Kurata Y, Yaguchi T, Someya A, Miyadoh S, Hoshiko S, Tsuruoka T, and Omoto S (1997) J Antibiot 50:304-308; Tabata Y, Hatsu M, Kurata Y, Miyajima K, Tani M, Sasaki T, Kodama Y, Tsuruoka T, and Omoto S (1997) J Antibiot 50:309-313]. The original skeleton of PF1092, tetrahydronaphthofuranone, was modified synthetically to produce a new skeleton, tetrahydrobenzindrone, and in the present study, biological activities of two derivatives, CP8816 [(4aR,5R,6R,7R)-6-(N,N-dimethylaminocarbonyl)oxy-7-methoxy-4a,5,6,7-tetrahydro-1,3,4a,5-tetramethylbenz[f]indol-2(4H)-one] and CP8863 [(4aR,5R,6R,7R)-7-hydroxy-6-(N-methylcarbamoyl)oxy-4a,5,6,7-tetrahydro-1,3,4a,5-tetramethylbenz[f]indol-2(4H)-one], were investigated. Both CP8816 and CP8863 demonstrated selective binding to progesterone receptor and partial agonistic activity in a progesterone-dependent endogenous alkaline phosphatase expression assay. In the Clauberg-McPhail test, progestational activity of CP8816 (0.1 mg/kg s.c. or 10 mg/kg p.o.) was comparable to that of progesterone (0.15 mg/kg s.c.), and oral administration of CP8863 at more than 1.0 mg/kg also exerted similar effects. Anti-estrogenic (antiuterotropic) activity was confirmed on daily oral application of more than 0.1 mg/kg CP8863 for 3 days by inhibition of estrogen-dependent uterine wet weight gain in ovariectomized rats. CP8816 also exerted antiuterotropic activity at doses of 10 mg/kg (s.c.) and 100 mg/kg (p.o.). These results indicate that our nonsteroidal progesterone ligands have affinity for the progesterone receptor with partial progestational activity in vitro and clear progestational effects in vivo. Thus, these progesterone receptor modulator profiles suggest that CP8863 and CP8816 are good candidate compounds for treatment of hormone-dependent gynecological disorders.

CP8668, a novel orally active nonsteroidal progesterone receptor modulator with tetrahydrobenzindolone skeleton.

We investigated progestational activity of a new nonsteroidal compound, CP8668, ((4aR,5R,6R,7R)-7-methoxy-6-(N-propylaminocarbonyl)oxy-4a,5,6,7-tetrahydro-1,3,4a,5-tetramethylbenz[f]indol-2(4H)-one). CP8668 showed selective affinity for human progesterone receptor equal in strength to other steroidal progestins. CP8668 showed no significant affinity for human glucocorticoid receptor or human estrogen receptor and very weak affinity for rat androgen receptor. In endogenous and exogenous progesterone-dependent enzyme expression assays using human mammary carcinoma T47D, CP8668 showed mixed agonist-antagonist activity. However, in a rabbit endometrial transformation test, CP8668 showed good progestational activity following s.c. and p.o. administration. These results suggest that CP8668 is a selective and orally active progesterone receptor modulator, which shows mixed agonist-antagonist activity in in vitro transcription tests and agonist activity in endometrial transformation assays in rabbits, and that it is potentially a promising lead compound for a new type of orally active progesterone receptor modulator.

In vitro and in vivo characterization of novel nonsteroidal progesterone receptor antagonists derived from the fungal metabolite PF1092C.

We studied the pharmacological effects of novel nonsteroidal progesterone receptor antagonists CP8661 and CP8754, which were synthesized from the fungal metabolite PF1092C. CP8661 possess a tetrahydrobenzindolone skeleton and CP8754 possess a tetrahydronaphthofuranone skeleton. In binding assays for steroid receptors, CP8661 and CP8754 inhibited [(3)H]-progesterone binding to human progesterone receptors (hPR), though they are less potent than RU486. CP8661 also showed moderate affinity to rat androgen receptors (rAR), although CP8754 did not. Neither compound showed affinity to human glucocorticoid receptors (hGR) or human estrogen receptors (hER). In exogeneous and endogeneous PR-dependent enzyme expression assays using human mammary carcinoma T47D, CP8661 and CP8754 showed pure antagonistic activity. In a rabbit endometrial transformation test, CP8661 and CP8754 showed anti-progestational activity by s.c. administration in a dose-dependent manner; meanwhile, these compounds showed no progestational activity at the same dose. These results suggested that CP8661 and CP8754 are in vivo effective pure progesterone receptor antagonists and presented the possibility of synthesizing pure progesterone receptor antagonists from both tetrahydronaphthofuranone and tetrahydrobenzindolone skeletons.

Priming effects of novel nonsteroidal progesterone receptor modulators CP8816 and CP8863 on the development of adenomyosis in the mouse uterus.

The possibility of therapeutic application of novel nonsteroidal progesterone receptor modulators CP8816 and CP8863 for preventing the development of uterine adenomyosis was investigated in mice. First priming effects of CP8816 on 17beta-estradiol (E2)-induced cell division in uterine tissues were examined. As a result, pretreatment with CP8816 or progesterone significantly suppressed the elevation of the mitotic activity in the luminal epithelial cells of mice treated with E2 later. Priming with CP8816 had little effect on the stromal cells, but progesterone priming caused an increase of stromal mitotic activity in mice treated with E2 later. To evaluate the inhibitory effect of these compounds on the development of adenomyosis induced experimentally by pituitary grafting, 7-week-old female mice were isografted with a single anterior pituitary in the uterus and divided into four groups. Two groups of mice were given daily subcutaneous injections of 1 mg of CP8816 or the vehicle alone for 6 weeks from the day after the grafting. Remaining two groups of mice were given oral administration of 1 mg of CP8863 or the vehicle only for 5 weeks starting one week after the grafting. The incidence of adenomyosis was significantly lower in the groups of mice treated with CP8816 and CP8863 than in the respective control groups. The mechanism by which CP compounds inhibited the development of adenomyosis might be related to their priming effects, i.e., their inhibitory effect on epithelial cell division and lack of effect on stromal cell division after subsequent exposure to E2.