JTP-117968, a novel selective glucocorticoid receptor modulator, exhibits significant anti-inflammatory effect while maintaining bone mineral density in mice.

Classic glucocorticoids have been prescribed for various inflammatory diseases, such as rheumatoid arthritis, due to their outstanding anti-inflammatory effects. However, glucocorticoids cause numerous unwanted side effects, including osteoporosis and diabetes. Hence, selective glucocorticoid receptor modulators (SGRMs), which retain anti-inflammatory effects with minimized side effects, are among the most anticipated drugs in the clinical field. The assumption is that there are two major mechanisms of action via glucocorticoid receptors, transrepression (TR) and transactivation (TA). In general, anti-inflammatory effects of glucocorticoids are largely due to TR, while the side effects associated with glucocorticoids are mostly mediated through TA. We previously reported that JTP-117968, a novel SGRM, maintained partial TR activity while remarkably reducing the TA activity. In this study, we investigated the anti-inflammatory effect of JTP-117968 on a lipopolysaccharide (LPS) challenge model and collagen-induced arthritis (CIA) model in mice. Meanwhile, we tested the effect of JTP-117968 on the bone mineral density (BMD) in mouse femur to evaluate the side effect. Based on the evaluation, JTP-117968 reduced the plasma levels of tumor necrosis factor α induced by LPS challenge in mice significantly. Remarkably, CIA development was suppressed by JTP-117968 comparably with prednisolone and PF-802, an active form of fosdagrocorat that has been developed clinically as an orally available SGRM. Strikingly, the side effect of JTP-117968 on mouse femoral BMD was much lower than those of PF-802 and prednisolone. Therefore, JTP-117968 has attractive potential as a new therapeutic option against inflammatory diseases with minimized side effects compared to classic glucocorticoids.

JTP-117968, a novel selective glucocorticoid receptor modulator, exhibits improved transrepression/transactivation dissociation.

Classic glucocorticoids that have outstanding anti-inflammatory effects are still widely prescribed for the treatment of various inflammatory and autoimmune diseases. Conversely, glucocorticoids cause numerous unwanted side effects, particularly systemically dosed glucocorticoids. Therefore, selective glucocorticoid receptor modulator (SGRM), which maintains beneficial anti-inflammatory effects while reducing the occurrence of side effects, is one of the most anticipated drugs. However, there have been no SGRMs marketed to date. The assumption is that there are two major mechanisms of action of glucocorticoids via glucocorticoid receptors, transrepression (TR) and transactivation (TA). In general, the anti-inflammatory effects of glucocorticoids are mostly mediated through TR, while the side effects associated with glucocorticoids are largely caused by TA. We started to evaluate novel orally available SGRMs that maintain anti-inflammatory effects while minimizing adverse effects by favoring TR over TA. Based on this evaluation, we discovered JTP-117968, (4b'S,7'R,8a'S)-4b'-benzyl-7'-hydroxy-N-(2-methylpyridin-3-yl)-7'-(trifluoromethyl)-4b',6',7',8',8a',10'-hexahydro-5'H-spiro[cyclopropane-1,9'-phenanthrene]-2'-carboxamide, a non-steroidal SGRM. JTP-117968 has partial TR activity, but exhibits extremely low TA activity. The maximum TR efficacy of JTP-117968 was comparable to its structural analogue, PF-802, (4bS,7R,8aR)-4b-Benzyl-7-hydroxy-N-(2-methylpyridin-3-yl)-7-(trifluoromethyl)-4b,5,6,7,8,8a,9,10-octahydrophenanthrene-2-carboxamide, which is the active form of Fosdagrocorat that has been developed clinically as a first-in-class orally available SGRM. Remarkably, the TA activity of JTP-117968 was much weaker than PF-802 not only in in vitro assays, but also in in vivo mice experiments. These findings indicate that JTP-117968 exhibits improved TR/TA dissociation because the compound has significantly lower TA activity compared with an already reported SGRM. Therefore, JTP-117968 is expected to be a useful compound for evaluating ideal SGRMs in the future.

Increased expression of IgE-dependent histamine-releasing factor in endometriotic implants.

A complex network of cytokines mediates the immunoregulatory responses leading to endometriosis. Recent intensive studies suggest that monocyte and T cell chemoattractants contribute to the inflammatory environment of endometriotic implants. The relationship between the inflammation present during endometriosis and the development of endometriotic implants in the peritoneal cavity remains unclear. On the other hand, the association between endometriosis and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) exposure has been discussed in recent years, and our previous results revealed that IgE-dependent histamine-releasing factor (HRF) is inducible by TCDD. The present study aimed to clarify the expression, localization, and function of HRF in endometriosis. Northern blot analysis demonstrated that HRF is overexpressed in endometriotic implants. RT-PCR with Southern blot analysis, however, showed that HRF overexpression was not always accompanied by CYP1A1 induction in endometriotic implants, suggesting that HRF is inducible in endometriosis without exposure to TCDD. HRF is also inducible by macrophage colony-stimulating factor (M-CSF). Immunohistochemistry showed CD68-positive macrophages in the stroma of endometriotic implants, adjacent to regions with prominent HRF accumulation. HRF-overexpressing cells exhibited high implantation efficiency in comparison to control cells when the cells were injected into the peritoneal cavities of nude mice. These results suggest that the accumulation of macrophages in endometriotic implants induces HRF; the overexpression of HRF accelerates the growth of endometriotic implants.