Discovery of FXR/PPARγ dual partial agonist.

Farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR)γ are nuclear receptor 1 superfamily of transcription factors. FXR and PPARγ agonists have been individually investigated in clinical trial of anti-diabetic agents in the patients with nonalcoholic fatty liver disease (NAFLD). Regarding recent agonist development, the partial agonists for FXR and PPARγ are drawing attention from the standpoint of avoiding overactive responses caused by full agonists. In this article, we report that 18 with a benzimidazole scaffold possesses FXR/PPARγ dual partial agonistic activity. In addition, 18 shares the ability to reduce cyclin-dependent kinase 5-mediated phosphorylation of PPARγ-Ser273 and the metabolic stability in mouse liver microsome assay. To date, there are no published reports on FXR/PPARγ dual partial agonists with biological profiles similar to 18. Thus, the analog would be a feasible candidate as an unprecedented approach to NAFLD associated with type 2 diabetes mellitus.

Design and identification of a new farnesoid X receptor (FXR) partial agonist by computational structure-activity relationship analysis: Ligand-induced H8 helix fluctuation in the ligand-binding domain of FXR may lead to partial agonism.

Farnesoid X receptor (FXR) controls gene-expression relevant to various diseases including nonalcoholic steatohepatitis and has become a drug target to regulate metabolic aberrations. However, some side effects of FXR agonists reported in clinical development such as an increase in blood cholesterol levels incentivize the development of partial agonists to minimize side effects. In this study, to identify a new partial agonist, we analyzed the computational structure-activity relationship (SAR) of FXR agonists previously developed in our laboratories using molecular dynamics simulations. SAR analysis showed that fluctuations in the H8 helix, by ligand binding, of the ligand-binding domain (LBD) of FXR may influence agonistic activity. Based on this observation, 6 was newly designed as a partial agonist and synthesized. As a result of biological evaluations, 6 showed weak agonistic activity (40.0% relative agonistic activity to the full-agonist GW4064) and a potent EC50 value (55.5 nM). The successful identification of the new potent partial agonist 6 suggested that helix fluctuation in the LBD induced by ligands could be one way to develop partial agonists.

Discovery of Orally Active and Nonsteroidal Farnesoid X Receptor (FXR) Antagonist with Propensity for Accumulation and Responsiveness in Ileum.

We describe the discovery of analog 15 (FLG249), which is an orally active and nonsteroidal farnesoid X receptor (FXR) antagonist in mice with unique profiles, such as a propensity for ileum distribution and the significant control in the expression level of three FXR target genes in mouse ileum. Key design features incorporated in 15 were the introduction of metabolically stable groups in potent and metabolically labile antagonist 9. Our pursuit ultimately identified FXR antagonist 15, which has enabled its assessment in a drug discovery program.

N1-Substituted benzimidazole scaffold for farnesoid X receptor (FXR) agonists accompanying prominent selectivity against vitamin D receptor (VDR).

As a cellular bile acid sensor, farnesoid X receptor (FXR) participates in regulation of bile acid, lipid and glucose homeostasis, and liver protection. With respect to the bone metabolism, FXR positively regulates bone metabolism through both bone formation and resorption of the bone remodeling pathways. Some of FXR agonists possessing isoxazole moiety are undergoing clinical trials for the treatment of non-alcoholic steatohepatitis. To date, therefore, the activation of FXR leads to considerable interest in FXR as potential therapeutic targets. We have identified a series of nonsteroidal FXR agonists bearing N1-methyl benzimidazole and isoxazole moieties that are bridged with aromatic derivatives. They showed affinity to FXR, but also weak affinity toward the vitamin D receptor (VDR) that involves regulation of calcium and phosphate homeostasis and is activated by bile acids. The deployment of FXR agonists without activity against VDR as off-target is therefore crucial in the development of FXR ligands. Our efforts focusing on increasing the agonist properties towards FXR led to the discovery of 19, which activates FXR at and below nanomolar levels (EC50 = 26.5 ± 10.5 nM TR-FRET and 0.8 ± 0.2 nM luciferase, respectively) and functions as a FXR agonist: the affinity toward FXR over eight nuclear receptors, including VDR [IC50 (VDR) / EC50 (FXR) > 5000] and TGR5, effects FXR target genes, and activates bone morphogenetic protein-2-induced differentiation of mouse bone marrow-derived mesenchymal stem cell-like ST2 cells into osteoblast.

Identification of potent farnesoid X receptor (FXR) antagonist showing favorable PK profile and distribution toward target tissues: Comprehensive understanding of structure-activity relationship of FXR antagonists.

Antagonizing transcriptional activity of farnesoid X receptor (FXR) in the intestine has been reported as an effective means for the treatment of nonalcoholic fatty liver disease, type 2 diabetes and obesity. We describe herein that the building blocks necessary to maintain the antagonism of our chemotype were investigated in order to modulate in vivo pharmacokinetic behavior and the tissue distribution without blunting the activity against FXR. A comprehensive understanding of the structure-activity relationship led to analog 30, which is superior to 12 in terms of its pharmacokinetic profiles by oral administration and its tissue distribution toward target tissues (liver and ileum) in rats while preserving the in vitro activity of 12 against FXR. Thus, 30 should be a candidate compound to investigate the effects of inhibiting FXR activity while simultaneously improving the outcome of nonalcoholic fatty liver disease, type 2 diabetes and obesity.

Labial salivary gland biopsy for diagnosing immunoglobulin light chain amyloidosis: a retrospective analysis.

Our goal was to evaluate the usefulness of labial salivary gland (LSG) biopsy for diagnosing immunoglobulin light chain (AL) amyloidosis, by comparing bone marrow and skin biopsies in the same patient population. This retrospective study included 34 consecutive patients who showed evidence of monoclonal proteins and symptoms considered to be due to amyloidosis, and who underwent a tissue biopsy from LSG between January 2005 and December 2012 at Nagoya City University Hospital. All samples of superficial tissues, including LSG, bone marrow, and skin, were independently evaluated as having amyloid deposits by a central review, which was blind to clinical information. An AL amyloidosis diagnosis was based on evidence of amyloid deposition in any biopsied tissue. Eighteen patients were diagnosed with AL amyloidosis. The sensitivity for detecting amyloid deposition was highest in biopsies of LSG at 89 %, followed by 77 % for bone marrow, and 72 % for skin. Amyloid deposition was detected in at least one superficial tissue of all the 18 patients. An LSG biopsy may be appropriate as a first-choice procedure to diagnose AL amyloidosis. Multiple biopsies of superficial tissues, including LSG, bone marrow, and skin, are recommended to increase the sensitivity for diagnosing AL amyloidosis.

Phase I study of once weekly treatment with bortezomib in combination with lenalidomide and dexamethasone for relapsed or refractory multiple myeloma.

Proteasome inhibitors (PIs) in combination with immunomodulatory drugs (IMiDs) have been shown to be effective against relapsed/refractory multiple myeloma (RRMM). To determine the optimal dosing schedule of once weekly bortezomib (BTZ) combined with lenalidomide (LEN) and dexamethasone (DEX), especially in the outpatient setting, we conducted a phase I dose escalation study. A 21-day cycle of BTZ 1.3 mg/m(2) on days 1 and 8, LEN 10 mg/day (cohort 1) or 15 mg/day (cohort 2) on days 1-14, and DEX 20 mg/day on days 1, 2, 8, and 9 was administered. Three patients were enrolled in each cohort. No dose-limiting toxicity was observed in either cohort. Although hematological toxicities estimated as >grade 3 were common, non-hematological toxicities of grade 3 or higher were rare. Two cases of newly diagnosed peripheral neuropathy (PN) were observed, while no grade 3/4 PN was observed. Two patients achieved partial response and two achieved stable disease. The recommended doses of BTZ and LEN were determined to be 1.3 mg/m(2) and 15 mg, respectively. Combination therapy of once weekly BTZ with LEN and DEX was well tolerated and shows promise as a regimen for patients with RRMM previously treated with both PIs and IMiDs.

[Transplant-Related Mortality Following Allogeneic Hematopoietic Stem Cell Transplantation Using Fludarabine/Busulfan-Based Reduced-Intensity Conditioning - A Retrospective Analysis in a Single Institution].

Reduced-intensity conditioning (RIC) has been shown to facilitate allogeneichematopoieticstem cell transplantation (allo-HSCT) for patients with comorbidities and the elderly. However, there are some concerns about transplant-related mortality (TRM). We retrospectively analyzed 37 consecutive patients who received allo-HSCT using RIC from January 2005 to December 2012 in our hospital. All patients received fludarabine(FLU), 180 mg/m2, and intravenous busulfan(BU), 6.4 mg/ kg (or oral BU 8 mg/kg), with or without TBI (2 or 4 Gy). Cyclosporine or tacrolimus alone, or in combination with shortterm methotrexate therapy was used for GVHD prophylaxis. Donor sources included related peripheral blood donors (n=4), and related (n=8) and unrelated (n=25) bone marrow donors. The underlying diseases were various, and 27 patients were considered to be at standard risk. Although one patient died of early disease progression, engraftment was achieved for the others. With a median follow-up of 28.5 months, the estimated 1-year and 5-year TRMs were 13% and 20%, respectively. Five patients died of transplant-related complications, which consisted of 2 cases of acute GVHD and 1 case each of interstitial pneumonitis, bronchiolitis obliterans, and infectious pneumonia. In conclusion, FLU/BU-based RIC is tolerable, but further optimization is needed to prevent transplant-related complications.

Novel type of plasmin inhibitors: providing insight into P4 moiety and alternative scaffold to pyrrolopyrimidine.

Here we report a series of plasmin inhibitors which were originally derived from the parent structure of 1 and 2. Our efforts focused on the optimization of the P4 moiety of 2 and on the quest of alternative scaffold to pyrrolopyrimidine in the parent compounds. The results of the former gave us pivotal information on the further optimization of the P4 moiety in plasmin inhibitors and those of the latter revealed that appropriate moieties extending from the benzimidazole scaffold engaged with S4 pocket in the active site of plasmin.

Reactivation of hepatitis B virus (HBV) infection in adult T-cell leukemia-lymphoma patients with resolved HBV infection following systemic chemotherapy.

Reactivation of hepatitis B virus (HBV) infection may occur in adult T-cell leukemia-lymphoma (ATL) patients with resolved HBV infection who receive monotherapy with the anti-CC chemokine receptor 4 monoclonal antibody, mogamulizumab. However, there is little evidence regarding the incidence and characteristics of HBV reactivation in ATL patients receiving systemic chemotherapy, including the use of this antibody. We conducted a retrospective study for 24 ATL patients with resolved HBV infection underwent regular HBV DNA monitoring to assess HBV reactivation in Nagoya City University Hospital between January 2005 and June 2013. With median HBV DNA follow-up of 238 days (range 57-1420), HBV reactivation (defined as the detection of HBV DNA) was observed in three (12.5 %) of 24 patients with resolved HBV infection. No hepatitis due to HBV reactivation occurred in those patients who were diagnosed with HBV DNA levels below 2.1 log copies/mL and who received antiviral drugs. Mogamulizumab was administered prior to HBV reactivation in two of three HBV-reactivated patients. In the mogamulizumab era, further well-designed prospective studies are warranted to estimate the incidence of HBV reactivation and to establish regular HBV DNA monitoring-guided preemptive antiviral therapy for such patients.