Phase III, open-label, single-arm study of a new MMR vaccine (JVC-001); measles AIK-C, mumps RIT 4385, rubella Takahashi, as a second vaccine dose in healthy Japanese children aged 5-6 years.

PURPOSE: This Phase III, multicenter, open-label, single-arm study evaluated the safety and immunogenicity of the measles-mumps-rubella (MMR) combined vaccine, JVC-001, as a second MMR vaccination. METHODS: Healthy Japanese children aged 5-6 years received a single dose of JVC-001 following a first measles, mumps, and rubella vaccination (measles-rubella bivalent and mumps monovalent vaccine [Hoshino or Torii strain] or JVC-001) or the MMR vaccine received between ages 1 to <4 years. Immunogenicity was evaluated using antibody titers before and after vaccination (Day 1/Day 43). The primary endpoint was the seroprotection rate of antibody titers against each virus; geometric mean titer (GMT) was also evaluated. Adverse events (AEs) and adverse drug reactions (ADRs) were monitored. RESULTS: One-hundred participants completed the study. The seroprotection rate of antibody titers against measles, rubella, and mumps virus (genotype D) were 100.0% (95% confidence interval [CI] 96.4%, 100.0%), 100.0% (95% CI 96.4%, 100.0%), and 100.0% (95% CI 96.3%, 100.0%), respectively. GMT (fold) increases (Day 1 to Day 43) were 16.0 to 55.7 for measles virus, 35.5 to 99.0 for rubella virus, and 25.7 to 89.5 for mumps virus (genotype D). Solicited ADRs occurred in 40.0% of participants (injection site, 34.0%; systemic, 13.0%). CONCLUSIONS: The second MMR vaccination with JVC-001 demonstrated sufficient antibody coverage against all three viruses; the safety profile was tolerable. CLINICAL TRIAL REGISTRATION: jRCT2080225022.

A splice-switching oligonucleotide treatment ameliorates glycogen storage disease type 1a in mice with G6PC c.648G>T.

Glycogen storage disease type 1a (GSD1a) is caused by a congenital deficiency of glucose-6-phosphatase-α (G6Pase-α, encoded by G6PC), which is primarily associated with life-threatening hypoglycemia. Although strict dietary management substantially improves life expectancy, patients still experience intermittent hypoglycemia and develop hepatic complications. Emerging therapies utilizing new modalities such as adeno-associated virus and mRNA with lipid nanoparticles are under development for GSD1a but potentially require complicated glycemic management throughout life. Here, we present an oligonucleotide-based therapy to produce intact G6Pase-α from a pathogenic human variant, G6PC c.648G>T, the most prevalent variant in East Asia causing aberrant splicing of G6PC. DS-4108b, a splice-switching oligonucleotide, was designed to correct this aberrant splicing, especially in liver. We generated a mouse strain with homozygous knockin of this variant that well reflected the pathophysiology of patients with GSD1a. DS-4108b recovered hepatic G6Pase activity through splicing correction and prevented hypoglycemia and various hepatic abnormalities in the mice. Moreover, DS-4108b had long-lasting efficacy of more than 12 weeks in mice that received a single dose and had favorable pharmacokinetics and tolerability in mice and monkeys. These findings together indicate that this oligonucleotide-based therapy could provide a sustainable and curative therapeutic option under easy disease management for GSD1a patients with G6PC c.648G>T.

DS-5670a, a novel mRNA-encapsulated lipid nanoparticle vaccine against severe acute respiratory syndrome coronavirus 2: Results from a phase 2 clinical study.

BACKGROUND: DS-5670a is a vaccine candidate for coronavirus disease 2019 (COVID-19) harnessing a novel modality composed of messenger ribonucleic acid (mRNA) encoding the receptor-binding domain (RBD) from the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encapsulated in lipid nanoparticles. Here, we report the safety, immunogenicity, and pharmacokinetic profile of DS-5670a from a phase 2 clinical trial in healthy adults who were immunologically naïve to SARS-CoV-2. METHODS: The study consisted of an open-label, uncontrolled, dose-escalation part and a double-blind, randomized, uncontrolled, 2-arm, parallel-group part. A total of 80 Japanese participants were assigned to receive intramuscular DS-5670a, containing either 30 or 60 µg of mRNA, as two injections administered 4 weeks apart. Safety was assessed by characterization of treatment-emergent adverse events (TEAEs). Immunogenicity was assessed by neutralization titers against SARS-CoV-2, anti-RBD immunoglobulin (Ig)G levels, and SARS-CoV-2 spike-specific T cell responses. Plasma pharmacokinetic parameters of DS-5670a were also evaluated. RESULTS: Most solicited TEAEs were mild or moderate with both the 30 and 60 µg mRNA doses. Four participants (10 %) in the 60 µg mRNA group developed severe redness at the injection site, but all cases resolved without treatment. There were no serious TEAEs and no TEAEs leading to discontinuation. Humoral immune responses in both dose groups were greater than those observed in human convalescent serum; the 60 µg mRNA dose produced better responses. Neutralization titers were found to be correlated with anti-RBD IgG levels (specifically IgG1). DS-5670a elicited antigen-specific T helper 1-polarized cellular immune responses. CONCLUSIONS: The novel mRNA-based vaccine candidate DS-5670a provided favorable immune responses against SARS-CoV-2 with a clinically acceptable safety profile. Confirmatory trials are currently ongoing to evaluate the safety and immunogenicity of DS-5670a as the primary vaccine and to assess the immunogenicity when administered as a heterologous or homologous booster. TRIAL REGISTRY: https://jrct.niph.go.jp/latest-detail/jRCT2071210086.

Discovery of DS68702229 as a Potent, Orally Available NAMPT (Nicotinamide Phosphoribosyltransferase) Activator.

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step of the nicotinamide adenine dinucleotide (NAD+) salvage pathway. Because NAD+ plays a pivotal role in energy metabolism and boosting NAD+ has positive effects on metabolic regulation, activation of NAMPT is an attractive therapeutic approach for the treatment of various diseases, including type 2 diabetes and obesity. Herein we report the discovery of 1-(2-phenyl-1,3-benzoxazol-6-yl)-3-(pyridin-4-ylmethyl)urea 12c (DS68702229), which was identified as a potent NAMPT activator. Compound 12c activated NAMPT, increased cellular NAD+ levels, and exhibited an excellent pharmacokinetic profile in mice after oral administration. Oral administration of compound 12c to high-fat diet-induced obese mice decreased body weight. These observations indicate that compound 12c is a promising anti-obesity drug candidate.

Discovery of 1-[2-(1-methyl-1H-pyrazol-5-yl)-[1,2,4]triazolo[1,5-a]pyridin-6-yl]-3-(pyridin-4-ylmethyl)urea as a potent NAMPT (nicotinamide phosphoribosyltransferase) activator with attenuated CYP inhibition.

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step of the NAD+ salvage pathway. Since NAD+ plays a pivotal role in many biological processes including metabolism and aging, activation of NAMPT is an attractive therapeutic target for treatment of diverse array of diseases. Herein, we report the continued optimization of novel urea-containing derivatives which were identified as potent NAMPT activators. Early optimization of HTS hits afforded compound 12, with a triazolopyridine core, as a lead compound. CYP direct inhibition (DI) was identified as an issue of concern, and was resolved through modulation of lipophilicity to culminate in 1-[2-(1-methyl-1H-pyrazol-5-yl)-[1,2,4]triazolo[1,5-a]pyridin-6-yl]-3-(pyridin-4-ylmethyl)urea (21), which showed potent NAMPT activity accompanied with attenuated CYP DI towards multiple CYP isoforms.

Energetic Trade-Offs and Hypometabolic States Promote Disease Tolerance.

Host defenses against pathogens are energetically expensive, leading ecological immunologists to postulate that they might participate in energetic trade-offs with other maintenance programs. However, the metabolic costs of immunity and the nature of physiologic trade-offs it engages are largely unknown. We report here that activation of immunity causes an energetic trade-off with the homeothermy (the stable maintenance of core temperature), resulting in hypometabolism and hypothermia. This immunity-induced physiologic trade-off was independent of sickness behaviors but required hematopoietic sensing of lipopolysaccharide (LPS) via the toll-like receptor 4 (TLR4). Metabolomics and genome-wide expression profiling revealed that distinct metabolic programs supported entry and recovery from the energy-conserving hypometabolic state. During bacterial infections, hypometabolic states, which could be elicited by competition for energy between maintenance programs or energy restriction, promoted disease tolerance. Together, our findings suggest that energy-conserving hypometabolic states, such as dormancy, might have evolved as a mechanism of tissue tolerance.

Synthesis and biological evaluation of novel imidazol-1-ylacetic acid derivatives as non-brain penetrant bombesin receptor subtype-3 (BRS-3) agonists.

Novel compounds based on 1a were synthesized with the focus of obtaining agonists acting upon peripheral BRS-3. To identify potent anti-obesity compounds without adverse effects on the central nervous system (CNS), a carboxylic acid moiety and a labile carboxylic ester with an antedrug functionality were introduced. Through the extensive synthetic exploration and the pharmacokinetic studies of intravenous administration in mice, the ester 2b was selected owing to its most suitable pharmacological profile. In the evaluation of food intake suppression in C57BL/6N mice, 2b showed significant in vivo efficacy and no clear adverse effects on blood pressure change in dogs administered the compound by intravenous infusion.

Perinatal Licensing of Thermogenesis by IL-33 and ST2.

For placental mammals, the transition from the in utero maternal environment to postnatal life requires the activation of thermogenesis to maintain their core temperature. This is primarily accomplished by induction of uncoupling protein 1 (UCP1) in brown and beige adipocytes, the principal sites for uncoupled respiration. Despite its importance, how placental mammals license their thermogenic adipocytes to participate in postnatal uncoupled respiration is not known. Here, we provide evidence that the "alarmin" IL-33, a nuclear cytokine that activates type 2 immune responses, licenses brown and beige adipocytes for uncoupled respiration. We find that, in absence of IL-33 or ST2, beige and brown adipocytes develop normally but fail to express an appropriately spliced form of Ucp1 mRNA, resulting in absence of UCP1 protein and impairment in uncoupled respiration and thermoregulation. Together, these data suggest that IL-33 and ST2 function as a developmental switch to license thermogenesis during the perinatal period. PAPERCLIP.

Synthesis and biological evaluation of novel chiral diazepine derivatives as bombesin receptor subtype-3 (BRS-3) agonists incorporating an antedrug approach.

Novel compounds based on the lead BRS-3 agonists from our HTS compounds 2a and 2b have been synthesized with the focus on obtaining peripheral BRS-3 agonists. To identify potent anti-obesity compounds without adverse effects on the central nerve system, a labile carboxylic ester with an antedrug functionality was introduced onto the terminal position. Through the extensive synthetic exploration and the pharmacokinetic studies of oral administration in mice, the phenol ester 17c was selected due to the most suitable pharmacological profile. In the evaluation of food intake suppression in B6 mice, 17c showed significant in vivo efficacy and no clear adverse effect on heart rate and blood pressure change in dog iv infusion. Our study paved the way for development of anti-diabetes and obesity drugs with a safer profile.

Identification of the 5,5-dioxo-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidine derivatives as highly selective PDE4B inhibitors.

A PDE4B subtype selective inhibitor is expected to have a wider therapeutic window than non-selective PDE4 inhibitors. In this Letter, two series of 7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidine derivatives and 5,5-dioxo-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidine derivatives were evaluated for their PDE4B subtype selectivity using human PDE4B2 and PDE4D2 full length enzymes. To improve their PDE4B selectivity over PDE4D, we optimized the substituents on the pyrimidine ring and the side chain phenyl ring, resulting in several derivatives with more than 100-fold selectivity for PDE4B. Consequently, we identified 2-(3-chloro-4-methoxy-phenyl)-5,5-dioxo-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidine derivative 54 as a highly selective PDE4B inhibitor, which had potent hPDE4B inhibitory activity with an IC50 value of 3.0 nM and 433-fold PDE4B selectivity over PDE4D.

Discovery of novel chiral diazepines as bombesin receptor subtype-3 (BRS-3) agonists with low brain penetration.

The discovery and optimization of a novel series of BRS-3 agonists are described. We explored a potent BRS-3 agonist with low brain penetration to avoid an adverse effect derived from central nervous system exposure. Through the derivatization process, chiral diazepines 9f and 9g were identified as possessing low brain penetration as well as potent in vitro activity against human and mouse BRS-3s.

Evaluation of the therapeutic index of a novel phosphodiesterase 4B-selective inhibitor over phosphodiesterase 4D in mice.

Phosphodiesterase 4 (PDE4) inhibitors have been developed for the treatment of pulmonary inflammatory diseases, but their clinical use was dose-limited by mainly gastric adverse effects. Recent studies suggested PDE4B-selective inhibitors over PDE4D are supposed to display a wider therapeutic index than subtype non-selective PDE4 inhibitors such as roflumilast. Compound A was identified as an orally active PDE4B-selective inhibitor over PDE4D both in humans (80-fold selective) and mice (29-fold selective). In this study, the therapeutic effects of compound A and roflumilast were evaluated on lipopolysaccaride (LPS) injection-induced plasma TNF-α elevation and on LPS inhalation-induced pulmonary neutrophilia in mice. The inhibitory effect on gastric emptying in mice was evaluated as a gastric adverse effect. The therapeutic index for TNF-α production (TI(TNF) = ID50 in gastric emptying / ID50 in LPS injection-induced plasma TNF-α elevation) of compound A was larger than roflumilast (9.0 and 0.2, respectively), whereas the therapeutic index for pulmonary neutrophilia (TI(Neu) = ID50 in gastric emptying / ID50 in LPS inhalation-induced pulmonary neutrophilia) of compound A was comparable to roflumilast (1.0 and 0.5, respectively). In conclusion, the TI(Neu) of compound A was not superior compared to that of roflumilast in spite of its high selectivity for PDE4B over PDE4D in mice.

Synthesis and biological evaluation of 5-carbamoyl-2-phenylpyrimidine derivatives as novel and potent PDE4 inhibitors.

5-Carbamoyl-2-phenylpyrimidine derivative 2 has been identified as a phosphodiesterase 4 (PDE4) inhibitor with moderate PDE4B inhibitory activity (IC50=200 nM). Modification of the carboxylic acid moiety of 2 gave N-neopentylacetamide derivative 10f, which had high in vitro PDE4B inhibitory activity (IC50=8.3 nM) and in vivo efficacy against lipopolysaccharide (LPS)-induced pulmonary neutrophilia in mice (ID50=16 mg/kg, ip). Furthermore, based on the X-ray crystallography of 10f bound to the human PDE4B catalytic domain, we designed 7,8-dihydro-6H-pyrido[4,3-d]pyrimidin-5-one derivative 39 which has a fused bicyclic lactam scaffold. Compound 39 exhibited excellent inhibitory activity against LPS-induced tumor necrosis factor alpha (TNF-α) production in mouse splenocytes (IC50=0.21 nM) and in vivo anti-inflammatory activity against LPS-induced pulmonary neutrophilia in mice (41% inhibition at a dose of 1.0 mg/kg, i.t.).

Identification of the fused bicyclic 4-amino-2-phenylpyrimidine derivatives as novel and potent PDE4 inhibitors.

2-Phenyl-4-piperidinyl-6,7-dihydrothieno[3,4-d]pyrimidine derivative (2) was found to be a new PDE4 inhibitor with moderate PDE4B activity (IC50=150 nM). A number of derivatives with a variety of 4-amino substituents and fused bicyclic pyrimidines were synthesized. Among these, 5,5-dioxo-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidine derivative (18) showed potent PDE4B inhibitory activity (IC50=25 nM). Finally, N-propylacetamide derivative (31b) was determined as a potent inhibitor for both PDE4B (IC50=7.5 nM) and TNF-α production in mouse splenocytes (IC50=9.8 nM) and showed good in vivo anti-inflammatory activity in the LPS-induced lung inflammation model in mice (ID50=18 mg/kg). The binding mode of the new inhibitor (31e) in the catalytic site of PDE4B is presented based on an X-ray crystal structure of the ligand-enzyme complex.

Formyl peptide receptor 1 and 2 dual agonist inhibits human neutrophil chemotaxis by the induction of chemoattractant receptor cross-desensitization.

Formyl peptide receptor 1 (FPR1) and FPR2/ALX are known to control neutrophil chemotaxis in response to various ligands. In this study, we investigated the inhibitory mechanism of compound 43 (Cpd43), an FPR1 and FPR2/ALX dual agonist, on human neutrophil chemotaxis. Precedent stimulation of human peripheral blood neutrophils with Cpd43 rendered the cells unresponsive in calcium mobilization induced by interleukin-8, C5a, or leukotriene B4. In addition, neutrophils pretreated with Cpd43 lost their chemotactic responses against these chemoattractants, wherein the expressions of chemoattractant receptors CXCR1, CXCR2, C5a receptor, and leukotriene B4 receptor 1 on the surface of neutrophils were all diminished significantly by treatment with Cpd43. By evaluating its pharmacological effect on 341 molecules, including receptors and enzymes, we also confirmed that Cpd43 has a highly specific affinity to FPR1 and FPR2/ALX and does not show binding affinity to the other chemoattractant receptors. These results indicate a previously unrecognized inhibitory mechanism of Cpd43 on neutrophil chemotaxis: the induction of cross-desensitization of multiple chemoattractant receptors in human neutrophils through its FPR1 and FPR2/ALX dual agonism.

Inhibition of neutrophil migration in mice by mouse formyl peptide receptors 1 and 2 dual agonist: indication of cross-desensitization in vivo.

It has been reported that the stimulation of neutrophils with N-formyl-Met-Leu-Phe (fMLF), an agonist for formyl peptide receptor (Fpr) 1, renders cells unresponsive to other chemoattractants in vitro. This is known as cross-desensitization, but its functional relevance in neutrophil migration in vivo has not been investigated. Here, we show that precedent stimulation of mouse neutrophils with compound 43, a non-peptidyl agonist for mouse Fpr1 and Fpr2, rendered the cells unresponsive to a second stimulation with C5a, leukotriene B4, or keratinocyte-derived cytokine (KC) in calcium mobilization and chemotaxis assays in vitro. The expression of chemokine (C-X-C motif) receptor 2 (CXCR2) on the surface of neutrophils was concomitantly diminished by stimulating the cells with the compound. Moreover, oral administration of the compound to mice before they were exposed to lipopolysaccharide (LPS) aerosol resulted in a dose-dependent reduction in the neutrophil count in bronchoalveolar lavage fluid. The expression of CXCR2 on blood neutrophils was also reduced in the compound-administered mice. The recipient mice that underwent adoptive transfer of fluorescence-labelled neutrophils that had been incubated with the compound showed a substantial decrease in neutrophil counts in bronchoalveolar lavage fluid after they were exposed to LPS, when compared with the control mice to which vehicle-treated neutrophils had been transferred. These results are consistent with the idea that the agonist for Fpr1 and Fpr2 induced cross-desensitization in neutrophils and attenuated neutrophil migration into the airways. Our results also revealed the unpredicted effect of an Fpr1 and Fpr2 dual agonist, which may act as a functional antagonist for multiple chemoattractant receptors in vivo.

The pyrazolone originally reported to be a formyl peptide receptor (FPR) 2/ALX-selective agonist is instead an FPR1 and FPR2/ALX dual agonist.

A pyrazolone compound acting as a formyl peptide receptor (FPR) 2/ALX-selective agonist has been reported, but its pharmacological activities on human FPRs (hFPRs) and mouse FPRs (mFprs) have not been well demonstrated. In this study, we found that this compound, designated as compound A, induced concentration-dependent calcium flux not only in Chinese hamster ovary (CHO) cells expressing hFPR2/ALX but also in cells expressing hFPR1, mFpr1, or mFpr2. It also induced the receptor internalization of hFPR1 and hFPR2/ALX and, accordingly, induced calcium influx and chemotactic responses in both human and mouse neutrophils. Our study revealed that compound A is in fact an FPR1 and FPR2/ALX dual agonist.

Naive CD4+ T cells exhibit distinct expression patterns of cytokines and cell surface molecules on their primary responses to varying doses of antigen.

The amount of an Ag used for stimulation affects the type and magnitude of T cell responses. In this study we have investigated the primary response of naive CD4(+) T cells derived from OVA-specific TCR-transgenic mice (OVA23-3) upon stimulation with varying doses of the antigenic peptide, OVA(323-339). IL-4 expression was maximal with 50 nM Ag and decreased significantly with increasing doses. In contrast, IFN-gamma expression, which was also detected at 50 nM Ag, increased with increasing doses. The expression patterns of mRNA for the Th2-specific transcription factors GATA-3 and c-Maf were parallel to that of IL-4. These expression profiles were not altered by the addition of anti-IL-4 plus anti-IL-12 mAbs, suggesting that cytokine receptor signaling is not essential. Naive CD4(+) T cells stimulated with 5 nM Ag elicited IgM secretion from cocultured B cells, whereas those stimulated with 50 nM Ag or more elicited apoptosis of B cells. This may be because at lower doses of Ag (5 nM), naive CD4(+) T cells express CD40 ligand and OX40, whereas at higher doses (50 nM), they express Fas ligand. Clearly, the expression of each type of molecule depends on the Ag dose, and different molecules had different expression patterns. Thus, in the primary response, naive CD4(+) T cells can exhibit different functions depending on the dose of Ag.