Candida albicans remains the leading causative agent of invasive fungal infection. Although the importance of filamentation in C. albicans pathogenesis has been extensively investigated, in vivo studies to date have been unable to dissect the role of this developmental process in the establishment of infection versus the development of active disease as characterized by damage to the host leading to mortality. To address this issue, we genetically engineered a C. albicans tet-NRG1 strain in which filamentation and virulence can be modulated both in vitro and in vivo simply by the presence or absence of doxycycline (DOX): this strain enabled us, in a prior study, to demonstrate that yeast-form cells were able to infect the deep organs but caused no disease unless filamentation (induced by the addition of DOX) was allowed to occur. In the present study, we examined whether inhibiting filamentation (by withdrawing the DOX) at 24 or 48 h postinfection could serve as an effective therapeutic intervention against candidiasis. The results obtained indicate that DOX removal led to an alteration in the morphology of the infecting fungal cells and a dramatic increase in survival, but as with conventional antifungal drug therapy regimens, mortality rates increased markedly the longer this intervention was delayed. These observations reinforce the importance of invasive filamentous growth in causing the damage to the host and the lethality associated with active disease and suggest this process could be fruitfully targeted for the development of new antifungal agents.Candida albicans, the main causative agent of invasive candidiasis, has become increasingly important in an expanding population of immunocompromised patients, with high morbidity and mortality rates and significant economic sequelae (1, 14-16). Management of these types of infections is complicated by the limited arsenal of antifungal drugs and the emergence of resistance to the existing classes of antifungal agents (10). Thus, there is a critical need for the development of new therapeutic approaches to combat invasive fungal infections.The role of morphogenetic changes in fungal physiology and pathogenesis has long been an active area of research, particularly in C. albicans. This opportunistic fungus grows as ovoid yeast-form cells under many laboratory conditions but transitions to a filamentous form of growth upon exposure to a mammalian host or host-like conditions (e.g., neutral pH or at 37°C in the presence of serum). The role of morphology in C. albicans pathogenesis has been explored using a number of defined mutants defective in this process and which therefore remain locked in either the nonfilamentous (yeast) or filamentous forms of growth. In general, mutants that are locked in either the yeast or filamentous forms are significantly reduced in virulence (2,3,5,6,9,12).Here, we utilize an engineered C. albicans strain that is able to filament and cause mortality when mice are fed doxycycline (DOX), yet remains nonfilamentous in the absence of DOX ...

In recent years, soluble guanylate cyclase (sGC, EC 4.6.1.2) has emerged as an attractive therapeutic target for treating cardiovascular diseases and diseases associated with fibrosis and end-organ failure. Herein, we describe our design and synthesis of a series of 4-hydroxypyrimidine sGC stimulators starting with an internally discovered lead. Our efforts have led to the discovery of IWP-051, a molecule that achieves good alignment of potency, stability, selectivity, and pharmacodynamic effects while maintaining favorable pharmacokinetic properties with once-daily dosing potential in humans. KEYWORDS: Soluble guanylate cyclase, sGC, NO-independent stimulators, heme-dependent sGC stimulators, nitric oxide, IWP-051 S oluble guanylate cyclase (sGC, EC 4.6.1.2) is a signaltransduction enzyme that binds nitric oxide (NO) and catalyzes the conversion of guanosine-5′-triphosphate (GTP) to the secondary messenger cyclic guanosine-3′,5′-monophosphate (cGMP). The NO-sGC-cGMP signal-transduction pathway is involved in the regulation of various physiological processes, including smooth muscle relaxation, platelet inhibition, and vasodilation. 1 The NO-sGC-cGMP pathway plays an important role in coordinating blood flow to tissues, providing oxygen and nutrients, and removing waste products in response to local demands. 2 Impairment of sGC and/or reduced NO bioavailability has been implicated in the pathogenesis of cardiovascular, pulmonary, renal, and hepatic diseases. 3 The therapeutic benefit of NO-donors such as organic nitrates is limited by lack of efficacy due to variable biometabolism 4 and the development of NO tolerance. 5 An alternative to NO-donors are sGC stimulators, a class of ligands that bind allosterically to the Fe(II) form of the hemecontaining enzyme and stimulate the formation of cGMP. 6,7 sGC stimulators can act both independently and in synergy with NO. In preclinical models, sGC stimulators have demonstrated anti-inflammatory and antifibrotic effects, as well as end-organ protections. 8−11 The first marketed sGC stimulator, Bayer's riociguat (Adempas) (Figure 1), was approved in 2013 by the FDA for the treatment of pulmonary arterial hypertension (PAH) and inoperable chronic thromboembolic pulmonary hypertension (CTEPH) based on its ability to improve exercise capacity and symptomatic profile with disease severity defined by the World Health Organization functional classification system. 12 We sought to design an sGC stimulator with a sustained pharmacokinetic and pharmacodynamic profile allowing once-daily dosing and potential to minimize the risk of hypotensive side effects.Some known sGC stimulators, such as riociguat and BAY 41-2272, 13 feature a fused ring structure (Figure 1). We have focused our discovery effort on sGC stimulators that utilize a novel, biaryl pyrazole structure, as exemplified by 1 14 ( Figure 1). 1 is a potent sGC stimulator as determined by production of cGMP in a human embryonic kidney (HEK) cellular assay in the presence of the NO-donor diethylenetriamine NONO...

Background: Edasalonexent is an orally administered small molecule designed to inhibit NF- κ B, which is activated from infancy in Duchenne muscular dystrophy and is central to causing muscle damage and preventing muscle regeneration. Objective: Evaluate the safety, tolerability, pharmacokinetics and exploratory pharmacodynamics of three doses of edasalonexent in ambulatory males ≥4 to <8 years of age with genetically confirmed Duchenne muscular dystrophy. Methods: This was a 1-week, open-label, multiple-dose study with 3 sequential ascending doses (33, 67 and 100 mg/kg/day) of edasalonexent administered under different dietary conditions to 17 males with a mean age of 5.5 years. Results: All doses of edasalonexent were well tolerated, with no serious adverse events, no drug discontinuations and no dose reductions. The majority of adverse events were mild, and the most common adverse events were gastrointestinal (primarily diarrhea). Edasalonexent was rapidly absorbed with peak levels observed 2–6 hours after dosing and exposures appeared to increase nearly proportionally to dose for the 2 lower and all 3 doses under low-fat and high-fat meal conditions, respectively. Only minor plasma accumulation of edasalonexent was observed with 7 days of dosing. After treatment with edasalonexent for 7 days, levels of NF- κ B-regulated genes and serum proteins were decreased. Conclusions: This first report of edasalonexent oral administration for one week in male pediatric patients with Duchenne muscular dystrophy showed that treatment was well tolerated and inhibited NF-kB pathways.

Interleukin-6 (IL-6) is an important member of the cytokine superfamily, exerting pleiotropic actions on many physiological processes. Over-production of IL-6 is a hallmark of immune-mediated inflammatory diseases such as Castleman’s Disease (CD) and rheumatoid arthritis (RA). Antagonism of the interleukin IL-6/IL-6 receptor (IL-6R)/gp130 signaling complex continues to show promise as a therapeutic target. Monoclonal antibodies (mAbs) directed against components of this complex have been approved as therapeutics for both CD and RA. To potentially provide an additional modality to antagonize IL-6 induced pathophysiology, a peptide-based antagonist approach was undertaken. Using a combination of molecular design, phage-display, and medicinal chemistry, disulfide-rich peptides (DRPs) directed against IL-6 were developed with low nanomolar potency in inhibiting IL-6-induced pSTAT3 in U937 monocytic cells. Targeted PEGylation of IL-6 binding peptides resulted in molecules that retained their potency against IL-6 and had a prolongation of their pharmacokinetic (PK) profiles in rodents and monkeys. One such peptide, PN-2921, contained a 40 kDa polyethylene glycol (PEG) moiety and inhibited IL-6-induced pSTAT3 in U937 cells with sub-nM potency and possessed 23, 36, and 59 h PK half-life values in mice, rats, and cynomolgus monkeys, respectively. Parenteral administration of PN-2921 to mice and cynomolgus monkeys potently inhibited IL-6-induced biomarker responses, with significant reductions in the acute inflammatory phase proteins, serum amyloid A (SAA) and C-reactive protein (CRP). This potent, PEGylated IL-6 binding peptide offers a new approach to antagonize IL-6-induced signaling and associated pathophysiology.

Chronic activation of NF-κB is a key driver of muscle degeneration and suppression of muscle regeneration in Duchenne muscular dystrophy. Edasalonexent (CAT-1004) is an orally-administered novel small molecule that covalently links two bioactive compounds (salicylic acid and docosahexaenoic acid) that inhibit NF-κB. This placebo-controlled, proof-of-concept phase 2 study with open-label extension in boys ≥4-< 8 years old with any dystrophin mutation examined the effect of edasalonexent (67 or 100 mg/kg/day) compared to placebo or off-treatment control. Endpoints were safety/tolerability, change from baseline in MRI T 2 relaxation time of lower leg muscles and functional assessment, as well as pharmacodynamics and biomarkers. Treatment was well-tolerated and the majority of adverse events were mild, and most commonly of the gastrointestinal system (primarily diarrhea). There were no serious adverse events in the edasalonexent groups. Edasalonexent 100 mg/kg was associated with slowing of disease progression and preservation of muscle function compared to an off-treatment control period, with decrease in levels of NF-κB-regulated genes and improvements in biomarkers of muscle health and inflammation. These results support investigating edasalonexent in future trials and have informed the design of the edasalonexent phase 3 clinical trial in boys with Duchenne.