Soluble Guanylate Cyclase Stimulator Research Articles

New Generation of sGC Stimulators: Discovery of Imidazo[1,2-a]pyridine Carboxamide BAY 1165747 (BAY-747), a Long-Acting Soluble Guanylate Cyclase Stimulator for the Treatment of Resistant Hypertension.

Herein, we describe the identification, chemical optimization, and preclinical characterization of novel soluble guanylate cyclase (sGC) stimulators. Given the very broad therapeutic opportunities for sGC stimulators, new tailored molecules for distinct indications with specific pharmacokinetics, tissue distribution, and physicochemical properties will be required in the future. Here, we report the ultrahigh-throughput (uHTS)-based discovery of a new class of sGC stimulators from an imidazo[1,2-a]pyridine lead series. Through the extensive and staggered optimization of the initial screening hit, liabilities such as potency, metabolic stability, permeation, and solubility could be substantially improved in parallel. These efforts resulted ultimately in the discovery of the new sGC stimulators 22 and 28. It turned out that BAY 1165747 (BAY-747, 28) could be an ideal treatment alternative for patients with hypertension, especially those not responding to standard anti-hypertensive therapy (resistant hypertension). BAY-747 (28) demonstrated sustained hemodynamic effects up to 24 h in phase 1 studies.

Correction to: 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

HomeCirculationVol. 147, No. 14Correction to: 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines Free AccessCorrectionPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessCorrectionPDF/EPUBCorrection to: 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines Originally published3 Apr 2023https://doi.org/10.1161/CIR.0000000000001142Circulation. 2023;147:e674This article corrects the following2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice GuidelinesIn the article by Heidenreich et al, “2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines,” which published ahead of print on April 1, 2022, and appeared in the May 3, 2022, issue of the journal (Circulation. 2022;145:e895–e1032. doi: 10.1161/CIR.0000000000001063), a correction was needed.On page e938, in Table 14, under section “7.3.8. GDMT Dosing: Sequencing and Uptitration,” digoxin was classified incorrectly as a soluble guanylate cyclase stimulator. A heading titled “Cardiac glycoside” was added above digoxin.This correction has been made to the current online version of the article, which is available at: https://www.ahajournals.org/doi/10.1161/CIR.0000000000001063.FootnotesCirculation is available at www.ahajournals.org/journal/circ Previous Back to top Next FiguresReferencesRelatedDetailsRelated articles2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice GuidelinesPaul A. Heidenreich, et al. Circulation. 2022;145:e895-e1032 April 4, 2023Vol 147, Issue 14 Advertisement Article InformationMetrics © 2023 American Heart Association, Inc.https://doi.org/10.1161/CIR.0000000000001142PMID: 37011077 Originally publishedApril 3, 2023 PDF download Advertisement

The first validated stability-indicating HPLC/DAD method for quantitation of Vericiguat in its pharmaceutical formulation; Application to degradation kinetic studies

The stability of innovative drug formulations and the development of appropriate stability-indicating methods remain major focuses of recent pharmaceutical analysis. In the present study, an efficient stability-indicating HPLC-DAD technique has been described and validated for the determination of Vericiguat (VER); a novel oral soluble guanylate cyclase (sGC) stimulator used in heart failure. VER's stability under various stress conditions was examined. It was shown that VER was sensitive to alkaline, oxidative and thermal degradation. Mass spectrometry (MS) in electrospray ionization mode was performed to figure out the structure of the alkaline and oxidative degradation products. Efficient separation of VER and its induced degradation products was accomplished using isocratic elution mode on the Inertsil ODS-C18 column. The mobile phase composed of water: acetonitrile (70:30 v/v) with 0.1% O-phosphoric acid; pH was adjusted to 2.22 and a flow rate of 0.80 mL/min. VER was detected at 332 nm over a concentration range of 2.00–20.00 μg/mL. The retention time was 4.500 ± 0.005 min and the correlation coefficient was 0.9996. Following the International Conference of Harmonization's guidelines, the analysis was validated to be specific, fast, simple, precise and accurate for utilization in routine analysis and quality control of VER in its pharmaceutical formulation. Additionally, the suggested technique was expanded to investigate the kinetics of alkaline, oxidative and dry heat degradation.

Vericiguat for the treatment of heart failure with reduced ejection fraction

ABSTRACT Introduction Despite significant therapeutic advancements in heart failure with reduced ejection fraction (HFrEF), the residual risk of all-cause mortality and hospitalizations remains high among patients with HFrEF. Vericiguat is a novel oral soluble guanylate cyclase (sGC) stimulator which was approved by the US Food and Drug administration (FDA) in January 2021 for use in patients with symptomatic chronic HF and an ejection fraction less than 45% following a hospitalization for HF or the need for outpatient intravenous diuretics. Areas covered We provide a concise review of the pharmacology, clinical efficacy, and tolerability of vericiguat in HFrEF. We also discuss the role of vericiguat in current clinical practice. Expert opinion Vericiguat reduces the risk of cardiovascular mortality or HF hospitalizations by an absolute event-rate reduction of 4.2 events per 100 patient-years with a number needed to treat of 24 patients, on a background of guideline-directed medical therapy. Almost 90% of the patients with HFrEF were adherent to the 10 mg dose of vericiguat in the VICTORIA trial with a favorable tolerability and safety profile. Considering the high residual risk that persists in HFrEF, vericiguat has a role to improve outcomes among patients with worsening HFrEF.

Restoration of Sinusoid Fenestrae Followed by Targeted Nanoassembly Delivery of an Anti-Fibrotic Agent Improves Treatment Efficacy in Liver Fibrosis.

During the onset of liver fibrosis, capillarized liver sinusoidal endothelial cells (LSECs) limit substance exchange between the blood and the Disse space, further accelerating hepatic stellate cell (HSCs) activation and fibrosis progression. Limited accessibility of therapeutics to the Disse space is often overlooked and remains a major bottleneck for HSCs-targeted therapy in liver fibrosis. Here, an integrated systemic strategy for liver fibrosis treatment is reported, utilizing pretreatment with the soluble guanylate cyclase stimulator, riociguat, followed by insulin growth factor 2 receptor-mediated targeted delivery of the anti-fibrosis agent, JQ1, via peptide-nanoparticles (IGNP-JQ1). The riociguat reversed the liver sinusoid capillarization to maintain a relatively normal LSECs porosity, thus facilitating the transport of IGNP-JQ1 through the liver sinusoid endothelium wall and enhancing the accumulation of IGNP-JQ1 in the Disse space. IGNP-JQ1 is then selectively taken up by activated HSCs, inhibiting their proliferation and decreasing collagen deposition in the liver. The combined strategy results in significant fibrosis resolution in carbon tetrachloride-induced fibrotic mice as well as methionine-choline-deficient-diet-induced nonalcoholic steatohepatitis (NASH) mice. The work highlights the key role of LSECs in therapeutics transport through the liver sinusoid. The strategy of restoring LSECs fenestrae by riociguat represents a promising approach for liver fibrosis treatment.

Atrophy signaling pathways in respiratory and limb muscles of guinea pigs exposed to chronic cigarette smoke: role of soluble guanylate cyclase stimulation.

Skeletal muscle dysfunction in chronic obstructive pulmonary disease (COPD) is characterized by a significant reduction in muscle strength and endurance. Preclinical studies show that stimulation of the soluble guanylate cyclase (sGC)-cGMP pathway attenuates muscle mass loss and prevents cigarette smoke-induced oxidative stress, indicating that pharmacological activation of the guanylyl cyclase pathway in COPD may provide a beneficial therapeutic strategy that reaches beyond the lung. In this study, conducted in an animal model of COPD, we first set out to assess the effect of cigarette smoke (CS) on biomarkers of muscle fatigue, such as protein degradation and its transcriptional regulation, in two types of muscles with different energy demands, i.e., the diaphragm and the gastrocnemius muscle of the limbs. Second, we evaluated the administration of an sGC stimulator on these markers to study the potential efficacy of such treatment in the recovery of skeletal muscle function. Exposure to CS led to weight loss, which was associated in the gastrocnemius with increased levels of proteolytic markers of muscle atrophy (MURF-1, Atrogin-1, proteasome C8 subunit 20 s, and total protein ubiquitination), whereas the size of fast-twitch muscle fibers decreased significantly. Long-term treatment with the sGC stimulator BAY 41-2272 resulted in a significant reduction in gastrocnemius levels of the aforementioned proteolytic markers, concomitant with a weight recovery and increased cGMP levels. Remarkably, levels of some of the analyzed biomarkers differed between respiratory and limb muscles. In conclusion, targeting sGC might exert beneficial effects on muscle alterations in patients with COPD.

Effects of a Soluble Guanylate Cyclase Stimulator Riociguat on Contractility of Isolated Pulmonary Artery and Hemodynamics of U46619-Induced Pulmonary Hypertension in Dogs

Soluble guanylate cyclase (sGC) stimulator riociguat is a relatively novel therapeutic agent for pulmonary hypertension (PH) in human medicine. Riociguat induces endothelium-independent pulmonary artery (PA) relaxation by directly activating the sGC-cyclic guanosine-3',5'-monophosphate (cGMP) pathway in muscle cells. Although riociguat may be effective in the treatment of dogs with refractory PH, basic studies on its clinical application in veterinary medicine are lacking. The present study aimed to explore the effects of riociguat on the contractility of an isolated canine PA and the hemodynamics of dogs with acute PH. In an isolated endothelium-denuded canine PA, the effects of riociguat on endothelin (ET)-1-induced contraction and cGMP levels were investigated using the Magnus method and ELISA, respectively. The effect of riociguat on the hemodynamics of the thromboxane A2 analog U46619-induced PH model dog was examined by invasive catheterization. Riociguat increased cGMP levels and reduced ET-1-induced contraction of the isolated PA. Riociguat inhibited the U46619-induced elevation of PA pressure and pulmonary vascular resistance and increased cardiac output, but it had no effect on basal systemic blood pressure. These results demonstrate for the first time that riociguat can inhibit the elevation of PA pressure through PA relaxation via an endothelium-independent increase in cGMP in dogs with PH.

Applicability of Vericiguat to Patients Hospitalized for Heart Failure in the United States

BackgroundIn January 2021, vericiguat, a soluble guanylate cyclase stimulator, was approved by the U.S. Food and Drug Administration (FDA) to reduce the risk of cardiovascular death and heart failure (HF) hospitalization among patients with a recent worsening HF event based on the VICTORIA (VerICiguaT Global Study in Subjects with Heart Failure with Reduced Ejection Fraction) trial. ObjectivesThis study sought to leverage a contemporary U.S. registry of patients hospitalized for heart failure (HF) to characterize patients who may be candidates for vericiguat based on FDA label and the VICTORIA trial eligibility criteria. MethodsThe authors studied patients hospitalized for HF with ejection fraction (EF) <45% across 525 sites in the GWTG-HF (Get With The Guidelines–Heart Failure) registry between January 2014 and December 2020. Approximate FDA label criteria (excluding estimated glomerular filtration rate [eGFR] <15 mL/min/1.73 m2, dialysis, or patients with heart transplantation or durable mechanical circulatory support) and eligibility criteria for the VICTORIA trial were applied to the GWTG-HF cohort. ResultsAmong 241,057 patients with EF <45% in the GWTG-HF registry, 221,730 (92%) could be candidates for vericiguat under the FDA label and 92,249 (38%) would have been eligible for the VICTORIA trial. The most frequent reasons for ineligibility for the FDA label were eGFR <15 mL/min/1.73 m2 (5.7%) and dialysis (1.6%). Although there were greater proportions of women and Black patients in the GWTG-HF registry, most clinical characteristics were qualitatively similar with patients enrolled in the VICTORIA trial. Among Medicare beneficiaries in the GWTG-HF registry eligible for vericiguat by either FDA label or VICTORIA trial criteria, 12-month postdischarge rates of mortality (36%-37%), HF hospitalization (33%-35%), all-cause hospitalization (64%-66%), and mean health care expenditure (U.S. $25,106-$25,428) were high. ConclusionsData from a large, contemporary U.S. registry of patients actively hospitalized for HF with EF <45% suggest that approximately 4 in 10 patients meet the criteria of the VICTORIA trial and that more than 9 in 10 patients are potential candidates for vericiguat based on the FDA label. Contemporary Medicare beneficiaries hospitalized for HF with EF <45% and eligible for vericiguat face high rates of postdischarge mortality and readmission and accrue substantial health care costs.

Stimulation of soluble guanylate cyclase by vericiguat reduces skeletal muscle atrophy of mice following chemotherapy.

Background: The chemotherapeutic doxorubicin (DOX) promotes severe skeletal muscle atrophy, which induces skeletal muscle weakness and fatigue. Soluble guanylate cyclase (sGC) contributes to a variety of pathophysiological processes, but whether it is involved in DOX-induced skeletal muscle atrophy is unclear. The present study aimed to stimulate sGC by vericiguat, a new oral sGC stimulator, to test its role in this process. Methods: Mice were randomly divided into four groups: control group, vericiguat group, DOX group, and DOX + vericiguat group. Exercise capacity was evaluated before the mice were sacrificed. Skeletal muscle atrophy was assessed by histopathological and molecular biological methods. Protein synthesis and degradation were monitored in mice and C2C12 cells. Results: In this study, a significant decrease in exercise capacity and cross-sectional area (CSA) of skeletal muscle fibers was found in mice following DOX treatment. Furthermore, DOX decreased sGC activity in mice and C2C12 cells, and a positive correlation was found between sGC activity and CSA of skeletal muscle fibers in skeletal muscle. DOX treatment also impaired protein synthesis, shown by puromycin detection, and activated ubiquitin-proteasome pathway. Following sGC stimulation, the CSA of muscle fibers was elevated, and exercise capacity was enhanced. Stimulation of sGC also increased protein synthesis and decreased ubiquitin-proteasome pathway. In terms of the underlying mechanisms, AKT/mTOR and FoxO1 pathways were impaired following DOX treatment, and stimulation of sGC restored the blunted pathways. Conclusion: These results unravel sGC stimulation can improve skeletal muscle atrophy and increase the exercise capacity of mice in response to DOX treatment by enhancing protein synthesis and inhibiting protein degradation. Stimulation of sGC may be a potential treatment of DOX-induced skeletal muscle dysfunction.

Assessment of Biomarkers of Myocardial injury, Inflammation, and Renal Function in Heart Failure With Reduced Ejection Fraction: The VICTORIA Biomarker Substudy

BackgroundCirculating biomarkers may be useful in understanding prognosis and treatment efficacy in heart failure with reduced ejection fraction. In the VICTORIA (Vericiguat Global Study in Subjects with Heart Failure with Reduced Ejection Fraction) trial, vericiguat, a soluble guanylate cyclase stimulator, decreased the primary outcome of cardiovascular death or heart failure hospitalization in heart failure with reduced ejection fraction. We evaluated biomarkers of cardiac injury, inflammation, and renal function for associations with outcomes and vericiguat treatment effect. Methods and ResultsHigh-sensitivity cardiac troponin T (hs-cTnT), growth differentiation factor-15 (GDF-15), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), and cystatin C were measured at baseline and 16 weeks. Associations of biomarkers with the primary outcome and its components were estimated. Interaction with study treatment was tested. Changes in biomarkers over time were examined by study treatment. One or more biomarkers were measured in 4652 (92%) of 5050 participants at baseline and 4063 (81%) at 16 weeks. After adjustment, higher values of hs-cTnT, growth differentiation factor-15, and interleukin-6 were associated with the primary outcome, independent of N-terminal pro-B-type natriuretic peptide. Higher hs-cTnT values were associated with a hazard ratio per log standard deviation of 1.21 (95% confidence interval 1.14–1.27). A treatment interaction with vericiguat was evident with hs-cTnT and cardiovascular death (P = .04), but not HF hospitalization (P = .38). All biomarkers except cystatin C decreased over 16 weeks and no relationship between treatment assignment and changes in biomarker levels was observed. Conclusionshs-cTnT, growth differentiation factor-15, and interleukin-6 levels were associated with risk of the primary outcome in VICTORIA (Vericiguat Global Study in Subjects with Heart Failure with Reduced Ejection Fraction). Uniquely, lower hs-cTnT was associated with a lower rate of cardiovascular death but not HF hospitalization after treatment with vericiguat.

Soluble guanylate cyclase stimulator riociguat in the palette of modern specific therapy for precapillary pulmonary hypertension: from the pathophysiological basis to the results of current research

Among the forms of precapillary pulmonary hypertension (PH) are pulmonary arterial hypertension (PAH) and chronic thromboembolic PH (CTEPH) with a diagnostic triad of hemodynamic parameters: mean pulmonary artery pressure &gt; 25 mm Hg (&gt; 20 mm Hg according to the new version of European guidelines 2022), pulmonary artery wedge pressure ≥ 15 mm Hg; pulmonary vascular resistance &gt; 3 Wood units (&gt; 2 Wood units in the new version of European guidelines 2022) by right heart catheterization at rest. The leading factors in the pathogenesis of PAH are an endothelial dysfunction with an imbalance between vasodilating and vasoconstrictor substances, activation of endothelial/smooth muscle cell proliferation and the blood coagulation system, which lead to remodeling of the vessels of the pulmonary circulation. In CTEPH there is a morphological substrate as a chronic obstruction of large and medium branches of pulmonary arteries, as well as secondary changes in the microcirculatory bed of the lungs, and chronic/organized thrombi/emboli in the elastic type of pulmonary arteries are detected after three months of effective anticoagulant therapy.As a result of a significant progress in the study of the pathophysiological aspects of PAH in recent years, specific therapy has been introduced into clinical practice with an impact on key targets of the pathogenesis of the disease. In CTEPH pulmonary endarterectomy remains the treatment of choice for all operable patients. In case of inoperable and residual forms of CTEPH, if technically feasible, pulmonary artery balloon angioplasty is performed while taking PAH-specific drugs, in particular, the only officially approved stimulator of soluble guanylate cyclase (sGC) riociguat.The most important aspects of PAH-specific therapy of patients with PAH, inoperable and residual forms of CTEPH; the targets of therapy are indicated, promising approaches to therapy with a focus on the sGC stimulator riociguat, the possibilities of combination therapy and switching strategies are discussed in the article. The optimal safety and efficacy profile of riociguat, demonstrated in large international studies and routine clinical practice, allows the drug to be widely used in the treatment of patients with PAH and CTEPH. Switching from phosphodiesterase type 5 (PDE5) inhibitors to riociguat is safe and appropriate, which is emphasized in the Eurasian and Russian clinical guidelines, in 2022. the strategy of switching to riociguat is approved in case of failure of PDE5 inhibitors as part of combination therapy with endothelin receptor antagonists in the new version of the European document.The originality of riociguat due to the presence of a dual mechanism of action by direct stimulation of sGC and sensitization of the enzyme to endogenous NO, allows its use not only as a long-term monotherapy, but also as part of a combination therapy, with the implementation of a switching strategy in case of clinical failure of PDE5 inhibitors.

Expert Opinion on the Identification and Pharmacological Management of Worsening Heart Failure

Worsening heart failure (WHF) is a distinct under-diagnosed and under-treated condition, independent of location of care. Heart failure (HF) progression is punctuated by repeated WHF events, each resulting in reduced cardiac function. One-third of the patients with HF with reduced ejection fraction experience a decompensation event. These decompensation events often result in the emergency department visits and HF hospitalization. Despite its inclusion in recent guidelines, there is no precise definition of WHF or its various forms. It is worth noting that WHF signals a need for treatment optimization as per guideline-directed medical therapy and the addition of novel drugs like a stimulator of soluble guanylate cyclase that benefit this high-risk patient population. This practical document is based on the expert opinion of cardiologists, cardiothoracic surgeons, and physicians that discussed the definition, assessment, pharmacological management, and monitoring of WHF patients in a hospitalized setting. In addition, there is also a need for an expert opinion for the management of WHF in an outpatient setting.

Worsening heart failure and current management strategies with a focus on soluble guanylate cyclase stimulators

Worsening heart failure and current management strategies with a focus on soluble guanylate cyclase stimulators

Possibilities of long-term effective treatment of idiopathic pulmonary arterial hypertension by replacing sildenafil with riociguat and using sequential combination therapy: case report

Modern pathogenetic therapy of idiopathic pulmonary arterial hypertension (IPAH), a severe life-threatening cardiovascular disease of unknown etiology, leads to a positive clinical effect due to reverse remodeling of the vessels of the microvasculature of the lungs. Highly effective drugs of specific therapy that act on the main targets of pathogenesis have now been introduced into clinical practice.The presented clinical case of a patient with diagnosed in 2014 IPAH with an initial functional class III according to the WHO classification demonstrates high long-term efficacy and safety of specific therapy based on the use of the soluble guanylate cyclase stimulator riociguat for 5 years after replacing previous therapy with sildenafil with further implementation of the strategy of sequential combination therapy due to the addition of ambrisentan and selexipag.

The Soluble Guanylate Cyclase Stimulator BAY 41-2272 Attenuates Transforming Growth Factor β1-Induced Myofibroblast Differentiation of Human Corneal Keratocytes

Corneal transparency, necessary for vision and depending on the high organization of stromal extracellular matrix, is maintained by keratocytes. Severe or continuous corneal injuries determine exaggerated healing responses resulting in the formation of irreversible fibrotic scars and vision impairment. Soluble guanylate cyclase (sGC) stimulation demonstrated antifibrotic effects in both experimental fibrosis and human lung and skin fibroblasts. Here, we assessed whether sGC stimulation with BAY 41-2272 could attenuate transforming growth factor β1 (TGFβ1)-induced myofibroblast differentiation of human corneal keratocytes. Cells were challenged with TGFβ1, with/without BAY 41-2272 preincubation, and subsequently assessed for viability, proliferation, migration, chemoinvasion, as well for the expression of myofibroblast/fibroblast activation markers and contractile abilities. Treatment with BAY 41-2272 did not affect keratocyte viability, while preincubation of cells with the sGC stimulator was able to inhibit TGFβ1-induced proliferation, wound healing capacity, and invasiveness. BAY 41-2272 was also able to attenuate TGFβ1-induced myofibroblast-like profibrotic phenotype of keratocytes, as demonstrated by the significant decrease in ACTA2, COL1A1, COL1A2, FN1 and PDPN gene expression, as well as in α-smooth muscle actin, α-1 chain of type I collagen, podoplanin, vimentin and N-cadherin protein expression. Finally, BAY 41-2272 significantly counteracted the TGFβ1-induced myofibroblast-like ability of keratocytes to contract collagen gels, reduced phosphorylated Smad3 protein levels, and attenuated gene expression of proinflammatory cytokines. Collectively, our data show for the first time that BAY 41-2272 is effective in counteracting keratocyte-to-myofibroblast transition, thus providing the rationale for the development of sGC stimulators as novel promising modulators of corneal scarring and fibrosis.

Praliciguat Promotes Ischemic Leg Reperfusion in Leptin Receptor-Deficient Mice.

Lower-limb peripheral artery disease is one of the major complications of diabetes. Peripheral artery disease is associated with poor limb and cardiovascular prognoses, along with a dramatic decrease in life expectancy. Despite major medical advances in the treatment of diabetes, a substantial therapeutic gap remains in the peripheral artery disease population. Praliciguat is an orally available sGC (soluble guanylate cyclase) stimulator that has been reported both preclinically and in early stage clinical trials to have favorable effects in metabolic and hemodynamic outcomes, suggesting that it may have a potential beneficial effect in peripheral artery disease. We evaluated the effect of praliciguat on hind limb ischemia recovery in a mouse model of type 2 diabetes. Hind limb ischemia was induced in leptin receptor-deficient (Leprdb/db) mice by ligation and excision of the left femoral artery. Praliciguat (10 mg/kg/day) was administered in the diet starting 3 days before surgery. Twenty-eight days after surgery, ischemic foot perfusion and function parameters were better in praliciguat-treated mice than in vehicle controls. Improved ischemic foot perfusion was not associated with either improved traditional cardiovascular risk factors (ie, weight, glycemia) or increased angiogenesis. However, treatment with praliciguat significantly increased arteriole diameter, decreased ICAM1 (intercellular adhesion molecule 1) expression, and prevented the accumulation of oxidative proangiogenic and proinflammatory muscle fibers. While investigating the mechanism underlying the beneficial effects of praliciguat therapy, we found that praliciguat significantly downregulated Myh2 and Cxcl12 mRNA expression in cultured myoblasts and that conditioned medium form praliciguat-treated myoblast decreased ICAM1 mRNA expression in endothelial cells. These results suggest that praliciguat therapy may decrease ICAM1 expression in endothelial cells by downregulating Cxcl12 in myocytes. Our results demonstrated that praliciguat promotes blood flow recovery in the ischemic muscle of mice with type 2 diabetes, at least in part by increasing arteriole diameter and by downregulating ICAM1 expression.

Effects of an inhaled soluble guanylate cyclase (sGC) stimulator MK-5475 in pulmonary arterial hypertension (PAH)

BackgroundNovel therapeutics for pulmonary arterial hypertension (PAH) with improved safety/tolerability profiles are needed to address continued high rates of morbidity/mortality. MethodsThis Phase 1 study evaluated efficacy/safety of inhaled single-dose MK-5475, an investigational, small-molecule stimulator of soluble guanylate cyclase designed for inhaled delivery via a dry-powder inhaler device, in participants with PAH (Clinicaltrials.gov: NCT03744637). Eligible participants were 18–70 years of age; body mass index ≤35 kg/m2; diagnosis of PAH (Group 1 pulmonary hypertension). In Part 1, participants received double-blind MK-5475 or placebo for safety assessment (primary outcome). In Part 2, 4 panels participated in ≤3 open-label periods. Part 2/Period 1 assessed safety/tolerability. Part 2/Periods 2 and 3, respectively, involved functional respiratory imaging for measuring pulmonary blood volume (secondary outcome) and right heart catheterization for measuring pulmonary vascular resistance (primary outcome). ResultsMK-5475 was generally well tolerated without systemic side effects on blood pressure or heart rate up to 24 h post dose. With respect to the primary pharmacodynamic outcome, mean reductions in pulmonary vascular resistance ranged from 21% to 30% across 120 μg and 360 μg doses. ConclusionsTreatment with inhaled single-dose MK-5475 showed rapid and sustained reductions in pulmonary vascular resistance and increases in pulmonary blood volume. MK-5475 was generally well tolerated versus placebo without vasodilatory systemic side effects. The promising pulmonary selectivity and favorable safety/tolerability profile of MK-5475 seen in this study of adult participants with PAH lays the foundation for further clinical development.

Association Between Copayment and Adherence to Medications for Pulmonary Arterial Hypertension.

Background Pharmacologic treatment for pulmonary arterial hypertension (PAH) improves exercise capacity, functional class, and hemodynamic indexes. However, monthly prescription costs often exceed $4000. We examined associations between (1) medication copayment and (2) annual household income with adherence to pulmonary vasodilator therapy among individuals with PAH. Methods and Results We used administrative claims data from an insured population in the United States to identify individuals diagnosed with PAH between 2015 and 2020. All individuals had ≥1 medication claim for endothelin receptor antagonists, phosphodiesterase type-5 inhibitors, prostanoids or prostacyclin receptor agonists, or the soluble guanylate cyclase stimulator riociguat. We defined copayments as low, medium, or high, as determined by their distributions for each medication class. Annual household income was categorized as <$40 000, $40 000 to $74 999, and ≥$75 000. The primary outcome was medication adherence, defined by proportion of days covered ≥80%. We studied 4025 adults (aged 65.9±13.3 years; 71.2% women). Compared with those with annual household income ≥$75 000, individuals in the <$40 000 and $40 000 to $74 999 categories had no significant differences in medication adherence. Compared with those with low copayments, individuals with high copayments had decreased adherence to prostanoids (odds ratio [OR], 0.36 [95% CI, 0.20-0.65]; P<0.001) and combination therapy with endothelin receptor antagonist and phosphodiesterase type-5 inhibitor (OR, 0.61 [95% CI, 0.38-0.97]; P=0.03). Conclusions We identified associations between copayment and adherence to prostanoids and combination therapy among individuals with PAH. Copayment may be a structural barrier to medication adherence and merits inclusion in studies examining access to pharmacotherapy among individuals with PAH.

Soluble guanylate cyclase stimulators in patients with heart failure with reduced ejection fraction across the risk spectrum.

Patients with heart failure with reduced ejection fraction (HFrEF) have a high residual risk of adverse outcomes, even when treated with optimal guideline-directed medical therapy and in a clinically stable state. Soluble guanylate cyclase (sGC) stimulators have the potential to lower this risk by modifying the nitric oxide-sGC-cyclic guanosine monophosphate cascade-a pathophysiological pathway that has been targeted with limited success in HFrEF previously. Vericiguat, an sGC stimulator, was shown to improve outcomes in patients with HFrEF in the VICTORIA (Vericiguat Global Study in Subjects with Heart Failure with Reduced Ejection Fraction) trial. However, this trial included patients with recently worsening disease. In this brief review, we discuss the rationale of evaluating sGC stimulators in lower-risk HFrEF patients. First, all key HFrEF medications have been evaluated in both higher- and lower-risk populations, and the treatment effect is not always consistent across the risk spectrum. Second, pre-clinical studies and post-hoc studies of the VICTORIA trial have suggested that sGC stimulators may have cardioprotective effects-these effects may be more apparent when the medication is initiated earlier in the disease process. Third, the effect of vericiguat on cardiovascular mortality remains uncertain and a trial with a longer follow-up in a lower-risk population may allow better assessment of its effect on cardiovascular mortality. Therefore, there is a pertinent need to investigate the effects of vericiguat in optimally treated, low-risk HFrEF patients (i.e. those without recently worsening heart failure).

Antihypertensive Effects of a Soluble Guanylate Cyclase Stimulator.

We studied antihypertensive activity of an indolinone derivative (compound GRS), a soluble guanylate cyclase stimulator and a drug with previously proven antiaggregant effects. Contraction activity of isolated aorta segments of Wistar-Kyoto (WKY) rats was assessed in vitro using a mechanographic method. Addition of GRS (0.1-100 μМ) resulted in dose-dependent relaxation of endothelium-denuded aorta segments. Pretreatment of aorta smooth muscle segments with a specific inhibitor of soluble guanylate cyclase (ODQ, 1 μM) weakened the vasodilatory effect of GRS. Antihypertensive activity of the indolinone derivative GRS was studied in spontaneously hypertensive SHR rats. Single oral administration of 5 and 10 mg/kg GRS was followed by a significant dose-dependent reduction of systolic and diastolic BP in SHR rats. Antihypertensive effect of GRS in a dose of 5 mg/kg was more potent than that of the reference drug isosorbide dinitrate. GRS in a dose of 10 mg/kg did not affect systolic and diastolic BP in normotensive WKY rats.