Exposure-response analyses of efzofitimod in patients with pulmonary sarcoidosis.

Background: Preliminary evidence for efficacy in pulmonary sarcoidosis has been shown for efzofitimod. Here we present supportive evidence of efficacy based on an exposure-response analysis. Methods: Data from two studies (Phase 1, N = 24, single dose in healthy volunteers, and Phase 1b/2a, N = 25, multiple doses over 24 weeks in participants with pulmonary sarcoidosis) were used to build a population pharmacokinetic model. Using this model, the relationship between efzofitimod exposure and three prespecified efficacy parameters [mean daily oral corticosteroid (OCS) dose, percent-predicted forced vital capacity (ppFVC) and King's Sarcoidosis Questionnaire-Lung (KSQ-Lung) score] was explored. Linear regression described the relationship of efzofitimod exposure and OCS reduction, ppFVC and KSQ-Lung score. Logistic regression related efzofitimod exposure to the probability of achieving a minimal clinically important difference for ppFVC and KSQ-Lung score. Due to the small study size, trends (not statistical significance) in relationships are reported. Results: In patients with pulmonary sarcoidosis, as efzofitimod exposure increased, the mean daily OCS dose decreased, and ppFVC and KSQ-Lung score improved over baseline. The slope for all the endpoints by both linear and logistic regression showed an improving trend with increased exposure. Conclusion: These preliminary findings of a positive exposure-response across multiple efficacy endpoints support the claim that proof of concept has been established for the use of efzofitimod in pulmonary sarcoidosis. Clinical Trial Registration: clinicaltrials.gov, identifier NCT03824392.

Efzofitimod: a novel anti-inflammatory agent for sarcoidosis.

Efzofitimod is a first-in-class biologic based on a naturally occurring splice variant of histidyl-tRNA synthetase (HARS) that downregulates immune responses via selective modulation of neuropilin-2 (NRP2). Preclinical data found high expression of NRP2 in sarcoidosis granulomas. Treatment with efzofitimod reduced the granulomatous inflammation induced by P. acnes in an animal model of sarcoidosis. A dose escalating trial of efzofitimod in sarcoidosis with chronic symptomatic pulmonary disease found that treatment with efzofitimod was associated with improved quality of life with a trend towards reduced glucocorticoid use and stable to improved pulmonary function. These studies have led to a large Phase 3 trial of efzofitimod in symptomatic pulmonary sarcoidosis.

Efzofitimod for the Treatment of Pulmonary Sarcoidosis.

BACKGROUND: Pulmonary sarcoidosis is characterized by the accumulation of immune cells that form granulomas affecting the lungs. Efzofitimod (ATYR1923), a novel immunomodulator, selectively binds neuropilin 2, which is upregulated on immune cells in response to lung inflammation. RESEARCH QUESTION: What is the tolerability, safety, and effect on outcomes of efzofitimod in pulmonary sarcoidosis? STUDY DESIGN AND METHODS: In this randomized, double-blind, placebo-controlled study evaluating multiple ascending doses of efzofitimod administered intravenously every 4 weeks for 24 weeks, randomized patients (2:1) underwent a steroid taper to 5 mg/d by week 8 or < 5 mg/d after week 16. The primary end point was the incidence of adverse events (AEs); secondary end points included steroid reduction, change in lung function, and patient-reported outcomes on health-related quality-of-life scales. RESULTS: Thirty-seven patients received at least one dose of study medication. Efzofitimod was well tolerated at all doses, with no new or unexpected AEs and no dose-dependent AE incidence. Average daily steroid doses through end of study were 6.8 mg, 6.5 mg, and 5.6 mg for the 1 mg/kg, 3 mg/kg, and 5 mg/kg groups compared with 7.2 mg for placebo, resulting in a baseline-adjusted relative steroid reduction of 5%, 9%, and 22%, respectively. Clinically meaningful improvements were achieved across several patient-reported outcomes, several of which reached statistical significance in the 5 mg/kg dose arm. A dose-dependent but nonsignificant trend toward improved lung function also was observed for 3 and 5 mg/kg. INTERPRETATION: Efzofitimod was safe and well tolerated and was associated with dose-dependent improvements of several clinically relevant end points compared with placebo. The results of this study support further evaluation of efzofitimod in pulmonary sarcoidosis. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03824392; URL: www. CLINICALTRIALS: gov.

Home-based gait analysis as an exploratory endpoint during a multicenter phase 1 trial in limb girdle muscular dystrophy type R2 and facioscapulohumeral muscular dystrophy.

INTRODUCTION/AIMS: Limb girdle muscular dystrophy type 2B (LGMDR2) and facioscapulohumeral muscular dystrophy (FSHD) are genetic muscular dystrophies with an increasing number of potential therapeutic approaches. The aim of this study is to report the data of exploratory digital outcomes extracted from wearable magneto-inertial sensors used in a non-controlled environment for ambulant patients with FSHD and LGMDR2 in a short-term, multicenter clinical study. METHODS: Digital outcomes (stride length, stride speed, and walk parameters in a non-controlled environment) were used as exploratory outcomes in the open-label study ATYR1940-C-004 in ambulant patients during the 3 mo of ATYR1940 treatment and 1 mo of follow-up. Activity and gait variables were calculated from the data recorded in 30-day sub-periods using the sensors. For each sub-period, activity and gait parameters were compared between FSHD and LGMDR2 patients. Change from baseline over the 4-mo study period was assessed. RESULTS: Ten patients (5 FSHD, 5 LGMDR2) were ambulant and compliant for analysis. Gait parameters, but not activity variables, were significantly lower in LGMDR2 compared to FSHD patients at baseline. Longitudinal analyses showed a slight but significant decrease in stride speed at month 4 for all subjects. Activity variables such as total number of strides per day were highly variable from month to month in individual patients, and no visit effects were found for this variable. DISCUSSION: The present study suggests that home-recorded stride speed constitutes a precise and sensitive outcome in ambulant patients with FSHD and LGMDR2.

Effects of Ranolazine in Patients With Chronic Angina in Patients With and Without Percutaneous Coronary Intervention for Acute Coronary Syndrome: Observations From the MERLIN-TIMI 36 Trial.

BACKGROUND: Ranolazine, a piperazine derivative with anti-ischemic effects, reduces the frequency of angina and improves exercise performance in patients with chronic angina. The effects of ranolazine in patients with established ischemic heart disease and chronic angina undergoing percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) is not well described. We hypothesized that ranolazine would reduce ischemic events, regardless of revascularization. METHODS: We examined the 1-year incidence of recurrent cardiovascular (CV) events in the subgroup of patients with prior chronic angina (n = 3565) enrolled in the randomized, double-blind, placebo-controlled Metabolic Efficiency with Ranolazine for Less Ischemia in Non-ST-Elevation ACS (MERLIN)-Thrombolysis In Myocardial Infarction (TIMI) 36 trial who did or did not have a PCI within 30 days of the index event. RESULTS: Ranolazine reduced the risk of recurrent ischemia following admission regardless of whether patients had (hazard ratio [HR], 0.69; 95% confidence interval [CI] 0.51-0.92] or did not have PCI (HR, 0.81; 95% CI, 0.66-0.99; P interaction = 0.39). CV death, myocardial infarction, and recurrent ischemia were similarly lower with ranolazine in the PCI group (HR, 0.71; 95% CI, 0.55-0.91) vs the non-PCI group (HR, 0.91; 95% CI, 0.78-1.06; P interaction = 0.10), with a nominally significant decrease in CV death (HR, 0.39; 95% CI, 0.16-0.93) in the PCI group vs no difference in the non-PCI group (HR, 1.19; 95% CI, 0.89-1.59; P interaction = 0.02). CONCLUSIONS: In patients with chronic angina, ranolazine reduced recurrent ischemic events, regardless of whether patients did or did not receive PCI within 30 days of a non-ST-segment ACS.

Use of ranolazine in patients with incomplete revascularization after percutaneous coronary intervention: design and rationale of the Ranolazine for Incomplete Vessel Revascularization Post-Percutaneous Coronary Intervention (RIVER-PCI) trial.

BACKGROUND: Incomplete revascularization (ICR) after percutaneous coronary intervention (PCI) is common and is associated with increased rates of rehospitalization, revascularization, and mortality. Adjunctive pharmacotherapy with ranolazine, an inhibitor of the late sodium current with anti-ischemic properties, may be effective in reducing recurrent events after PCI in patients with ICR. TRIAL DESIGN: RIVER-PCI is a phase 3, randomized, double-blind, placebo-controlled, international event-driven clinical trial evaluating the efficacy of ranolazine in patients with a history of chronic angina and ICR after PCI. Approximately 2,600 participants with ICR post-PCI will be randomized in a 1:1 ratio to ranolazine or matched placebo within 14 days of an index PCI. The primary end point of the trial is time to the first occurrence of ischemia-driven revascularization or ischemia-driven hospitalization without revascularization. Participants will be followed up for a minimum of 1 year and until at least 720 confirmed primary end point events have occurred. Secondary end points include sudden cardiac death, cardiovascular death, myocardial infarction, and measures of quality of life and cost-effectiveness. The evaluation of long-term safety will include all-cause mortality, stroke, transient ischemic attack, and hospitalization for heart failure. Enrollment commenced in November 2011 and was completed in summer 2013. CONCLUSIONS: RIVER-PCI is a novel, large-scale, international, randomized, double-blind, placebo-controlled clinical trial evaluating the role of ranolazine in the long-term medical management of patients with ICR post-PCI.

Anticipated classes of new medications and molecular targets for pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) remains a life-limiting condition with a major impact on the ability to lead a normal life. Although existing therapies may improve the outlook in some patients there remains a major unmet need to develop more effective therapies in this condition. There have been significant advances in our understanding of the genetic, cell and molecular basis of PAH over the last few years. This research has identified important new targets that could be explored as potential therapies for PAH. In this review we discuss whether further exploitation of vasoactive agents could bring additional benefits over existing approaches. Approaches to enhance smooth muscle cell apotosis and the potential of receptor tyrosine kinase inhibition are summarised. We evaluate the role of inflammation, epigenetic changes and altered glycolytic metabolism as potential targets for therapy, and whether inherited genetic mutations in PAH have revealed druggable targets. The potential of cell based therapies and gene therapy are also discussed. Potential candidate pathways that could be explored in the context of experimental medicine are identified.

Effects of rifampicin (rifampin) on the pharmacokinetics and safety of ambrisentan in healthy subjects: a single-sequence, open-label study.

BACKGROUND: Ambrisentan is a once-daily, endothelin (ET) type A receptor-selective antagonist approved for the treatment of pulmonary arterial hypertension. Ambrisentan is primarily metabolized by glucuronidation and undergoes cytochrome P450 (CYP)-mediated oxidation to a lesser extent. OBJECTIVE: To assess the effects of rifampicin (rifampin), a potent inducer of CYP3A4 and inhibitor of organic anion transporter polypeptides (OATPs), on the steady-state pharmacokinetics, safety and tolerability of ambrisentan. METHODS: This was a 14-day, single-sequence, open-label study that was conducted in 24 healthy adults. Subjects were administered oral doses of ambrisentan (10 mg) once daily on days 1 through 5 and were then co-administered ambrisentan (10 mg) plus rifampicin (600 mg) once daily on days 6 through 13. The steady-state pharmacokinetics of ambrisentan and its oxidative metabolite 4-hydroxymethyl ambrisentan were determined in the absence and presence of repeated administration of rifampicin. The main outcome measure was the analysis of ambrisentan pharmacokinetics (area under the plasma concentration-time curve during a dosage interval [AUC(τ)], maximum plasma drug concentration [C(max)] and minimum plasma drug concentration [C(min)]) for steady-state ambrisentan alone (day 5) as compared with steady-state ambrisentan plus steady-state rifampicin (day 13). Adverse events (AEs), ECG recordings, vital signs and clinical laboratory parameters were monitored throughout the study and at follow-up. RESULTS: A transient increase (+87% [95% CI 79, 95]) in ambrisentan steady-state systemic exposure (AUC(τ)) was observed during the first 2 days of rifampicin co-administration. However, in the presence of steady-state rifampicin, ambrisentan C(max) and AUC(τ) values were similar (+2% [95% CI -7, 12] and -4% [-9, 2], respectively) to those observed for ambrisentan alone. Relative systemic exposure of 4-hydroxymethyl ambrisentan was unaffected by either acute or steady-state rifampicin. No serious AEs or AEs leading to withdrawal were reported and there were no clinically significant changes in vital signs, ECG recordings or clinical laboratory parameters with co-administration of ambrisentan and rifampicin. CONCLUSION: Steady-state rifampicin had no clinically relevant effects on the steady-state pharmacokinetics of ambrisentan. The overall safety profile of ambrisentan was similar in the presence and absence of rifampicin. No dose adjustment of ambrisentan should be required when it is co-administered with rifampicin, a strong inducer of CYP3A4 activity and inhibitor of OATPs.

Effect of steady-state ambrisentan on the pharmacokinetics of a single dose of the oral contraceptive norethindrone (norethisterone) 1 mg/ethinylestradiol 35 microg in healthy subjects: an open-label, single-sequence, single-centre study.

BACKGROUND: Ambrisentan is an oral, once-daily endothelin receptor antagonist (ERA) that is approved for the treatment of pulmonary arterial hypertension (PAH). Pregnancy is not recommended for women of childbearing potential with PAH, due to an increased risk of mortality. Additionally, the ERA class is teratogenic in animal studies. A highly effective method of contraception is therefore strongly recommended for women of childbearing potential who are treated with an ERA for PAH. OBJECTIVE: This study investigated the effect of ambrisentan on the pharmacokinetics (PK) of the oral contraceptive norethindrone (norethisterone) 1 mg/ethinylestradiol 35 microg (NT 1 mg/EE 35 microg). METHODS: The study was an open-label, single-sequence, PK study designed to assess the effect of multiple doses of ambrisentan (Letairis; Volibris) on the PK of a single oral dose of NT 1 mg/EE 35 microg (Ortho-Novum 1/35) in a single clinical research centre in the US. The study included 28 healthy female subjects in general good health, aged 18-45 years, and who had a body mass index of 18.5-29.9 kg/m2. A single oral dose of NT 1 mg/EE 35 microg was administered on day 1. On day 10, following a wash-out period, fasted subjects received once-daily 10 mg doses of ambrisentan for 12 days. On day 22, a single oral dose of NT 1 mg/EE 35 microg and a single 10 mg oral dose of ambrisentan were coadministered; thereafter, subjects continued to receive once-daily oral doses of ambrisentan 10 mg on days 23 through 26. The primary PK endpoints included maximum observed plasma drug concentration (C(max)), time to reach C(max) (t(max)), and the area under the plasma concentration-time curve from time zero to the time of last measurable concentration (AUC(last)). RESULTS: Ethinylestradiol C(max) was slightly decreased (geometric mean ratio [GMR] 91.7%; 90% CI 86.1, 97.8) and AUC(last) was similar (GMR 99.1%; 90% CI 91.0, 107.9) in the presence of ambrisentan compared with NT 1 mg/EE 35 microg. Norethindrone C(max) (GMR 113.2%; 90% CI 102.4, 125.1) and AUC(last) (GMR 112.9%; 90% CI 104.9, 121.6) were slightly increased in the presence of ambrisentan. The 90% CIs were within the pre-defined no-effect boundaries for all PK parameters, except for the C(max) of norethindrone, which was slightly above the upper limit of 125%. No safety concerns were apparent with the coadministration of NT 1 mg/EE 35 microg and ambrisentan. CONCLUSION: No dose adjustment of the oral contraceptive NT 1 mg/EE 35 microg is warranted with the coadministration of ambrisentan.

The pharmacokinetics and pharmacodynamics of warfarin in combination with ambrisentan in healthy volunteers.

AIMS: Ambrisentan is an oral, propanoic acid-based endothelin receptor antagonist often co-administered with warfarin to patients with pulmonary arterial hypertension. The aim of this study was to evaluate the potential for ambrisentan to affect warfarin pharmacokinetics and pharmacodynamics. METHODS: In this open-label cross-over study, 22 healthy subjects received a single dose of racemic warfarin 25 mg alone and after 8 days of ambrisentan 10 mg once daily. Assessments included exposure (AUC(0-last)) and maximum plasma concentration (C(max)) for R- and S-warfarin, and International Normalized Ratio maximum observed value (INR(max)) and area under the curve (INR(AUC(0-last))). The effects of warfarin on ambrisentan steady-state pharmacokinetics and the safety of ambrisentan/warfarin co-administration were assessed. Data are presented as geometric mean ratios. RESULTS: Ambrisentan had no significant effects on the AUC(0-last) of R-warfarin [104.7; 90% confidence interval (CI) 101.7, 107.7) or S-warfarin (101.6; 90% CI 98.4, 105.0). Similarly, ambrisentan had no significant effects on the C(max) of R-warfarin (91.6; 90% CI 86.2, 97.4) or S-warfarin (89.9; 90% CI 84.8, 95.3). Consistent with these observations, little pharmacodynamic change was observed for INR(max) (85.3; 90% CI 82.4, 88.2) or INR(AUC(0-last)) (93.0; 90% CI 90.8, 95.3). In addition, co-administration of warfarin did not alter ambrisentan steady-state pharmacokinetics. Adverse events were infrequent, and there were no bleeding adverse events. CONCLUSIONS: Multiple doses of ambrisentan had no clinically relevant effects on the pharmacokinetics and pharmacodynamics of a single dose of warfarin. Therefore, significant dose adjustments of either drug are unlikely to be required with co-administration.

Effect of ketoconazole on the pharmacokinetic profile of ambrisentan.

Ambrisentan is an endothelin type A (ET(A))-selective receptor antagonist that is metabolized primarily by glucuronidation but also undergoes oxidative metabolism by CYP3A4. The potential for ketoconazole, the archetypal strong inhibitor of CYP3A4, to alter the pharmacokinetic profile of ambrisentan and its oxidative metabolite, 4-hydroxymethyl ambrisentan, was assessed in an open-label, nonrandomized, 2-period, single-sequence study in 16 healthy men. Participants received a single dose of ambrisentan 10 mg alone and after 4 days of ketoconazole 400 mg administered once daily. In the presence of multiple doses of ketoconazole, single-dose ambrisentan AUC(0-infinity) estimate was increased by 35.3%, whereas C(max) was increased by 20.0%. For the 4-hydroxymethyl ambrisentan metabolite, AUC(0-infinity) estimate was decreased by 4.0%, whereas C(max) was decreased by 16.5%. Concomitant administration of ambrisentan and ketoconazole was well tolerated. In summary, ketoconazole had no clinically significant effect on the pharmacokinetics or safety profile of ambrisentan; therefore, no changes in ambrisentan dose should be necessary when the drug is administered concomitantly with known CYP3A4 inhibitors.

Designing scaffolds for valvular interstitial cells: cell adhesion and function on naturally derived materials.

Valvular interstitial cells (VICs) possess many properties that make them attractive for use in the construction of a tissue-engineered valve; however, we have found that the surfaces to which VICs will adhere and spread are limited. For example, VICs adhere and spread on collagen and laminin-coated surfaces, but display altered morphology and do not proliferate. Interestingly, fibronectin (FN) was one adhesion protein that facilitated VIC adhesion and proliferation. Yet VICs did not spread on surfaces modified with RGD, a ubiquitous cell-adhesive peptide, nor with other FN-specific peptide sequences such as EILDV and PHSRN. Hyaluronic acid (HA) is a highly elastic polysaccharide that is involved in natural valve morphogenesis and possesses binding interactions with FN. Hyaluronic acid was modified to form photopolymerizable hydrogels, and VICs were found to spread and proliferate on HA-based gels, forming a confluent monolayer on the gels within 4 days. Modified HA retained its ability to specifically bind FN, allowing for the formation of gels containing both HA and FN. Valvular interstital cells cultured on HA surfaces displayed significantly increased production of extracellular matrix proteins, indicating that HA-based scaffolds may provide useful biological cues to stimulate heart valve tissue formation.

Valvular myofibroblast activation by transforming growth factor-beta: implications for pathological extracellular matrix remodeling in heart valve disease.

The pathogenesis of cardiac valve disease correlates with the emergence of muscle-like fibroblasts (myofibroblasts). These cells display prominent stress fibers containing alpha-smooth muscle actin (alpha-SMA) and are believed to differentiate from valvular interstitial cells (VICs). However, the biological factors that initiate myofibroblast differentiation and activation in valves remain unidentified. We show that transforming growth factor-beta1 (TGF-beta1) mediates differentiation of VICs into active myofibroblasts in vitro in a dose-dependent manner, as determined by a significant increase in alpha-SMA and the dramatic augmentation of stress fiber formation and alignment. Additionally, TGF-beta1 and increased mechanical stress function synergistically to enhance contractility. In turn, contractile valve myofibroblasts exert tension on the extracellular matrix, resulting in a dramatic realignment of extracellular fibronectin fibrils. TGF-beta1 also inhibits valve myofibroblast proliferation without enhancing apoptosis. Our results are consistent with activation of a highly contractile myofibroblast phenotype by TGF-beta1 and are the first to connect valve myofibroblast contractility with pathological valve matrix remodeling. We suggest that the activation of contractile myofibroblasts by TGF-beta1 may be a significant first step in promoting alterations to the valve matrix architecture that are evident in valvular heart disease.