Dual A1/A2B Receptor Blockade Improves Cardiac and Renal Outcomes in a Rat Model of Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is prevalent and often accompanied by metabolic syndrome. Current treatment options are limited. Here, we test the hypothesis that combined A1/A2B adenosine receptor blockade is beneficial in obese ZSF1 rats, an animal model of HFpEF with metabolic syndrome. The combined A1/A2B receptor antagonist 3-[4-(2,6-dioxo-1,3-dipropyl-7H-purin-8-yl)-1-bicyclo[2.2.2]octanyl]propanoic acid (BG9928) was administered orally (10 mg/kg/day) to obese ZSF1 rats (n = 10) for 24 weeks (from 20 to 44 weeks of age). Untreated ZSF1 rats (n = 9) served as controls. After 24 weeks of administration, BG9928 significantly lowered plasma triglycerides (in mg/dl: control group, 4351 ± 550; BG9928 group, 2900 ± 551) without adversely affecting plasma cholesterol or activating renin release. BG9928 significantly decreased 24-hour urinary glucose excretion (in mg/kg/day: control group, 823 ± 179; BG9928 group, 196 ± 80) and improved oral glucose tolerance, polydipsia, and polyuria. BG9928 significantly augmented left ventricular diastolic function in association with a reduction in cardiac vasculitis and cardiac necrosis. BG9928 significantly reduced 24-hour urinary protein excretion (in mg/kg/day: control group, 1702 ± 263; BG9928 group, 1076 ± 238), and this was associated with a reduction in focal segmental glomerulosclerosis, tubular atrophy, tubular dilation, and deposition of proteinaceous material in the tubules. These findings show that, in a model of HFpEF with metabolic syndrome, A1/A2B receptor inhibition improves hyperlipidemia, exerts antidiabetic actions, reduces HFpEF, improves cardiac histopathology, and affords renal protection. We conclude that chronic administration of combined A1/A2B receptor antagonists could be beneficial in patients with HFpEF, in particular those with comorbidities such as obesity, diabetes, and dyslipidemias.

Anti-JC virus antibody levels in serum or plasma further define risk of natalizumab-associated progressive multifocal leukoencephalopathy.

OBJECTIVE: The increased risk of progressive multifocal leukoencephalopathy (PML) with natalizumab treatment is associated with the presence of anti-JC virus (JCV) antibodies. We analyzed whether anti-JCV antibody levels, measured as index, may further define PML risk in seropositive patients. METHODS: The association between serum or plasma anti-JCV antibody levels and PML risk was examined in anti-JCV antibody-positive multiple sclerosis (MS) patients from natalizumab clinical studies and postmarketing sources. For PML and non-PML patients, the probabilities of having an index below and above a range of anti-JCV antibody index thresholds were calculated using all available data and applied to the PML risk stratification algorithm. Longitudinal stability of anti-JCV antibody index was also evaluated. RESULTS: Anti-JCV antibody index data were available for serum/plasma samples collected >6 months prior to PML diagnosis from 71 natalizumab-treated PML patients and 2,522 non-PML anti-JCV antibody-positive patients. In patients with no prior immunosuppressant use, anti-JCV antibody index distribution was significantly higher in PML patients than in non-PML patients (p < 0.0001). Among patients who were anti-JCV antibody negative at baseline in the AFFIRM and STRATIFY-1 trials, 97% remained consistently negative or below an index threshold of 1.5 over 18 months. Retrospective analyses of pre-PML samples collected longitudinally from PML patients displayed sustained higher anti-JCV antibody index over time. INTERPRETATION: Anti-JCV antibody levels in serum/plasma, measured as index, may differentiate PML risk in anti-JCV antibody-positive MS patients with no prior immunosuppressant use. Continued evaluation of anti-JCV antibody index and PML risk is warranted.

MS disease activity in RESTORE: a randomized 24-week natalizumab treatment interruption study.

OBJECTIVE: RESTORE was a randomized, partially placebo-controlled exploratory study evaluating multiple sclerosis (MS) disease activity during a 24-week interruption of natalizumab. METHODS: Eligible patients were relapse-free through the prior year on natalizumab and had no gadolinium-enhancing lesions on screening brain MRI. Patients were randomized 1:1:2 to continue natalizumab, to switch to placebo, or to receive alternative immunomodulatory therapy (other therapies: IM interferon ß-1a [IM IFN-ß-1a], glatiramer acetate [GA], or methylprednisolone [MP]). During the 24-week randomized treatment period, patients underwent clinical and MRI assessments every 4 weeks. RESULTS: Patients (n = 175) were randomized to natalizumab (n = 45), placebo (n = 42), or other therapies (n = 88: IM IFN-ß-1a, n = 17; GA, n = 17; MP, n = 54). Of 167 patients evaluable for efficacy, 49 (29%) had MRI disease activity recurrence: 0/45 (0%) natalizumab, 19/41 (46%) placebo, 1/14 (7%) IM IFN-ß-1a, 8/15 (53%) GA, and 21/52 (40%) MP. Relapse occurred in 4% of natalizumab patients and in 15%-29% of patients in the other treatment arms. MRI disease activity recurred starting at 12 weeks (n = 3 at week 12) while relapses were reported as early as 4-8 weeks (n = 2 in weeks 4-8) after the last natalizumab dose. Overall, 50/167 patients (30%), all in placebo or other-therapies groups, restarted natalizumab early because of disease activity. CONCLUSIONS: MRI and clinical disease activity recurred in some patients during natalizumab interruption, despite use of other therapies. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with MS taking natalizumab who are relapse-free for 1 year, stopping natalizumab increases the risk of MS relapse or MRI disease activity as compared with continuing natalizumab.

Clinical pharmacokinetics of tonapofylline: evaluation of dose proportionality, oral bioavailability, and gender and food effects in healthy human subjects.

Tonapofylline is an antagonist of adenosine A1 receptor being developed for heart failure. In the present studies, pharmacokinetic characteristics, including dose proportionality, bioavailability, and effects of gender and food, were evaluated in healthy subjects receiving single-dose tonapofylline (0.2-375 mg) in a parallel or crossover design. Following oral administration, tonapofylline concentrations mostly peaked within 3 hours and declined over time in a multiple phasic manner. Based on a power model, dose proportionality of peak concentration (C(max)), area under the time-concentration curve for all values (AUC(all)), and area under the time-concentration curve to infinity (AUC(inf)) was concluded in a clinical setting. The bioavailability of tonapofylline was 81.2% (90% confidence interval, 70.6%-93.5%). Following intravenous administration, the steady-state volume of distribution of tonapofylline was estimated to be 756 mL/kg. The total clearance of tonapofylline was low (64.8 mL/h/kg), approximately 5% of hepatic blood flow. The terminal half-life was variable within groups and ranged from 11.2 to 24.2 hours across the dose range. Female subjects showed significantly higher C(max), AUC(all), and AUC(inf) than male subjects (P < .05). Food decreased C(max) by approximately 39%, whereas it did not appear to affect AUC(all) and AUC(inf). The intersubject variability of the pharmacokinetic parameters of tonapofylline was generally less than 30%. In these studies, a single dose of tonapofylline was safe and well tolerated.

Effects of BG9928, an adenosine A1 receptor antagonist, in patients with congestive heart failure.

Previous studies suggest that adenosine A1 receptor antagonists may promote natriuresis without deleterious effects on renal function. This study evaluated renal and hemodynamic effects as well as safety, pharmacokinetics, and tolerability of BG9928, a selective adenosine A1-receptor antagonist, in patients with heart failure. In this multicenter, randomized, double-blind, placebo-controlled, dose-escalation study, 33 patients received a single dose of BG9928 (0.03, 0.3, 1.0, or 3.0 mg/kg) or placebo intravenously. Change from baseline in urinary sodium excretion for the 8-hour postdose interval was greater for all dosing groups versus placebo. The 0.03-mg/kg and 0.3-mg/kg groups had significant reductions in body weight versus placebo (-0.8 kg, -1.1 kg, 0.3 kg, respectively; P < 005). No changes in creatinine clearance or hemodynamic parameters were observed among any of the BG9928 groups versus placebo. However, pulmonary capillary wedge pressure tended to decrease and correlated with weight loss. Across the range of doses studied, pharmacokinetic parameters were linear and predictable. One patient who received the highest dose (3.0 mg/kg) developed seizures, and no further patients received that dose. Single intravenous BG9928 doses of up to 1.0 mg/kg were well tolerated and increased sodium excretion without worsening renal function. Further studies are needed to determine the clinical benefit of adenosine A1 receptor antagonism.

Protective effect of tonapofylline (BG9928), an adenosine A1 receptor antagonist, against cisplatin-induced acute kidney injury in rats.

BACKGROUND/AIMS: Cisplatin (CIS) induces nephrotoxicity partly through renal vasoconstriction and decreased glomerular filtration effects thought to involve adenosine acting on adenosine A(1) receptors (A1Rs). We studied the effect of the orally active, A1R antagonist tonapofylline (BG9928) on biochemical measures of renal function in CIS-induced acute kidney injury (AKI) in rats. METHODS: Tonapofylline, 1 mg/kg b.i.d., p.o., was administered on days 0-1 or 0-6 to rats treated with CIS 5.5 mg/kg i.v. Prednisolone (PRED) 5 mg/kg s.c. (day 0) served as a positive control. Serum creatinine and urea nitrogen (BUN) were measured in serial blood samples taken over the 13-day study period. RESULTS: CIS produced significant elevations in creatinine, reduction in body weight and marked proximal tubular injury throughout the renal cortex and outer medulla. Tonapofylline, days 0-1 or 0-6 and PRED all produced sustained reductions in post-CIS serum creatinine and BUN levels compared with controls, improved body weight recovery and significant attenuation of CIS-induced kidney pathology scores. CONCLUSION: These data support the involvement of A1Rs in CIS-induced AKI in rats. Tonapofylline may be useful in the clinical setting for the prevention of kidney failure induced by nephrotoxic agents such as CIS.

Effects of multiple oral doses of an A1 adenosine antagonist, BG9928, in patients with heart failure: results of a placebo-controlled, dose-escalation study.

OBJECTIVES: This study sought to assess the pharmacokinetics and clinical effects of oral BG9928 in heart failure (HF) patients. BACKGROUND: Declining renal function during HF treatment is associated with poor outcomes. BG9928, a selective inhibitor of the A1 adenosine receptor, is proposed to cause natriuresis without causing a decline in renal function. METHODS: A randomized, double-blind, placebo-controlled study was conducted in patients with HF and systolic dysfunction who were receiving standard therapy. Patients were randomized to receive BG9928 (3, 15, 75, or 225 mg) or placebo orally for 10 days. The primary end point was change in sodium excretion. Changes in potassium excretion, creatinine clearance, and body weight also were evaluated. RESULTS: A total of 50 patients were studied. BG9928 increased sodium excretion compared with placebo, and natriuresis was maintained over 10 days with little kaliuresis. A linear trend in dose response was observed on day 1 (p = 0.04) but not on days 6 or 10. Adjusted creatinine clearance was unchanged over the 10 days. Patients who received 15, 75, or 225 mg of BG9928 had a reduction in body weight compared with placebo (-0.6, -0.7, -0.5, vs. +0.3 kg, respectively) at the end of study. BG9928 was well tolerated. The pharmacokinetic profile of BG9928 was consistent with once-daily dosing. CONCLUSIONS: Oral BG9928 over the dose range of 3 to 225 mg/day produced significant increases in sodium excretion in patients with stable HF without causing kaliuresis or reducing renal function.

Alefacept in combination with ultraviolet B phototherapy for the treatment of chronic plaque psoriasis: results from an open-label, multicenter study.

Combination therapy for moderate to severe psoriasis is often used to enhance efficacy and minimize treatment-related side effects; however, data are limited on combination therapy with the newer biologic agents. The current study examined patients who received alefacept in combination with ultraviolet B phototherapy as part of an international, open-label study evaluating up to 3 courses of alefacept in combination with other psoriasis therapies. Physician Global Assessment [corrected] scores improved by [greater than or equal to] 1 category in 88% [corrected] of patients and by [greater than or equal to] 2 categories in 76% [corrected] of patients in course A; [corrected] corresponding response rates were 100% and 55% in Course [corrected] B, and 85% and 77% in Course [corrected] C. At week 14, a PGA of "almost clear" or "clear" was achieved by 13%, 14%, and 8% of patients in courses A, B, and C, respectively. There was no evidence of a cumulative effect on T cells after multiple courses of therapy. The combination of alefacept and ultraviolet B was well tolerated and provided improvement in psoriasis.

An integrated analysis of thirteen trials summarizing the long-term safety of alefacept in psoriasis patients who have received up to nine courses of therapy.

BACKGROUND: Information on longer-term safety and tolerability is needed to confidently prescribe alefacept therapy for chronic plaque psoriasis beyond 1 or 2 courses. OBJECTIVE: The aim of this work was to further examine the safety profile of alefacept by integrating data from clinical trials involving patients with chronic plaque psoriasis who received up to 9 courses of therapy over a 5-year period. METHODS: Data from 13 clinical trials conducted in patients with plaque psoriasis were integrated because they had similar inclusion/exclusion criteria and assessments. Patients who enrolled in the analyzed trials were aged > or =15 years with chronic plaque psoriasis for > or =12 months that involved > or =10% of body surface area, and CD4+ T lymphocyte counts above the lower limit of normal (>404 cells/microL). The incidences of adverse events (AEs), serious AEs, discontinuations for AEs, infections, serious infections, malignancies, and anti-alefacept antibodies were summarized for each course of alefacept. The incidence of infections was stratified according to CD4+ T lymphocyte counts (<250 cells/microL vs > or =250 cells/microL). RESULTS: Data from 13 clinical trials of alefacept were integrated and summarized (multicenter, randomized, double-blind studies, n = 6; multicenter, open-label studies, n = 5; other, n = 2). The analyzed population (n = 1869) included 1291 (69.1%) men and 578 (30.9%) women, between the ages of 15 and 84 years (mean, 44.8 years), of whom 1648 (88.2%) were white. Weights ranged from 40 kg to 206 kg (mean, 90.0 kg). A total of 1369 of these patients had been included in a previous analysis. Among the most commonly reported AEs in each treatment course were headache (0%-14.2%), nasopharyngitis (7.7%-25.0%), influenza (0%-8.1%), upper respiratory tract infection (0%-12.5%), and pruritus (0%-7.5%). The rates of discontinuations due to AEs (0%-4.8%), serious AEs (0%-4.8%), serious infections (0%-0.9%), or malignancies (0%-4.8%) did not appear to increase with repeated exposure. Fewer than 1 % of patients in each course developed a serious infection. No opportunistic infections or infection-related deaths were reported. The incidence of infections appeared to be unrelated to CD4+ T lymphocyte counts. Fewer than 2.5% of patients tested positive for anti-alefacept antibodies during any course of therapy. CONCLUSIONS: This integrated analysis of data from 13 trials with 1869 patients supports the safety and tolerability of alefacept for longer-term treatment of psoriasis.

Comparison of three different A1 adenosine receptor antagonists on infarct size and multiple cycle ischemic preconditioning in anesthetized dogs.

A(1) adenosine receptor (AR) antagonists are effective diuretic agents that may be useful for treating fluid retention disorders including congestive heart failure. However, antagonism of A(1)ARs is potentially a concern when using these agents in patients with ischemic heart disease. To address this concern, the present study was designed to compare the actions of the A(1)AR antagonists CPX (1,3-dipropyl-8-cyclopentylxanthine), BG 9719 (1,3-dipropyl-8-[2-(5,6-epoxynorbornyl)]xanthine), and BG 9928 (1,3-dipropyl-8-[1-(4-propionate)-bicyclo-[2,2,2]octyl]xanthine) on acute myocardial ischemia/reperfusion injury and ischemic preconditioning (IPC) in an in vivo dog model of infarction. Barbital-anesthetized dogs were subjected to 60 min of left anterior descending coronary artery occlusion followed by 3 h of reperfusion, after which infarct size was assessed by staining with triphenyltetrazolium chloride. IPC was elicited by four 5-min occlusion/5-min reperfusion cycles produced 10 min before the 60-min occlusion. Multiple-cycle IPC produced a robust reduction ( approximately 65%) in infarct size; this effect of IPC on infarct size was not abrogated in dogs pretreated with any of the three AR antagonists. Surprisingly, in the absence of IPC, pretreatment with CPX or BG 9928 before occlusion or immediately before reperfusion resulted in significant reductions ( approximately 40-50%) in myocardial infarct size. However, treatment with an equivalent dose of BG 9719 had no similar effect. We conclude that the A(1)AR antagonists BG 9719, BG 9928, and CPX do not exacerbate cardiac injury and do not interfere with IPC induced by multiple ischemia/reperfusion cycles. We discuss the possibility that the cardioprotective actions of CPX and BG 9928 may be related to antagonism of A(2B)ARs.

BG9719 (CVT-124), an A1 adenosine receptor antagonist, protects against the decline in renal function observed with diuretic therapy.

BACKGROUND: Adenosine may adversely affect renal function via its effects on renal arterioles and tubuloglomerular feedback, but effects of adenosine blockade in humans receiving furosemide and ACE inhibitors is unknown. METHODS AND RESULTS: This was a randomized, double-blind, ascending-dose, crossover study evaluating 3 doses of BG9719 in 63 patients with congestive heart failure. Patients received placebo or 1 of 3 doses of BG9719 on 1 day and the same medication plus furosemide on a separate day. Renal function and electrolyte and water excretion were assessed. BG9719 alone caused an increase in urine output and sodium excretion (P<0.05). Although administration of furosemide alone caused a large diuresis, addition of BG9719 to furosemide increased diuresis, which was significant at the 0.75-microg/mL concentration. BG9719 alone improved glomerular filtration rate (GFR) at the 2 lower doses. Furosemide alone caused a decline in GFR. When BG9719 was added to furosemide, however, creatinine clearance remained at baseline at the 2 lower doses. CONCLUSIONS: In patients with congestive heart failure on standard therapy, including ACE inhibitors, BG9719 increased both urine output and GFR. In these same patients, furosemide increased urine output at the expense of decreased GFR. When BG9719 was given in addition to furosemide, urine volume additionally increased and there was no deterioration in GFR. A1 adenosine antagonism might preserve renal function while simultaneously promoting natriuresis during treatment for heart failure.