Effects of orally administered crofelemer on the incidence and severity of neratinib-induced diarrhea in female dogs.

Targeted therapies have increased cancer therapy-related diarrhea (CTD) burden, with high incidence and/or severity of diarrhea for some agents that inhibit epidermal growth factor receptor and receptor tyrosine kinases. Neratinib is a pan-HER tyrosine kinase inhibitor approved for breast cancer treatment and causes severe diarrhea in >95% of patients. Crofelemer, a novel intestinal chloride ion channel modulator, is an approved antidiarrheal drug for symptomatic relief of noninfectious diarrhea in patients with HIV/AIDS receiving antiretroviral therapy. The objective of this study was to evaluate the effectiveness of crofelemer prophylaxis in reducing the incidence /severity of neratinib-induced diarrhea without concomitant administration of loperamide in female beagle dogs. A pilot study using 3 dogs determined a maximum daily tolerated dose of neratinib was between 40 and 80 mg; this dose would induce a consistent incidence/severity of diarrhea without risking severe dehydration. In the definitive study, 24 female beagle dogs (8/group) received neratinib once daily and placebo capsules (CTR) four times/day, or neratinib once daily and crofelemer 125 mg delayed-release tablets given two times (BID), or neratinib once daily and crofelemer 125 mg delayed-release tablets given four times per day (QID). Fecal scores were collected twice daily using an established canine stool scoring scale called the Purina Fecal Scoring (PFS) System. After 28 days, using analysis of covariance (ANCOVA), dogs in the CTR group had a significantly higher average number of weekly loose/watery stools (PFS of 6 or 7) when compared to either crofelemer BID (8.71±2.2 vs. 5.96±2.2, p = 0.028) or crofelemer QID (8.70±2.2 vs. 5.74±2.2, p = 0.022) treatment groups. The average number of weekly loose/watery stools were not different between the crofelemer BID and QID treatment groups (p = 0.84). This study showed that crofelemer prophylaxis reduced the incidence/severity of neratinib-associated diarrhea in female beagle dogs without the need for any loperamide administration.

Diagnostic performance of circulating biomarkers for non-alcoholic steatohepatitis.

There are no approved diagnostic biomarkers for at-risk non-alcoholic steatohepatitis (NASH), defined by the presence of NASH, high histological activity and fibrosis stage ≥2, which is associated with higher incidence of liver-related events and mortality. FNIH-NIMBLE is a multi-stakeholder project to support regulatory approval of NASH-related biomarkers. The diagnostic performance of five blood-based panels was evaluated in an observational (NASH CRN DB2) cohort (n = 1,073) with full spectrum of non-alcoholic fatty liver disease (NAFLD). The panels were intended to diagnose at-risk NASH (NIS4), presence of NASH (OWLiver) or fibrosis stages >2, >3 or 4 (enhanced liver fibrosis (ELF) test, PROC3 and FibroMeter VCTE). The prespecified performance metric was an area under the receiver operating characteristic curve (AUROC) ≥0.7 and superiority over alanine aminotransferase for disease activity and the FIB-4 test for fibrosis severity. Multiple biomarkers met these metrics. NIS4 had an AUROC of 0.81 (95% confidence interval: 0.78-0.84) for at-risk NASH. The AUROCs of the ELF test, PROC3 and FibroMeterVCTE for clinically significant fibrosis (≥stage 2), advanced fibrosis (≥stage 3) or cirrhosis (stage 4), respectively, were all ≥0.8. ELF and FibroMeter VCTE outperformed FIB-4 for all fibrosis endpoints. These data represent a milestone toward qualification of several biomarker panels for at-risk NASH and also fibrosis severity in individuals with NAFLD.

The Nimble Stage 1 Study Validates Diagnostic Circulating Biomarkers for Nonalcoholic Steatohepatitis.

Background There are no approved noninvasive tests (NIT) for the diagnosis of nonalcoholic steatohepatitis (NASH) and its histological phenotypes. Methods The FNIH-NIMBLE consortium tested 5 serum-based NIT panels for the following intended uses: NIS4: At-risk NASH, a composite of NASH with NAFLD activity score (NAS) ≥ 4 and fibrosis stage ≥ 2, OWLiver: NASH and NAS ≥ 4, enhanced liver fibrosis (ELF), PROC3 and Fibrometer VCTE: fibrosis stages ≥ 2, ≥ 3 or 4. Aliquots from a single blood sample obtained within 90 days of histological confirmation of NAFLD were tested. The prespecified performance metric tested for was a diagnostic AUROC greater than 0.7 and superiority to ALT for diagnosis of NASH or NAS ≥ 4 and to FIB-4 for fibrosis. Results A total of 1073 adults including NASH (n = 848), at-risk NASH (n = 539) and fibrosis stages 0-4 (n = 222, 114, 262, 277 and 198 respectively) were studied. The AUROC of NIS4 for at-risk NASH was 0.81 and superior to ALT and FIB4 (p < 0.001 for both). OWliver diagnosed NASH with sensitivity and specificity of 77.3% and 66.8% respectively. The AUROCs (95% CI) of ELF, PROC3 and Fibrometer VCTE respectively for fibrosis were as follows: ≥ stage 2 fibrosis [0.82 (0.8-0.85), 0.8 (0.77-0.83), and 0.84 (0.79-0.88)], ≥ stage 3 [0.83 (0.8-0.86), 0.76 (0.73-0.79), 0.85 (0.81-0.9), stage 4 [0.85 (0.81-0.89), 0.81 (0.77-0.85), 0.89 (0.84-0.95)]. ELF and Fibrometer VCTE were significantly superior to FIB-4 for all fibrosis endpoints (p < 0.01 for all). Conclusions These data support the further development of NIS4, ELF and Fibrometer VCTE for their intended uses.

Efficacy and safety of elinzanetant, a selective neurokinin-1,3 receptor antagonist for vasomotor symptoms: a dose-finding clinical trial (SWITCH-1).

OBJECTIVE: Neurokinin (NK)-3 and NK-1 receptors have been implicated in the etiology of vasomotor symptoms (VMS) and sleep disturbances associated with menopause. This phase 2b, adaptive, dose-range finding study aimed to assess the efficacy and safety of multiple doses of elinzanetant (NT-814), a selective NK-1,3 receptor antagonist, in women experiencing VMS associated with menopause, and investigate the impact of elinzanetant on sleep and quality of life. METHODS: Postmenopausal women aged 40 to 65 years who experienced seven or more moderate-to-severe VMS per day were randomized to receive elinzanetant 40, 80, 120, or 160 mg or placebo once daily using an adaptive design algorithm. Coprimary endpoints were reduction in mean frequency and severity of moderate-to-severe VMS at weeks 4 and 12. Secondary endpoints included patient-reported assessments of sleep and quality of life. RESULTS: Elinzanetant 120 mg and 160 mg achieved reductions in VMS frequency versus placebo from week 1 throughout 12 weeks of treatment. Least square mean reductions were statistically significant versus placebo at both primary endpoint time points for elinzanetant 120 mg (week 4: -3.93 [SE, 1.02], P < 0.001; week 12: -2.95 [1.15], P = 0.01) and at week 4 for elinzanetant 160 mg (-2.63 [1.03]; P = 0.01). Both doses also led to clinically meaningful improvements in measures of sleep and quality of life. All doses of elinzanetant were well tolerated. CONCLUSIONS: Elinzanetant is an effective and well-tolerated nonhormone treatment option for postmenopausal women with VMS and associated sleep disturbance. Elinzanetant also improves quality of life in women with VMS.

Safety and Pharmacokinetics of Recombinant Human Plasma Gelsolin in Patients Hospitalized for Nonsevere Community-Acquired Pneumonia.

There remains an unmet need to address the substantial morbidity and mortality associated with severe community-acquired pneumonia (sCAP). Recombinant human plasma gelsolin (rhu-pGSN) improves disease outcomes in diverse animal models of infectious and noninfectious inflammation. This blinded dose-escalation safety study involved non-intensive care unit (ICU) patients admitted for mild CAP and randomized 3:1 to receive adjunctive rhu-pGSN or placebo intravenously. Thirty-three subjects were treated: 8 in the single-dose phase and 25 in the multidose phase. For the single-dose phase, rhu-pGSN at 6 mg/kg of body weight was administered once. For the multidose phase, a daily rhu-pGSN dose of 6, 12, or 24 mg/kg was given on 3 consecutive days. Adverse events (AEs) were generally mild in both treatment groups irrespective of dose. The only serious AE (SAE) in the single-dose phase was a non-drug-related pneumonia in a rhu-pGSN recipient who died after institution of comfort care. One single-dose placebo recipient had a drug-related AE (maculo-papular rash). In the multidose phase, there were 2 SAEs in 1 placebo recipient, including a fatal pulmonary embolism. In the 18 rhu-pGSN recipients in the multidose phase, there were no serious or drug-related AEs, and nausea and increased blood pressure were each reported in 2 patients. The median rhu-pGSN half-life exceeded 17 h with all dosing regimens, and supraphysiologic levels were maintained throughout the 24-h dosing interval in the 2 highest dosing arms. Rhu-pGSN was well tolerated overall in CAP patients admitted to non-ICU beds, justifying a larger proof-of-concept trial in an ICU population admitted with sCAP. (This study has been registered at ClinicalTrials.gov under identifier NCT03466073.).

Antisense oligonucleotide eluforsen improves CFTR function in F508del cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. In this study we assessed the effect of antisense oligonucleotide eluforsen on CFTR biological activity measured by Nasal Potential Difference (NPD) in patients with the most common mutation, F508del-CFTR. METHODS: This multi-centre, exploratory, open-label study recruited adults with CF homozygous or compound heterozygous for the F508del-CFTR mutation. Subjects received intranasal eluforsen three times weekly for 4 weeks. The primary endpoint was the within-subject change from baseline in total chloride transport (Cl-free+iso), as assessed by NPD. Secondary endpoints included within-subject change from baseline in sodium transport. RESULTS: In the homozygous cohort (n = 7; per-protocol population), mean change (90% confidence interval) in Cl-free+iso was -3.0 mV (-6.6; 0.6) at day 15, -4.1 mV (-7.8; -0.4, p = .04) at day 26 (end of treatment) and - 3.7 mV (-8.0; 0.6) at day 47. This was supported by improved sodium transport as assessed by an increase in average basal potential difference at day 26 of +9.4 mV (1.1; 17.7, p = .04). The compound heterozygous cohort (n = 7) did not show improved chloride or sodium transport NPD values. Eluforsen was well tolerated with a favourable safety profile. CONCLUSIONS: In F508del-CFTR homozygous subjects, repeated intranasal administration of eluforsen improved CFTR activity as measured by NPD, an encouraging indicator of biological activity.

Optimizing adaptive design for Phase 2 dose-finding trials incorporating long-term success and financial considerations: A case study for neuropathic pain.

In this paper, we propose an adaptive randomization design for Phase 2 dose-finding trials to optimize Net Present Value (NPV) for an experimental drug. We replace the traditional fixed sample size design (Patel, et al., 2012) by this new design to see if NPV from the original paper can be improved. Comparison of the proposed design to the previous design is made via simulations using a hypothetical example based on a Diabetic Neuropathic Pain Study.

Topical safety and vasoconstrictive assay-based bioequivalence of a new reformulated mometasone cream.

OBJECTIVES: A new improved mometasone furoate (Elocon™) cream with an emulsification system that produces a stable emulsion has been developed. In order to register the product in various markets, it was essential to ensure the cream was topically well tolerated and that it was bioequivalent to the reference product. METHODS: Phase I clinical studies were performed to assess the local safety and tolerability upon multiple dosing of this new cream as well as to assess the single-dose bioequivalence relative to the marketed product. Bioequivalence was assessed using a vasoconstrictive assay (VCA) after a dose-duration pilot study was completed with the marketed Elocon cream. KEY FINDINGS: The new mometasone cream and its vehicle were nonirritating in healthy subjects during 21-day patch application (MCII <0.025). The positive control was moderately irritating in the same study. The pivotal VCA study enrolled 162 subjects with 105 detectors included in the analysis of bioequivalence. In the 105 detectors, the ratio (×100%) of AUEC values at ED50 for test vs. standard (90% CI) was 112.91% (105.55, 120.87), within the bioequivalence criteria of (80, 125). CONCLUSIONS: These studies supported the registration of reformulated mometasone cream in various markets.

Methodological Extensions of Phase 2 Trial Designs Based on Program-Level Considerations: Further Development of a Case Study in Neuropathic Pain.

BACKGROUND: Traditionally, sample size considerations for Phase 2 (Ph2) trials are based on the desired properties of the design and response information from the trials. METHODS: This work extends that of Patel et al (2012) to design Ph2 trials based on program-level optimization (ie, optimizing the entire Ph2/3 trial design strategy). It describes a framework to evaluate the impact that several Ph2 design features have on the probability of Phase 3 (Ph3) success and the expected net present value (eNPV) of the product. These factors include the Ph2 sample size, decision rules to select Ph3 dose(s) and sample sizes, as well as number of Ph3 trials. Using neuropathic pain as an example, simulations illustrate the framework and show the benefit of including these factors in the overall decision process. Patel et al considered one dose of test drug in each of exactly two Ph3 trials. This work extends that to consider 1 or 2 doses in each of 2 Ph3 trials and, if needed, 1 or 2 additional Ph3 trials to substantiate the usefulness of the second dose. RESULTS: We found that employing a quantitative algorithmic strategy to choose 1 or 2 doses for Ph3 based on trial results does not substantially alter the eNPV compared to a strategy of always taking 2 doses to Ph3, if appropriate. Similar to the findings by Patel et al, for 1 Ph3 dose, we found that Ph2 sample size can be optimized at small to modest sizes when allowing for the possibility of taking 2 doses to Ph3. We found that choice of number of Ph2 doses depends on the magnitudes and shapes of the true underlying efficacy and safety dose-response curves. CONCLUSION: Simulating a sequence of clinical trials can inform trial design and drug development strategy.

A randomized, phase 2 study investigating TRV130, a biased ligand of the µ-opioid receptor, for the intravenous treatment of acute pain.

Efficacy of conventional opioids can be limited by adverse events (AEs). TRV130 is a structurally novel biased ligand of the µ-opioid receptor that activates G protein signaling with little ß-arrestin recruitment. In this phase 2, randomized, placebo- and active-controlled study, we investigated the efficacy and tolerability of TRV130 in acute pain after bunionectomy. We used an adaptive study design in which 144 patients experiencing moderate-to-severe acute pain after bunionectomy were randomized to receive double-blind TRV130, placebo, or morphine in a pilot phase. After pilot phase analysis, 195 patients were randomized to receive double-dummy TRV130 0.5, 1, 2, or 3 mg every 3 hours (q3h); placebo; or morphine 4 mg q4h intravenously. The primary end point was the time-weighted average change in numeric rating scale pain intensity over the 48-hour treatment period. Secondary end points included stopwatch and categorical assessments of pain relief. Safety and tolerability were also assessed. TRV130 2 and 3 mg q3h, and morphine 4 mg q4h produced statistically greater mean reductions in pain intensity than placebo over 48 hours (P < 0.005). TRV130 at 2 and 3 mg produced significantly greater categorical pain relief than morphine (P < 0.005) after the first dose, with meaningful pain relief occurring in under 5 minutes. TRV130 produced no serious AEs, with tolerability similar to morphine. These results demonstrate that TRV130 rapidly produces profound analgesia in moderate-to-severe acute pain, suggesting that G-protein-biased µ-opioid receptor activation is a promising target for development of novel analgesics.

An intra-articular, extended-release formulation of triamcinolone acetonide prolongs and amplifies analgesic effect in patients with osteoarthritis of the knee: a randomized clinical trial.

BACKGROUND: Intra-articular corticosteroids are a mainstay in the treatment of knee osteoarthritis, and in clinical trials, they demonstrate a large initial analgesic effect that wanes over one to four weeks with the rapid efflux of drug from the joint. The present study was undertaken to determine if FX006, an extended-release formulation of triamcinolone acetonide, can provide pain relief that is superior to the current standard of care, immediate-release triamcinolone acetonide. METHODS: In this Phase-2, double-blind, multicenter study, 228 patients with moderate to severe knee osteoarthritis pain were randomized to a single intra-articular injection of FX006 (containing 10, 40, or 60 mg of triamcinolone acetonide) or 40 mg of immediate-release triamcinolone acetonide. Data on the mean daily pain on the 11-point Numeric Rating Scale were collected over twelve weeks; the primary efficacy end point was the change from baseline to each of eight, ten, and twelve weeks in the weekly mean of the mean daily pain intensity scores analyzed with a longitudinal mixed-effects model. RESULTS: The 10-mg dose of FX006 produced pain relief that was improved relative to immediate-release triamcinolone acetonide at two through twelve weeks, although the difference in pain relief was not significant (p ≥ 0.05). The 40-mg dose of FX006 produced pain relief that was improved at two through twelve weeks and was significantly superior to immediate-release triamcinolone acetonide at five to ten weeks (p < 0.05 at each time point). At the 40-mg dose of FX006, prespecified secondary analyses, including responder analyses and all Western Ontario and McMaster Universities subscales, were significantly superior (p < 0.05) to immediate-release triamcinolone acetonide at eight weeks, and the time-weighted mean pain relief (assessed with mean daily pain intensity scores) was significantly superior to immediate-release triamcinolone acetonide over one to twelve weeks (p = 0.04). The 60-mg dose did not provide additional improvement relative to the 40-mg dose. Adverse events were generally mild and similar across all treatments. CONCLUSIONS: Intra-articular injection of FX006, an extended-release formulation of triamcinolone acetonide, provided a clinically relevant improvement in pain relief in patients with knee osteoarthritis relative to immediate-release triamcinolone acetonide, the current standard of care. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Early Clinical Development Planning via Biomarkers, Clinical Endpoints, and Simulation: A Case Study to Optimize for Phase 3 Dose Selection.

BACKGROUND: This study investigated a framework that leverages the relationship between biomarkers and a target clinical endpoint to optimize an early development plan. METHODS: Different biomarker designs were assessed for proof of concept (PoC) and dose finding (DF) to improve phase 2b (Ph2b) design as well as phase 3 (Ph3) dose choice. A case study using a Bayesian trivariate normal distribution model for 2 biomarkers and a clinically relevant endpoint was utilized with simulation to assess performance characteristics. RESULTS: We found the following: (1) at typical sample sizes for early development trials, biomarkers appear useful for PoC but not for clinical endpoint DF; and (2) even with large amounts of prior information and near perfect correlation between biomarkers and clinical endpoints, Ph2b variability is only overcome by increased Ph2b sample sizes to improve Ph3 dose choice. CONCLUSIONS: For highly variable clinical endpoints, the fastest path should be to demonstrate PoC by biomarkers and then go directly to Ph2b to measure the target clinical endpoint.

Evaluation of an Adaptive Maximizing Design Study Based on Clinical Utility Versus Morphine for TRV130 Proof-of-Concept and Dose-Regimen Finding in Patients With Postoperative Pain After Bunionectomy.

BACKGROUND: Conventional opioids provide powerful analgesia but also produce efficacy-limiting adverse effects, limiting their clinical utility (CU). TRV130 is being evaluated to determine whether CU can be expanded by way of increased efficacy, decreased adverse effects, or some combination thereof. METHODS: This phase 2 study of TRV130 blends traditional objectives with novel design features aimed toward the specific strategic goal of optimizing the attributes of TRV130 efficacy and tolerability compared with the conventional opioid, morphine. The adaptive maximizing design (AMD) was developed to maximize assignment of future patients to doses that demonstrate maximum balance between efficacy and tolerability (ie, CU) assessed via a CU function. RESULTS: Our evaluation of the AMD performance characteristics reveals that the AMD has a strong capacity to estimate the TRV130 dose-regimens with maximum CU, assign more patients to the TRV130 dose-regimens with maximum CU, and, conversely, assign fewer patients to doses away from the those with maximum or near-maximum CU. CONCLUSIONS: Based on this evaluation of performance characteristics of the AMD versus a traditional study design, the AMD was selected for this proof-of-concept and dose-regimen finding study of TRV130.

Predicting response to pregabalin from pretreatment pain quality: clinical applications of the pain quality assessment scale.

OBJECTIVE: The aim of this study is to assess the Pain Quality Assessment Scale (PQAS) in predicting pregabalin in peripheral neuropathic pain (NP). STUDY DESIGN: Post hoc analysis of a double-blind, placebo-controlled, enriched enrollment, randomized withdrawal trial evaluating pregabalin in 99 patients with NP who completed the PQAS, which comprises 20 questions regarding individual pain domains and qualities that are scored into three scales: paroxysmal, deep, and surface. METHODS: Patients rated the average pain intensity and pain quality using the PQAS at baseline; average pain intensity was assessed again after 40 days of treatment with pregabalin. Associations between pretreatment PQAS scores and treatment response were estimated using Pearson's r. Logistic regression was used to identify pretitration PQAS scores contributing unique variance to predicting treatment response. RESULTS: Fifty participants provided baseline PQAS scores and received pregabalin for the entire length of the study. Nine of 23 PQAS baseline scales and items were significantly associated with treatment response to pregabalin: the paroxysmal and deep scales, and the items assessing the following pain domains and qualities: intensity, electric, tingling, cramping, radiating, throbbing, and deep (P values range, 0.002-0.045; rs range, 0.28-0.43). The PQAS items assessing sharp, hot, and unpleasant pain items demonstrated nonsignificant trends (P < 0.10) to be associated with treatment response. In the logistic regression analysis, pretitration PQAS scores had 77% sensitivity and 83% specificity to correctly identify pregabalin responders. Significantly correlated PQAS items had a sensitivity of 85% and specificity of 76%. CONCLUSION: Pretitration PQAS scores reliably predicted pregabalin responders in patients with NP.

Ultrasound of metacarpophalangeal joints is a sensitive and reliable endpoint for drug therapies in rheumatoid arthritis: results of a randomized, two-center placebo-controlled study.

INTRODUCTION: We aimed to investigate the sensitivity and reliability of two-dimensional ultrasonographic endpoints at the metacarpophalageal joints (MCPJs) and their potential to provide an early and objective indication of a therapeutic response to treatment intervention in rheumatoid arthritis (RA). METHODS: A randomized, double-blind, parallel-group, two-center, placebo-controlled trial investigated the effect on ultrasonographic measures of synovitis of repeat dose oral prednisone, 15 mg or 7.5 mg, each compared to placebo, in consecutive two-week studies; there were 18 subjects in a 1:1 ratio and 27 subjects in a 2:1 ratio, respectively. All subjects met the 1987 American College of Rheumatology criteria for the diagnosis of RA, were ≥18 years-old with RA disease duration ≥6 months, and had a Disease Activity Score 28 based on C-reactive protein (DAS28(CRP)) ≥3.2. Subjects underwent high-frequency (gray-scale) and power Doppler ultrasonography at Days 1 (baseline), 2, 8 and 15 in the dorsal transverse and longitudinal planes of all 10 MCPJs to obtain summated scores of quantitative and semi-quantitative measures of synovial thickness as well as vascularity. The primary endpoint was the summated score of power Doppler area measured quantitatively in all 10 MCPJs in the transverse plane at Day 15. Clinical efficacy was assessed at the same time points by DAS28(CRP). RESULTS: All randomized subjects completed the trial. The comparison between daily 15 mg prednisone and placebo at Day 15 yielded a statistically significant treatment effect (effect size = 1.17, P = 0.013) in change from baseline in the primary endpoint, but borderline for prednisone 7.5 mg daily versus placebo (effect size = 0.61, P = 0.071). A significant treatment effect for DAS28(CRP) was only observed at Day 15 in the prednisone 15 mg group (effect size = 0.95, P = 0.032). However, significant treatment effects at all time points for a variety of ultrasound (US) endpoints were detected with both prednisone doses; the largest observed effect size = 2.33. Combining US endpoints with DAS28(CRP) improved the registration of significant treatment effects. The parallel scan inter-reader reliability of summated 10 MCPJ scores were good to excellent (ICC values >0.61) for the majority of US measures. CONCLUSIONS: Ultrasonography of MCPJs is an early, reliable indicator of therapeutic response in RA with potential to reduce patient numbers and length of trials designed to give preliminary indications of efficacy. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT00746512.

Segmental bioimpedance for measuring amlodipine-induced pedal edema: a placebo-controlled study.

BACKGROUND: The development of antihypertensives requires efficient and accurate tools for identifying pedal edema. Methodologies used to gauge the potential of an agent to induce pedal edema in short-term (<4-week) clinical trials have not been reported in the literature. OBJECTIVE: The purpose of this study was to identify a robust and practical method for measuring drug-induced pedal edema for use in the clinical development of antihypertensives. The efficacy of segmental bioimpedance in the detection of increased pedal edema was compared with that of clinical pitting assessment, ankle circumference, and water displacement volumetry. METHODS: The study population consisted of male and female healthy subjects and patients with stage 1 or 2 hypertension who were otherwise healthy. Participants were randomly assigned to receive amlodipine 10 mg or placebo once daily in this 6-week, double-blind, parallel-group study. Amlodipine was used as a means of inducing ankle edema, and not for the treatment of hypertension. Patients with hypertension were required to undergo a washout of antihypertensive therapies. Edema was evaluated using segmental bioimpedance at 10 kHz, clinical pitting assessment, ankle circumference, and water displacement at weeks 2, 4, and 6. The ANOVA model used included treatment and baseline values as covariates, with treatment pairs compared via t tests derived from the model. RESULTS: A total of 47 individuals were randomized (49% male; 29 [62%] with hypertension; mean [SD] age, 59 [5.9] years; baseline body mass index, 28.6 kg/m(2) [2.8]; blood pressure 146.6 [10.7]/93.5 [6.5] and 139.3 [8.3]/89.5 [4.5] in individuals with and without hypertension, respectively; amlodipine 10 mg, n = 24; placebo, n = 23). At weeks 2, 4, and 6, statistically significant treatment differences in changes from baseline were detected using water displacement (mean [90% CI] treatment differences, +39.0 g [+17.9 to +60.1], +61.9 g [+36.1 to +87.6], and +72.2 g [+42.3 to +102.1], respectively; all, P ≤ 0.001), ankle circumference (+4.74 mm [+2.38 to +7.11; P < 0.001], +2.92 mm [+0.33 to +5.49; P = 0.032], and +5.16 mm [+2.21 to +8.11; P = 0.002]), and bioimpedance (-11.7 Ω [-18.1 to -5.4], -18.3 Ω [-26.2 to -10.4], and -20.9 Ω [-29.7 to -12.0]; all, P≤0.001), but no significant differences were detected using clinical assessment of pitting. CONCLUSION: In this population of healthy subjects and patients with hypertension, segmental bioimpedance was comparable to water displacement and ankle circumference and outperformed clinical assessment of pitting for the detection of ankle edema, supporting the use of segmental bioimpedance as a drug-development tool to objectively quantify amlodipine-induced pedal edema.

Correlation between arterial FDG uptake and biomarkers in peripheral artery disease.

OBJECTIVES: A prospective, multicenter (18)fluorine-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging study was performed to estimate the correlations among arterial FDG uptake and atherosclerotic plaque biomarkers in patients with peripheral artery disease. BACKGROUND: Inflammation within atherosclerotic plaques is associated with instability of the plaque and future cardiovascular events. Previous studies have shown that (18)F-FDG-PET/CT is able to quantify inflammation within carotid artery atherosclerotic plaques, but no studies to date have investigated this correlation in peripheral arteries with immunohistochemical confirmation. METHODS: Thirty patients across 5 study sites underwent (18)F-FDG-PET/CT imaging before SilverHawk atherectomy (FoxHollow Technologies, Redwood City, California) for symptomatic common or superficial femoral arterial disease. Vascular FDG uptake (expressed as target-to-background ratio) was measured in the carotid arteries and aorta and femoral arteries, including the region of atherectomy. Immunohistochemistry was performed on the excised atherosclerotic plaque extracts, and cluster of differentiation 68 (CD68) level as a measure of macrophage content was determined. Correlations between target-to-background ratio of excised lesions, as well as entire arterial regions, and CD68 levels were determined. Imaging was performed during the 2 weeks before surgery in all cases. RESULTS: Twenty-one patients had adequate-quality (18)F-FDG-PET/CT peripheral artery images, and 34 plaque specimens were obtained. No significant correlation between lesion target-to-background ratio and CD68 level was observed. CONCLUSIONS: There were no significant correlations between CD68 level (as a measure of macrophage content) and FDG uptake in the peripheral arteries in this multicenter study. Differences in lesion extraction technique, lesion size, the degree of inflammation, and imaging coregistration techniques may have been responsible for the failure to observe the strong correlations with vascular FDG uptake observed in previous studies of the carotid artery and in several animal models of atherosclerosis.

A randomized clinical trial comparing point-of-care platelet function assays and bleeding time in healthy subjects treated with aspirin or clopidogrel.

Traditional assays of the coagulation status of patients, bleeding time assessment (BT) and light transmission aggregometry (LTA), are useful in clinical drug development. However, these assays are both labor intensive and expensive. BT results can be operator dependent and by its nature can inhibit subject enrollment in a clinical trial. The preparation of platelet-rich plasma necessary for LTA requires specialized training and laboratory support. Alternatives to these methods are desirable. The goal of this study was identification of a quantitative, easy-to-use, point-of-care device with minimal technical variables that could facilitate assessment of platelet aggregation in clinical drug development. This was a double-blind, placebo-controlled, randomized, three-period cross-over study in healthy volunteers designed to compare the abilities of BT, LTA, and three point-of-care devices, Multiplate®, Platelet Function Analyzer-100®, and VerifyNow® to quantitate the effects on platelet function of 3 days of treatment with aspirin, clopidogrel, or placebo. The effect size (difference in treatment means divided by the pooled standard deviations [SD]) of the three point-of-care devices was greater than or similar to BT and LTA for all treatment comparisons examined. VerifyNow® had the highest effect size comparing ASA to placebo. Multiplate® had the highest effect size comparing clopidogrel to placebo. From this study, we conclude that any one of the three simple-to-use point-of-care devices can reliably assess the treatment effect of ASA and CLP on platelet function in comparison with BT or LTA at the study population level

The pain quality response profile of pregabalin in the treatment of neuropathic pain.

OBJECTIVE: To identify and describe the response profile of pregabalin on the qualities of pain associated with peripheral neuropathy. METHODS: A post hoc analysis to examine the effects of pregabalin on pain quality in patients with moderate-to-severe peripheral neuropathic pain was performed using data from an enriched enrollment randomized withdrawal proof-of-concept study. Patients rated the quality of their pain experience using the Pain Quality Assessment Scale (PQAS) at baseline, after a 12-day titration period, after a 9-day maintenance period, and after a 19-day randomized withdrawal period. Pretitration to posttitration and prewithdrawal to postwithdrawal changes in PQAS paroxysmal, surface, and deep pain scale scores were examined. RESULTS: PQAS data were available for 99 of the 104 participants who entered all phases of the study. There were significant (P<0.006, Bonferroni adjusted for multiple tests) improvements pretitration to posttitration in all 3 PQAS subscales, with a greater effect on paroxysmal and deep pain than on surface pain. During the withdrawal phase, pregabalin was significantly (P<0.006) more effective than placebo for improvements in paroxysmal and surface pain only, although the pregabalin group continued to show numerical improvement in deep pain relative to placebo. DISCUSSION: Pregabalin had a greater effect on PQAS-assessed paroxysmal pain than on surface or deep pain in patients with peripheral neuropathy. The findings corroborate previous research demonstrating differential effects of analgesic drugs across pain qualities, further emphasizing the need to assess individual pain qualities in addition to overall pain intensity.

Impact of responder definition on the enriched enrollment randomized withdrawal trial design for establishing proof of concept in neuropathic pain.

The objective of this study was to evaluate how enrichment for responders increases assay sensitivity in an enriched enrollment randomized withdrawal (EERW) proof-of-concept (POC) study in neuropathic pain. Adults with moderate to severe peripheral neuropathic pain entered a 3- to 4-day screening period, followed by a 12-day titration to the highest tolerated dose that provided pain control (pregabalin 50-200mg t.i.d.), and then a 9-day maintenance period. Subjects were stratified as primary responders (⩾30%), secondary responders (⩾10% to <30%), or nonresponders (<10%) based on decrease in pain intensity and were randomized to placebo or pregabalin during the randomized withdrawal period. The primary endpoint was mean of average 24-h pain intensity during the last 3days of treatment period relative to the 3days before randomization. Time-to-efficacy-failure was the key secondary endpoint. Other features included not requiring discontinuation of current analgesic therapies and blinding investigators to study design elements that could contribute to non-treatment-related responses. Effect size (ES) (mean treatment difference/SD) was used to measure assay sensitivity. Pregabalin-treated subjects (n=52) had significantly less pain than those receiving placebo (n=51) (P⩽.003). Effect size of the primary endpoint was 0.72 for primary responders and decreased if secondary and nonresponders were included in the analysis. The highest ES (1.68) was demonstrated for the endpoint time-to-efficacy-failure seen in primary responders with painful diabetic neuropathy. The EERW trial design using time-to-efficacy-failure may provide a sensitive and efficient method to conduct POC studies of novel therapies in patients with neuropathic pain. Enriching a study population with patients who have achieved a 30% decrease in pain with an investigational therapy, and using time-to-efficacy-failure during the randomized withdrawal phase as the primary endpoint, can be used for a proof-of-concept study to optimize assay sensitivity and efficiently determine the analgesic potential of a new treatment for neuropathic pain.