Multiple-Ascending-Dose Phase 1 Clinical Study of the Safety, Tolerability, and Pharmacokinetics of CRS3123, a Narrow-Spectrum Agent with Minimal Disruption of Normal Gut Microbiota.

CRS3123 is a novel small molecule that potently inhibits methionyl-tRNA synthetase of Clostridioides difficile, inhibiting C. difficile toxin production and spore formation. CRS3123 has been evaluated in a multiple-ascending-dose placebo-controlled phase 1 trial. Thirty healthy subjects, ages 18 to 45 years, were randomized into three cohorts of 10 subjects each, receiving either 200, 400, or 600 mg of CRS3123 (8 subjects per cohort) or placebo (2 subjects per cohort) by oral administration twice daily for 10 days. CRS3123 was generally safe and well tolerated, with no serious adverse events (SAEs) or severe treatment-emergent adverse events (TEAEs) reported. All subjects completed their assigned treatment and follow-up visits, and there were no trends in systemic, vital sign, or laboratory TEAEs. There were no QTcF interval changes or any clinically significant changes in other electrocardiogram (ECG) intervals or morphology. CRS3123 showed limited but detectable systemic uptake; although absorption increased with increasing dose, the increase was less than dose proportional. Importantly, the bulk of the oral dose was not absorbed, and fecal concentrations were substantially above the MIC90 value of 1 µg/ml at all dosages tested. Subjects receiving either of the two lower doses of CRS3123 exhibited minimal disruption of normal gut microbiota after 10 days of twice-daily dosing. CRS3123 was inactive against important commensal anaerobes, including Bacteroides, bifidobacteria, and commensal clostridia. Microbiome data showed favorable differentiation compared to other CDI therapeutics. These results support further development of CRS3123 as an oral agent for the treatment of CDI. (This study has been registered at Clinicaltrials.gov under identifier NCT02106338.).

NGX426, an oral AMPA-kainate antagonist, is effective in human capsaicin-induced pain and hyperalgesia.

BACKGROUND: Non-N-methyl-D-aspartate receptor subtypes modulate neurotransmitter release and mediate fast excitatory postsynaptic potentials. This study evaluated the effects of an oral prodrug to tezampanel, a selective α-amino-3-hydroxy-5-methly-4-isoxazole-proprionic acid/kainate receptor antagonist, on intradermal capsaicin-induced pain and hyperalgesia. METHODS: This was a randomized, double blind, crossover, placebo-controlled study. Eighteen subjects received 150 or 90 mg NGX426, or placebo, separated by a washout of 6 ± 2 days. In each treatment period, two intradermal injections of capsaicin were given in the volar region of alternate forearms at 30- and 120-minute drug/placebo administration. Spontaneous pain, elicited pain, and area of hyperalgesia were determined at certain time points after each injection. Subjects were asked to rate the painfulness of a 1-minute long 45°C heat stimulus (brief thermal stimulation [BTS]) applied to the anterior thigh at 4 hours and 30 minutes following drug administration, then every 30 minutes through 6 hours following drug administration. RESULTS: The 150-mg dose produced a statistically definitive reduction in spontaneous pain for all time points relative to placebo. The 90-mg dose produced a statistically significant reduction for the early time point and the entire time interval. Both doses significantly reduced elicited pain at all time points. For the BTS, the 150-mg group reached statistical significance compared with placebo at the 270-minute time point only. CONCLUSIONS: This study demonstrated that NGX426 reduces capsaicin-induced pain and hyperalgesia in human volunteers with low incidence of side effects that suggests that this class of drug may be effective in the treatment of clinical pain.

Pharmacokinetic properties and tolerability of bevirimat and atazanavir in healthy volunteers: an open-label, parallel-group study.

BACKGROUND: Bevirimat, an inhibitor of HIV-1 maturation, is currently in clinical development for the treatment of HIV-1 infection. It undergoes glucuronidation via uridine diphosphate glucuronosyltransferases (UGTs). The protease inhibitor atazanavir is a potent inhibitor of UGT1A1. Because of this inhibition, high atazanavir plasma levels are associated with increases in plasma bilirubin. OBJECTIVES: The purposes of this study were to assess the pharmacokinetic (PK) properties and tolerability profiles of bevirimat administered as monotherapy and in combination with atazanavir. METHODS: This was an open-label, parallel-group study in healthy volunteers. Nonsmoking men and women aged 18 to 60 years were eligible for inclusion in the study. After being stratified in a 1:1 ratio by sex, subjects were randomly assigned to 1 of 2 groups to receive bevirimat 200 mg/d for 14 days or atazanavir 400 mg/d on days 1 through 21 and bevirimat 200 mg/d on days 8 through 21. Bevirimat PK properties were assessed on day 14 in the monotherapy group and on day 21 in the combination group. Atazanivir PK properties were assessed on days 7 and 21 in the combination group. Serum bilirubin was assessed daily. Tolerability was assessed by monitoring of adverse events using physical examination and clinical laboratory evaluation, including recording of vital signs and electrocardiography throughout the study. RESULTS: A total of 48 healthy volunteers (24 men, 24 women; mean age, 33 years; mean weight, 83.6 kg; mean body mass index, 27.8 kg/m(2)) were included in the study. There were no significant between-group effects on the PK properties with respect to geometric least squares mean ratios of C(max) and AUC(0-tau) (95.9 [90% CI, 84.5-108.8] and 92.0 [90% CI, 80.5- 105.2], bevirimat monotherapy vs bevirimat + atazanivir, respectively; and 93.9 [90% CI, 82.3-107.1 and 94.1 [90% CI, 78.2-113.1], atazanivir monotherapy vs bevirimat + atazanivir, respectively). Bevirimat was not associated with any significant changes from baseline in serum bilirubin concentrations, whereas 7-day atazanavir monotherapy was associated with a appromixately 5-fold increase. Coadministration was not associated with significant bilirubin concentration elevations compared with the administration of atazanavir alone. Dosing was discontinued in 4 subjects (atazanavir-induced hyperbilirubinemia, 3; atazanavir-induced rash, 1). In addition, 17 subjects (35.4%) experienced treatment-emergent adverse events including: ocular icterus, 5; headache, 5; unconjugated blood bilirubin increases, 4; diarrhea, 3; upper respiratory tract infection, 3; and yellow skin, 3. CONCLUSIONS: In this study, there were no significant differences in PK properties in atazanavir or bevirimat administered as monotherapy or in combination in this small, select group of healthy volunteers. The coadministration of bevirimat and atazanavir was reasonably well tolerated. Bevirimat did not significantly increase serum bilirubin concentrations and had no significant effect on atazanavir-induced hyperbilirubinemia, potentially providing a further option in the management of HIV-1 infection following evaluation in HIV-infected patients.

Postponed development of disability in elderly runners: a 13-year longitudinal study.

BACKGROUND: The magnitude and duration of the benefit of running and other aerobic exercise on disability and mortality in elderly persons are not well understood. We sought to quantify the benefits of aerobic exercise, including running, on disability and mortality in elderly persons and to examine whether morbidity can be compressed into later years of life by regular exercise. METHODS: A 13-year prospective cohort study of 370 members of a runners' club for persons aged 50 and older and 249 control subjects initially aged 50 to 72 years (mean, 59 years), with annual ascertainment of the Health Assessment Questionnaire disability score, noting any deaths and their causes. Linear mixed models were used to compute postponement in disability, and survival analysis was conducted to determine the time to and causes of death. RESULTS: Significantly (P<.001) lower disability levels in runners' club members vs controls and in ever runners vs never runners were sustained for at least 13 years. Reaching a Health Assessment Questionnaire disability level of 0.075 was postponed by 8.7 (95% confidence interval [CI], 5.5-13.7) years in runners' club members vs controls. Running club membership and participation in other aerobic exercise protected against mortality (rate ratio, 0.36 [95% CI, 0.20-0.65] and 0.88 [95% CI, 0.77-0.99], respectively), while male sex and smoking were detrimental (rate ratio, 2.4 [95% CI, 1.4-4.2] and 2.2 [95% CI, 1.1-4.6], respectively). Controls had a 3.3 times higher rate of death than runners' club members, with higher death rates in every disease category. Accelerated rates of disability and mortality were still not seen in the runners' club members; true compression of morbidity was not yet observable through an average age of 72 years. CONCLUSION: Running and other aerobic exercise in elderly persons protect against disability and early mortality, and are associated with prolongation of a disability-free life.

Evaluation of the pharmacodynamics of acetylsalicylic acid 81 mg with or without esomeprazole 20 mg in healthy volunteers.

BACKGROUND: The absence of a pharmacokinetic interaction between the proton pump inhibitor esomeprazole (40 mg) and acetylsalicylic acid (aspirin, ASA; 325 mg) has previously been established. OBJECTIVE: This study set out to investigate the potential for pharmacodynamic interaction between low-dose ASA and esomeprazole in healthy volunteers, by measuring ASA antiplatelet activity. STUDY DESIGN: This was a single-center, open-label, two-period, randomized crossover study. PARTICIPANTS: Healthy male and female volunteers aged 18-75 years were included. All volunteers received ASA 81 mg once daily for 5 days prior to the study (pre-screen). Subjects were eligible for inclusion if they had aspirin reactivity units (ARU, as measured by the VerifyNow ASA assay) of <550 on Day 6. INTERVENTION: After pre-screening and a washout period of at least 14 days, eligible volunteers received ASA 81 mg with or without esomeprazole 20 mg once daily for 5 days in randomized order, with a 14-day washout between treatments. MAIN OUTCOME MEASURE: The main outcome measure was the antiplatelet activity of ASA, as assessed by ARU ratio relative to baseline in the VerifyNow ASA assay; suppression of serum thromboxane B(2) (TXB(2)) was a secondary endpoint. Statistical comparisons were made using linear mixed models. RESULTS: A total of 29 volunteers (19 aged ≥50 years; 8 women; 21 men) were evaluable for pharmacodynamic analysis (per protocol). All volunteers on both treatments achieved ARU <550 at Day 6. The geometric mean ratio of Day 6 to Day 1 (baseline) platelet aggregation was 0.70 (95% confidence interval [CI] 0.68, 0.72) with ASA alone and 0.71 (95% CI 0.69, 0.74) with ASA + esomeprazole. The ratio of platelet aggregation (ASA + esomeprazole/ASA) was 1.02 (95% CI 0.99, 1.05). ASA administered alone or with esomeprazole reduced serum TXB(2) by more than 99.5%. The ratio of suppression of serum TXB(2) levels (ASA + esomeprazole/ASA) was 1.06 (95% CI 0.88, 1.29). The combination of ASA and esomeprazole was well tolerated. CONCLUSION: No pharmacodynamic interaction between low-dose ASA and esomeprazole was found with regard to platelet function. TRIAL REGISTRATION: Registered at ClinicalTrials. gov as NCT01199328.

The methotrexate therapeutic response in rheumatoid arthritis.

OBJECTIVE: Methotrexate (MTX) is used frequently as a disease modifying antirheumatic drug (DMARD) for rheumatoid arthritis (RA), and patients tend to continue taking this drug for longer periods than alternative single agents. The shape of the therapeutic response beyond one or 2 years, however, has not been fully studied. We examined the properties of the pure MTX "therapeutic segment," that period that begins with start of MTX and terminates when MTX is discontinued or another DMARD is added, by observational study. METHODS: We studied new MTX starts for the period 1988 through 1996 for 437 patients from a parent cohort of 4253 patients. Patients were drawn from 8 Arthritis, Rheumatism, and Aging Medical Information System (ARAMIS) data centers: 2 community based populations; 2 private rheumatological practices; 2 university referral practices; and 2 university clinics for underserved minority urban populations. Health Assessment Questionnaire (HAQ) Disability Index scores (0-3) were obtained prospectively each 6 months. RESULTS: At MTX start, patients had relatively long average disease duration of 16.7 years, and had moderately severe disability, with an initial HAQ mean disability score of 1.48. Over the 10 year period examined in the parent cohort of 4253 patients (and thus irrespective of therapy), the prevalence of MTX use rose from 19% to 45%, while mean HAQ disability declined from 1.34 to 1.11. This correspondence is consistent with an accrual of benefits from more frequent use of MTX and other DMARD over this period. The MTX therapeutic segment revealed a distinct shape. HAQ-Disability Index values began at 1.48 at baseline and declined to a maximal improvement of 1.23 at 30 months. This long period to maximum benefit may have been partly driven by a slow titration upward to an optimal dosage. After 42 months, disability for this population began to re-progress and reached 1.39 at 84 months, still below the pretreatment baseline. Re-progression to baseline was about 8 or more years. Cumulative disability averted with MTX treatment for this population was roughly 1.30 disability-unit-years. CONCLUSION: MTX treatment of RA in practice differs substantially from common perception and appears suboptimal by being too little, too late, and too long to treatment change. A modification of the "sawtooth strategy" in which the disease is "ratcheted down" by change of MTX therapy at 3 years or when re-progression has proceeded halfway to baseline, rather than waiting for return to baseline, is suggested by these data. Also suggested is the need for more rapid upward dosage titration and longer maintenance of an optimal or highest tolerated dosage. "Therapeutic segment" data provide insights into strategic approaches to management of RA since they allow estimation of population aggregate properties such as time to maximum benefit and the time to return to baseline.