Kenneth Liu

Immediate antecedents of cigarette smoking: an analysis from ecological momentary assessment.

: The authors assessed the association between smoking and situational cues, including affect, in real-world contexts. Using ecological momentary assessment, 304 smokers monitored ad-lib smoking for 1 week, recording each cigarette on palm-top computers. Generalized estimating equations contrasted 10,084 smoking and 11,155 nonsmoking situations. After controlling for smoking restrictions, smoking was strongly related to smoking urges and modestly related to consumption of coffee and food, the presence of other smokers, and several activities. Smoking was unrelated to negative or positive affect or to arousal, although it was associated with restlessness. Thus, in daily life, affect appears to exert little influence over ad-lib smoking in heavy smoking adults.

Dynamic effects of self-efficacy on smoking lapse and relapse.

Self-efficacy (SE) is thought to be critical to success in smoking cessation both as an individual difference and as a dynamic process after a quit attempt. In this study, 214 smokers used palm-top computers to record day-to-day variations in SE during 4 weeks after quitting. SE remained at high and stable levels prior to a 1st lapse but decreased and became more variable thereafter. The authors used event history models with time-varying covariates to assess the effect of daily SE on lapse and relapse risk. Daily SE measures predicted an initial lapse on the subsequent day. However, this relationship was accounted for by stable baseline differences in SE (assessed by questionnaire), rather than by day-to-day dynamics in SE. Progression from 1st lapse to relapse was also examined. In this instance, daily SE predicted subsequent relapse risk, even when baseline SE and concurrent smoking were accounted for, suggesting the importance of SE dynamics for this stage of the relapse process.

Orexin receptor antagonism for treatment of insomnia A randomized clinical trial of suvorexant

ABSTRACT Objective: To assess the utility of orexin receptor antagonism as a novel approach to treating insomnia. Methods: We evaluated suvorexant, an orexin receptor antagonist, for treating patients with primary insomnia in a randomized, double-blind, placebo-controlled, 2-period (4 weeks per period) crossover polysomnography study. Patients received suvorexant (10 mg [n = 62], 20 mg [n = 61], 40 mg [n = 59], or 80 mg [n = 61]) in one period and placebo (n = 249) in the other. Polysomnography was performed on night 1 and at the end of week 4 of each period. The coprimary efficacy end points were sleep efficiency on night 1 and end of week 4. Secondary end points were wake after sleep onset and latency to persistent sleep. Results: Suvorexant showed significant (p values <0.01) dose-related improvements vs placebo on the coprimary end points of sleep efficiency at night 1 and end of week 4. Dose-related effects were also observed for sleep induction (latency to persistent sleep) and maintenance (wake after sleep onset). Suvorexant was generally well tolerated. Conclusions: The data suggest that orexin receptor antagonism offers a novel approach to treating insomnia. Classification of evidence: This study provides Class I evidence that suvorexant improves sleep efficiency over 4 weeks in nonelderly adult patients with primary insomnia.

Tildrakizumab versus placebo or etanercept for chronic plaque psoriasis (reSURFACE 1 and reSURFACE 2): results from two randomised controlled, phase 3 trials

BACKGROUND Tildrakizumab is a high-affinity, humanised, IgG1 κ antibody targeting interleukin 23 p19 that represents an evolving treatment strategy in chronic plaque psoriasis. Previous research suggested clinical improvement with inhibition of interleukin 23 p19. We did two phase 3 trials to investigate whether tildrakizumab is superior to placebo and etanercept in the treatment of chronic plaque psoriasis. METHODS We did two three-part, parallel group, double-blind, randomised controlled studies, reSURFACE 1 (at 118 sites in Australia, Canada, Japan, the UK, and the USA) and reSURFACE 2 (at 132 sites in Europe, Israel, and the USA). Participants aged 18 years or older with moderate-to-severe chronic plaque psoriasis (body surface area involvement ≥10%, Physicians Global Assessment [PGA] score ≥3, and Psoriasis Area and Severity Index [PASI] score ≥12) were randomised (via interactive voice and web response system) to tildrakizumab 200 mg, tildrakizumab 100 mg, or placebo in reSURFACE 1 (2:2:1), or to tildrakizumab 200 mg, tildrakizumab 100 mg, placebo, or etanercept 50 mg (2:2:1:2). Randomisation was done by region and stratified for bodyweight (≤90 kg or >90 kg) and previous exposure to biologics therapy for psoriasis. Investigators, participants, and study personnel were blinded to group allocation and remained blinded until completion of the studies. Assigned medication was identical in appearance and packaging. Tildrakizumab was administered subcutaneously at weeks 0 and 4 during part 1 and at week 16 during part 2 (weeks 12 and 16 for participants re-randomised from placebo to tildrakizumab; etanercept was given twice weekly in part 1 of reSURFACE 2 and once weekly during part 2). The co-primary endpoints were the proportion of patients achieving PASI 75 and PGA response (score of 0 or 1 with ≥2 grade score reduction from baseline) at week 12. Safety was assessed in the all-participants-as-treated population, and efficacy in the full-analysis set. These trials are registered with ClinicalTrials.gov, numbers NCT01722331 (reSURFACE 1) and NCT01729754 (reSURFACE 2). These studies are completed, but extension studies are ongoing. FINDINGS reSURFACE 1 ran from Dec 10, 2012, to Oct 28, 2015. reSURFACE 2 ran from Feb 12, 2013, to Sept 28, 2015. In reSURFACE 1, 772 patients were randomly assigned, 308 to tildrakizumab 200 mg, 309 to tildrakizumab 100 mg, and 155 to placebo. At week 12, 192 patients (62%) in the 200 mg group and 197 patients (64%) in the 100 mg group achieved PASI 75, compared with 9 patients (6%) in the placebo group (p<0·0001 for comparisons of both tildrakizumab groups vs placebo). 182 patients (59%) in the 200 mg group and 179 patients (58%) in the 100 mg group achieved PGA responses, compared with 11 patients (7%) in the placebo group (p<0·0001 for comparisons of both tildrakizumab groups vs placebo). In reSURFACE 2, 1090 patients were randomly assigned, 314 to tildrakizumab 200 mg, 307 to tildrakizumab 100 mg, 156 to placebo, and 313 to etanercept. At week 12, 206 patients (66%) in the 200 mg group, and 188 patients (61%) in the 100 mg group achieved PASI 75, compared with 9 patients (6%) in the placebo group and 151 patients (48%) in the etanercept group (p<0·0001 for comparisons of both tildrakizumab groups vs placebo; p<0·0001 for 200 mg vs etanercept and p=0·0010 for 100 mg vs etanercept). 186 patients (59%) in the 200 mg group, and 168 patients (59%) [corrected] in the 100 mg group achieved a PGA response, compared with 7 patients (4%) in the placebo group and 149 patients (48%) in the etanercept group (p<0·0001 for comparisons of both tildrakizumab groups vs placebo; p=0·0031 for 200 mg vs etanercept and p=0·0663 for 100 mg vs etanercept). Serious adverse events were similar and low in all groups in both trials. One patient died in reSURFACE 2, in the tildrakizumab 100 mg group; the patient had alcoholic cardiomyopathy and steatohepatitis, and adjudication was unable to determine the cause of death. INTERPRETATION In two phase 3 trials, tildrakizumab 200 mg and 100 mg were efficacious compared with placebo and etanercept and were well tolerated in the treatment of patients with moderate-to-severe chronic plaque psoriasis. FUNDING Merck & Co.

Immunogenicity and safety of the 9-valent HPV vaccine in men.

OBJECTIVES This study was designed to evaluate the immunogenicity and tolerability of a prophylactic 9-valent HPV (types 6/11/16/18/31/33/45/52/58) VLP (9vHPV) vaccine in young men 16-26 years of age in comparison to young women 16-26 years of age (the population that was used to establish 9vHPV vaccine efficacy). Safety and immunogenicity data from this study will be used to bridge 9vHPV vaccine efficacy findings in 16-26 year old women to 16-26 year old men. METHODS This study enrolled 1106 heterosexual men (HM) and 1101 women who had not yet received HPV vaccination. In addition, 313 men having sex with men (MSM) were enrolled and were evaluated separately for immunogenicity because previous results showed that antibody responses to quadrivalent HPV (types 6/11/16/18) VLP (qHPV) vaccine were lower in MSM than in HM. All subjects were administered a 3-dose regimen (Day 1, Month 2, Month 6) of 9vHPV vaccine. Serum samples were collected for anti-HPV assays. Safety information was collected for ∼ 12 months. RESULTS The geometric mean titers (GMTs) for HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 for HM were non-inferior to those of women at Month 7. For all vaccine HPV types, Month 7 GMTs were numerically lower in MSM than in HM. Over 99.5% of subjects were seropositive at Month 7 for each vaccine HPV type. Administration of 9vHPV vaccine to both 16-26 year old men and women was generally well tolerated. CONCLUSIONS These results support bridging the efficacy findings with 9vHPV vaccine in young women 16-26 years of age to men 16-26 years of age.

PCPT: Evidence that finasteride reduces risk of most frequently detected intermediate- and high-grade (Gleason score 6 and 7) cancer.

OBJECTIVES To determine the effect of finasteride relative to placebo on prostate cancer (PCa) risk at each individual Gleason score in the Prostate Cancer Prevention Trial using a post hoc generalization of a prespecified, exploratory, biopsy sampling density-adjusted analysis. METHODS The Prostate Cancer Prevention Trial enrolled 18 882 men aged >or=55 years with a prostate-specific antigen level of <3.0 ng/mL and normal digital rectal examination findings, and randomized them to finasteride 5 mg daily or placebo. PCa data from evaluable biopsies obtained within 7 years plus <or=90 days of randomization were examined. Polytomous logistic regression analysis of PCa risk was performed across individual Gleason scores using no PCa as the reference group, with no adjustment for multiplicity. The analysis model included treatment, age, race, first-degree family history of PCa, baseline prostate-specific antigen level, and the postrandomization variables of prostate volume and the number of biopsy cores at biopsy as covariates. RESULTS Finasteride significantly reduced the PCa risk relative to placebo across multiple Gleason scores (4 through 7), including a 58% reduction in Gleason score 5 PCa risk (P < .0001), a 52% reduction in Gleason score 6 PCa risk (P < .0001), and a 22% reduction in Gleason score 7 PCa risk (P = .0368). Finasteride had no significant effect on the risk of Gleason score 2, 3, or 8-10 cancer. CONCLUSIONS After adjusting for biopsy sampling density, finasteride significantly reduced the PCa risk relative to placebo across multiple Gleason scores in the Prostate Cancer Prevention Trial, including the most frequently detected intermediate- and high-grade cancers (Gleason scores 6 and 7).

Randomized controlled study of the histamine H3 inverse agonist MK-0249 in adult attention-deficit/hyperactivity disorder.

BACKGROUND It has been suggested that the histamine subtype 3 receptor inverse agonists such as MK-0249 might be effective in treating attention-deficit/hyperactivity disorder (ADHD). We evaluated the effects of MK-0249 in adults with ADHD. METHOD A randomized, double-blind, placebo-controlled, incomplete block, 2-period crossover study of MK-0249 5-10 mg/d and osmotic-release oral system (OROS) methylphenidate 54-72 mg/d (active comparator) was performed in 72 men and women aged ≥ 18 to ≤ 55 years who met DSM-IV criteria for ADHD of either inattentive or combined subtype and who had a chronic course of behavior disorder. The study was conducted from August 2007 through April 2008 at 6 US sites. Primary efficacy was assessed by the mean change from baseline in the Adult ADHD Investigator Symptom Rating Scale (AISRS) total score after 4 weeks of treatment. RESULTS Change from baseline in AISRS at week 4 for MK-0249 was not different from placebo (P = .341), whereas a significant benefit was seen for OROS methylphenidate versus placebo (P < .001). Analysis of secondary end points, including the Conners Adult ADHD Rating Scales, showed results consistent with the AISRS. A similar percentage of patients reported adverse events for MK-0249 compared with placebo (73% versus 69%, respectively). However, a greater percentage of patients reported insomnia as an adverse event with MK-0249 treatment compared with placebo (32% versus 11%, respectively). CONCLUSIONS MK-0249 10 mg/d is not effective for the treatment of adult ADHD. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT00475735.

An adaptive design for identifying the dose with the best efficacy/tolerability profile with application to a crossover dose‐finding study

Proof-of-concept in clinical trials has traditionally focused on the identification of a maximum tolerated dose with the assumption that the higher doses provide better efficacy. However, adverse events associated with a maximum tolerated dose may have a negative effect on efficacy. We present an efficient adaptive dose-finding strategy that concentrates patient assignments at and around the dose which has the best efficacy/tolerability profile based on a utility function. The strategy is applied within the setting of a crossover design. While the strategy may also be applied to parallel studies, a crossover design provides more power for a given sample size for comparisons between the optimal dose versus placebo and/or active control when it is reasonable to assume no carryover effects.

On power and sample size computation for multiple testing procedures

Power and sample size determination has been a challenging issue for multiple testing procedures, especially stepwise procedures, mainly because (1) there are several power definitions, (2) power calculation usually requires multivariate integration involving order statistics, and (3) expansion of these power expressions in terms of ordinary statistics, instead of order statistics, is generally a difficult task. Traditionally power and sample size calculations rely on either simulations or some recursive algorithm; neither is straightforward and computationally economic. In this paper we develop explicit formulas for minimal power and r-power of stepwise procedures as well as complete power of single-step procedures for exchangeable and non-exchangeable bivariate and trivariate test statistics. With the explicit power expressions, we were able to directly calculate the desired power, given sample size and correlation. Numerical examples are presented to illustrate the relationship among power, sample size and correlation.

Alertness and psychomotor performance effects of the histamine-3 inverse agonist MK-0249 in obstructive sleep apnea patients on continuous positive airway pressure therapy with excessive daytime sleepiness: a randomized adaptive crossover study.

OBJECTIVES We aimed to evaluate the efficacy of the selective H3 receptor inverse agonist MK-0249 to treat excessive daytime sleepiness (EDS). METHODS In this three-period, double-blind, crossover study, 125 patients (100 men, 25 women; mean age, 48.6 years) with obstructive sleep apnea receiving nasal continuous positive airway pressure therapy who had refractory EDS were randomized to 2 weeks each of daily MK-0249 (5, 8, 10, or 12 mg, adaptively assigned), modafinil 200 mg, and placebo. At baseline and after each treatment period, six maintenance of wakefulness tests (MWT) and Psychomotor Vigilance Tasks (PVT) were conducted at 2-h intervals, beginning 1h postdose (∼09:00). The Epworth sleepiness scale (ESS), Clinical Global Impression of Severity (CGIS) and Digit Symbol Substitution Test (DSST) also were assessed. The primary end point was MWT sleep latency averaged over the first four time points (MWT-early). RESULTS MWT-early mean change from baseline sleep latency at week 2 was 1.2 min for placebo, 2.1 min for MK-0249 (top two doses pooled; P>.05 vs. placebo), and 5.9 min for modafinil (P < or = .001 vs. placebo). MK-0249 showed improvements vs placebo on secondary and exploratory end points of ESS, CGIS, PVT, and DSST. Insomnia adverse events (AEs) were greater for MK-0249 (combined doses, 17.5%) than for placebo (0.9%) or modafinil (1.8%). CONCLUSION MK-0249 did not significantly affect MWT sleep latency. However, the pattern of improvement on subjective ratings and psychomotor performance end points suggested that MK-0249 was associated with changes in aspects of cognition and performance not captured by the MWT.