Cristina Russ

Neuropsychiatric safety and efficacy of varenicline, bupropion, and nicotine patch in smokers with and without psychiatric disorders (EAGLES): a double-blind, randomised, placebo-controlled clinical trial.

BACKGROUND Substantial concerns have been raised about the neuropsychiatric safety of the smoking cessation medications varenicline and bupropion. Their efficacy relative to nicotine patch largely relies on indirect comparisons, and there is limited information on safety and efficacy in smokers with psychiatric disorders. We compared the relative neuropsychiatric safety risk and efficacy of varenicline and bupropion with nicotine patch and placebo in smokers with and without psychiatric disorders. METHODS We did a randomised, double-blind, triple-dummy, placebo-controlled and active-controlled (nicotine patch; 21 mg per day with taper) trial of varenicline (1 mg twice a day) and bupropion (150 mg twice a day) for 12 weeks with 12-week non-treatment follow-up done at 140 centres (clinical trial centres, academic centres, and outpatient clinics) in 16 countries between Nov 30, 2011, and Jan 13, 2015. Participants were motivated-to-quit smokers with and without psychiatric disorders who received brief cessation counselling at each visit. Randomisation was computer generated (1:1:1:1 ratio). Participants, investigators, and research personnel were masked to treatment assignments. The primary endpoint was the incidence of a composite measure of moderate and severe neuropsychiatric adverse events. The main efficacy endpoint was biochemically confirmed continuous abstinence for weeks 9-12. All participants randomly assigned were included in the efficacy analysis and those who received treatment were included in the safety analysis. The trial is registered at ClinicalTrials.gov (number NCT01456936) and is now closed. FINDINGS 8144 participants were randomly assigned, 4116 to the psychiatric cohort (4074 included in the safety analysis) and 4028 to the non-psychiatric cohort (3984 included in the safety analysis). In the non-psychiatric cohort, 13 (1·3%) of 990 participants reported moderate and severe neuropsychiatric adverse events in the varenicline group, 22 (2·2%) of 989 in the bupropion group, 25 (2·5%) of 1006 in the nicotine patch group, and 24 (2·4%) of 999 in the placebo group. The varenicline-placebo and bupropion-placebo risk differences (RDs) for moderate and severe neuropsychiatric adverse events were -1·28 (95% CI -2·40 to -0·15) and -0·08 (-1·37 to 1·21), respectively; the RDs for comparisons with nicotine patch were -1·07 (-2·21 to 0·08) and 0·13 (-1·19 to 1·45), respectively. In the psychiatric cohort, moderate and severe neuropsychiatric adverse events were reported in 67 (6·5%) of 1026 participants in the varenicline group, 68 (6·7%) of 1017 in the bupropion group, 53 (5·2%) of 1016 in the nicotine patch group, and 50 (4·9%) of 1015 in the placebo group. The varenicline-placebo and bupropion-placebo RDs were 1·59 (95% CI -0·42 to 3·59) and 1·78 (-0·24 to 3·81), respectively; the RDs versus nicotine patch were 1·22 (-0·81 to 3·25) and 1·42 (-0·63 to 3·46), respectively. Varenicline-treated participants achieved higher abstinence rates than those on placebo (odds ratio [OR] 3·61, 95% CI 3·07 to 4·24), nicotine patch (1·68, 1·46 to 1·93), and bupropion (1·75, 1·52 to 2·01). Those on bupropion and nicotine patch achieved higher abstinence rates than those on placebo (OR 2·07 [1·75 to 2·45] and 2·15 [1·82 to 2·54], respectively). Across cohorts, the most frequent adverse events by treatment group were nausea (varenicline, 25% [511 of 2016 participants]), insomnia (bupropion, 12% [245 of 2006 participants]), abnormal dreams (nicotine patch, 12% [251 of 2022 participants]), and headache (placebo, 10% [199 of 2014 participants]). Efficacy treatment comparison did not differ by cohort. INTERPRETATION The study did not show a significant increase in neuropsychiatric adverse events attributable to varenicline or bupropion relative to nicotine patch or placebo. Varenicline was more effective than placebo, nicotine patch, and bupropion in helping smokers achieve abstinence, whereas bupropion and nicotine patch were more effective than placebo. FUNDING Pfizer and GlaxoSmithKline.

Psychiatric adverse events in randomized, double-blind, placebo-controlled clinical trials of varenicline: a pooled analysis.

AbstractBackground: Varenicline (Chantix®, Champix®) has shown efficacy and tolerability as an aid to smoking cessation. In postmarketing surveillance, neuropsychiatric symptoms have appeared; however, their incidence and causal relationship to varenicline is not known. Objective: We assessed the incidence and relative risk (RR) of psychiatric disorders in ten randomized, double-blind, placebo-controlled trials of varenicline for smoking cessation. Methods: All smoking cessation phase II, III and IV randomized controlled clinical trials of varenicline versus placebo completed as of 31 December 2008, on file with the manufacturer (Pfizer, Inc.), were included. All studies have been published. All 3091 participants who received at least one dose of varenicline and all 2005 participants who received placebo were included in this analysis. These were men and women smoking ≥10 cigarettes/day, aged 18–75 years and without current psychiatric disease who received varenicline or placebo for 6 (one study), 12 (eight studies) or 52 (one study) weeks. Adverse events were recorded at each study visit and classified according to standard Medical Dictionary for Regulatory Activities (MedDRA®) terms (version 11.0). Results: The incidence of psychiatric disorders other than solely sleep disorders and disturbances was 10.7% in subjects treated with varenicline and 9.7% in subjects treated with placebo, with an RR of 1.02 (95% CI 0.86, 1.22). The RRs (95% CI) versus placebo of psychiatric adverse events with an incidence ≥1% in the varenicline group were 0.86 (0.67, 1.12) for anxiety disorders and symptoms, 0.76 (0.42, 1.39) for changes in physical activity, 1.42 (0.96, 2.08) for depressed mood disorders and disturbances, 1.21 (0.79, 1.83) for mood disorders and disturbances not elsewhere classified and 1.70 (1.50, 1.92) for sleep disorders and disturbances. There were no cases of suicidal ideation or behaviour in varenicline-treated subjects in the ten placebo-controlled studies analysed. However, among three trials that were excluded from the analysis because of their open-label design, two cases of suicidal ideation and one completed suicide were reported in patients who had been treated with varenicline. With the exception of sleep disorders and disturbances, there was no evidence of dose-responsivity. Conclusions: There was no significant increase in overall psychiatric disorders, other than sleep disorders and disturbances, in varenicline-treated subjects in this sample of smokers without current psychiatric disorders. Ongoing studies are testing the use of varenicline in psychiatric patients.

The Fagerström Test for Nicotine Dependence as a Predictor of Smoking Abstinence: A Pooled Analysis of Varenicline Clinical Trial Data

INTRODUCTION We explored the relationship between the Fagerström Test for Nicotine Dependence (FTND) and smoking abstinence rates in 10 randomized, double-blind placebo-controlled Phase 2-4 varenicline studies. METHODS Participants were adult smokers (≥10 cigarettes/day) who were motivated to quit. Efficacy end points included continuous abstinence rate (CAR) for weeks 9-24 analyzed, by baseline FTND and Heaviness of Smoking Index (HSI) scores, and treatment. Data were analyzed using logistic regression models. RESULTS Overall, 2,763 varenicline (M [SD] FTND score: 5.6 [2.2]) and 2,229 placebo subjects (5.5 [2.1]) were included in the analysis. An increase of one unit in baseline FTND or HSI score decreased the odds of abstinence at Week 24 by 11% (odds ratio [OR] 0.89, 95% CI 0.86-0.92, p < .0001) and 18% (OR 0.82, 95% CI 0.79-0.87, p < .0001), respectively. Treatment had a significant impact on CAR 9-24: odds of abstinence were increased threefold for varenicline versus placebo (OR 3.3, 95% CI 2.8-3.8, p < .0001). There was no interaction between treatment and FTND (p = .98) or HSI score (p = .97) for CAR 9-24. The HSI score predicted abstinence outcome as effectively as the FTND score. CONCLUSION Abstinence rates decreased with increasing dependence scores. There was no interaction between treatment and baseline FTND or HSI score, suggesting that they have no effect on the efficacy of varenicline versus placebo. These results also suggest that the HSI may be as effective at predicting smoking cessation outcome as the whole FTND questionnaire.

Effects of Varenicline on Smoking Cessation in Adults With Stably Treated Current or Past Major Depression: A Randomized Trial

UNLABELLED Chinese translation BACKGROUND Depression is overrepresented in smokers. OBJECTIVE To evaluate smoking abstinence and changes in mood and anxiety levels in smokers with depression treated with varenicline versus placebo. DESIGN Phase 4, multicenter, parallel, 1:1 allocation, double-blind, randomization trial. Randomization, stratified by antidepressant use and depression score at baseline, was blocked in sizes of 4. (ClinicalTrials.gov: NCT01078298). SETTING 38 centers in 8 countries. PARTICIPANTS 525 adult smokers with stably treated current or past major depression and no recent cardiovascular events. INTERVENTION Varenicline, 1 mg twice daily, or placebo for 12 weeks, with 40-week nontreatment follow-up. MEASUREMENTS Primary outcome was carbon monoxide-confirmed continuous abstinence rate (CAR) for weeks 9 to 12. Other outcomes included CARs assessed during nontreatment follow-up and ratings of mood, anxiety, and suicidal ideation or behavior. RESULTS 68.4% versus 66.5% of the varenicline and placebo groups, respectively, completed the study. Varenicline-treated participants had higher CARs versus placebo at weeks 9 to 12 (35.9% vs. 15.6%; odds ratio [OR], 3.35 [95% CI, 2.16 to 5.21]; P < 0.001), 9 to 24 (25.0% vs. 12.3%; OR, 2.53 [CI, 1.56 to 4.10]; P < 0.001), and 9 to 52 (20.3% vs. 10.4%; OR, 2.36 [CI, 1.40 to 3.98]; P = 0.001). There were no clinically relevant differences between groups in suicidal ideation or behavior and no overall worsening of depression or anxiety in either group. The most frequent adverse event was nausea (varenicline, 27.0%; placebo, 10.4%). Two varenicline-group participants died during the nontreatment phase. LIMITATIONS Some data were missing, and power to detect differences between groups was low in rare events. Smokers with untreated depression, with co-occurring psychiatric conditions, or receiving mood stabilizers and antipsychotics were not included. CONCLUSION Varenicline increased smoking cessation in smokers with stably treated current or past depression without exacerbating depression or anxiety. PRIMARY FUNDING SOURCE Pfizer.

Effect of Varenicline on Smoking Cessation Through Smoking Reduction: A Randomized Clinical Trial

IMPORTANCE Some cigarette smokers may not be ready to quit immediately but may be willing to reduce cigarette consumption with the goal of quitting. OBJECTIVE To determine the efficacy and safety of varenicline for increasing smoking abstinence rates through smoking reduction. DESIGN, SETTING, AND PARTICIPANTS Randomized, double-blind, placebo-controlled, multinational clinical trial with a 24-week treatment period and 28-week follow-up conducted between July 2011 and July 2013 at 61 centers in 10 countries. The 1510 participants were cigarette smokers who were not willing or able to quit smoking within the next month but willing to reduce smoking and make a quit attempt within the next 3 months. Participants were recruited through advertising. INTERVENTIONS Twenty-four weeks of varenicline titrated to 1 mg twice daily or placebo with a reduction target of 50% or more in number of cigarettes smoked by 4 weeks, 75% or more by 8 weeks, and a quit attempt by 12 weeks. MAIN OUTCOMES AND MEASURES Primary efficacy end point was carbon monoxide-confirmed self-reported abstinence during weeks 15 through 24. Secondary outcomes were carbon monoxide-confirmed self-reported abstinence for weeks 21 through 24 and weeks 21 through 52. RESULTS The varenicline group (n = 760) had significantly higher continuous abstinence rates during weeks 15 through 24 vs the placebo group (n = 750) (32.1% for the varenicline group vs 6.9% for the placebo group; risk difference (RD), 25.2% [95% CI, 21.4%-29.0%]; relative risk (RR), 4.6 [95% CI, 3.5-6.1]). The varenicline group had significantly higher continuous abstinence rates vs the placebo group during weeks 21 through 24 (37.8% for the varenicline group vs 12.5% for the placebo group; RD, 25.2% [95% CI, 21.1%-29.4%]; RR, 3.0 [95% CI, 2.4-3.7]) and weeks 21 through 52 (27.0% for the varenicline group vs 9.9% for the placebo group; RD, 17.1% [95% CI, 13.3%-20.9%]; RR, 2.7 [95% CI, 2.1-3.5]). Serious adverse events occurred in 3.7% of the varenicline group and 2.2% of the placebo group (P = .07). CONCLUSIONS AND RELEVANCE Among cigarette smokers not willing or able to quit within the next month but willing to reduce cigarette consumption and make a quit attempt at 3 months, use of varenicline for 24 weeks compared with placebo significantly increased smoking cessation rates at the end of treatment, and also at 1 year. Varenicline offers a treatment option for smokers whose needs are not addressed by clinical guidelines recommending abrupt smoking cessation. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01370356.

A Randomized Placebo-Controlled Trial of Varenicline for Smoking Cessation Allowing Flexible Quit Dates

Introduction: Current smoking cessation guidelines recommend setting a quit date prior to starting pharmacotherapy. However, providing flexibility in the date of quitting may be more acceptable to some smokers. The objective of this study was to compare varenicline 1 mg twice daily (b.i.d.) with placebo in subjects using a flexible quit date paradigm after starting medication. Methods: In this double-blind, randomized, placebo-controlled international study, smokers of ≥10 cigarettes/day, aged 18–75 years, and who were motivated to quit were randomized (3:1) to receive varenicline 1 mg b.i.d. or placebo for 12 weeks. Subjects were followed up through Week 24. Subjects were instructed to quit between Days 8 and 35 after starting medication. The primary endpoint was carbon monoxide–confirmed continuous abstinence during Weeks 9–12, and a key secondary endpoint was continuous abstinence during Weeks 9–24. Results: Overall, 493 subjects were randomized to varenicline and 166 to placebo. Continuous abstinence was higher for varenicline than for placebo subjects at the end of treatment (Weeks 9–12: 53.1% vs. 19.3%; odds ratio [OR] 5.9; 95% CI, 3.7–9.4; p < .0001) and through 24 weeks follow-up (Weeks 9–24: 34.7% vs. 12.7%; OR 4.4; 95% CI, 2.6–7.5; p < .0001). Serious adverse events occurred in 1.2% varenicline (none were psychiatric) and 0.6% placebo subjects. Fewer varenicline than placebo subjects reported depression-related adverse events (2.3% vs. 6.7%, respectively). Conclusions: Varenicline 1 mg b.i.d. using a flexible quit date paradigm had similar efficacy and safety compared with previous fixed quit date studies.

Effect of varenicline on individual nicotine withdrawal symptoms: a combined analysis of eight randomized, placebo-controlled trials.

INTRODUCTION Concerns exist that varenicline may cause neuropsychiatric side effects. Some of these symptoms (e.g., depression, irritability) have been measured in clinical trials using nicotine withdrawal scales. This study assessed the effect of varenicline on neuropsychiatric and other symptoms, as measured by the Minnesota Nicotine Withdrawal Scale (MNWS). METHODS We analyzed weekly individual MNWS symptom ratings in 8 randomized double-blind, placebo-controlled smoking cessation trials funded by Pfizer with similar methodology (n = 2,403 varenicline; n = 1,434 placebo). Ratings for the past 24hr were obtained prior to quitting and starting treatment and at Weeks 1-6 and 11 after the quit date. RESULTS In repeated measures analyses controlling for baseline values, ratings for 5 neuropsychiatric symptoms (depressed mood, irritability, anxiety, difficulty concentrating, and restlessness) and urge to smoke were lower (p < .01) for varenicline than placebo at each timepoint. Worsening in scores from 0-2 (baseline) to 4 was less frequent on varenicline than placebo for all ratings except appetite- (significantly more frequent for varenicline, p < .0001) and sleep-related items. Repeated measures analysis for individuals with low levels of exhaled carbon monoxide revealed similar patterns except for a nonsignificant difference for increased appetite. CONCLUSIONS Use of varenicline while trying to quit smoking reduces and does not increase neuropsychiatric symptoms such as depressed mood and irritability measured on the MNWS in smokers without current psychiatric disorders. It is associated with increases in sleep disturbance and appetite although the latter appears due to enabling more subjects to abstain from smoking.

Varenicline treatment for smoking cessation in Asian populations: a pooled analysis of placebo-controlled trials conducted in six Asian countries

Abstract Objective: A pooled analysis to evaluate the efficacy and safety of varenicline versus placebo for smoking cessation in Asian populations. A secondary objective was to compare the data to pooled trials among predominantly Western populations. Research design and methods: Smokers (n = 893) in three randomized, double-blind, placebo-controlled, multicenter, phase IIb or III trials conducted in six Asian countries (Japan, Taiwan, Korea, China, Singapore, and Thailand), received varenicline (1 mg twice daily; n = 447) or placebo (n = 446) for 12 weeks. Non-treatment follow-up lasted 12 weeks (40 weeks in Japan). Primary endpoint was the carbon monoxide-confirmed continuous abstinence rate (CAR) for weeks 9–12 (last 4 weeks of treatment). Secondary endpoint was CAR for weeks 9–24. Results: CAR was higher for varenicline than placebo during weeks 9–12 (58.6 vs. 34.3%; odds ratio [OR]: 2.74; 95% confidence interval [CI]: 2.08–3.60; p < 0.0001), and through 12 weeks of follow-up (CAR weeks 9–24; 41.4 vs. 25.3%; OR: 2.08; 95% CI: 1.56–2.77; p < 0.0001). The most frequent adverse events (AEs) in the varenicline group (greater incidence than the placebo group) were: nausea (31.5%), headache (8.5%), dizziness (7.8%), insomnia (7.4%), and upper abdominal pain (5.4%). Serious AEs occurred in four varenicline and five placebo participants. Discontinuations due to AEs occurred in 3.6% of varenicline and 1.6% of placebo participants. Compared with the Western studies, abstinence rates for both varenicline and placebo were numerically higher in the Asian studies, although treatment effects were similar between the two populations. AEs reported in the Asian trials were largely similar to those in the Western populations. Conclusions: Varenicline significantly improved smoking abstinence in Asian populations from six countries. AEs were predominantly of mild or moderate intensity. These data were largely the same as those seen in Western populations, but the studies were not designed to explore racial or cultural differences.

Functional Interactions of Varenicline and Nicotine With nAChR Subtypes Implicated in Cardiovascular Control

INTRODUCTION It has been suggested that varenicline-induced activation of nicotinic acetylcholine receptors (nAChRs) could play a role in the cardiovascular (CV) safety of varenicline. However, since preclinical studies showed that therapeutic varenicline concentrations have no effect in models of CV function, this study examined in vitro profiles of varenicline and nicotine at nAChR subtypes possibly involved in CV control. METHODS Concentration-dependent functional effects of varenicline and nicotine at human α3β4, α3α5β4, α7, and α4β2 nAChRs expressed in oocytes were determined by electrophysiology. The proportion of nAChRs predicted to be activated and inhibited by concentrations of varenicline (1mg b.i.d.) and of nicotine in smokers was derived from activation-inhibition curves for each nAChR subtype. RESULTS Human varenicline and nicotine concentrations can desensitize and inhibit nAChRs but cause only low-level activation of α3β4, α4β2 (<2%), α7 (<0.05%), and α3α5β4 (<0.01%) nAChRs, which is consistent with literature data. Nicotine concentrations in smokers are predicted to inhibit larger fractions of α3β4 (48%) and α3α5β4 (10%) nAChRs than therapeutic varenicline concentrations (11% and 0.6%, respectively) and to inhibit comparable fractions of α4β2 nAChRs (42%-56%) and α7 nAChRs (16%) as varenicline. CONCLUSIONS Nicotine and varenicline concentrations in patients and smokers are predicted to cause minimal activation of ganglionic α3β4* nAChRs, while their functional profiles at α3β4, α3α5β4, α7, and α4β2 nAChRs cannot explain that substituting nicotine from tobacco with varenicline would cause CV adverse events in smokers who try to quit. Other pharmacological properties that could mediate varenicline-induced CV effects have not been identified.

Association of deferring a quit attempt with smoking cessation success: a secondary analysis.

Several smoking cessation treatments ask smokers to wait to quit to obtain treatment. We report a secondary analysis of whether a later quit attempt is associated with less success. In a placebo-controlled trial of varenicline that allowed smokers to set their quit date within 5 weeks after starting medication, 24% had their first quit attempt during week 1, and 27%, 19%, 18% and 12% in subsequent weeks. Continuous abstinence between 9 and 24 weeks declined over time; that is, from 36% to 37%, 35%, 29%, and 18% across the 5 weeks (p<0.001). The only statistically significant difference was between the last week and prior weeks. Whether a later quit attempt actually causes less success or is a marker for other variables (e.g., low motivation) is unclear.