Cardiovascular Efficacy and Safety of Bococizumab in High-Risk Patients

BACKGROUND

Bococizumab is a humanized monoclonal antibody that inhibits proprotein convertase subtilisin–kexin type 9 (PCSK9) and reduces levels of low-density lipoprotein (LDL) cholesterol. We sought to evaluate the efficacy of bococizumab in patients at high cardiovascular risk.

METHODS

In two parallel, multinational trials with different entry criteria for LDL cholesterol levels, we randomly assigned the 27,438 patients in the combined trials to receive bococizumab (at a dose of 150 mg) subcutaneously every 2 weeks or placebo. The primary end point was nonfatal myocardial infarction, nonfatal stroke, hospitalization for unstable angina requiring urgent revascularization, or cardiovascular death; 93% of the patients were receiving statin therapy at baseline. The trials were stopped early after the sponsor elected to discontinue the development of bococizumab owing in part to the development of high rates of antidrug antibodies, as seen in data from other studies in the program. The median follow-up was 10 months.

RESULTS

At 14 weeks, patients in the combined trials had a mean change from baseline in LDL cholesterol levels of −56.0% in the bococizumab group and +2.9% in the placebo group, for a between-group difference of –59.0 percentage points (P<0.001) and a median reduction from baseline of 64.2% (P<0.001). In the lower-risk, shorter-duration trial (in which the patients had a baseline LDL cholesterol level of ≥70 mg per deciliter [1.8 mmol per liter] and the median follow-up was 7 months), major cardiovascular events occurred in 173 patients each in the bococizumab group and the placebo group (hazard ratio, 0.99; 95% confidence interval [CI], 0.80 to 1.22; P=0.94). In the higher-risk, longer-duration trial (in which the patients had a baseline LDL cholesterol level of ≥100 mg per deciliter [2.6 mmol per liter] and the median follow-up was 12 months), major cardiovascular events occurred in 179 and 224 patients, respectively (hazard ratio, 0.79; 95% CI, 0.65 to 0.97; P=0.02). The hazard ratio for the primary end point in the combined trials was 0.88 (95% CI, 0.76 to 1.02; P=0.08). Injection-site reactions were more common in the bococizumab group than in the placebo group (10.4% vs. 1.3%, P<0.001).

CONCLUSIONS

In two randomized trials comparing the PCSK9 inhibitor bococizumab with placebo, bococizumab had no benefit with respect to major adverse cardiovascular events in the trial involving lower-risk patients but did have a significant benefit in the trial involving higher-risk patients. (Funded by Pfizer; SPIRE-1 and SPIRE-2 ClinicalTrials.gov numbers, NCT01975376 and NCT01975389.)

N Engl J Med 2017; 376:1527-1539

Cardiovascular event rates and mortality according to achieved systolic and diastolic blood pressure in patients with stable coronary artery disease: an international cohort study

Background

The optimum blood pressure target in hypertension remains debated, especially in coronary artery disease, given concerns for reduced myocardial perfusion if diastolic blood pressure is too low. We aimed to study the association between achieved blood pressure and cardiovascular outcomes in patients with coronary artery disease and hypertension.

Methods

We analysed data from 22 672 patients with stable coronary artery disease enrolled (from Nov 26, 2009, to June 30, 2010) in the CLARIFY registry (including patients from 45 countries) and treated for hypertension. Systolic and diastolic blood pressures before each event were averaged and categorised into 10 mm Hg increments. The primary outcome was the composite of cardiovascular death, myocardial infarction, or stroke. Hazard ratios (HRs) were estimated with multivariable adjusted Cox proportional hazards models, using the 120–129 mm Hg systolic blood pressure and 70–79 mm Hg diastolic blood pressure subgroups as reference.

Findings

After a median follow-up of 5·0 years, increased systolic blood pressure of 140 mm Hg or more and diastolic blood pressure of 80 mm Hg or more were each associated with increased risk of cardiovascular events. Systolic blood pressure of less than 120 mm Hg was also associated with increased risk for the primary outcome (adjusted HR 1·56, 95% CI 1·36–1·81). Likewise, diastolic blood pressure of less than 70 mm Hg was associated with an increase in the primary outcome (adjusted HR 1·41 [1·24–1·61] for diastolic blood pressure of 60–69 mm Hg and 2·01 [1·50–2·70] for diastolic blood pressure of less than 60 mm Hg).

Interpretation

In patients with hypertension and coronary artery disease from routine clinical practice, systolic blood pressure of less than 120 mm Hg and diastolic blood pressure of less than 70 mm Hg were each associated with adverse cardiovascular outcomes, including mortality, supporting the existence of a J-curve phenomenon. This finding suggests that caution should be taken in the use of blood pressure-lowering treatment in patients with coronary artery disease.

Funding

Servier.

Reference: The Lancet, Volume 388, No. 10056, p2142–2152, 29 October 2016

Antidepressant use and risk of cardiovascular outcomes in people aged 20 to 64: cohort study using primary care database

Objective To assess associations between different antidepressant treatments and rates of three cardiovascular outcomes (myocardial infarction, stroke or transient ischaemic attack, and arrhythmia) in people with depression.

Design Cohort study.

Setting UK general practices contributing to the QResearch primary care database.

Participants 238 963 patients aged 20 to 64 years with a first diagnosis of depression between 1 January 2000 and 31 July 2011.

Exposures Antidepressant class (tricyclic and related antidepressants, selective serotonin reuptake inhibitors, other antidepressants), dose, duration of use, and commonly prescribed individual antidepressant drugs.

Main outcome measures First diagnoses of myocardial infarction, stroke or transient ischaemic attack, and arrhythmia during five years’ follow-up. Cox proportional hazards models were used to estimate hazard ratios, adjusting for potential confounding variables.

Results During five years of follow-up, 772 patients had a myocardial infarction, 1106 had a stroke or transient ischaemic attack, and 1452 were diagnosed as having arrhythmia. No significant associations were found between antidepressant class and myocardial infarction over five years’ follow-up. In the first year of follow-up, patients treated with selective serotonin reuptake inhibitors had a significantly reduced risk of myocardial infarction (adjusted hazard ratio 0.58, 95% confidence interval 0.42 to 0.79) compared with no use of antidepressants; among individual drugs, fluoxetine was associated with a significantly reduced risk (0.44, 0.27 to 0.72) and lofepramine with a significantly increased risk (3.07, 1.50 to 6.26). No significant associations were found between antidepressant class or individual drugs and risk of stroke or transient ischaemic attack. Antidepressant class was not significantly associated with arrhythmia over five years’ follow-up, although the risk was significantly increased during the first 28 days of treatment with tricyclic and related antidepressants (adjusted hazard ratio 1.99, 1.27 to 3.13). Fluoxetine was associated with a significantly reduced risk of arrhythmia (0.74, 0.59 to 0.92) over five years, but citalopram was not significantly associated with risk of arrhythmia even at high doses (1.11, 0.72 to 1.71 for doses ≥40 mg/day).

Conclusions This study found no evidence that selective serotonin reuptake inhibitors are associated with an increased risk of arrhythmia or stroke/transient ischaemic attack in people diagnosed as having depression between the ages of 20 to 64 or that citalopram is associated with a significantly increased risk of arrhythmia. It found some indication of a reduced risk of myocardial infarction with selective serotonin reuptake inhibitors, particularly fluoxetine, and of an increased risk with lofepramine.

By Carol Coupland et al, BMJ 2016;352:i1350

Effect of Naltrexone-Bupropion on Major Adverse Cardiovascular Events in Overweight and Obese Patients With Cardiovascular Risk Factors

Importance  Few cardiovascular outcomes trials have been conducted for obesity treatments. Withdrawal of 2 marketed drugs has resulted in controversy about the cardiovascular safety of obesity agents.

Objective  To determine whether the combination of naltrexone and bupropion increases major adverse cardiovascular events (MACE, defined as cardiovascular death, nonfatal stroke, or nonfatal myocardial infarction) compared with placebo in overweight and obese patients.

Design, Setting, and Participants  Randomized, multicenter, placebo-controlled, double-blind noninferiority trial enrolling 8910 overweight or obese patients at increased cardiovascular risk from June 13, 2012, to January 21, 2013, at 266 US centers. After public release of confidential interim data by the sponsor, the academic leadership of the study recommended termination of the trial and the sponsor agreed.

Interventions  An Internet-based weight management program was provided to all participants. Participants were randomized to receive placebo (n=4454) or naltrexone, 32 mg/d, and bupropion, 360 mg/d (n=4456).

Main Outcomes and Measures  Time from randomization to first confirmed occurrence of a MACE. The primary analysis planned to assess a noninferiority hazard ratio (HR) of 1.4 after 378 expected events, with a confidential interim analysis after approximately 87 events (25% interim analysis) to assess a noninferiority HR of 2.0 for consideration of regulatory approval.

Results  Among the 8910 participants randomized, mean age was 61.0 years (SD, 7.3 years), 54.5% were female, 32.1% had a history of cardiovascular disease, and 85.2% had diabetes, with a median body mass index of 36.6 (interquartile range, 33.1-40.9). For the 25% interim analysis, MACE occurred in 59 placebo-treated patients (1.3%) and 35 naltrexone-bupropion–treated patients (0.8%; HR, 0.59; 95% CI, 0.39-0.90). After 50% of planned events, MACE occurred in 102 patients (2.3%) in the placebo group and 90 patients (2.0%) in the naltrexone-bupropion group (HR, 0.88; adjusted 99.7% CI, 0.57-1.34). Adverse effects were more common in the naltrexone-bupropion group, including gastrointestinal events in 14.2% vs 1.9% (P < .001) and central nervous system symptoms in 5.1% vs 1.2% (P < .001).

Conclusions and Relevance  Among overweight or obese patients at increased cardiovascular risk, based on the interim analyses performed after 25% and 50% of planned events, the upper limit of the 95% CI of the HR for MACE for naltrexone-bupropion treatment, compared with placebo, did not exceed 2.0. However, because of the unanticipated early termination of the trial, it is not possible to assess noninferiority for the prespecified upper limit of 1.4. Accordingly, the cardiovascular safety of this treatment remains uncertain and will require evaluation in a new adequately powered outcome trial.

Trial Registration  clinicaltrials.gov Identifier: NCT01601704

By Steven E. Nissen et al, JAMA. 2016;315(10):990-1004. doi:10.1001/jama.2016.1558.