Baseline Characteristics
The summary included 1427 patients: 477 treated with ezetimibe and 950 with evolocumab. Each study that contributed to this analysis randomized patients in a 1:2 ratio to ezetimibe and evolocumab—154 ezetimibe and 306 evolocumab in monotherapy patients, 111 ezetimibe and 220 evolocumab in low-intensity statin patients, 110 ezetimibe and 219 evolocumab in high-intensity statin patients, and 102 ezetimibe and 205 evolocumab in the statin-intolerant population (Table 1).
Within each patient population, baseline demographics (age, sex, and body mass index), CV risk factors (smoking, peripheral arterial disease, coronary artery disease, and others), and baseline lipids (LDL-C, non–HDL-C, HDL-C, VLDL-C, and others) were well matched between the ezetimibe and evolocumab treatment groups (Table 2). Overall, 53% of patients were female, and 90% were Caucasian. All patients in the low- and high-intensity statin populations received statins at baseline. One-third of the patients in the statin-intolerant population used lipid-lowering therapy at baseline. Of the latter, 18% received a low-dose statin [18].
Table 2 Baseline demographics and clinical characteristics Effects of Ezetimibe and Evolocumab on LDL-C and Non–HDL-C
Table 3 shows lipid efficacy results for evolocumab and ezetimibe. Across the four patient populations evaluated, evolocumab reduced LDL-C by a mean 55–61% from baseline to week 12, and ezetimibe lowered LDL-C by 18–20% from baseline, resulting in a mean difference of 38–43% favoring evolocumab compared with ezetimibe (p < 0.0001). These percentage reductions corresponded to lower achieved LDL-C levels at week 12 in evolocumab- vs. ezetimibe-treated patients in all groups studied (Fig. 1), with absolute reductions in LDL-C following evolocumab treatment of 59.9–104 mg/dL. These were greater than the absolute reductions in LDL-C seen with ezetimibe (16.5–35.3 mg/dL). Evolocumab also reduced non–HDL-C from baseline by a mean of 48–53% across the four populations, and ezetimibe reduced non–HDL-C from baseline by a mean of 16–17%, resulting in a mean difference between groups of 33–37% favoring evolocumab (p < 0.0001).
Table 3 Efficacy outcomes The greater reduction in LDL-C achieved with evolocumab vs. ezetimibe led to higher proportions of patients on evolocumab achieving LDL-C and non–HDL-C treatment goals (Table 3). In the monotherapy treatment groups, 69% of evolocumab- and 1% of ezetimibe-treated patients achieved an LDL-C level < 70 mg/dL. In patients on low-intensity background statin therapy, 85% (evolocumab) and 21% (ezetimibe) achieved an LDL-C level < 70 mg/dL. In patients on high-intensity background statin therapy, 92% (evolocumab) and 54% (ezetimibe) achieved an LDL-C level < 70 mg/dL. In the statin-intolerant patient population, 44% (evolocumab) and 1% (ezetimibe) achieved an LDL-C level < 70 mg/dL. All these comparisons favored evolocumab (p < 0.0001). Achievement of an LDL-C < 70 mg/dL goal was more likely to occur in patients with lower baseline LDL-C levels than in those with higher baseline LDL-C levels (Fig. 2). Similarly, for LDL-C < 100 mg/dL, evolocumab led to significantly higher proportions of patients achieving LDL-C goals across all patient populations, with the greatest treatment differences seen in the statin-intolerant (67% evolocumab vs. ezetimibe) and monotherapy groups (67% evolocumab vs. ezetimibe; p < 0.0001 for both).
Achievement of non–HDL-C < 100 mg/dL occurred significantly more often with evolocumab compared with ezetimibe across each population—80% and 6% in monotherapy patients, 87% and 34% in low-intensity statin patients, 93% and 63% in high-intensity statin patients, and 44% and 0% in statin-intolerant patients (all p < 0.0001). For the less stringent goal for non–HDL-C < 130 mg/dL, 72–97% of evolocumab-treated patients and 11%–81% of ezetimibe-treated patients achieved the goal (evolocumab vs. ezetimibe; p < 0.0001 for all patient populations).
Changes in Other Lipids Following Treatment with Ezetimibe or Evolocumab
Evolocumab compared with ezetimibe also had favorable effects on other atherogenic lipoproteins (Table 3). For example, patients treated with ezetimibe had a mean percent change from baseline in Lp(a) of 1.9% (monotherapy), 5.2% (low-intensity statin), 9.4% (high-intensity statin), and 2.0% (statin intolerance). In contrast, patients treated with evolocumab had a mean percent change from baseline in Lp(a) of −22% (monotherapy) and −24% (low-intensity statin, high-intensity statin, and statin intolerance), resulting in mean treatment differences vs. ezetimibe of −23%, −28%, −34%, and −26% in the monotherapy, low-intensity statin, high-intensity statin, and statin-intolerant populations, respectively (p < 0.0001 favoring evolocumab in all groups). Additionally, the mean treatment difference between groups in the reduction in ApoB (evolocumab vs. ezetimibe) was 33–36% across the patient populations (p < 0.0001 favoring evolocumab in all groups).
Ezetimibe treatment resulted in a mean percent change from baseline in triglycerides of −4.9 to 3.3% across patient populations. Evolocumab treatment resulted in a mean percent change from baseline in triglycerides of −3.4 to −8.3%. The treatment difference between ezetimibe and evolocumab was −0.3 to −11%, a difference that reached significance for the monotherapy and low-intensity statin populations (p < 0.05 in favor of evolocumab for both) but not for the high-intensity statin or statin-intolerant populations. Treatment with ezetimibe resulted in a mean percent change from baseline in HDL-C of −1.2 to 2.2%. In contrast, evolocumab treatment increased levels of HDL-C by a mean percent change from baseline of 4.8% in the monotherapy patient population, 7.4% in the low-intensity statin patient population, 8.5% in the high-intensity statin patient population, and 6.2% in the statin-intolerant patient population. Treatment differences for HDL-C for evolocumab vs. ezetimibe ranged from 4.3 to 8.6% across patient populations (p < 0.05 in all groups; Table 3).
Twelve weeks of evolocumab treatment significantly reduced PCSK9 levels from baseline by a mean of 54% in the monotherapy patient population, 45% in the low-intensity statin patient population, 32% in the high-intensity statin patient population, and 45% in the statin-intolerant patient population. In contrast, mean percent changes in PCSK9 levels in ezetimibe-treated patients were 16%, 13%, 17%, and 0.9% across the above populations, resulting in significant treatment differences of −64%, −57%, −49%, and −44% (p < 0.0001 favoring evolocumab in all groups), respectively.
Safety and Tolerability
Table 4 shows AE rates across the groups examined in this report. Overall, AEs appear balanced between evolocumab- and ezetimibe-treated patients. Statin-intolerant patients reported AEs more frequently than other populations. Serious AEs occurred in 0–3.9% of patients across the patient populations receiving ezetimibe, and in 1.3–2.9% across the patient populations receiving evolocumab. Calculations of the incidence of potential muscle events used Standardised MedDRA (Medical Dictionary for Regulatory Activities) Queries terms. These events occurred at rates of (ezetimibe vs. evolocumab) 3.2% vs. 2.6%, 4.5% vs. 0.9%, 2.7% vs. 1.8%, and 22.5% vs. 12.2% in the monotherapy, low-intensity statin, high-intensity statin, and statin-intolerant populations, respectively.
The decision to discontinue SC treatment by patients and/or physicians occurred at rates comparable to the discontinuation rates for oral treatment in the high-intensity statin and monotherapy treatment groups. In the statin-intolerant group, discontinuation occurred in 13.7% (ezetimibe) and 8.3% (evolocumab) of patients receiving blinded oral drug and 5.9% (ezetimibe) and 3.9% (evolocumab) of patients receiving blinded SC drug. In the low-intensity statin group, discontinuation occurred in 6.3% (ezetimibe) and 3.2% (evolocumab) of patients receiving oral drug and 8.1% (ezetimibe) and 4.1% (evolocumab) of patients receiving SC drug. Rates of drug discontinuation due to muscle events were < 1% in each group except for statin-intolerant patients. In the statin-intolerant population, 5.9% vs. 2.4% of patients in the ezetimibe- vs. evolocumab-treated groups stopped oral drug treatment due to muscle symptoms. In the same population, 2.9% vs. 0.5% of patients in the ezetimibe- vs. evolocumab-treated groups discontinued parenteral drug treatment due to muscle symptoms.