CLINICAL PHARMACOLOGY
Mechanism Of Action
Evolocumab is a human monoclonal IgG2 directed against human proprotein convertase subtilisin kexin 9 (PCSK9). Evolocumab binds to PCSK9 and inhibits circulating PCSK9 from binding to the low density lipoprotein (LDL) receptor (LDLR), preventing PCSK9-mediated LDLR degradation and permitting LDLR to recycle back to the liver cell surface. By inhibiting the binding of PCSK9 to LDLR, evolocumab increases the number of LDLRs available to clear LDL from the blood, thereby lowering LDL-C levels.
Pharmacodynamics
Following single subcutaneous administration of 140 mg or 420 mg of evolocumab, maximum suppression of circulating unbound PCSK9 occurred by 4 hours. Unbound PCSK9 concentrations returned toward baseline when evolocumab concentrations decreased below the limit of quantitation.
Pharmacokinetics
Evolocumab exhibits non-linear kinetics as a result of binding to PCSK9. Administration of the 140 mg
dose in healthy volunteers resulted in a Cmax mean (standard deviation [SD]) of 18.6 (7.3) μg/mL and
AUClast mean (SD) of 188 (98.6) day•μg/mL. Administration of the 420 mg dose in healthy volunteers
resulted in a Cmax mean (SD) of 59.0 (17.2) μg/mL and AUClast mean (SD) of 924 (346) day•μg/mL.
Following a single 420 mg intravenous dose, the mean (SD) systemic clearance was estimated to be
12 (2) mL/hr. An approximate 2-to 3-fold accumulation was observed in trough serum concentrations
(Cmin [SD] 7.21 [6.6]) following 140 mg doses administered subcutaneously every 2 weeks or following
420 mg doses administered subcutaneously monthly (Cmin [SD] 11.2 [10.8]), and serum trough
concentrations approached steady state by 12 weeks of dosing.
Absorption
Following a single subcutaneous dose of 140 mg or 420 mg evolocumab administered to healthy adults,
median peak serum concentrations were attained in 3 to 4 days, and estimated absolute bioavailability was
72%.
Distribution
Following a single 420 mg intravenous dose, the mean (SD) steady-state volume of distribution was estimated to be 3.3 (0.5) L.
Metabolism And Elimination
Two elimination phases were observed for REPATHA. At low concentrations, the elimination is predominately through saturable binding to target (PCSK9), while at higher concentrations the elimination of REPATHA is largely through a non-saturable proteolytic pathway. REPATHA was estimated to have an effective half-life of 11 to 17 days.
Specific Populations
The pharmacokinetics of evolocumab were not affected by age, gender, race, or creatinine clearance across all approved populations [see Use In Specific Populations].
The exposure of evolocumab decreased with increasing body weight. These differences are not clinically meaningful.
Renal Impairment
Since monoclonal antibodies are not known to be eliminated via renal pathways, renal function is not expected to impact the pharmacokinetics of evolocumab.
In a clinical trial of 18 patients with either normal renal function (estimated glomerular filtration rate [eGFR] ≥ 90 mL/min/1.73 m2, n=6), severe renal impairment (eGFR < 30 mL/min/1.73 m2, n=6), or end-stage renal disease (ESRD) receiving hemodialysis (n=6), exposure to evolocumab after a single 140 mg subcutaneous dose was decreased in patients with severe renal impairment or ESRD receiving hemodialysis. Reductions in PCSK9 levels in patients with severe renal impairment or ESRD receiving hemodialysis was similar to those with normal renal function [see Use In Specific Populations].
Hepatic Impairment
Following a single 140 mg subcutaneous dose of evolocumab in patients with mild or moderate hepatic impairment, a 20-30% lower mean Cmax and 40-50% lower mean AUC were observed as compared to healthy patients; however, no dose adjustment is necessary in these patients.
Pregnancy
The effect of pregnancy on evolocumab pharmacokinetics has not been studied [see Use In Specific Populations].
Drug Interaction Studies
An approximately 20% decrease in the Cmax and AUC of evolocumab was observed in patients co-administered with a high-intensity statin regimen. This difference is not clinically meaningful and does not impact dosing recommendations.
Animal Toxicology And/Or Pharmacology
During a 3-month toxicology study of 10 and 100 mg/kg once every 2 weeks evolocumab in combination with 5 mg/kg once daily rosuvastatin in adult monkeys, there were no effects of evolocumab on the humoral immune response to keyhole limpet hemocyanin (KLH) after 1 to 2 months exposure. The highest dose tested corresponds to exposures 54-and 21-fold higher than the recommended human doses of 140 mg every 2 weeks and 420 mg once monthly, respectively, based on plasma AUC. Similarly, there were no effects of evolocumab on the humoral immune response to KLH (after 3 to 4 months exposure) in a 6-month study in cynomolgus monkeys at dose levels up to 300 mg/kg once weekly evolocumab corresponding to exposures 744-and 300-fold greater than the recommended human doses of 140 mg every 2 weeks and 420 mg once monthly, respectively, based on plasma AUC.
Clinical Studies
Prevention Of Cardiovascular Events
Study 1 (FOURIER, NCT01764633) was a double-blind, randomized, placebo-controlled, event-driven trial in 27,564 (13,784 REPATHA, 13,780 placebo) adult patients with established cardiovascular disease and with LDL-C ≥70 mg/dL and/or non-HDL-C ≥100 mg/dL despite high-or moderate-intensity statin therapy. Patients were randomly assigned 1:1 to receive either subcutaneous injections of REPATHA (140 mg every 2 weeks or 420 mg once monthly) or placebo; 86% used the every-2-week regimen throughout the trial. The median follow-up duration was 26 months. Overall, 99.2% of patients were followed until the end of the trial or death.
The mean (SD) age at baseline was 63 (9) years, with 45% being at least 65 years old; 25% were women. The trial population was 85% White, 2% Black, and 10% Asian; 8% identified as Hispanic ethnicity. Regarding prior diagnoses of cardiovascular disease, 81% had prior myocardial infarction, 19% prior non-hemorrhagic stroke, and 13% had symptomatic peripheral arterial disease. Selected additional baseline risk factors included hypertension (80%), diabetes mellitus (1% type 1; 36% type 2), current daily cigarette smoking (28%), New York Heart Association class I or II congestive heart failure (23%), and eGFR < 60 mL/min per 1.73 m2 (6%). Most patients were on a high-(69%) or moderate-intensity (30%) statin therapy at baseline, and 5% were also taking ezetimibe. Most patients were taking at least one other cardiovascular medication including anti-platelet agents (93%), beta blockers (76%), angiotensin converting enzyme (ACE) inhibitors (56%), or angiotensin receptor blockers (23%). On stable background lipid-lowering therapy, the median [Q1, Q3] LDL-C at baseline was 92 [80, 109] mg/dL; the mean (SD) was 98 (28) mg/dL.
REPATHA significantly reduced the risk for the primary composite endpoint (time to first occurrence of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization; p<0.0001) and the key secondary composite endpoint (time to first occurrence of cardiovascular death, myocardial infarction, or stroke; p<0.0001). The Kaplan-Meier estimates of the cumulative incidence of the primary and key secondary composite endpoints over time are shown in Figure 1 and Figure 2 below.
The results of primary and secondary efficacy endpoints are shown in Table 3 below.
Table 3. Effect of REPATHA on Cardiovascular Events in Patients with Established Cardiovascular Disease in FOURIER
|
Placebo |
REPATHA |
REPATHA vs.Placebo |
N = 13780 n (%) |
Incidence Rate (per 100 patient years) |
N = 13784 n (%) |
Incidence Rate (per 100 patient years) |
Hazard Ratio (95% CI) |
Primary composite endpoint |
Time to first occurrence of cardiovascular death, myocardial infarction, stroke, coronary revascularization, hospitalization for unstable angina |
1563 (11.3) |
5.2 |
1344 (9.8) |
4.5 |
0.85 (0.79,0.92) |
Key secondary composite endpoint |
Time to first occurrence of cardiovascular death, myocardial infarction, stroke |
1013 (7.4) |
3.4 |
816 (5.9) |
2.7 |
0.80 (0.73, 0.88) |
Other secondary endpoints |
Time to cardiovascular death |
240 (1.7) |
0.8 |
251 (1.8) |
0.8 |
1.05 (0.88, 1.25) |
Time to death by any causea |
426 (3.1) |
1.4 |
444 (3.2) |
1.5 |
1.04 (0.91, 1.19) |
Time to first fatal or non-fatal myocardial infarction |
639 (4.6) |
2.1 |
468 (3.4) |
1.6 |
0.73 (0.65, 0.82) |
Time to first fatal or non-fatal stroke |
262 (1.9) |
0.9 |
207 (1.5) |
0.7 |
0.79 (0.66, 0.95) |
Time to first coronary revascularization |
965 (7.0) |
3.2 |
759 (5.5) |
2.5 |
0.78 (0.71, 0.86) |
Time to first hospitalization for unstable anginab |
239 (1.7) |
0.8 |
236 (1.7) |
0.8 |
0.99 (0.82, 1.18) |
aTime to death by any cause is not a component of either the primary composite endpoint or key secondary composite endpoint.
b Not a prespecified endpoint; an ad hoc analysis was performed to ensure results are provided for each individual component of the primary endpoint. |
Figure 1. Estimated Cumulative Incidence of Primary Composite Endpoint Over 3 Years in
FOURIER
Figure 2. Estimated Cumulative Incidence of Key Secondary Composite Endpoint Over 3 Years in
FOURIER
The difference between REPATHA and placebo in mean percent change in LDL-C from baseline to Week 12 was -63% (95% CI: -63%, -62%) and from baseline to Week 72 was -57% (95% CI: -58%, -56%). At Week 48, the median [Q1, Q3] LDL-C was 26 [15, 46] mg/dL in the REPATHA group, with 47% of patients having LDL-C <25 mg/dL.
Considering all assessments, among the patients treated with REPATHA, 10401 (76%) had at least one LDL-C value < 25 mg/dL. Although not a randomized comparison, the safety profile was similar between REPATHA-treated patients with post-baseline LDL-C < 25 mg/dL compared with REPATHA-treated patients with higher post-baseline LDL-C (LDL-C ≥ 40 mg/dL).
In EBBINGHAUS (NCT02207634), a substudy of 1974 patients enrolled in the FOURIER trial, REPATHA was non-inferior to placebo on selected cognitive function domains as assessed with the use of neuropsychological function tests over a median follow-up of 19 months.
Primary Hyperlipidemia (Including Heterozygous Familial Hypercholesterolemia)
Study 2 (LAPLACE-2, NCT01763866) was a multicenter, double-blind, randomized controlled 12-week trial in which patients were initially randomized to an open-label specific statin regimen for a 4-week lipid stabilization period followed by random assignment to subcutaneous injections of REPATHA 140 mg every 2 weeks, REPATHA 420 mg once monthly, or placebo for 12 weeks. The trial included 1896 patients with hyperlipidemia who received REPATHA, placebo, or ezetimibe as add-on therapy to daily doses of statins (atorvastatin, rosuvastatin, or simvastatin). Ezetimibe was also included as an active control only among those assigned to background atorvastatin. Overall, the mean age at baseline was 60 years (range: 20 to 80 years), 35% were ≥ 65 years old, 46% women, 94% White, 4% were Black, and 1% Asian; 5% identified as Hispanic or Latino ethnicity. After 4 weeks of background statin therapy, the mean baseline LDL-C ranged between 77 and 127 mg/dL across the five background therapy arms.
The difference between REPATHA and placebo in mean percent change in LDL-C from baseline to Week 12 was -71% (95% CI: -74%, -67%; p < 0.0001) and -63% (95% CI: -68%, -57%; p < 0.0001) for the 140 mg every 2 weeks and 420 mg once monthly dosages, respectively. The difference between REPATHA and ezetimibe in mean percent change in LDL-C from baseline to Week 12 was -45% (95%
CI: -52%, -39%; p < 0.0001) and -41% (95% CI: -47%, -35%; p < 0.0001) for the 140 mg every 2 weeks and 420 mg once monthly dosages, respectively. For additional results see Table 4 and Figure 3.
Table 4. Effect of REPATHA on Lipid Parameters in Patients with Hyperlipidemia on Background Statin Regimens (Mean % Change from Baseline to Week 12 in LAPLACE-2)
Treatment Group |
LDL-C |
Non-HDL-C |
Apo B |
Total Cholesterol |
REPATHA every 2 weeks vs. Placebo every 2 weeks
(Background statin: atorvastatin 10mg or 80mg; rosuvastatin 5mg or 40mg; simvastatin 40mg) |
Placebo every 2 weeks (n = 281) |
8 |
6 |
5 |
4 |
REPATHA 140 mg every 2 weeks† (n = 555) |
-63 |
-53 |
-49 |
-36 |
Mean difference from placebo (95% CI) |
-71 (-74, -67) |
-59 (-62, -55) |
-55 (-58, -52) |
-40 (-43, -38) |
REPATHA once monthly vs. Placebo once monthly
(Background statin: atorvastatin 10mg or 80mg; rosuvastatin 5mg or 40mg; simvastatin 40mg) |
Placebo once monthly (n = 277) |
4 |
5 |
3 |
2 |
REPATHA 420 mg once monthly (n = 562) |
-59 |
-50 |
-46 |
-34 |
Mean difference from placebo (95% CI) |
-63 (-68, -57) |
-54 (-58, -50) |
-50 (-53, -47) |
-36 (-39, -33) |
REPATHA every 2 weeks vs. Ezetimibe 10 mg daily
(Background statin: atorvastatin 10mg or 80mg) |
Ezetimibe 10 mg daily (n = 112) |
-17 |
-16 |
-14 |
-12 |
REPATHA 140 mg every 2 weeks† (n = 219) |
-63 |
-52 |
-49 |
-36 |
Mean difference from Ezetimibe (95% CI) |
-45 (-52, -39) |
-36 (-41, -31) |
-35 (-40, -31) |
-24 (-28, -20) |
REPATHA once monthly vs. Ezetimibe 10 mg daily
(Background statin: atorvastatin 10mg or 80mg) |
Ezetimibe 10 mg daily (n = 109) |
-19 |
-16 |
-11 |
-12 |
REPATHA 420 mg once monthly (n = 220) |
-59 |
-50 |
-46 |
-34 |
Mean difference from Ezetimibe (95% CI) |
-41 (-47, -35) |
-35 (-40, -29) |
-34 (-39, -30) |
-22 (-26, -19) |
Estimates based on a multiple imputation model that accounts for treatment adherence.
†140 mg every 2 weeks or 420 mg once monthly yield similar reductions in LDL-C |
Figure 3. Effect of REPATHA on LDL-C in Patients with Hyperlipidemia when Combined with
Statins (Mean % Change from Baseline to Week 12 in LAPLACE-2)
 |
Estimates based on a multiple imputation model that accounts for treatment adherence Error bars indicate 95% confidence intervals |
Study 3 (DESCARTES, NCT01516879) was a multicenter, double-blind, randomized, placebo-controlled, 52-week trial that included 901 patients with hyperlipidemia who received protocol-determined background lipid-lowering therapy of a cholesterol-lowering diet either alone or in addition to atorvastatin (10 mg or 80 mg daily) or the combination of atorvastatin 80 mg daily with ezetimibe. After stabilization on background therapy, patients were randomly assigned to the addition of placebo or REPATHA 420 mg administered subcutaneously once monthly. Overall, the mean age at baseline was 56 years (range: 25 to 75 years), 23% were ≥ 65 years, 52% women, 80% White, 8% Black, and 6% Asian; 6% identified as Hispanic or Latino ethnicity. After stabilization on the assigned background therapy, the mean baseline LDL-C ranged between 90 and 117 mg/dL across the four background therapy groups.
In these patients with hyperlipidemia on a protocol-determined background therapy, the difference between REPATHA 420 mg once monthly and placebo in mean percent change in LDL-C from baseline to Week 52 was -55% (95% CI: -60%, -50%; p < 0.0001) (Table 5 and Figure 4). For additional results see Table 5.
Table 5. Effect of REPATHA on Lipid Parameters in Patients with Hyperlipidemia* (Mean % Change from Baseline to Week 52 in DESCARTES)
Treatment Group |
LDL-C |
Non-HDL-C |
Apo B |
Total Cholesterol |
Placebo once monthly (n = 302) |
8 |
8 |
2 |
5 |
REPATHA 420 mg once monthly (n = 599) |
-47 |
-39 |
-38 |
-26 |
Mean difference from placebo (95% CI) |
-55 (-60,-50) |
-46 (-50,-42) |
-40 (-44,-37) |
-31 ( -34,-28) |
Estimates based on a multiple imputation model that accounts for treatment adherence
*Prior to randomization, patients were stabilized on background therapy consisting of a cholesterol-lowering diet either alone or in addition to atorvastatin (10 mg or 80 mg daily) or the combination of atorvastatin 80 mg daily with ezetimibe. |
Figure 4. Effect of REPATHA 420 mg Once Monthly on LDL-C in Patients with Hyperlipidemia in DESCARTES
 |
Estimates based on a multiple imputation model that accounts for treatment adherence Error bars indicate 95% confidence intervals |
Study 4 (MENDEL-2, NCT01763827) was a multicenter, double-blind, randomized, placebo-and active-controlled, 12-week trial that included 614 patients with hyperlipidemia who were not taking lipid-lowering therapy at baseline. Patients were randomly assigned to receive subcutaneous injections of REPATHA 140 mg every 2 weeks, REPATHA 420 mg once monthly, or placebo for 12 weeks. Blinded administration of ezetimibe was also included as an active control. Overall, the mean age at baseline was 53 years (range: 20 to 80 years), 18% were ≥ 65 years old, 66% were women, 83% White, 7% Black, and 9% Asian; 11% identified as Hispanic or Latino ethnicity. The mean baseline LDL-C was 143 mg/dL.
The difference between REPATHA and placebo in mean percent change in LDL-C from baseline to Week 12 was -55% (95% CI: -60%, -50%; p < 0.0001) and -57% (95% CI: -61%, -52%; p < 0.0001) for the 140 mg every 2 weeks and 420 mg once monthly dosages, respectively. The difference between REPATHA and ezetimibe in mean percent change in LDL-C from baseline to Week 12 was -37% (95%
CI: -42%, -32%; p < 0.0001) and -38% (95% CI: -42%, -34%; p < 0.0001) for the 140 mg every 2 weeks and 420 mg once monthly dosages, respectively. For additional results see Table 6.
Table 6. Effect of REPATHA on Lipid Parameters in Patients with Hyperlipidemia (Mean % Change from Baseline to Week 12 in MENDEL-2)
Treatment Group |
LDL-C |
Non-HDL-C |
Apo B |
Total Cholesterol |
Placebo every 2 weeks (n = 76) |
1 |
0 |
1 |
0 |
Ezetimibe 10 mg daily (n = 77) |
-17 |
-14 |
-13 |
-10 |
REPATHA 140 mg every 2 weeks† (n = 153) |
-54 |
-47 |
-44 |
-34 |
Mean difference from placebo (95% CI) |
-55 (-60, -50) |
-47 (-52, -43) |
-45 (-50, -41) |
-34 (-37, -30) |
Mean difference from Ezetimibe (95% CI) |
-37 (-42, -32) |
-33 (-37, -29) |
-32 (-36, -27) |
-23 (-27, -20) |
Placebo once monthly (n = 78) |
1 |
2 |
2 |
0 |
Ezetimibe 10 mg daily (n = 77) |
-18 |
-16 |
-13 |
-12 |
REPATHA 420 mg once monthly (n = 153) |
-56 |
-49 |
-49 |
-35 |
Mean difference from placebo (95% CI) |
-57 (-61, -52) |
-51 (-54, -47) |
-48 (-52, -44) |
-35 (-38, -32) |
Mean difference from Ezetimibe (95% CI) |
-38 (-42, -34) |
-32 (-36, -29) |
-33 (-36, -29) |
-23 (-26, -20) |
Estimates based on a multiple imputation model that accounts for treatment adherence
†140 mg every 2 weeks or 420 mg once monthly yield similar reductions in LDL-C |
Study 5 (RUTHERFORD-2, NCT01763918) was a multicenter, double-blind, randomized, placebo-controlled, 12-week trial in 329 patients with heterozygous familial hypercholesterolemia (HeFH) on statins with or without other lipid-lowering therapies. Patients were randomized to receive subcutaneous injections of REPATHA 140 mg every two weeks, 420 mg once monthly, or placebo. HeFH was diagnosed by the Simon Broome criteria (1991). In Study 5, 38% of patients had clinical atherosclerotic cardiovascular disease. The mean age at baseline was 51 years (range: 19 to 79 years), 15% of the patients were ≥ 65 years old, 42% were women, 90% were White, 5% were Asian, and 1% were Black. The average LDL-C at baseline was 156 mg/dL with 76% of the patients on high-intensity statin therapy.
The differences between REPATHA and placebo in mean percent change in LDL-C from baseline to Week 12 was -61% (95% CI: -67%, -55%; p < 0.0001) and -60% (95% CI: -68%, -52%; p < 0.0001) for the 140 mg every 2 weeks and 420 mg once monthly dosages, respectively. For additional results see Table 7 and Figure 5.
Table 7. Effect of REPATHA on Lipid Parameters in Patients with HeFH (Mean % Change from Baseline to Week 12 in RUTHERFORD-2)
Treatment Group |
LDL-C |
Non-HDL-C |
Apo B |
Total Cholesterol |
Placebo every 2 weeks (n = 54) |
-1 |
-1 |
-1 |
-2 |
REPATHA 140 mg every 2 weeks† (n = 110) |
-62 |
-56 |
-49 |
-42 |
Mean difference from placebo (95% CI) |
-61 (-67, -55) |
-54 (-60, -49) |
-49 (-54, -43) |
-40(-45, -36) |
Placebo once monthly (n = 55) |
4 |
4 |
4 |
2 |
REPATHA 420 mg once monthly(n = 110) |
-56 |
-49 |
-44 |
-37 |
Mean difference from placebo (95% CI) |
-60 (-68, -52) |
-53 (-60, -46) |
-48 (-55, -41) |
-39 (-45, -33) |
Estimates based on a multiple imputation model that accounts for treatment adherence
†140 mg every 2 weeks or 420 mg once monthly yield similar reductions in LDL-C |
Figure 5. Effect of REPATHA on LDL-C in Patients with HeFH (Mean % Change from Baseline to
Week 12 in RUTHERFORD-2)
 |
N=number of patients randomized and dosed in the full analysis set
Estimates based on a multiple imputation model that accounts for treatment adherence
Error bars indicate 95% confidence intervals |
Homozygous Familial Hypercholesterolemia (HoFH)
Study 6 (TESLA, NCT01588496) was a multicenter, double-blind, randomized, placebo-controlled, 12-week trial in 49 patients (not on lipid-apheresis therapy) with homozygous familial hypercholesterolemia (HoFH). In this trial, 33 patients received subcutaneous injections of 420 mg of REPATHA once monthly and 16 patients received placebo as an adjunct to other lipid-lowering therapies (e.g., statins, ezetimibe). The mean age at baseline was 31 years, 49% were women, 90% White, 4% were Asian, and 6% other. The trial included 10 adolescents (ages 13 to 17 years), 7 of whom received REPATHA. The mean LDL-C at baseline was 349 mg/dL with all patients on statins (atorvastatin or rosuvastatin) and 92% on ezetimibe. The diagnosis of HoFH was made by genetic confirmation or a clinical diagnosis based on a history of an untreated LDL-C concentration > 500 mg/dL together with either xanthoma before 10 years of age or evidence of HeFH in both parents.
The difference between REPATHA and placebo in mean percent change in LDL-C from baseline to Week 12 was -31% (95% CI: -44%, -18%; p < 0.0001). For additional results see Table 8.
Patients known to have two LDL-receptor negative alleles (little to no residual function) did not respond to REPATHA.
Table 8. Effect of REPATHA on Lipid Parameters in Patients with HoFH (Mean % Change from Baseline to Week 12 in TESLA)
Treatment Group |
LDL-C |
Non-HDL-C |
Apo B |
Total Cholesterol |
Placebo once monthly (n = 16) |
9 |
8 |
4 |
8 |
REPATHA 420 mg once monthly (n = 33) |
-22 |
-20 |
-17 |
-17 |
Mean difference from placebo (95% CI) |
-31 (-44, -18) |
-28 (-41, -16) |
-21 (-33, -9) |
-25 (-36, -14) |
Estimates based on a multiple imputation model that accounts for treatment adherence |