Pharmacotherapeutic group: lipid modifying agents, other lipid modifying agents, ATC code: C10AX16
Mechanism of action
Inclisiran is a cholesterol-lowering, double-stranded, small interfering ribonucleic acid (siRNA), conjugated on the sense strand with triantennary N-acetylgalactosamine (GalNAc) to facilitate uptake by hepatocytes. In hepatocytes, inclisiran utilises the RNA interference mechanism and directs catalytic breakdown of mRNA for proprotein convertase subtilisin kexin type 9. This increases LDL-C receptor recycling and expression on the hepatocyte cell surface, which increases LDL-C uptake and lowers LDL-C levels in the circulation.
Pharmacodynamic effects
Following a single subcutaneous administration of 284 mg inclisiran, LDL-C reduction was apparent within 14 days post-dose. Mean reductions of 49-51% for LDL-C were observed 30 to 60 days post-dose. At day 180, LDL-C levels were still reduced by approximately 53%.
Clinical efficacy and safety
In clinical studies and some publications, the 284 mg inclisiran dose is equivalent and referred to as 300 mg inclisiran sodium salt.
The efficacy of inclisiran was evaluated in three phase III studies in patients with atherosclerotic cardiovascular disease (ASCVD) (coronary heart disease, cerebrovascular disease or peripheral artery disease), ASCVD risk equivalents (type 2 diabetes mellitus, familial hypercholesterolaemia, or 10-year risk of 20% or greater of having a cardiovascular event assessed by Framingham Risk Score or equivalent) and/or familial hypercholesterolaemia (FH).
Patients were taking a maximally tolerated dose of statin with or without other lipid-modifying therapy and required additional LDL-C reduction (patients unable to reach their treatment goals). Approximately 17% of patients were statin intolerant. Patients were administered subcutaneous injections of 284 mg inclisiran or placebo on day 1, day 90, day 270 and day 450. Patients were followed until day 540.
The effect of inclisiran on cardiovascular morbidity and mortality has not yet been determined.
In the phase III pooled analysis, subcutaneously administered inclisiran lowered LDL-C between 50% and 55% as early as day 90 (Figure 1), which was maintained during long-term therapy. Maximal LDL-C reduction was achieved at day 150 following a second administration. Small but statistically significant increased LDL-C reductions up to 65% were associated with lower baseline LDL-C levels (approximately <2 mmol/l [77 mg/dl]), higher baseline PCSK9 levels and higher statin doses and statin intensity.
Figure 1 Mean percentage change from baseline LDL-C in patients with primary hypercholesterolaemia and mixed dyslipidaemia treated with inclisiran compared to placebo (pooled analysis)
ASCVD and ASCVD risk equivalents
Two studies were conducted in patients with ASCVD and ASCVD risk equivalents (ORION-10 and ORION-11). Patients were taking a maximally tolerated dose of statins with or without other lipid-modifying therapy, such as ezetimibe, and required additional LDL-C reduction. As lowering LDL-C is expected to improve cardiovascular outcomes, the co-primary endpoints in each study were the percentage change in LDL-C from baseline to day 510 relative to placebo and the time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 to estimate the integrated effect on LDL-C over time.
ORION-10 was a multicentre, double-blind, randomised, placebo-controlled 18-month study conducted in 1 561 patients with ASCVD.
The mean age at baseline was 66 years (range: 35 to 90 years), 60% were ≥65 years old, 31% were women, 86% were White, 13% were Black, 1% were Asian and 14% were Hispanic or Latino ethnicity. The mean baseline LDL C was 2.7 mmol/l (105 mg/dl). Sixty-nine percent (69%) were taking high-intensity statins, 19% were taking medium-intensity statins, 1% were taking low-intensity statins and 11% were not on a statin. The most commonly administered statins were atorvastatin and rosuvastatin.
Inclisiran significantly reduced the mean percentage change in LDL-C from baseline to day 510 compared to placebo by 52% (95% CI: -56%, -49%; p <0.0001) (Table 2).
Inclisiran also significantly reduced the time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 by 54% compared to placebo (95% CI: -56%, -51%; p <0.0001). For additional results, see Table 2.
Table 2 Mean percentage change from baseline and difference from placebo in lipid parameters at day 510 in ORION-10
| Treatment group | LDL-C | Total cholesterol | Non-HDL-C | Apo-B | Lp(a)* |
| Mean baseline value in mg/dl** | 105 | 181 | 134 | 94 | 122 |
| Day 510 (mean percentage change from baseline) |
| Placebo (n=780) | 1 | 0 | 0 | -2 | 4 |
| Inclisiran (n=781) | -51 | -34 | -47 | -45 | -22 |
| Difference from placebo (LS mean) (95% CI) | -52 (-56, -49) | -33 (-35, -31) | -47 (-50, -44) | -43 (-46, -41) | -26 (-29, -22) |
| *At day 540; median percentage change in Lp(a) values **Mean baseline value in nmol/l for Lp(a) |
At day 510, the LDL-C target of <1.8 mmol/l (70 mg/dl) was achieved by 84% of inclisiran patients with ASCVD compared to 18% of placebo patients.
Consistent and statistically significant (p<0.0001) reductions in percentage change in LDL-C from baseline to day 510 and time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 were observed across all subgroups irrespective of baseline demographics, baseline disease characteristics (including gender, age, body mass index, race and baseline statin use), comorbidities and geographic regions.
ORION-11 was an international, multicentre, double-blind, randomised, placebo-controlled 18-month study which evaluated 1 617 patients with ASCVD or ASCVD risk equivalents. More than 75% of patients were receiving a high-intensity statin background treatment, 87% of patients had ASCVD and 13% were ASCVD risk equivalent.
The mean age at baseline was 65 years (range: 20 to 88 years), 55% were ≥65 years old, 28% were women, 98% were White, 1% were Black ,1% were Asian and 1% were Hispanic or Latino ethnicity. The mean baseline LDL-C was 2.7 mmol/l (105 mg/dl). Seventy-eight percent (78%) were taking high-intensity statins, 16% were taking medium-intensity statins, 0.4% were taking low-intensity statins and 5% were not on a statin. The most commonly administered statins were atorvastatin and rosuvastatin.
Inclisiran significantly reduced the mean percentage change in LDL-C from baseline to day 510 compared to placebo by 50% (95% CI: -53%, -47%; p<0.0001) (Table 3).
Inclisiran also significantly reduced time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 by 49% compared to placebo (95% CI: -52%, -47%; p<0.0001). For additional results, see Table 3.
Table 3 Mean percentage change from baseline and difference from placebo in lipid parameters at day 510 in ORION-11
| Treatment group | LDL-C | Total cholesterol | Non-HDL-C | Apo-B | Lp(a)* |
| Mean baseline value in mg/dl** | 105 | 185 | 136 | 96 | 107 |
| Day 510 (mean percentage change from baseline) |
| Placebo (n=807) | 4 | 2 | 2 | 1 | 0 |
| Inclisiran (n=810) | -46 | -28 | -41 | -38 | -19 |
| Difference from placebo (LS mean) (95% CI) | -50 (-53, -47) | -30 (-32, -28) | -43 (-46, -41) | -39 (-41, -37) | -19 (-21, -16) |
| *At day 540; median percentage change in Lp(a) values **Mean baseline value in nmol/l for Lp(a) |
At day 510, the LDL-C target of <1.8 mmol/l (70 mg/dl) was achieved by 82% of inclisiran patients with ASCVD compared to 16% of placebo patients. In patients with an ASCVD risk equivalent, the LDL-C target of <2.6 mmol/l (100 mg/dl) was achieved by 78% of inclisiran patients compared to 31% of placebo patients.
Consistent and statistically significant (p<0.05) percentage change in LDL-C from baseline to day 510 and time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 was observed across all subgroups irrespective of baseline demographics, baseline disease characteristics (including gender, age, body mass index, race and baseline statin use), comorbidities, and geographic regions.
Heterozygous familial hypercholesterolaemia
ORION-9 was an international, multicentre, double-blind, randomised, placebo-controlled 18-month trial in 482 patients with heterozygous familial hypercholesterolaemia (HeFH). All patients were taking maximally tolerated doses of statins with or without other lipid-modifying therapy, such as ezetimibe, and required additional LDL-C reduction. The diagnosis of HeFH was made either by genotyping or clinical criteria (“definite FH” using either the Simon Broome or WHO/Dutch Lipid Network criteria).
The co-primary endpoints were the percentage change in LDL-C from baseline to day 510 relative to placebo, and the time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 to estimate the integrated effect on LDL-C over time. Key secondary endpoints were the absolute change in LDL-C from baseline to day 510, the time-adjusted absolute change in LDL-C from baseline after day 90 and up to day 540 and the percentage change from baseline to day 510 in PCSK9, total cholesterol, Apo-B, and non-HDL-C. Additional secondary endpoints included the, individual responsiveness to inclisiran and the proportion of patients attaining global lipid targets for their level of ASCVD risk.
The mean age at baseline was 55 years (range: 21 to 80 years), 22% were ≥65 years old, 53% were women, 94% were White, 3% were Black, 3% were Asian and 3% were Hispanic or Latino ethnicity. The mean baseline LDL-C was 4.0 mmol/l (153 mg/dl). Seventy-four percent (74%) were taking high-intensity statins, 15% were taking medium-intensity statins and 10% were not on a statin. Fifty-two percent (52%) of patients were treated with ezetimibe. The most commonly administered statins were atorvastatin and rosuvastatin.
Inclisiran significantly reduced the mean percentage change in LDL-C from baseline to day 510 compared to placebo by 48% (95% CI: -54%, -42%; p<0.0001) (Table 4).
Inclisiran also significantly reduced the time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 by 44% compared to placebo (95% CI: -48%, -40%; p<0.0001). For additional results, see Table 4.
Table 4 Mean percentage change from baseline and difference from placebo in lipid parameters at day 510 in ORION-9
| Treatment group | LDL-C | Total cholesterol | Non-HDL-C | Apo-B | Lp(a)* |
| Mean baseline value in mg/dl** | 153 | 231 | 180 | 124 | 121 |
| Day 510 (mean percentage change from baseline) |
| Placebo (n=240) | 8 | 7 | 7 | 3 | 4 |
| Inclisiran (n=242) | -40 | -25 | -35 | -33 | -13 |
| Difference from placebo (LS mean) (95% CI) | -48 (-54, -42) | -32 (-36, -28) | -42 (-47, -37) | -36 (-40, -32) | -17 (-22, -12) |
| *At day 540; median percentage change in Lp(a) values **Mean baseline value in nmol/l for Lp(a) |
At day 510, 52.5% of inclisiran patients with ASCVD achieved their LDL-C target of <1.8 mmol/l (70 mg/dl) compared to 1.4% of placebo patients with ASCVD, while in the group with ASCVD risk equivalents 66.9% of inclisiran patients achieved their LDL-C target of <2.6 mmol/l (100 mg/dl) compared to 8.9% of placebo patients.
Consistent and statistically significant (p<0.05) percentage change in LDL-C from baseline to day 510 and time-adjusted percentage change in LDL-C from baseline after day 90 and up to day 540 were observed across all subgroups irrespective of baseline demographics, baseline disease characteristics (including gender, age, body mass index, race and baseline statin use), comorbidities, and geographic regions.
Paediatric population
The European Medicines Agency has deferred the obligation to submit the results of studies with inclisiran in one or more subsets of the paediatric population in the treatment of elevated cholesterol (see section 4.2 for information on paediatric use).