Source: European Medicines Agency (EU) Revision Year: 2023 Publisher: Noden Pharma DAC, DOlier Chambers, 16A DOlier Street, Dublin 2, Ireland
Pharmacotherapeutic group: Agents acting on the renin-angiotensin system; renin inhibitor
ATC code: C09XA02
Aliskiren is an orally active, non-peptide, potent and selective direct inhibitor of human renin.
By inhibiting the enzyme renin, aliskiren inhibits the RAAS at the point of activation, blocking the conversion of angiotensinogen to angiotensin I and decreasing levels of angiotensin I and angiotensin II. Whereas other agents that inhibit the RAAS (ACEI and angiotensin II receptor blockers (ARB)) cause a compensatory rise in plasma renin activity (PRA), treatment with aliskiren decreases PRA in hypertensive patients by approximately 50 to 80%. Similar reductions were found when aliskiren was combined with other antihypertensive agents. The clinical implications of the differences in effect on PRA are not known at the present time.
In hypertensive patients, once-daily administration of aliskiren at doses of 150 mg and 300 mg provided dose-dependent reductions in both systolic and diastolic blood pressure that were maintained over the entire 24-hour dose interval (maintaining benefit in the early morning) with a mean peak to trough ratio for diastolic response of up to 98% for the 300 mg dose. 85 to 90% of the maximal blood-pressure-lowering effect was observed after 2 weeks. The blood-pressure-lowering effect was sustained during long-term treatment, and was independent of age, gender, body mass index and ethnicity. Aliskiren has been studied in 1,864 patients aged 65 years or older, and in 426 patients aged 75 years or older.
Aliskiren monotherapy studies have shown blood pressure lowering effects comparable to other classes of antihypertensive agents including ACEI and ARB. Compared to a diuretic (hydrochlorothiazide – HCTZ), Rasilez 300 mg lowered systolic/diastolic blood pressure by 17.0/12.3 mmHg, compared to 14.4/10.5 mmHg for HCTZ 25 mg after 12 weeks of treatment.
Combination therapy studies are available for aliskiren added to the diuretic hydrochlorothiazide, the calcium channel blocker amlodipine and the beta blocker atenolol. These combinations were well tolerated. It induced an additive blood-pressure-lowering effect when added to hydrochlorothiazide. In patients who did not adequately respond to 5 mg of the calcium channel blocker amlodipine, the addition of aliskiren 150 mg had a blood-pressure-lowering effect similar to that obtained by increasing amlodipine dose to 10 mg, but had a lower incidence of oedema (aliskiren 150 mg/amlodipine 5 mg 2.1% vs. amlodipine 10 mg 11.2%).
The efficacy and safety of aliskiren-based therapy were compared to ramipril-based therapy in a 9-month non-inferiority study in 901 elderly patients (≥65 years) with essential systolic hypertension. Aliskiren 150 mg or 300 mg per day or ramipril 5 mg or 10 mg per day were administered for 36 weeks with optional add-on therapy of hydrochlorothiazide (12.5 mg or 25 mg) at week 12, and amlodipine (5 mg or 10 mg) at week 22. Over the 12 week period, aliskiren monotherapy lowered systolic/diastolic blood pressure by 14.0/5.1 mmHg, compared to 11.6/3.6 mmHg for ramipril, consistent with aliskiren being non-inferior to ramipril at the doses chosen and the differences in systolic and diastolic blood pressure were statistically significant. Tolerability was comparable in both treatment arms, however cough was more often reported with the ramipril regimen than the aliskiren regimen (14.2% vs. 4.4%), whilst diarrhoea was more common with the aliskiren regimen than for the ramipril regimen (6.6% vs. 5.0%).
In a 8-week study in 754 hypertensive elderly (≥65 years) and very elderly patients (30% ≥75 years) aliskiren at doses of 75 mg, 150 mg and 300 mg provided statistically significant superior reduction in blood pressure (both systolic and diastolic) when compared to placebo. No additional blood pressure lowering effect was detected with 300 mg aliskiren compared to 150 mg aliskiren. All three doses were well tolerated in both elderly and very elderly patients. In a pooled analysis of efficacy and safety data from clinical studies up to 12 months duration, there was no statistically significant difference in blood pressure reduction between aliskiren 300 mg and aliskiren 150 mg in elderly patients (≥65 years).
In obese hypertensive patients who did not adequately respond to HCTZ 25 mg, add-on treatment with aliskiren 300 mg provided additional blood pressure reduction that was comparable to add-on treatment with irbesartan 300 mg or amlodipine 10 mg.
There has been no evidence of first-dose hypotension and no effect on pulse rate in patients treated in controlled clinical studies. Excessive hypotension was uncommonly (0.1%) seen in patients with uncomplicated hypertension treated with aliskiren alone. Hypotension was also uncommon (<1%) during combination therapy with other antihypertensive agents. With cessation of treatment, blood pressure gradually returned towards baseline levels over a period of several weeks, with no evidence of a rebound effect for blood pressure or PRA.
In a 36-week study involving 820 patients with ischaemic left ventricular dysfunction, no changes in ventricular remodelling as assessed by left ventricular end systolic volume were detected with aliskiren compared to placebo on top of background therapy.
The combined rates of cardiovascular death, hospitalisation for heart failure, recurrent heart attack, stroke and resuscitated sudden death were similar in the aliskiren group and the placebo group. However, in patients receiving aliskiren there was a significantly higher rate of hyperkalaemia, hypotension and kidney dysfunction when compared to the placebo group.
Aliskiren was evaluated for cardiovascular and/or renal benefit in a double-blind placebo controlled randomised trial in 8,606 patients with type 2 diabetes and chronic kidney disease (evidenced by proteinuria and/or GFR <60 ml/min/1.73 m²) with or without cardiovascular disease. In most patients arterial blood pressure was well controlled at baseline. The primary endpoint was a composite of cardiovascular and renal complications.
In this study, aliskiren 300 mg was compared to placebo when added to standard of care which included either an angiotensin converting enzyme inhibitor or an angiotensin receptor blocker. The study was discontinued prematurely because the participants were unlikely to benefit from aliskiren. The final study results indicated a hazard ratio for the primary endpoint of 1.097 in favour of placebo (95.4% Confidence Interval: 0.987, 1.218, 2-sided p=0.0787). In addition, an increased incidence of adverse events was observed with aliskiren compared to placebo (38.2% versus 30.3%). In particular there was an increased incidence of renal dysfunction (14.5% versus 12.4%), hyperkalaemia (39.1% versus 29.0%), hypotension-related events (19.9% versus 16.3%) and adjudicated stroke endpoints (3.4% versus 2.7%). The increased incidence of stroke was greater in patients with renal insufficiency.
Aliskiren 150 mg (increased to 300 mg if tolerated) added to conventional therapy was evaluated in a double-blind placebo-controlled randomised trial in 1,639 patients with reduced ejection fraction hospitalised for an episode of acute heart failure (NYHA Class III–IV) who were haemodynamically stable at baseline. The primary endpoint was cardiovascular death or heart failure rehospitalisation within 6 months; secondary endpoints were assessed within 12 months.
The study showed no benefit of aliskiren when administered on top of standard therapy for acute heart failure and an increased risk of cardiovascular events in patients with diabetes mellitus. Study results indicated a non-significant effect of aliskiren with a hazard ratio of 0.92 (95% Confidence Interval: 0.76-1.12; p=0.41, aliskiren vs. placebo). Different treatment effects of aliskiren were reported for overall mortality within 12 months dependent on diabetes mellitus status. In the subgroup of patients with diabetes mellitus the hazard ratio was 1.64 in favour of placebo (95% Confidence Interval: 1.15-2.33), whereas the hazard ratio in the subgroup of patients without diabetes was 0.69 in favour of aliskiren (95% Confidence Interval: 0.50-0.94); p-value for interaction = 0.0003. An increased incidence of hyperkalaemia (20.9% versus 17.5%), renal impairment/renal failure (16.6% versus 12.1%) and hypotension (17.1% versus 12.6%) was observed in the aliskiren group compared with placebo and was greater in patients with diabetes.
Aliskiren was evaluated for cardiovascular mortality and morbidity benefit in a double-blind active controlled randomised study in 7,064 patients with chronic heart failure and reduced left ventricular ejection fraction, of which 62% had a history of hypertension. The primary endpoint was a composite of cardiovascular death and first hospitalisation for heart failure.
In this study, aliskiren at a target dose of 300 mg was compared to enalapril at a target dose of 20 mg when added to standard of care which included a beta blocker (and a mineralocorticoid receptor antagonist in 37% of patients) and a diuretic as needed. The study also evaluated the combination of aliskiren and enalapril. Mean duration of follow-up was 3.5 years. The final results of the study did not demonstrate statistically that aliskiren was non-inferior to enalapril on the primary endpoint, however there was essentially no difference in the observed incidence rates between aliskiren and enalapril (hazard ratio of 0.99 with 95% Confidence Interval: 0.90-1.10). There was no significant benefit of adding aliskiren to enalapril (primary endpoint: hazard ratio of 0.93 with 95% Confidence Interval: 0.85-1.03; p=0.1724, combination versus enalapril). Treatment effects were similar in patients with diabetes and with renal insufficiency. The incidence of adjudicated stroke was not significantly different between the aliskiren and enalapril groups (4.4% versus 4.0%; HR 1.12, 95% CI 0.848, 1.485) or between the combination and enalapril groups (3.7% versus 4.0%; HR 0.93, 95% CI 0.697, 1.251). The incidence of adverse events tended to be higher in patients with diabetes, or with GFR <60 ml/min/1.73 m², or with age ≥65 years; however, there was no difference between patients treated with aliskiren and those treated with enalapril.
The incidence of certain adverse events was similar between aliskiren and enalapril groups while there was an increased incidence of adverse events with the combination of aliskiren and enalapril: hyperkalaemia (21.4%, 13.2%, and 15.9% for combination, aliskiren and enalapril respectively); renal impairment/renal failure (23.2%, 17.4% and 18.7%) and hypotension related events (27.0%, 22.3% and 22.4%).
There was a statistically significant increased incidence of syncope with the combination of aliskiren and enalapril compared to enalapril in the overall population (4.2% versus 2.8%; RR 1.51, 95% CI 1.11-2.05) and in the subgroups NYHA I/II overall (4.8% versus 3.0%; RR 1.62, 95% CI 1.14-2.29).
The incidence of atrial fibrillation was 11.1%, 13.3%, and 11.0% in the combination, aliskiren, and enalapril groups, respectively.
Statistically significantly higher incidences in the occurrence of cardiac failure and ischaemic stroke were also found for aliskiren compared to enalapril in patients with NYHA I/II with hypertension, and in the occurrence of chronic cardiac failure and ventricular extrasystole in patients with NYHA III/IV with hypertension. For the combination of aliskiren and enalapril there were statistically significant differences in the rate of angina unstable compared to enalapril.
No clinically relevant differences in efficacy or safety results were observed in the subpopulation of elderly patients with a history of hypertension and chronic heart failure Class I-II compared to the overall study population.
No effect on QT interval was reported in a randomised, double-blind, placebo, and active-controlled study using standard and Holter electrocardiography.
In a multicentre, randomised, double-blind, 8-week study with aliskiren monotherapy (3 dose groups by weight category [≥20 kg to <50 kg; ≥50 kg to <80 kg; ≥80 kg to ≤150 kg]: low 6.25/12.5/25 mg [0.13-0.31 mg/kg]; mid 37.5/75/150 mg [0.75-1.88 mg/kg]; and high dose 150/300/600 mg [3.0-7.5 mg/kg], with a wide dose ratio between the low, mid and high dose groups [1:6:24]) in 267 paediatric hypertensive patients aged 6 to 17 years, mostly overweight/obese, aliskiren lowered office and ambulatory blood pressure in a dose-dependent manner during the initial 4 week dose-finding phase of the study (Phase 1). However, in the subsequent 4 week randomised withdrawal phase of the study (Phase 2), the effect of aliskiren overlapped with the effects observed in patients switched to placebo in all dose groups (low, p=0.8894; mid, p=0.9511; high, p=0.0563). The average differences between aliskiren and placebo for the low and mid dose groups were <0.2 mmHg. The treatment with aliskiren was well tolerated in this study.
This study was extended with a 52-week double-blind, randomised study to evaluate the safety, tolerability and efficacy of aliskiren compared to enalapril in 208 paediatric hypertensive patients aged 6 to 17 years (at baseline in the previous study). The starting dose in each group was assigned depending on weight with three groups: ≥20 to <50 kg, ≥50 to <80 kg, and ≥80 to ≤150 kg. The starting doses for aliskiren were 37.5/75/150 mg in the low, mid and high weight groups, respectively. The starting doses for enalapril were 2.5/5/10 mg in the low, mid and high weight groups, respectively. Optional titration of the respective study drug doses to the next highest weight-based dose level was available by doubling the dose with each of the two allowed dose titrations, up to 600 mg (highest studied dose in adults) for aliskiren and 40 mg for enalapril in the ≥80 to ≤150 kg weight group, if medically necessary to control the mean sitting systolic blood pressure (i.e. msSBP should be less than the 90th percentile for age, gender and height). Overall, the mean age of the patients was 11.8 years with 48.6% of patients being in the 6-11 years age group and 51.4% in the 12-17 years age group. Mean weight was 68.0 kg with 57.7% of patients having BMI greater than or equal to the 95th percentile for age and gender. At the end of this extension study, changes in msSBP from baseline were similar with aliskiren compared to enalapril (-7.63 mmHg vs. -7.94 mmHg) in the full analysis set. However, the significance of the non-inferiority testing was not maintained when the analysis was performed on the per-protocol set in which the least square mean change in msSBP from baseline was -7.84 mmHg with aliskiren and -9.04 mmHg with enalapril. In addition, due to the possibility of up-titration if medically necessary to control the msSBP, no conclusion can be drawn on the appropriate posology of aliskiren in patients aged 6 to 17 years.
After the first 52 week extension study, eligible male and female paediatric patients aged 6 to 17 years with primary or secondary hypertension, were enrolled in a 52 to 104 week off-therapy noninterventional observational extension study designed to evaluate the LT growth and development, through height and weight measurement, with added neurocognitive and renal function evaluations as follow-up measures performed only in patients with secondary hypertension (19 patients: 9 previously treated with aliskiren and 10 previously treated with enalapril).
There were no statistically significant differences in the mean changes in weight, height, or BMI between the treatment groups from Baseline to LT Visit 18 (Week 104) (primary analysis).
In patients after 104 weeks (at LT Visit 19 [Week 156]), there were LS mean decreases from Baseline in weight and BMI in both treatment groups, with a slightly larger decrease in the aliskiren compared to the enalapril treatment group.
There was a greater LS mean increase from Baseline in height after 104 weeks (at LT Visit 19 [Week 156], secondary hypertension patients) compared to the increase observed after 52 weeks (at LT Visit 18 [Week 104], primary hypertension patients), which is expected in these growing paediatric patients.
Results of the neurocognitive assessments showed some improvements in most of the test scores, with no meaningful difference between the treatment groups.
The European Medicines Agency has deferred the obligation to submit the results of studies with aliskiren in one or more subsets of the paediatric population in hypertension (see section 4.2 for information on paediatric use).
Following oral absorption, peak plasma concentrations of aliskiren are reached after 1-3 hours. The absolute bioavailability of aliskiren is approximately 2-3%. Meals with a high fat content reduce Cmax by 85% and AUC by 70%. At steady state meals with low fat content reduce Cmax by 76% and AUC0-tau by 67% in hypertensive patients. However the efficacy of aliskiren was similar when taken with a light meal or under fasted state. Steady-state-plasma concentrations are reached within 5-7 days following once-daily administration and steady-state levels are approximately 2-fold greater than with the initial dose.
MDR1/Mdr1a/1b (P-gp) was found to be the major efflux system involved in intestinal absorption and biliary excretion of aliskiren in pre-clinical studies.
Following intravenous administration, the mean volume of distribution at steady state is approximately 135 litres, indicating that aliskiren distributes extensively into the extravascular space. Aliskiren plasma protein binding is moderate (47-51%) and independent of the concentration.
Approximately 1.4% of the total oral dose is metabolised. The enzyme responsible for this metabolism is CYP3A4.
The mean half-life is about 40 hours (range 34-41 hours). Aliskiren is mainly eliminated as unchanged compound in the faeces (78%). Approximately 0.6% of the dose is recovered in urine following oral administration. Following intravenous administration, the mean plasma clearance is approximately 9 l/h.
Exposure to aliskiren increased more than in proportion to the increase in dose. After single dose administration in the dose range of 75 to 600 mg, a 2-fold increase in dose results in a ~2.3 and 2.6-fold increase in AUC and Cmax, respectively. At steady state the non-linearity may be more pronounced. Mechanisms responsible for deviation from linearity have not been identified. A possible mechanism is saturation of transporters at the absorption site or at the hepatobiliary clearance route.
Aliskiren is an effective once-a-day antihypertensive treatment in adult patients, regardless of gender, age, body mass index and ethnicity.
The pharmacokinetics of aliskiren were evaluated in patients with varying degrees of renal insufficiency. Relative AUC and Cmax of aliskiren in subjects with renal impairment ranged between 0.8 to 2 times the levels in healthy subjects following single dose administration and at steady state. These observed changes, however, did not correlate with the severity of renal impairment. No adjustment of the initial dosage of treatment is required in patients with mild to moderate renal impairment (see sections 4.2 and 4.4). It is not recommended in patients with severe renal impairment (glomerular filtration rate (GFR) <30 ml/min/1.73 m²).
The pharmacokinetics of aliskiren were evaluated in patients with end stage renal disease receiving haemodialysis. Administration of a single oral dose of 300 mg aliskiren was associated with very minor changes in the pharmacokinetics of aliskiren (change in Cmax of less than 1.2 fold; increase in AUC of up to 1.6 fold) compared to matched healthy subjects. Timing of haemodialysis did not significantly alter the pharmacokinetics of aliskiren in ESRD patients. Therefore, if administration of aliskiren in ESRD patients receiving haemodialysis is considered necessary, no dose adjustment is warranted in these patients. However, the use of aliskiren is not recommended in patients with severe renal impairment (see section 4.4).
The pharmacokinetics of aliskiren were not significantly affected in patients with mild to severe liver disease. Consequently, no adjustment of the initial dose of aliskiren is required in patients with mild to severe hepatic impairment.
The AUC is 50% higher in elderly (>65 years) than in young subjects. Gender, weight and ethnicity have no clinically relevant influence on aliskiren pharmacokinetics.
In a pharmacokinetic study of aliskiren treatment in 39 paediatric hypertensive patients aged 6 to 17 years given daily doses of 2 mg/kg or 6 mg/kg aliskiren administered as granules (3.125 mg/tablet), pharmacokinetic parameters were similar to those in adults. The results of this study did not suggest that age, body weight or gender have any significant effect on aliskiren systemic exposure (see section 4.2).
In an 8-week randomised, double-blind study with aliskiren monotherapy in 267 paediatric hypertensive patients aged 6 to 17 years, mostly overweight/obese, fasting trough aliskiren concentrations at day 28 were comparable to those observed in other studies in both adults and children using similar aliskiren doses (see section 5.1).
Results from an in vitro MDR1 human tissue study suggested an age and tissue dependent pattern of MDR1 (P-gp) transporter maturation. A high inter-individual variability of mRNA expression levels was observed (up to 600-fold). Hepatic MDR1 mRNA expression was statistically significantly lower in samples from foetuses, neonates and infants up to 23 months.
The age at which the transporter system is mature cannot be determined. There is a potential for aliskiren overexposure in children with an immature MDR1 (P-gp) system (see “Transporters” above and sections 4.2, 4.4 and 5.3).
Safety pharmacology studies did not reveal any adverse effects on central nervous, respiratory or cardiovascular function. Findings during repeat-dose toxicity studies in animals were consistent with the known local (gastrointestinal tract) irritation potential or the expected pharmacological effects of aliskiren.
No carcinogenic potential for aliskiren was detected in a 2-year rat study and a 6-month transgenic mouse study. One colonic adenoma and one caecal adenocarcinoma recorded in rats at the dose of 1500 mg/kg/day were not statistically significant.
Although aliskiren has known local (gastrointestinal tract) irritation potential, safety margins obtained in humans at the dose of 300 mg during a study in healthy volunteers were considered to be appropriate at 9-11-fold based on faecal concentrations or 6-fold based on mucosa concentrations in comparison with 250 mg/kg/day in the rat carcinogenicity study.
Aliskiren was devoid of any mutagenic potential in the in vitro and in vivo mutagenicity studies.
Reproductive toxicity studies with aliskiren did not reveal any evidence of embryofoetal toxicity or teratogenicity at doses up to 600 mg/kg/day in rats or 100 mg/kg/day in rabbits. Fertility, pre-natal development and post-natal development were unaffected in rats at doses up to 250 mg/kg/day. The doses in rats and rabbits provided systemic exposures of 1 to 4 and 5 times higher, respectively, than the maximum recommended human dose (300 mg).
In a juvenile toxicity study in 8-day-old rats, aliskiren administration at 100 mg/kg/day and 300 mg/kg/day (2.3- and 6.8-fold the maximum recommended human dose) was associated with high mortality and severe morbidity. In another juvenile toxicity study in 14-day-old rats, aliskiren administration at 300 mg/kg/day (8.5-fold the maximum recommended human dose) was associated with delayed mortality. The systemic exposure to aliskiren in 8-day old rats was >400-fold higher than in adult rats. Results from a mechanistic study showed that the MDR1 (P-gp) gene expression in juvenile rats was significantly lower when compared to adult rats. The increased aliskiren exposure in juvenile rats appears to be attributed mainly to lack of maturation of P-gp in the gastrointestinal tract. There is therefore a potential for aliskiren overexposure in paediatric patients with immature MDR1 efflux system (see sections 4.2, 4.3 and 5.2).
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