Pharmacotherapeutic group: Antihypertensives, other antihypertensives, ATC code: C02KN01
Mechanism of action
Endothelin (ET)-1, via its receptors (ETA and ETB), mediates a variety of effects such as vasoconstriction, fibrosis, cell proliferation, and inflammation and is upregulated in hypertension. Aprocitentan is a dual ERA that inhibits the binding of ET-1 to ETA and ETB receptors and hence the effects mediated by these receptors.
Pharmacodynamic effects
Cardiac electrophysiology
In a thorough QT study in healthy subjects, once-daily administration of 25 mg (maximum therapeutic dose) aprocitentan at steady state did not prolong the QTc interval as the upper limit of the 90% confidence interval of the mean change from baseline in placebo-corrected QTc was less than 10 ms.
At four times the maximum therapeutic dose (100 mg), the upper limit of the 90% confidence interval of the mean change from baseline in placebo-corrected QTc was 10.4 ms.
Clinical efficacy and safety
The efficacy of aprocitentan was evaluated in one randomized, double-blind, placebo-controlled Phase 3 multicentre study.
Patients with uncontrolled BP (systolic blood pressure [SBP] ≥ 140 mmHg) despite the use of at least three antihypertensive medicinal products and following exclusion of pseudo-resistant hypertension (e.g., white coat effect, inappropriate BP measurement, secondary causes of hypertension) were considered to have resistant hypertension.
The patients were switched to standardised background antihypertensive therapy consisting of an angiotensin receptor blocker (valsartan 160 mg), a calcium channel blocker (amlodipine 5 or 10 mg), and a diuretic (hydrochlorothiazide 25 mg) throughout the study. Patients with concomitant use of beta-blockers continued this treatment throughout the study, in addition to the standardised background antihypertensive therapy and study treatment.
A total of 730 patients received either aprocitentan 12.5 mg, aprocitentan 25 mg, or placebo once daily during the initial 4-week DB treatment (part 1). Thereafter, patients received aprocitentan 25 mg once daily during the 32-week SB treatment (part 2). At the end of the 32 weeks, patients were re-randomised to receive either aprocitentan 25 mg or placebo, once daily, during the 12-week DB-WD treatment (part 3) (Table 2).
Table 2: Design of the Phase 3 study
| | Treatment | Part 1 (4 weeks) | Part 2 (32 weeks) | Part 3 (12 weeks) |
| Design | | DB, placebo-controlled, randomized (1:1:1) | SB | DB-WD, placebo-controlled, randomized (1:1) |
| Duration | | Week 0 – Week 4 | Week 4 – Week 36 | Week 36 – Week 48 |
| Treatment as add-on to background therapy* | Aprocitentan 25 mg Aprocitentan 12.5 mg Placebo | N = 243 N = 243 N = 244 | N = 704 | N = 307 N = 307 |
* ARB, CCB, and a diuretic.
ARB = angiotensin receptor blocker; CCB = calcium channel blocker; DB = double-blind; DB-WD = double-blind withdrawal; N = number of patients; SB = single-blind.
The primary efficacy endpoint was the change in sitting SBP (SiSBP) from baseline to Week 4 during DB treatment (part 1), measured at trough by unattended automated office blood pressure (uAOBP).
The key secondary endpoint was the change in SiSBP measured at trough by uAOBP from DB-WD baseline (Week 36) to Week 40 (part 3).
Patients had a mean age of 61.7 years (range 24 to 84 years; 34.1% were ≥ 65 and < 75 years; 9.9% were ≥ 75 years) and 59.5% were male. Patients were White (82.9%), African American (11.2%) or Asian (5.2%). The mean body weight was 97.6 kg (range 46 to 196 kg) and mean BMI was 33.7 kg/m2 (range 18 to 64 kg/m2).
Patients had a medical history of type 2 diabetes mellitus (54.1%), ischaemic heart disease (30.8%), central nervous system vascular disorders (23.0%), chronic kidney disease stages 3 and 4 (22.2%; 19.3% of patients had eGFR 30–59 mL/min/1.73 m2 and 2.9% had eGFR 15–29 mL/min/1.73 m2), congestive heart failure (19.6%), and sleep apnoea syndrome (14.1%). 63.0% of patients had four or more antihypertensive medicinal products.
Populations not studied in the Phase 3 study are described in sections 4.2, 4.3 and 4.4.
Doses of aprocitentan 12.5 and 25 mg showed a statistically significant reduction vs placebo on SiSBP at Week 4. The treatment effect was consistent for sitting diastolic BP (SiDBP) (Table 3).
Table 3: Reduction in sitting trough BP (mmHg) measured by uAOBP at Week 4 of DB treatment
| | | | Difference to placebo |
| Treatment group | N | Baseline # Mean | LS Mean | LS Mean | p-value |
| SiSBP (primary endpoint) | LS Mean (97.5% CL) | LS Mean (97.5% CL) |
| 12.5 mg | 243 | 153.2 | −15.3 (−17.4, −13.2) | −3.8 (−6.8, −0.8) | 0.0042* |
| 25 mg | 243 | 153.3 | −15.2 (−17.3, −13.1) | −3.7 (−6.7, −0.8) | 0.0046* |
| Placebo | 244 | 153.3 | −11.5 (−13.6, −9.4) | - | - |
| SiDBP | | LS Mean (95% CL) | LS Mean (95% CL) |
| 12.5 mg | 243 | 87.9 | −10.4 (−11.6, −9.3) | −3.9 (−5.6, −2.3) | <0.0001 |
| 25 mg | 243 | 87.7 | −11.0 (−12.1, −9.8) | −4.5 (−6.1, −2.9) | <0.0001 |
| Placebo | 244 | 87.1 | −6.5 (−7.6, −5.3) | - | - |
| # Observed baseline value. * Statistically significant at the 2.5% level as prespecified in the testing strategy. CL = confidence limit; DB = double-blind; DB-WD = double-blind withdrawal; LS Mean = least squares mean; SiDBP = sitting diastolic blood pressure; SiSBP = sitting systolic blood pressure. |
The persistence of the BP-lowering effect of aprocitentan was shown in DB-WD treatment (part 3). In patients re-randomised to placebo, the mean SiSBP increased, whereas in patients re-randomised to aprocitentan 25 mg the mean effect on SiSBP was stable, resulting in a statistically significant difference. The treatment effect was consistent for SiDBP (Table 4).
Table 4: Sustained reduction in sitting trough BP (mmHg) measured by uAOBP at Week 40 of DB-WD treatment
| | | | | Difference to placebo | |
| Treatment group | N | DB-WD Baseline# Mean | LS Mean (95% CL) | LS Mean (95% CL) | p-value |
| SiSBP (key secondary endpoint) |
| 25 mg | 307 | 135.3 | −1.5 (−3.0, 0.0) | −5.8 (−7.9, −3.7) | <0.0001* |
| Placebo | 307 | 136.4 | 4.4 (2.9, 5.8) | - | - |
| SiDBP | | | | | |
| 25 mg | 307 | 76.1 | −0.5 (−1.5, 0.5) | −5.2 (−6.6, −3.8) | <0.0001 |
| Placebo | 307 | 76.3 | 4.7 (3.7, 5.7) | - | - |
| # Observed baseline value. DB-WD baseline: Week 36. * Statistically significant at the 5% level as prespecified in the testing strategy. CL = confidence limit; DB-WD = double-blind-withdrawal; LS Mean = least squares mean; SiDBP = sitting diastolic blood pressure; SiSBP = sitting systolic blood pressure. |
The effect was also consistent across SBP and DBP measured by ambulatory BP monitoring (ABPM) and assessed as daytime, night-time, and 24 h periods at Week 4 (Figure 1) and Week 40.
Figure 1: Placebo-corrected changes from baseline in systolic and diastolic BP measured by ABPM at Week 4
ABPM = ambulatory blood pressure monitoring; BP = blood pressure; CL = confidence limits; DBP = diastolic blood pressure; LS Mean Diff. = least squares mean difference versus placebo; SBP = systolic blood pressure.
A substantial proportion (i.e., at least 90%) of the BP-lowering effect was observed within the first two weeks of treatment with aprocitentan.
Figure 2: Mean sitting systolic BP measured by uAOBP over 48 weeks
The effect of aprocitentan was consistent across subgroups of age (including patients ≥ 75 years), sex, race (including patients with Black or African American origin), BMI, baseline urine albumin-to-creatinine ratio (UACR), baseline eGFR and medical history of diabetes, and was consistent with the effect in the overall population.
Effects on UACR/eGFR
At 4 weeks, a reduction in UACR of 30% (95% confidence limits 20–39%) and 34% (95% confidence limits 25–42%) was observed with aprocitentan 12.5 and 25 mg, respectively, compared to subjects randomised to placebo. This effect disappeared upon treatment discontinuation. As for eGFR, a mean decrease of −1.2 mL/min /1.73 m2 for aprocitentan 12.5 mg and −2.4 mL/min /1.73 m2 for aprocitentan 25 mg occurred during the first 4 weeks of treatment (vs −0.6 mL/min /1.73 m2 for placebo), followed by a stabilisation of eGFR, including in patients with low (< 60 mL/min) baseline values, until the end of the study. The effect of aprocitentan on end organ protection has not been studied.
Effects on mortality and cardiovascular morbidity
The effects of aprocitentan on mortality and cardiovascular morbidity have not been studied.
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies with aprocitentan in all subsets of the paediatric population in the treatment of hypertension (see section 4.2 for information on paediatric use).