CLEVIPREX Emulsion for infusion Ref.[27458] Active ingredients: Clevidipine

Cleviprex is titrated to the desired reduction in blood pressure. The effect of Cleviprex appears to plateau at approximately 25% of baseline systolic pressure. The infusion rate for which half the maximal effect is observed is approximately 10 mg/hour.

Onset of Effect: In the perioperative patient population, Cleviprex produces a 4-5% reduction in systolic blood pressure within 2-4 minutes after starting a 0.4 mcg/kg/min infusion (approximately 1-2 mg/hr).

Maintenance of Effect: In studies up to 72 hours of continuous infusion, there was no evidence of tolerance or hysteresis.

Offset of Effect: In most patients, full recovery of blood pressure is achieved in 5-15 minutes after the infusion is stopped.

In studies up to 72 hours of continuous infusion, in patients that were not transitioned to other antihypertensive therapies, there was some evidence of rebound hypertension following Cleviprex discontinuation.

Hemodynamics: Cleviprex causes a dose-dependent decrease in systemic vascular resistance.

Heart Rate: An increase in heart rate is a normal response to vasodilation and decrease in blood pressure; in some patients these increases in heart rate may be pronounced [see Warnings and Precautions (5.2)].

Electrophysiologic Effects: In healthy volunteers, clevidipine or its major carboxylic acid metabolite, at therapeutic and supratherapeutic concentrations (approximately 2.8 times steady-state), did not prolong cardiac repolarization.

Clevidipine is rapidly distributed and metabolized resulting in a very short half life. The arterial blood concentration of clevidipine declines in a multi-phasic pattern following termination of the infusion. The initial phase half-life is approximately 1 minute, and accounts for 85-90% of clevidipine elimination. The terminal half-life is approximately 15 minutes.

Distribution

Clevidipine is >99.5% bound to proteins in plasma at 37°C. The steady-state volume of distribution was determined to be 0.17 L/kg in arterial blood.

Metabolism and Elimination

Clevidipine is rapidly metabolized by hydrolysis of the ester linkage, primarily by esterases in the blood and extravascular tissues, making its elimination unlikely to be affected by hepatic or renal dysfunction. The primary metabolites are the carboxylic acid metabolite and formaldehyde formed by hydrolysis of the ester group. The carboxylic acid metabolite is inactive as an antihypertensive. This metabolite is further metabolized by glucuronidation or oxidation to the corresponding pyridine derivative. The clearance of the primary dihydropyridine metabolite is 0.03 L/h/kg and the terminal half-life is approximately 9 hours.

In vitro studies show that clevidipine and its metabolite at the concentrations achieved in clinical practice will not inhibit or induce any CYP enzyme.

In a clinical study with radiolabeled clevidipine, 83% of the drug was excreted in urine and feces. The major fraction, 63-74% is excreted in the urine, 7-22% in the feces. More than 90% of the recovered radioactivity is excreted within the first 72 hours of collection.

Clevidipine displayed positive genotoxic potential in vitro in the Ames test, mouse lymphoma thymidine kinase locus assay, and chromosomal aberration assay, but not in vivo in the mouse micronucleus test. Formaldehyde, a metabolite of clevidipine, a known genotoxicant in vitro and a probable human carcinogen, appears to be at least partially responsible for the positive in vitro results. Long-term studies for evaluation of carcinogenic potential have not been performed with clevidipine due to the intended short-term duration of human use. There were no adverse effects on fertility or mating behavior of male rats at clevidipine doses of up to 55 mg/kg/day, approximately equivalent to the maximum recommended human dose (MRHD) of 504 mg/day (21 mg/hour x 24 hours) on a body surface area basis. Female rats demonstrated pseudopregnancy and changes in estrus cycle at doses as low as 13 mg/kg/day (about ¼^th the MRHD); however, doses of up to 55 mg/kg/day did not affect mating performance or fertility.

14.1 Perioperative Hypertension

Cleviprex was evaluated in two double-blind, randomized, parallel, placebo-controlled, multicenter trials of cardiac surgery patients—pre-operative use in ESCAPE-1 (n=105) and post-operative use in ESCAPE-2 (n=110). Patients were undergoing coronary artery bypass grafting, with or without valve replacement. Inclusion in ESCAPE-1 required a systolic pressure ≥160 mmHg. In ESCAPE-2, the entry criterion was systolic pressure of ≥140 mmHg within 4 hours of the completed surgery. The mean baseline blood pressure was 178/77 mmHg in ESCAPE -1 and 150/71 mmHg in ESCAPE-2. The population of both studies included 27% females and 47% patients older than age 65.

Cleviprex was infused in ESCAPE-1 preoperatively for 30 minutes, until treatment failure, or until induction of anesthesia, whichever came first. Cleviprex was infused in ESCAPE-2 postoperatively for a minimum of 30 minutes unless alternative therapy was required. The maximum infusion time allowed in the ESCAPE studies was 60 minutes.

In both studies infusion of Cleviprex was started at a dose of 1- 2 mg/hour and was titrated upwards, as tolerated, in doubling increments every 90 seconds up to an infusion rate of 16 mg/hour in order to achieve the desired blood pressure-lowering effect. At doses above 16 mg/hour, increments were 7 mg/hour. The average Cleviprex infusion rate in ESCAPE-1 was 15.3 mg/hour and in ESCAPE-2 it was 5.1 mg/hour. The mean duration of exposure in the same ESCAPE studies was 30 minutes for the Cleviprex-treated patients.

Approximately 4% of Cleviprex-treated subjects in ESCAPE-1 and 41% in ESCAPE-2 were on concomitant vasodilators during the first 30 minutes of Cleviprex administration.

Cleviprex lowered blood pressure within 2-4 minutes. The change in systolic blood pressure over 30 minutes for ESCAPE-1 (preoperative) and ESCAPE-2 (postoperative) are shown in Figure 1 and 2.

Figure 1. Mean change in systolic blood pressure (mmHg) during 30-minute infusion, ESCAPE-1 (preoperative):

Figure 2. Mean change in systolic blood pressure (mmHg) during 30-minute infusion, ESCAPE-2 (postoperative):

The change in heart rate over 30 minutes for ESCAPE-1 (preoperative) and ESCAPE-2 (postoperative) are shown in Figure 3 and 4.

Figure 3. Mean change in heart rate (bpm) during 30-minute infusion, ESCAPE-1 (preoperative):

Figure 4. Mean change in heart rate (bpm) during 30-minute infusion, ESCAPE-2 (postoperative):

In three Phase 3 open-label clinical trials (ECLIPSE), 1512 patients were randomized to receive Cleviprex, nitroglycerin (perioperative hypertension), sodium nitroprusside (perioperative hypertension), or nicardipine (postoperative hypertension), for the treatment of hypertension in cardiac surgery. The mean exposure in the ECLIPSE studies was 8 hours at 4.5 mg/hour for the 752 patients who were treated with Cleviprex. Blood pressure control was assessed by measuring the magnitude and duration of SBP excursions outside the predefined pre- and post-operative SBP target range of 75-145 mmHg and the predefined intra-operative SBP range of 65-135 mmHg. In general, blood pressure control was similar with the four treatments.

14.2 Severe Hypertension

Cleviprex was evaluated in an open-label, uncontrolled clinical trial (VELOCITY) in 126 patients with severe hypertension (SBP >180 mmHg or diastolic blood pressure [DBP] >115 mmHg). Cleviprex infusion was initiated at 2 mg/hour and up-titrated every 3 minutes, doubling up to a maximum dose of 32 mg/hour as required to achieve a prespecified target blood pressure range within 30 minutes (primary endpoint). The transition to oral antihypertensive therapy was assessed for up to 6 hours following cessation of Cleviprex infusion.

The blood pressure effect in this study is shown in Figure 5. The average infusion rate was 9.5 mg/hour. The mean duration of Cleviprex exposure was 21 hours.

Figure 5. Mean percent change in SBP (%) during the first 30 minutes of infusion, VELOCITY (severe hypertension)
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Oral antihypertensive therapy was instituted 1 hour prior to the anticipated cessation of Cleviprex infusion. Transition to oral antihypertensive therapy within 6 hours after discontinuing Cleviprex infusion was successful in 91% (115/126) of patients. No patient had IV antihypertensive therapy reinstituted following transition to oral therapy.

14.3 Essential Hypertension

Cleviprex was evaluated in a randomized, placebo-controlled, single-blind, parallel 72-hour continuous infusion study in 61 mild to moderate essential hypertensives. The mean baseline blood pressure was 151/86 mmHg.

Subjects were randomized to placebo or to 2, 4, 8, or 16 mg/hour. Doses above 2 mg/hour were started at 2 mg/hour and force-titrated in 2-fold increments at 3-minute intervals. Blood pressure, heart rate, and blood levels of clevidipine were measured during the infusion period. Blood levels were monitored 1 hour after the infusion was discontinued. Blood pressure and heart rate were monitored for 8 hours and also at 96 hours after the termination of infusion. Systolic blood pressure effect was related to the concentration of clevidipine and plateaued at higher measured concentrations, with the maximal effect estimated at 25% of baseline systolic blood pressure. The estimated infusion rate necessary to achieve half of this maximal effect was approximately 10 mg/hour.