Adverse Reactions Leading to Study Discontinuation

The discontinuation rate due to adverse reactions was 18% among patients treated with VYLEESI and 2% among patients treated with placebo. The most common adverse reactions leading to study drug discontinuation in the VYLEESI group were nausea (8%), headache (2%), vomiting (1%), flushing (1%), injection site reactions (1%), flu-like symptoms (<1%) and increased blood pressure (<1%).

Common Adverse Reactions

Table 1 provides the incidence of common adverse reactions (those reported in at least 2% of patients in the VYLEESI treatment group and at an incidence that was greater than in the placebo group). The most common adverse reactions included nausea, flushing, injection site reactions and headache. The majority of events were reported to be mild (31%) to moderate (40%) in intensity and transient.

Nausea

In the pooled phase 3 placebo-controlled trials, nausea was the most common adverse reaction, reported in 40% of VYLEESI-treated patients compared to 1% of placebo-treated patients. The median onset of nausea was within one-hour post-dose and lasted about two hours in duration. The incidence of nausea was highest after the first VYLEESI dose (reported in 21% of patients) then declined to about 3% after subsequent doses. Thirteen percent of VYLEESI-treated patients received an anti-emetic medication. Overall, 8% of VYLEESI-treated patients and no placebo-treated patients prematurely discontinued the trials due to nausea. [see Warnings and Precautions (5.3)]

In a phase 4, single-dose, placebo-controlled clinical study, pre-treatment with oral ondansetron (a 5-HT3 receptor antagonist) did not reduce the incidence of nausea associated with VYLEESI treatment. In this study, 228 healthy women were randomized (1:1) to receive 8 mg ondansetron or placebo orally 30 minutes prior to a single administration of 1.75 mg of VYLEESI given subcutaneously. No significant difference in the incidence of VYLEESI-associated nausea was seen between the treatment groups. Therefore, pre-treatment with oral ondansetron given 30 minutes prior to VYLEESI administration does not reduce the incidence of VYLEESI-associated nausea and is not recommended. Treatment with ondansetron after VYLEESI administration or after the onset of nausea has not been formally studied.

Headache

In the pooled phase 3 placebo-controlled trials, headache occurred at a higher incidence in VYLEESI-treated patients (11%) than placebo-treated patients (2%). One patient experienced a headache event that was serious (intractable pain leading to hospitalization) and 1% of patients who received VYLEESI discontinued the study due to headache.

Flushing

In the pooled phase 3 placebo-controlled trials, flushing occurred more frequently in VYLEESI-treated patients (20%) than placebo-treated patients (<1%). None of the flushing events were serious and few were severe (<1%), and 1% of patients who received VYLEESI discontinued the study due to flushing.

Less Common Adverse Reactions

Less common adverse reactions occurring in <2% of VYLEESI-treated patients and at an incidence greater than in the placebo group were upper abdominal pain, diarrhea, myalgia, arthralgia, pain, restless leg syndrome, rhinorrhea, increased creatine phosphokinase, blood pressure increased, pain in extremity and focal skin hyperpigmentation.

Acute hepatitis

In the open-label, uncontrolled extension phase of one study, a single case of acute hepatitis was reported in a patient who had received 10 doses of VYLEESI over one year. She presented with serum transaminases exceeding 40 times the upper limit of normal (ULN), total bilirubin 6 times the ULN, and alkaline phosphatase less than 2 times ULN. Liver tests returned to normal 4 months after study drug discontinuation. Because another etiology was not identified, the role of VYLEESI could not definitively be excluded. There was no imbalance between treatment groups in serum transaminase outliers or other signals for hepatotoxicity in the clinical development program.

Pregnancy Exposure Registry

There will be a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to VYLEESI during pregnancy. Pregnant women exposed to VYLEESI and healthcare providers are encouraged to call the VYLEESI Pregnancy Exposure Registry at (800) 972-5220.

Risk Summary

The few pregnancies in women exposed to VYLEESI in clinical trials are insufficient for determining whether there is a drug-associated risk for major birth defects, miscarriage or adverse maternal or fetal outcomes.

Based on findings in animal studies, the use of VYLEESI in pregnant women may be associated with the potential for fetal harm. In animal reproduction and development studies, daily subcutaneous administration of bremelanotide to pregnant dogs during the period of organogenesis at exposures greater than or equal to 16 times the maximum recommended dose (based on area under the concentration-time curve or AUC) produced fetal harm. In mice subcutaneously dosed with bremelanotide during pregnancy and lactation, developmental effects were observed in the offspring at greater than or equal to 125-times the maximum recommended dose (based on AUC) [see Data]. However, the lowest bremelanotide dose associated with fetal harm has not been identified for either species. For this reason, women should use effective contraception while taking VYLEESI and discontinue VYLEESI if pregnancy is suspected.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Data

Human Data

There were 7 pregnancies reported in the clinical trials of more than 1057 patients treated with VYLEESI for up to 12 months. Among these 7 pregnancies, no major congenital anomalies were reported. There was one spontaneous abortion (miscarriage), five full-term live births, and one outcome was unknown due to loss to follow-up.

Animal Data

An embryofetal development study was conducted in the dog and a pre- and postnatal development study was conducted in the mouse to inform developmental risk. These two species are not routinely used for reproductive toxicity assessment but were the only two species that could be successfully dosed by the subcutaneous route during gestation.

Bremelanotide was administered subcutaneously to pregnant dogs (8/dose) at 2, 8, or 20 mg/kg from gestation day (GD) 18-35, corresponding to the period from implantation to late embryogenesis in the dog. Embryofetal toxicity, as measured by post-implantation loss, was elevated approximately 3 to 8-fold compared to controls across all treated groups but was not dose-dependent. A developmental no-observed-effect level (NOEL) was not set. At the low dose of 2 mg/kg/day in the dog, exposure was approximately 16 times the human exposure based on AUC.

In a pre- and postnatal development study, female mice (30/dose) were dosed subcutaneously at 0, 30, 75, and 150 mg/kg/day from GD 6 through lactation day (LD) 28, and two generations of offspring were assessed (F1 and F2). There were no effects on reproductive parameters in parental (F0) or F1 generation animals at doses up to 150 mg/kg/day (approximately 760 times the human AUC). However, developmental delays were observed in the F1 generation mice at ≥ 30 mg/kg/day (approximately 125 times the human AUC). For that reason, a developmental NOEL was not set. There were no significant effects on the growth and development of F2 generation pups.

Risk Summary

There is no information on the presence of bremelanotide or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production.

The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for VYLEESI and any potential adverse effects on the breastfed child from VYLEESI or from the underlying maternal condition.

Contraception

Use of VYLEESI during pregnancy is not recommended [see Use in Specific Populations (8.1)]. Advise females of reproductive potential to use effective contraception while taking VYLEESI, and to discontinue VYLEESI if pregnancy is suspected.

Transient Increases in Blood Pressure

In an open-label ambulatory blood pressure monitoring study of 127 premenopausal women receiving VYLEESI once daily, there was a mean increase of 1.9 mmHg (95% CI: 1.0 to 2.7) in daytime systolic blood pressure (SBP) and a mean increase of 1.7 mmHg (95% CI: 0.9 to 2.4) in daytime diastolic blood pressure (DBP) after 8 days of dosing. The increase in SBP and DBP was transient with a mean peak effect in SBP of 2.8 mmHg between 4 to 8 hours post-dose and 2.7 mmHg for DBP at 0 to 4 hours post-dose. The increase in BP after 8 days of dosing was accompanied by a simultaneous and transient mean decrease in heart rate of 0.5 beats per minute (95% CI: -1.6 to -0.7). The SBP and DBP values 12 to 24-hours post-dose were similar to the pre-dose values [see Warnings and Precautions (5.1)].

Alcohol Interaction

A placebo-controlled, randomized, double-blind, three-period, three-way crossover study was conducted to assess the safety of a single intranasal 20 mg dose of bremelanotide co-administered with alcohol in 12 healthy male and 12 healthy female subjects. Intranasal bremelanotide or placebo spray was administered 10 minutes after consumption of placebo drink or 0.6 g/kg ethanol (equivalent of three 12 ounce cans of beer containing 5% alcohol content, three 5 ounce glasses of wine containing 12% alcohol content, or three 1.5 ounce shots of 80-proof spirit in a 70 kg person).

The 20 mg intranasal dose achieves a 2.5-fold higher mean Cmax than that of VYLEESI. Alcohol consumption had no effect on the pharmacokinetic profile of bremelanotide. The incidence of flushing was higher with bremelanotide plus ethanol compared to ethanol alone, but similar to the incidence with bremelanotide alone. The incidence of headache was higher with bremelanotide plus ethanol compared to bremelanotide alone, but similar to the incidence with ethanol alone. The incidence of other adverse reactions was similar across the treatment groups. The incidence of abnormal orthostatic blood pressure reductions was comparable between the bremelanotide plus ethanol group and the ethanol alone group. No participants discontinued due to adverse reactions.

Cardiac Electrophysiology

A 20 mg intranasal dose of bremelanotide does not prolong the QTc interval to any clinically relevant extent.

Absorption

Bremelanotide median Tmax is approximately 1.0 hour (range: 0.5 - 1.0 hours) in plasma. The absolute bioavailability of bremelanotide following subcutaneous administration of VYLEESI was about 100%. The site of subcutaneous administration (abdomen and thigh) had no significant effect on the systemic exposure to bremelanotide.

Distribution

Twenty-one percent of bremelanotide binds to human serum protein. The mean (SD) volume of distribution after a single subcutaneous administration of VYLEESI is 25.0 ± 5.8 L.

Elimination

Following a single subcutaneous administration of VYLEESI, mean terminal half-life of bremelanotide is approximately 2.7 hours (range: 1.9– 4.0 hours) and the mean (± SD) clearance (CL/F) is 6.5 ±1.0 L/hr.

Metabolism

As a peptide with 7 amino acids, the primary metabolic pathway of bremelanotide involves multiple hydrolyses of the amide bond of the cyclic peptide.

Excretion

Following administration of a radiolabeled dose, 64.8% of the total radioactivity was recovered in urine and 22.8% in feces.

Specific Populations

Patients with Renal Impairment

Following a single subcutaneous dose of VYLEESI, bremelanotide exposure (AUC) increased 1.2-fold in patients with mild (eGFR, 60 to 89 mL/min/1.73 m2) renal impairment, 1.5-fold in patients with moderate (eGFR, 30 to 59 mL/min/1.73 m2) renal impairment, and 2-fold in patients with severe (eGFR, <30 mL/min/1.73 m2) renal impairment [see Use in Specific Populations (8.6)].

Patients with Hepatic Impairment

Following a single subcutaneous dose of VYLEESI, bremelanotide exposure (AUC0-inf) increased 1.2-fold in patients with mild (Child-Pugh A; score of 5-6) hepatic impairment and 1.7-fold in patients with moderate (Child-Pugh B; score of 7-9) hepatic impairment [see Use in Specific Populations (8.7)]. The effect of severe hepatic impairment on the pharmacokinetics of bremelanotide was not studied.

Drug Interaction Studies

Potential for VYLEESI to Influence the Pharmacokinetics of Other Drugs

VYLEESI may reduce the rate and extent of absorption of concomitantly administered oral medications, likely due to slowing gastric motility. In clinical pharmacology studies, VYLEESI did not affect the absorption of the tested orally administered concomitant medications to any clinically relevant degree, except for naltrexone and indomethacin [see Drug Interactions (7)].

The effects of bremelanotide on the pharmacokinetics of other drugs are summarized below as change relative to the other drug administered alone (test/reference) (Figure 1).

Figure 1: Effects of Bremelanotide 1.75 mg SC on the Pharmacokinetic Exposures of Orally Administered Medications

Note: AUC = area under the plasma concentration-time curve; BMT = bremelanotide; CI = confidence interval; Cmax = maximum plasma concentration; SC = subcutaneous.

Carcinogenesis

There were no significant increases in tumor incidence in two-year carcinogenicity studies with intranasal administration (0.5, 2.5, and 5 mg/animal/day) of bremelanotide to male and female rats, and subcutaneous administration (3, 9, and 15 mg/kg/day) to male and female mice. Multiples of exposure were calculated based on average Cmax at the high dose over the course of the study and were 1.1-fold and 111-fold the human Cmax for rats and mice, respectively.

Mutagenesis

Bremelanotide was not genotoxic or mutagenic in a battery of tests, including the in vitro bacterial reverse mutation assay, the in vitro chromosomal aberration test in Chinese Hamster Ovary cells, and the in vivo mouse micronucleus assay.

Impairment of Fertility

There were no effects on fertility in male (75 mg/kg/day, approximately 375 times the human AUC) or female (150 mg/kg/day, approximately 760 times the human AUC) mice following subcutaneous administration.