Myalept Drug Information

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Open-Label, Single-Arm Study The safety of MYALEPT was evaluated in 48 patients with generalized lipodystrophy in a single-arm, open-label study. The median duration of exposure in this trial was 2.7 years with a range of 3.6 months to 10.9 years.

The most frequent adverse reactions are summarized in Table 3. Table 3: Adverse Reactions of 5% or Greater Incidence in Patients with Generalized Lipodystrophy Receiving MYALEPT in an Open-Label, Single-Arm Study All Subjects N=48 (%) 1. Hypoglycemic events were assessed as mild, moderate, severe, or life threatening based on the protocol specified definitions: Mild: Documentation of low plasma glucose values with no symptoms; Moderate: Presence of clinical symptoms requiring ingestion of glucose, self-alleviated; Severe: Presence of neuroglycopenic symptoms requiring assistance from others for alleviation; Life threatening: Loss of consciousness and/or requiring intervention by administration of intravenous glucose or intramuscular glucagon. Headache 6 Hypoglycemia 1 6 Decreased weight 6 Abdominal pain 5 Arthralgia 4 Dizziness 4 Ear infection 4 Fatigue 4 Nausea 4 Ovarian cyst 4 Upper respiratory tract infection 4 Anemia 3 Back pain 3 Diarrhea 3 Paresthesia 3 Proteinuria 3 Pyrexia 3 In patients with generalized lipodystrophy receiving MYALEPT in this study, less common adverse reactions included injection-site erythema and urticaria (N=2 ). Six patients (13%) had 7 adverse reactions of hypoglycemia, 6 of which occurred in the setting of concomitant insulin use, with or without oral antihyperglycemic agents. Two patients (4%) had events of pancreatitis, both of whom had a medical history of pancreatitis.

Immunogenicity As with all therapeutic proteins, there is potential for immunogenicity. Anti-metreleptin

antibodies were detected in 84% (36/43) of generalized lipodystrophy patients studied in the MYALEPT trials. Total anti-metreleptin antibody titers ranged between 1:5 and 1:1,953,125. The incompleteness of the current immunogenicity database precludes understanding of the magnitude and persistence of the observed anti-drug antibody responses. Anti-metreleptin antibodies with neutralizing activity associated with adverse events consistent with loss of endogenous leptin activity and/or loss of MYALEPT efficacy were observed in 6% (2/33) of the patients with generalized lipodystrophy tested.

Adverse events reported in these two patients included severe infections and worsening of metabolic control (increases in HbA 1c and/or triglycerides). Test for anti-metreleptin antibodies with neutralizing activity in patients who develop severe infections or show signs suspicious for loss of MYALEPT efficacy during treatment. Contact Chiesi Farmaceutici S.p.A. at 1-866-216-1526 for testing of clinical samples. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay.

The immunogenicity assays utilized in clinical trials lacked sensitivity, resulting in potential underestimation of the number of samples positive for anti-metreleptin antibodies with neutralizing activity. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to metreleptin with the incidence of antibodies to other products may be misleading.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of MYALEPT. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Incorrect dose administered, accidental overdose Injection site reaction, including inflammation and hyperpigmentation

No formal drug interaction studies were performed. Leptin is a cytokine and may have the potential to alter the formation of cytochrome P450 (CYP450) enzymes. This should be taken into account when prescribing concomitant drugs metabolized by CYP450 (e.g., oral contraceptives and drugs with a narrow therapeutic index). The effect of metreleptin on CYP450 enzymes may be clinically relevant for CYP450 substrates with narrow therapeutic index, where the dose is individually adjusted.

Upon initiation or discontinuation of MYALEPT, in patients being treated with these types of agents, therapeutic monitoring of effect (e.g., warfarin) or drug concentration (e.g., cyclosporine or theophylline) should be performed and the individual dose of the agent adjusted as needed.

Pregnancy Pregnancy Exposure Registry There is a program that monitors outcomes in women exposed to MYALEPT during pregnancy. Women who become pregnant during MYALEPT treatment are encouraged to enroll. Patients or their physicians should call 1-855-669-2537 to enroll.

Risk Summary Available pharmacovigilance reports with the use of MYALEPT in pregnant women are insufficient to evaluate for any drug-associated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes. These reports describe similar adverse pregnancy outcomes as those documented in women with lipodystrophy (see Clinical Considerations ). In an animal reproduction study, no adverse developmental effects were observed with subcutaneous administration of metreleptin to pregnant mice during organogenesis at doses 7- and 15-fold the maximum recommended clinical dose, based on body surface area of a 20- and 60-kg patient, respectively. In a pre- and postnatal development study in mice, subcutaneous administration of metreleptin caused prolonged gestation and dystocia resulting in maternal death during parturition and lower survival of offspring in the immediate postnatal period at doses starting approximately at the maximum recommended clinical dose (see Data ). MYALEPT contains benzyl alcohol when reconstituted with BWFI. MYALEPT contains no preservative when reconstituted with WFI. Because benzyl alcohol is rapidly metabolized by a pregnant woman, benzyl alcohol exposure in the fetus is unlikely.

However, adverse reactions have occurred in premature neonates and low birth weight infants who received intravenously administered benzyl alcohol-containing drugs. Therefore, if therapy with MYALEPT is needed during pregnancy, consider using preservative-free WFI when reconstituting. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.

In the U.S. general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Disease-Associated Maternal and Fetal Risk Lipodystrophy in pregnancy can result in an increased rate of gestational diabetes, macrosomia, eclampsia, intrauterine growth retardation, intrauterine death, and miscarriage. Labor and Delivery The effects of MYALEPT on labor and delivery in pregnant women are unknown.

In a published in vitro study of human myometrial tissue exposed to a recombinant leptin, human uterine contractility was inhibited. In animal studies with metreleptin, prolonged gestation and dystocia were observed (see Data ). Data Animal Data Metreleptin administered to pregnant mice during the period of organogenesis was not teratogenic at doses ranging between 7- and 15-fold the maximum recommended clinical dose, based on body surface area of a 20- and 60-kg patient, respectively. In a pre- and postnatal development study in mice, metreleptin administered at doses of 3, 10, and 30 mg/kg (approximately 1-, 5-, and 15-fold the clinical dose for a 60-kg subject, based on body surface area) from gestation day 6 to lactation day 21 caused prolonged gestation and dystocia at all doses, starting at approximately the maximum recommended clinical dose.

Prolonged gestation resulted in the death of some females during parturition and lower survival of offspring within the immediate postnatal period. Consistent with metreleptin pharmacology, decreased maternal body weight was observed from gestation throughout lactation at all doses and resulted in reduced weight of offspring at birth, which persisted into adulthood. However, no developmental abnormalities were observed and reproductive performance of the first or second generations was not affected at any dose.

Placental transfer of metreleptin into the fetus was low (approximately 1%) following subcutaneous dosing.

Pediatric Use The MYALEPT study included a total of 35 pediatric patients (73%) with an age range from 1 to 17 years. No clinically meaningful differences were observed in the efficacy and safety of MYALEPT between pediatric and adult patients. MYALEPT contains benzyl alcohol when reconstituted with BWFI. MYALEPT contains no preservative when reconstituted with WFI. Preservative-free WFI is recommended for use in neonates and infants.

The preservative benzyl alcohol has been associated with serious adverse events and death, particularly in pediatric patients. The "gasping syndrome" (characterized by central nervous system depression, metabolic acidosis, gasping respirations, and high levels of benzyl alcohol and its metabolites found in the blood and urine) has been associated with benzyl alcohol dosages >99 mg/kg/day in neonates and low-birth weight infants. Additional symptoms may include gradual neurological deterioration, seizures, intracranial hemorrhage, hematologic abnormalities, skin breakdown, hepatic and renal failure, hypotension, bradycardia, and cardiovascular collapse.

Although normal therapeutic doses of this product deliver amounts of benzyl alcohol that are substantially lower than those reported in association with the "gasping syndrome," the minimum amount of benzyl alcohol at which toxicity may occur is not known. Premature and low-birth-weight infants, as well as patients receiving high dosages, may be more likely to develop toxicity. Practitioners administering this and other medications containing benzyl alcohol should consider the combined daily metabolic load of benzyl alcohol from all sources.

When reconstituted with 2.2 mL of BWFI, MYALEPT contains 1.76 mg of benzyl alcohol per mg of metreleptin or 9 mg of benzyl alcohol per mL of reconstituted product.

General Obesity

MYALEPT is contraindicated in patients with general obesity not associated with congenital leptin deficiency. MYALEPT has not been shown to be effective in treating general obesity, and the development of anti-metreleptin antibodies with neutralizing activity has been reported in obese patients treated with MYALEPT.

Hypersensitivity

MYALEPT is contraindicated in patients with prior severe hypersensitivity reactions to metreleptin or to any of the product components. Known hypersensitivity reactions have included anaphylaxis, urticaria and generalized rash.

In one post-marketing case, a dose miscalculation resulted in an infant being exposed to a 10-fold overdose of metreleptin for 8 months. In this case, prolonged overdose was associated with severe anorexia causing vitamin and zinc deficiencies, iron deficiency anemia, protein calorie malnutrition, and poor weight gain, which resolved following supportive treatment and dose adjustment. In the event of an overdose, patients should be monitored and appropriate supportive treatment be initiated as dictated by the patient's clinical status.