The U.S. Food and Drug Administration approved Victoza (liraglutide) injection for treatment of pediatric patients 10 years or older with type 2 diabetes. Victoza is the first non-insulin drug approved to treat type 2 diabetes in pediatric patients since metformin was approved for pediatric use in 2000. Victoza has been approved to treat adult patients with type 2 diabetes since 2010.
Type 2 diabetes is the most common form of diabetes, occurring when the pancreas cannot make enough insulin to keep blood sugar at normal levels. Although type 2 diabetes primarily occurs in patients over the age of 45, the prevalence rate among younger patients has been rising dramatically over the past couple of decades. The Diabetes Report Card published by the U.S. Centers for Disease Control and Prevention estimates that more than 5,000 new cases of type 2 diabetes are diagnosed each year among U.S. youth younger than age 20.
VICTOZA contains liraglutide, an analog of human GLP-1 and acts as a GLP-1 receptor agonist. The peptide precursor of liraglutide, produced by a process that includes expression of recombinant DNA in Saccharomyces cerevisiae, has been engineered to be 97% homologous to native human GLP-1 by substituting arginine for lysine at position 34. Liraglutide is made by attaching a C-16 fatty acid (palmitic acid) with a glutamic acid spacer on the remaining lysine residue at position 26 of the peptide precursor.
The molecular formula of liraglutide is C172H265N43O51 and the molecular weight is 3751.2 Daltons. The structural formula:
Mechanism of Action
Liraglutide is an acylated human Glucagon-Like Peptide-1 (GLP-1) receptor agonist with 97% amino acid sequence homology to endogenous human GLP-1(7-37). GLP-1(7-37) represents <20% of total circulating endogenous GLP-1. Like GLP-1(7-37), liraglutide activates the GLP-1 receptor, a membranebound cell-surface receptor coupled to adenylyl cyclase by the stimulatory G-protein, Gs, in pancreatic beta cells. Liraglutide increases intracellular cyclic AMP (cAMP) leading to insulin release in the presence of elevated glucose concentrations. This insulin secretion subsides as blood glucose
concentrations decrease and approach euglycemia. Liraglutide also decreases glucagon secretion in a glucose-dependent manner. The mechanism of blood glucose lowering also involves a delay in gastric emptying. GLP-1(7-37) has a half-life of 1.5-2 minutes due to degradation by the ubiquitous endogenous enzymes, dipeptidyl peptidase IV (DPP-IV) and neutral endopeptidases (NEP). Unlike native GLP-1, liraglutide is stable against metabolic degradation by both peptidases and has a plasma half-life of 13 hours after
subcutaneous administration. The pharmacokinetic profile of liraglutide, which makes it suitable for once daily administration, is a result of self-association that delays absorption, plasma protein binding and stability against metabolic degradation by DPP-IV and NEP.
Victoza improves blood sugar levels by creating the same effects in the body as the glucagon-like peptide (GLP-1) receptor protein in the pancreas. GLP-1 is often found in insufficient levels in type 2 diabetes patients. Like GLP-1, Victoza slows digestion, prevents the liver from making too much glucose (a simple sugar), and helps the pancreas produce more insulin when needed. As noted on the label, Victoza is not a substitute for insulin and is not indicated for patients with type 1 diabetes or those with diabetic ketoacidosis, a condition associated with diabetes where the body breaks down fat too quickly because there is inadequate insulin or none at all. Victoza is also indicated to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes and established cardiovascular disease; however, its effect on major adverse cardiovascular events in pediatrics was not studied and it is not indicated for this use in children.
The efficacy and safety of Victoza for reducing blood sugar in patients with type 2 diabetes was studied in several placebo-controlled trials in adults and one placebo-controlled trial with 134 pediatric patients 10 years and older for more than 26 weeks. Approximately 64% of patients in the pediatric study had a reduction in their hemoglobin A1c (HbA1c) below 7% while on Victoza, compared to only 37% who achieved these results with the placebo. HbA1c is a blood test that is routinely performed to evaluate how well a patient’s diabetes is controlled, and a lower number indicates better control of the disease. These results occurred regardless of whether the patient also took insulin at the same time. Adult patients who took Victoza with insulin or other drugs that increase the amount of insulin the body makes (e.g., sulfonylurea) may have an increased risk of hypoglycemia (low blood sugar). Meanwhile, pediatric patients 10 years and older taking Victoza had a higher risk of hypoglycemia regardless of whether they took other therapies for diabetes.
The prescribing information for Victoza includes a Boxed Warning to advise health care professionals and patients about the increased risk of thyroid C-cell tumors. For this reason, patients who have had, or have family members who have ever had medullary thyroid carcinoma (MTC) should not use Victoza, nor should patients who have an endocrine system condition called multiple endocrine neoplasia syndrome type 2 (MEN 2). In addition, people who have a prior serious hypersensitivity reaction to Victoza or any of the product components should not use Victoza. Victoza also carries warnings about pancreatitis, Victoza pen sharing, hypoglycemia when used in conjunction with certain other drugs known to cause hypoglycemia including insulin and sulfonylurea, renal impairment or kidney failure, hypersensitivity and acute gallbladder disease. The most common side effects are nausea, diarrhea, vomiting, decreased appetite, indigestion and constipation.
The FDA granted this application Priority Review. The approval of Victoza was granted to Novo Nordisk.