Novo Nordisk needed a year and three days, but it has finally won FDA approval for Saxenda® (liraglutide [rDNA origin] injection), the company’s first obesity treatment and a higher-dosage version of its already-marketed diabetes drug Victoza (liraglutide).
Saxenda is the first once-daily human glucagon-like peptide-1 (GLP-1) analog authorized for obesity, according to the FDA. Saxenda is an injection drug indicated for chronic weight management in addition to a reduced-calorie diet and physical activity for adults in with a BMI 30 kg/m2 or greater, or 27 kg/m2 or greater in the presence of at least one weight-related comorbidity.
Saxenda enters a market segment of obesity drugs approved in recent years by the FDA. These drugs—all of them pills—include Belviq by Eisai and Arena Pharmaceuticals; Contrave by Orexigen Therapeutics and Takeda Pharmaceutical; and Qsymia, marketed by Vivus.
As a GLP-1 receptor agonist, the FDA cautioned, Saxenda should not be used in combination with any other drug in the class—including the type 2 diabetes treatment Victoza, which is marketed for Type 2 diabetes at 1.2 and 1.8 mg once-daily, as well as 0.9 mg in Japan, compared with 3 mg for Saxenda.
The FDA’s approval came two months past its October 20 Prescription Drug User Fee Act (PDUFA) date for completion of its review of Saxenda’s NDA, which was submitted to the agency on December 20, 2013. The path to agency approval became clearer in September, when the FDA’s Endocrinologic and Metabolic Drugs Advisory Committee voted 14–1 to recommend approval of Saxenda.
The FDA approved Saxenda with a Risk Evaluation and Mitigation Strategy (REMS), intended to inform health care professionals about the serious risks associated with Saxenda.
Concerns about potential side-effects have prompted FDA to approve Saxenda with a boxed warning that thyroid C-cell tumors have been observed in rodent studies, while adding that it is unknown whether those tumors—including medullary thyroid carcinoma (MTC) in humans is actually caused by the drug.
The warning also states that Saxenda should not be used in patients with a personal or family history of MTC, or in patients with multiple endocrine neoplasia syndrome type 2, which predisposes them to MTC.
Also, the FDA required Novo Nordisk to conduct post-marketing studies for Saxenda that will:
- Evaluate dosing, safety, and efficacy in pediatric patients;
- Assess potential effects on growth, sexual maturation, and central nervous system development and function in immature rats;
- Identify any increase in MTC incidence related to Saxenda, through an MTC case registry stretching back at least 15 years, and;
- Evaluate the potential risk of breast cancer with Saxenda in ongoing clinical trials.
Saxenda’s cardiovascular safety continues to be investigated in an ongoing cardiovascular outcomes trial.
The FDA said Saxenda was approved based on results from three clinical trials that included approximately 4,800 obese and overweight patients, with and without significant weight-related conditions. All patients were counseled on the need for lifestyle modifications that included a reduced-calorie diet and regular physical activity, the FDA said.
In all its clinical trials, the most common side effects observed in patients taking Saxenda were nausea, diarrhea, constipation, vomiting, low blood sugar, and decreased appetite. However, some patients reported serious side effects, such as pancreatitis, gallbladder disease, renal impairment, and suicidal thoughts.
According to an average of seven analysts’ estimates compiled by Bloomberg News, Saxenda is expected to generate $566 million in sales in 2017 compared with $2.8 billion for Victoza, which racked up sales of DKK 9.416 billion ($1.544 billion) during the first nine months of 2014, up 12% from Q1-Q3 2013.
Novo Nordisk has viewed Saxenda as the first of several obesity treatments it hopes to launch, as the company builds a therapeutic area around weight-management drugs.
In September, the company confirmed it will establish an obesity R&D hub in Seattle near an existing Type 1 diabetes research center. The obesity hub will initially employ 10 staffers, but grow by 2016 to about 60 of an eventual 300 researchers focused on obesity.