Obesity and associated comorbidities strain the healthcare system, so why has R&D for new weight loss medications been lackluster?
Obesity is a significant population health issue and remains a top driver of total healthcare costs.
It accounts for 20% of the United States annual direct healthcare cost, according to a study published in the Journal of Health Economics. According to the Robert Wood Johnson Foundation, it is responsible for $61.8 billion in Medicare and Medicaid spending.
Obesity is a chronic disease that affects almost every system of the body resulting in comorbidities such as hypertension, diabetes, cardiovascular disease, osteoarthritis, infertility, depression, and cancer. These comorbidities result in increase healthcare utilization (i.e., physician visits, medications, testing) and healthcare cost.
"Obesity should be on managed care’s radar as it is driving up the cost of providing health benefits by way of treating its comorbidities," says Taraneh Soleymani, MD, FTOS, assistant professor, department of nutrition sciences, at the University of Alabama at Birmingham (UAB), and codirector, UAB Weight Loss Medicine. "Furthermore appropriate obesity treatment coverage should be on managed care’s radar as the lack of it will result in poor quality of care for individuals with obesity, further driving up the healthcare cost."
Lifestyle modification (diet, physical activity, behavior change), medications, and bariatric surgery are the three principal modalities of obesity treatment, according to Soleymani.
"Across the United States, many healthcare systems do not cover these treatment options or there is inconsistent coverage of them leaving the beneficiary to gain more weight and acquire obesity related comorbidities," she says. "Keep in mind that healthcare systems do cover the treatment of obesity related comorbidities such as hypertension and diabetes."
According to Soleymani, 5% to 10% weight loss significantly improves obesity-related comorbidities. “Therefore, paying for obesity treatment has significant implications for the payers including decreased healthcare cost, improved quality of care, and decreased disease burden,” she says.
When medications are used to treat obese patients, generic phentermine and bupropion are currently prescribed more than other weight loss agents, says Michael J. Sax, PharmD, president, The Pharmacy Group LLC.
Other medications include phentermine-topiramate (Qsymia, Vivus Inc.) as well as liraglutide (Saxenda, Novo Nordisk). Orlistat, marketed as Alli and Xenical, is available over-the-counter for weight loss. It is a drug that promotes loss of weight by preventing the digestion and absorption of fat in food.
Non-pharmaceutical approaches include sound nutrition counseling, behavioral modification and physical activity, says Sax. "Medications can only be effective if these are maintained," he says. "The success rate of overweight/obese patients meeting weight loss goals is less than 20%."
Next: Pipeline Analysis
R&D for new weight loss medications has been lackluster-and medications recently approved aren't providing significant improvements in reduction of long-term primary outcomes (i.e., prevention of diabetes, heart attack, stroke, etc.), says Craig Mattson, RPh, senior director of formulary development at Prime Therapeutics.
"Many weight loss medications lack proven long-term clinical outcomes and return on investment and the vast majority of commercially insured employers exclude coverage for weight loss medications," Mattson says.
F. Randy Vogenberg, PhD, partner, Access Market Intelligence, and cofounder National Institute of Collaborative Healthcare, agrees. "The problem is that the drugs-mainly generics-are marginally effective," Vogenberg says. "The question is: What is the minimal dose that will really be effective? And, the drugs would need to be done in combination with other drugs that affect a person’s behavior. The reception is not very high for some new drugs. Although there is a need, the solutions are not effective."
There is a belief that obesity is a lifestyle issue, according to Vogenberg. "The current treatments are some form of antidepressants in combination in minimal dose, affecting CNS receptors to encourage the patient to stop eating or have a full feeling," he says. "The analogy would be smoking cessation, products that will work with counseling and other efforts, in several cycles of failure and success."
However, there will be more mechanisms of action introduced to the market, according to Mattson. For example, he says that beloranib (Zafgen) is being studied as a first-in-class obesity therapy that demonstrates a unique mechanism of action through methionine aminopeptidase 2 (MetAP2) inhibition.
According to a manufacturer press release, MetAP2 inhibitors work by balancing how the body packages and metabolizes fat. Inhibitors of MetAP2 reduce the production of new fatty acid molecules by the liver and help to convert stored fats into useful energy.
"Most other drugs use other forms of signaling such as the serotonergic system," Mattson says.
Some of the new products being introduced today to address obesity are actually repackaged forms of existing products, says Mattson. For example, Saxenda (Novo Nordisk) was approved in late 2014 for the treatment of obesity. Saxenda’s active ingredient, liraglutide, is actually the same as Novo’s type 2 diabetes drug Victoza.
"Payers are not too concerned about anti-obesity pipeline other than the cost of drugs," he says. "If the next anti-obesity drugs are more effective than the current ones, they would not necessarily be more expensive."
Sax shares a similar viewpoint. "Many payers are reluctant to cover these drugs due to safety concerns as well as costs," he says. "Health plans want to cover treatment, which has an immediate impact for the plan, and have not focused on preventive care in the long term. But as the link between obesity and the comorbidities of diabetes and heart disease increases, I believe the use of these agents will increase."
"Many benefit designs across our commercial book at the employer level exclude coverage for weight loss medications because of the lack of proven long-term clinical outcomes and return on investment-and we don’t see that changing," Mattson says. "Health and wellness, and lifestyle modifications with diet and exercise will continue to be a focus in the battle against obesity."
Still, he says, Prime monitors all approved weight loss drugs for their safety and efficacy and will continue to do so as more drugs in this category are approved.
Tracey Walker is content manager for Managed Healthcare Executive.