Lisa Jarvis

New Weight-Loss Drugs Work, But Who's Paying?

After decades of failure, weight loss drugs seem finally poised to become big pharma’s newest blockbuster category. Bloomberg Intelligence sees the US obesity drug market alone as worth $12 billion in 2028. Morgan Stanley Research recently made a far more bullish prediction, forecasting global sales of obesity drugs could reach $54 billion by 2030.

The enthusiasm is merited. These newer drugs offer more profound and sustained weight loss than any of the medicines that came before them, and there are many people who could benefit from them: According to the US Government Accountability Office, between 2013 and 2016, only 3% of the people eligible for an obesity medication were taking one.

But those lofty sales goals will only be reached if the medical field can overcome the structural barriers to their use.

The new drugs are typically once-a-week injections that mimic gut hormones that regulate the feeling of satiety. The approach seems to be solving the field’s problems with safety and efficacy. Data on Novo Nordisk’s Wegovy, approved in June 2021, and Eli Lilly & Co.’s Mounjaro, expected to be approved next year, suggest these drugs can help people shed, on average, as much as 15-20% of their body weight. We have only a snippet of data on Amgen’s early-stage weight-loss drug, AMG 133, but it has already generated intense interest from investors based on hopes that it could offer similar or potentially higher weight loss as Mounjaro with a once-a-month shot. Amgen said this week that people taking a high dose of the drug had lost on average about 14.5% of their body weight about three months into its phase 1 trial. Full data from that study will be disclosed at a conference early next month.

Results like those would make the new drugs 2-3 times more effective than older diet drugs, which also carried a litany of side effects ranging from the unpleasant (leaky stools) to downright dangerous (increased risk of heart attacks or cancer).

People are eager to try the new treatments. At a conference on obesity last week, experts in the field traded stories of the long waits for new patients seeking an appointment with weight-loss specialists. The Massachusetts General Hospital Weight Center, for example, has over 4,000 people on its wait list, says Fatima Cody Stanford, an obesity medicine physician there.

“The demand is overwhelming the workforce,” says Robert Kushner, who specializes in obesity medicine at Northwestern Medicine.

Pharma companies are also struggling to keep up with demand. Lilly has had trouble keeping up its supply of Mounjaro, even though it’s currently only approved for diabetes. When it gets an expected nod from the Food and Drug Administration as an obesity treatment in the second half of 2023, at least one analyst believes it could swiftly become one of the best-selling drugs in the history of the industry. And although Novo Nordisk’s Wegovy has been on the market for more than a year, it has been in a constant state of short supply, first because of unexpectedly high demand, and later due to manufacturing issues.

Novo expects that supply constraint to be resolved by the end of this year, a situation that could finally provide some answers to key questions on the market. For one, the magnitude of demand could become clearer; currently, it’s complicated by people turning to diabetes treatments that use the same ingredients as weight-loss drugs. And once supply is steady, it should be easier to gauge how long people are sticking with these once-a-week injections, a factor that will affect just how big of a blockbuster drug they become.

But all of this enthusiasm assumes the field will work out some fundamental challenges that could hold back widespread use of these weight loss drugs.

One major problem? Primary care physicians have been reluctant to prescribe the drugs. One issue is that doctors today aren’t typically trained in addressing obesity, and some still take the antiquated view that the disease is solely a lifestyle rather than a medical issue. Until that group gets more comfortable using these treatments, “I fear that all of these advances are going to remain on the shelf,” says Kushner, who consults for Novo Nordisk and led a Phase 3 study of Wegovy.

Affordability is also a huge issue. Wegovy was launched with a monthly price of more than $1,600, and insurance coverage has been spotty. A patchwork of laws dictate access to weight-loss drugs around the country, making them more accessible in some states than others. In Massachusetts, for example, private insurers will pay for obesity drugs, but Stanford says getting Medicaid to cover the drugs for her patients has remained difficult. In Pennsylvania, meanwhile, a bill that would allow the treatments to be covered for state Medicaid recipients has inched closer to passing after languishing for years. And Medicare currently excludes coverage of obesity drugs completely.

Also worth considering: The story about the long-term safety of this new generation of drugs is still being written. Past experience in the weight-loss arena has shown that side effects can emerge after the drugs hit the market. That worry is compounded by the drugs being potentially used in situations where there’s no evidence for their efficacy or safety — namely, in people who aren’t considered medically obese, but would like help shedding pounds. (Elon Musk, for example, recently made headlines when he credited his fitness to fasting and Wegovy, though it’s not clear he actually would qualify for the treatment.)

The demand for the treatments is indisputable. But meeting it — and thus hitting the high end of all those lofty sales forecasts — will require structural changes in how these drugs are prescribed and covered by insurance.