Christmas has come early for Eli Lilly this year, courtesy of a fresh FDA approval for the Indianapolis drugmaker’s obesity star Zepbound.

With the FDA’s green light on Friday, Lilly’s dual GIP/GLP-1 blockbuster Zepbound has become the first prescription medicine cleared to treat adults with moderate to severe obstructive sleep apnea (OSA) and obesity.

The nod marks the second indication for Zepbound after the inaugural obesity approval it scored in November 2023. The molecule underpinning the drug, tirzepatide, is also approved at lower doses for Type 2 diabetes under the brand name Mounjaro.

Aside from obesity and sleep apnea, Lilly is also testing its tirzepatide franchise in other cardiometabolic conditions such as heart failure, prediabetes and metabolic dysfunction-associated steatohepatitis (MASH).

For Zepbound specifically, the FDA based its latest approval decision on Lilly’s phase 3 SURMOUNT-OSA trials. The trials assessed the injection at 10-mg and 15-mg doses in patients with OSA and obesity over the course of a year, enrolling patients who were on positive airway pressure (PAP) therapy and those who were not.

In the pair of studies, Zepbound achieved a mean reduction of up to 62.8% on the apnea-hypopnea index, which measures OSA severity by tracking sleep-related breathing issues per hour of rest, Lilly said in a June data drop. Those results translated to about 30 fewer blocks or restrictions of a patient’s airflow per hour of sleep versus placebo, Lilly explained at the time.

In its approval announcement, Lilly noted that Zepbound alone helped patients lose an average of 45 pounds, or 18% of their body weight, in the studies. Patients who received both the Lilly drug and PAP therapy lost an average of 50 pounds, or 20% of their body weight, the company said.

While the most common side effects for patients on Zepbound are gastrointestinal in nature, such as nausea, diarrhea, vomiting and indigestion, the drug’s OSA nod does include a warning about the potential for the GIP/GLP-1 agonist to cause tumors in the thyroid, including thyroid cancer.

Lilly is advising patients to watch for possible symptoms of the severe side effect, including lumps or swelling in the neck, hoarseness, trouble swallowing or shortness of breath.

OSA is a sleep-related breathing disorder characterized by complete or partial collapses of the upper airway during sleep. This can cause pauses in breathing, known as apnea, or shallow breathing (hypoapnea), as well as a potential decrease in oxygen saturation.

The most common hallmark of OSA is snoring, though the condition, which Lilly says is “easily overlooked,” can also lead to fatigue, excessive daytime sleepiness and disrupted sleep.

Zepbound’s sleep apnea nod caps off a banner year for the tirzepatide franchise, which has been key to Lilly’s growth and expansion prospects in recent months.

In its bread-and-butter weight loss indication, Zepbound recently bested its Novo Nordisk rival Wegovy by 47% in the head-to-head SURMOUNT-5 study. Specifically, patients taking Zepbound lost an average of 20.2% of their weight after 72 weeks compared to an average weight loss of 13.7% among participants on Wegovy.

Prior to that, Lilly in November unveiled impressive results from the three-year SURMOUNT-1 trial showing that tirzepatide curbed the risk of disease progression to diabetes by 94% versus placebo in adult prediabetes patients who are obese or overweight.

As for other potential indications on the horizon for Lilly’s metabolic blockbuster, the company in June unwrapped detailed results showing the potential for three separate doses of tirzepatide to help patients with MASH, the fatty liver disease previously known as NASH.

In the midstage SYNERGY-NASH trial, 54.9% of patients on tirzepatide 5 mg, 51.3% of patients on tirzepatide 10 mg and 51% of patients on tirzepatide 15 mg saw their fibrosis decrease by at least one stage without their MASH worsening.

That compared with just 29.7% of MASH patients in the placebo group who saw their fibrosis improve.