Mounjaro misses for Lilly in Q4, but big surge expected

After referring to the launch of its type 2 diabetes therapy Mounjaro as viral earlier this year, its fourth-quarter sales came as a bit of a disappointment – albeit still setting it up as a future blockbuster.

The dual GLP-1 and GIP agonist brought in just under $280 million in the last three months of 2022 –behind analyst consensus expectations of $39 million – taking its total since it was launched in the US in June to $482 million. Shares in Lilly fell around 4% after the financial update.  

The company said that there had been "intermittent delays" at wholesalers and pharmacies in the delivery of some dose formats of Mounjaro (tirzepatide) and as well as GLP-1 agonist Trulicity (dulaglutide), which played a factor, but noted it has made manufacturing investments to bolster supply of these incretin drugs.

A new facility in North Carolina for the drug is expected to come online sometime later this year, according to chief financial officer Anat Ashkenazi.

She said that another factor was Lilly's decision to introduce a savings programme to limit the cost of the drug to patients not yet covered for the drug to $25 per month – rather than around $1,000.

That included measures to make sure that prescriptions for Mounjaro were only being written for people with type 2 diabetes, and not for people seeking to access the drug for weight loss.

Lilly is running trials of tirzepatide as a treatment for obesity but hasn't yet secured approval of the drug for this use, with a decision by the FDA expected later this year.

Meanwhile, Novo Nordisk's GLP-1 agonist Wegovy (semaglutide) has been approved for obesity, with demand outstripping supply fuelled by media reports about its weight loss properties.

Ashkenazi said Lilly believes that new prescription volumes beginning in late November were affected by the restrictions on off-label use, and that around 40% of prescriptions were fully paid and the remainder via the access programme.

Analysts have predicted that approval in obesity could help sales of Mounjaro rocket to more than $2 billion next year, assuming Lilly's manufacturing can keep up with demand.

She added that around 75% of prescriptions for the new drug were written for diabetes patients new to incretin therapy, with only around 10% switching from Trulicity, which held up pretty well in the quarter – sales came in at $1.94 billion, up 3%.

Overall, Lilly reported sales of $7.3 billion for the fourth quarter, down 9% in part as a result of dwindling sales of its COVID-19 antibodies, which are no longer authorised by the FDA.