With yesterday’s 14-1 US advisory panel backing Novo Nordisk’s liraglutide looks likely to become the fourth novel drug to get the nod for obesity over the past couple of years, though it would be the first to be injected rather than given orally.
While this might pose less potential for abuse, if Novo wants to make more than a small dent in the potential market for obesity drugs it still has huge barriers to overcome. Post-marketing study requirements and pricing – the drug is already available for diabetes – are two open questions.
It was a major new phase IV programme for Contrave, along with a punitive label, that put a dampener on Orexigen’s party yesterday (Orexigen joins the fight for small advantages, September 11, 2014). Still, Novo bulls will point to Contrave’s approval as evidence that the FDA is no longer scared of approving new obesity drugs.
Moreover, they will point to the US panel’s endorsement of Novo’s current cardiovascular outcomes trial, coded Leader, and of liraglutide’s favourable safety and efficacy. However, the 9,340-patient Leader study only tests liraglutide up to its maximum approved dose in diabetes – 1.8mg; in obesity the drug is to be dosed at 3mg.
Whether the FDA takes a similar view to the panel will become apparent by the October 20 approval action date. Concerns over cardiovascular safety are likely to restrict liraglutide’s use in patients with a history of heart problems, and a post-marketing study to assess cancer risk also seems likely.
The GLP-1 inhibitor class’s known association with pancreatitis did not seem to trouble the panellists, even considering the higher proposed dose of liraglutide.
EvaluatePharma computes sellside consensus 2020 sales from liraglutide in all indications at $4.3bn. Two banks that do split out obesity sales and have up-to-date models – Bernstein and Bank of America – forecast $327m in 2016 and $741m in 2020 respectively.
But how will Novo segment this market? It is clear that the obesity indication will pitch liraglutide, under the Saxenda brand, as a distinct drug from Victoza, the name under which it is sold for diabetes.
Obviously there is a significant overlap, and many type 2 diabetics are obese. Saxenda’s arrival on the market could simply be seen as a green light to raise a patient’s liraglutide dose, presumably at a higher price.
That said, Bryan Garnier analysts expect initial penetration of the market to be slow, given the likelihood of free sampling to gain popularity with doctors. Also, Saxenda use is likely to be curtailed by a requirement that patients who do not lose a certain amount of weight within a certain time come off treatment; a similar constraint has been put on the prescribing of Contrave.
As such, and given the novelty of an injectable drug potentially being prescribed for obesity, estimating Saxenda revenue is little more than guesswork.
|Leader||9,340 type II diabetics||Liraglutide 1.8mg vs placebo, cardiovascular outcomes study||NCT01179048|