Novo Nordisk (NYSE:NVO) attempt to reclaim the initiative in the obesity drug race has backfired, after its experimental next-generation treatment failed to prove it was as effective as a rival therapy from Eli Lilly.
The Danish drugmaker's shares were off 14% ahead of the bell in the US (it fell as much as 15% in Europe), after it disclosed that CagriSema did not meet its primary objective of demonstrating non-inferiority to Lilly's tirzepatide in terms of weight loss over 84 weeks.
Patients on a 2.4mg dose of CagriSema lost an average of 23% of their body weight, against 25.5% for those on a 15mg dose of tirzepatide. Lilly's stock rose around 3.5% in premarket trading.
The result is a significant setback for a company already under pressure. Novo warned earlier this month that sales and profit growth could slow by 5% to 13%, as competition stiffens, US prices fall and some of its key products lose exclusivity in certain markets.
Tirzepatide, the active ingredient in Lilly's Mounjaro and Zepbound treatments, has recently overtaken Novo's semaglutide brands Ozempic and Wegovy in US prescription volumes.
CagriSema combines semaglutide with cagrilintide, a pancreatic hormone that influences appetite. Novo's chief scientific officer Martin Holst Lange insisted the drug could still become the first GLP-1 and amylin combination therapy for obesity, and argued that cagrilintide adds meaningful additional weight loss on top of existing treatments. The company said it plans further trials, including those testing higher-dose combinations.
That may yet prove true. But for now, Novo's story has shifted from one of almost unstoppable momentum to something more complicated: a company defending its lead in a market it once appeared to have locked up.