- Eli Lilly’s experimental diabetes injection tirzepatide outperformed Novo Nordisk’s drug Ozempic in a phase 3 study, showing greater reductions in blood sugar and weight loss, the company reported Thursday. The data could help Lilly’s shot find acceptance, should it be approved.
- However, study participants taking tirzepatide reported gastrointestinal side effects slightly more common than those taking Ozempic, and more likely to discontinue treatment, although rates were low. Doctors may also want to wait for long-term cardiovascular results from a tirzepatid study due to be read aloud in 2024.
- Lilly and Novo, longstanding rivals in diabetes drug manufacturing, have competing glucose-lowering drugs known as GLP-1 agonists. Lilly’s once-weekly Trulicity has become a blockbuster drug with sales of $ 5.1 billion last year, and tirzepatid could reinvigorate the market if approved.
Tirzepatid increases the production of two hormones, which in turn help increase insulin production after meals. By increasing GIP levels along with GLP-1, Lilly said, the treatment could lower glucose in more than just targeting GLP-1 alone.
This hypothesis appears to have been confirmed by the new data from Lilly’s study called SURPASS-2.
After 40 weeks, three different once weekly doses of tirzepatide added to metformin lowered blood sugar significantly more than Ozempic and metformin, which met the main objective of the study. The 15-milligram dose of tirzepatide lowered blood sugar by an average of 8.3% by 2.5 percentage points, while the 10-milligram dose lowered the values by 2.4 percentage points. In comparison, treatment with Ozempic lowered blood sugar by 1.9 percentage points.
Tirzepatid was also judged by researchers to be superior on secondary endpoints, including weight loss and the proportion of participants who achieved blood sugar levels of 7% or less, a goal in diabetes management. At the lowest dose tested – 5 milligrams – 88% of participants hit 7% blood sugar levels, compared to 81% of Ozempic patients.
More Tirzepatid volunteer students achieved values of 5.7% or less, which were also observed in non-diabetics.
Ozempic appeared to have fewer side effects, however. Approximately 5% of people who received low-dose tirzepatide stopped treatment due to adverse events, and increased to almost 8% of those who received the highest dose. In comparison, less than 4% of people given Ozempic in the study stopped taking the drug.
The most common side effects were nausea, vomiting, and diarrhea.
SURPASS-2 is one of several Phase 3 studies comparing tirzepatide with placebo and other medicines such as insulin. One of the most important, however, is a cardiovascular outcomes study that is expected to deliver results by 2024. To be widespread, tirzepatide must likely prove on par with Trulicity when it comes to reducing cardiac complications or death from diabetes with heart disease. Trulicity reduced these risks by 12% compared to placebo.
Until these data report, doctors may be reluctant to prescribe tirzepatide to explain its new mechanism of action, Mizuho Securities analyst Vamil Divan wrote in a March 4 notice to customers. This could give Novo time to build market share for Ozempic and its newer GLP-1, Rybelsus, the first oral drug in its class.
In addition, the Danish pharmaceutical industry has asked the FDA to approve a 2 milligram dose of Ozempic, which could improve the drug’s competitive profile versus tirzepatide.
For Lilly, the success of Tirzepatid is critical to the long-term strength of its diabetes business. Trulicity is the Indiana-based company’s top seller but will lose patent protection in 2027.