A once-weekly form of insulin being developed by Eli Lilly proved just as effective at controlling blood sugar in adults with diabetes as commonly used daily injections, according to results from two clinical trials that were released by the drugmaker Thursday.

Lilly is betting that its experimental drug, dubbed insulin efsitora alfa, could provide a longer-lasting and more convenient option than daily treatment for managing diabetes. 

“With efsitora, we have an opportunity to provide an innovative once-weekly solution that safely achieves and maintains A1C control, reduces treatment burden of traditional daily injections and potentially improves adherence for people with diabetes,” said Jeff Emmick, a senior vice president of product development for Lilly, in a statement on the trial results. 

Along with rival Novo Nordisk, Lilly is one of the dominant makers of diabetes medicines, selling a range of products that includes several insulins. Recently, more attention has been paid to the companies’ so-called GLP-1 drugs, which help treat diabetes by boosting the body’s secretion of insulin but have also proved powerfully effective at reducing weight. 

While those drugs have become overnight blockbusters, inflating Lilly’s and Novo’s market value by hundreds of billions of dollars, both companies are still investing in developing new insulin products. Efsitora is Lilly’s answer to Novo’s insulin icodec, which is also administered as a once-weekly injection and was recently recommended for approval in Europe. Food and Drug Administration advisers are meeting next week to discuss Novo’s application for approval in the U.S. 

Lilly is running five Phase 3 trials of efsitora, two of which read out results Thursday. The first, dubbed QWINT-2, tested efsitora versus once-daily insulin degludec for one year among insulin-naive adults with Type 2 diabetes. At week 52, efsitora treatment had reduced A1C levels — a measure of blood sugar — by 1.34%, versus 1.26% for insulin degludec. In both groups, A1C levels were below the 7% level that is commonly the goal of treatment.

Efsitora was similarly “non-inferior” to insulin degludec regardless of whether study participants were taking a GLP-1 agonist, Lilly said.

The second, QWINT-4, studied efsitora in a sicker group of diabetes who had previously been treated with basal insulin and at least two injections per day of mealtime insulin. After 26 weeks, both efsitora and the daily comparator, insulin glargine, reduced A1C levels by 1.07%.

Lilly described efsitora as “safe and well-tolerated” in both studies, but didn’t break out specific side effects in Thursday’s press release excepting severe or clinically significant hypoglycemic events. In QWINT-2, investigators reported 0.58 hypoglycemic events per patient-year of exposure among those given efsitora, compared to 0.45 among those on insulin degludec. The respective rates were 6.6 and 5.9 for efsitora and insulin glargine in QWINT-4.

Lilly expects results from studies QWINT-1, QWINT-3 and QWINT-5 later this year. Full data from QWINT-2 and QWINT-4 will be presented at the annual meeting of the European Association for the Study of Diabetes, the company said.

Both Lilly and Novo, as well as one-time rival Sanofi, have been in the spotlight for their pricing of currently marketed insulin products. Last year, in response to sustained political pressure, all three lowered the list prices of their on-market insulins. The move coincided with recent changes in law that eliminated a cap on rebates paid into Medicaid, as well as placed a $35 monthly cap on out-of-pocket costs for insulin in Medicare. 

The companies had been paying substantial rebates to insurers for their insulin products, meaning that net prices of the drugs were substantially lower than their list price.