FDA approves Lilly’s Onswik (insulin efsitora alfa-gobe), a once-weekly basal insulin for type 2 diabetes, based on Phase 3 QWINT data.
Written By: Mayuri Vaja, PharmD
Reviewed By: Pharmacally Editorial Team
Eli Lilly has received U.S. FDA approval for Onswik (insulin efsitora alfa-gobe), a once-weekly basal insulin for adults with type 2 diabetes. The approval is supported by the Phase 3 QWINT program, which evaluated more than 3,400 participants and showed non-inferior HbA1c reduction with weekly efsitora compared with once-daily insulin glargine U-100 or insulin degludec U-100.
FDA Approval Introduces Once-Weekly Basal Insulin
The FDA approved Onswik as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes. The therapy provides basal insulin coverage across a seven-day dosing interval, reducing administration frequency compared with conventional once-daily basal insulin.
The approval expands Lilly’s diabetes portfolio to include a once-weekly basal insulin alongside its existing insulin, incretin-based, oral and injectable therapies. The Onswik KwikPen is expected to become available in the U.S. in the coming months in two concentrations: 500 units/mL, containing 1,500 units per pen, and 1,000 units/mL, containing 3,000 units per pen.
QWINT Program Supports Non-Inferior HbA1c Reduction
The FDA decision is based on four Phase 3 QWINT studies that evaluated efsitora across different type 2 diabetes treatment settings.
QWINT-1 (NCT05662332) randomized 795 insulin-naive adults to once-weekly efsitora or once-daily insulin glargine for 52 weeks. Efsitora used a fixed-dose escalation approach, with subsequent adjustments based on fasting blood glucose.
QWINT-2 (NCT05362058) enrolled 928 insulin-naive adults and compared weekly efsitora with once-daily insulin degludec over 52 weeks. The study included participants receiving and not receiving GLP-1 receptor agonists.
QWINT-3 (NCT05275400) evaluated 986 adults already receiving basal insulin. Participants received efsitora or insulin degludec, with the primary efficacy assessment conducted at week 26 during a 78-week study period.
QWINT-4 (NCT05462756) enrolled 730 adults with type 2 diabetes who were already receiving basal insulin plus at least two daily mealtime insulin injections. Participants received weekly efsitora or daily insulin glargine alongside insulin lispro for 26 weeks.
Across the QWINT program, efsitora met the primary endpoint of non-inferior HbA1c reduction compared with the daily basal insulin comparators. Lilly also reported an overall safety profile similar to the basal insulins evaluated in the respective trials.
Safety Profile Remains Consistent with Basal Insulin
The safety findings were broadly consistent with established basal insulin therapy. Reported adverse effects include hypoglycemia, allergic reactions, injection-site reactions, lipodystrophy, itching, rash, peripheral edema and weight gain.
Onswik is not indicated for people with type 1 diabetes because of the increased risk of severe hypoglycemia.
The weekly administration schedule could reduce the number of basal insulin injections from approximately 365 per year with once-daily therapy to about 52 with Onswik, representing more than 300 fewer basal insulin injections annually. The clinical benefit of this reduced administration frequency will depend on appropriate patient selection, dose titration and glucose monitoring.
Fourth Global Regulatory Milestone
The U.S. approval adds to Onswik’s expanding international regulatory and health-technology assessment profile. Before the FDA decision, Onswik had received regulatory actions in the European Union, Mexico and Japan, while the UK’s National Institute for Health and Care Excellence (NICE) issued final draft guidance in August 2026 recommending insulin efsitora alfa as an option for adults with type 2 diabetes. The NICE recommendation was subject to MHRA marketing authorization before the therapy could be made available through the NHS.
The international regulatory progress expands the development and commercialization pathway for efsitora across multiple major diabetes markets.
U.S. Launch Will Use Two KwikPen Concentrations
Lilly plans to introduce Onswik in the U.S. through the KwikPen delivery system. The 500 units/mL formulation contains 1,500 units per pen, while the 1,000 units/mL formulation contains 3,000 units per pen.
The availability of two concentrations provides dosing options for adults requiring different basal insulin doses, while the weekly administration schedule distinguishes Onswik from conventional daily basal insulin products.
For Lilly, the FDA approval adds a weekly basal insulin option to an increasingly broad type 2 diabetes portfolio. For clinicians, the QWINT results provide comparative evidence for using efsitora as an alternative to established once-daily basal insulin regimens.
Reference
U.S. Food and Drug Administration (FDA) approves Lilly’s Onswik™ (insulin efsitora alfa-gobe), a once-weekly basal insulin injection treatment for adults living with type 2 diabetes, Eli Lilly, 24 September 2026
A Study of Insulin Efsitora Alfa (LY3209590) Compared to Glargine in Adult Participants With Type 2 Diabetes Who Are Starting Basal Insulin for the First Time (QWINT-1) (QWINT-1), ClinicalTrials.gov ID NCT05662332
A Study of Insulin Efsitora Alfa (LY3209590) Compared to Degludec in Adults With Type 2 Diabetes Who Are Starting Basal Insulin for the First Time (QWINT-2), ClinicalTrials.gov ID NCT05362058
A Study of Insulin Efsitora Alfa (LY3209590) Compared With Insulin Degludec in Participants With Type 2 Diabetes Currently Treated With Basal Insulin, ClinicalTrials.gov ID NCT05275400
A Study of Insulin Efsitora Alfa (LY3209590) as a Weekly Basal Insulin Compared to Insulin Glargine in Adult Participants With Type 2 Diabetes on Multiple Daily Injections (QWINT-4), ClinicalTrials.gov ID NCT05462756
About the Writer
Mayuresh Sunil Salvi (Linkedin) is a PharmD professional and healthcare writer with a strong interest in pharmacovigilance, drug safety, and emerging medical research. He is passionate about exploring new drug discoveries, clinical research, and advances in evidence-based medicine. His interests also include ward rounds, prescription audits, and treatment analysis to support rational pharmacotherapy and improved patient care.