Diabetes Dialogue: Weekly Insulin Efsitora Alfa Gets FDA Approval for Type 2 Diabetes

The diabetes community welcomed its second approved once-weekly insulin on September 24, 2026, as the US Food and Drug Administration (FDA) approval of insulin efsitora alfa-gobe (Onswik) for adults with type 2 diabetes less than 7 months after the approval of insulin icodec (Awiqli).

On a recent episode of Diabetes Dialogue, hosts Diana Isaacs, PharmD, and Natalie Bellini, DNP, FNP-BC, examined the approval, the phase 3 QWINT data behind it, and the practical demands of weekly dosing.

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Across the QWINT program, efsitora met its noninferiority end point for HbA1c reduction against once-daily glargine U-100 or degludec U-100, with reductions of 0.81 to 1.26 percentage points.¹⁻³ In insulin-naive adults in QWINT-1, a fixed-dose regimen lowered the rate of clinically significant or severe hypoglycemia by 43% vs glargine (rate ratio, 0.57; 95% CI, 0.39-0.84).¹ The hosts linked this advantage to a flatter pharmacokinetic profile, free of the end-of-interval waning seen with daily basal analogues.

Dosing departs from familiar basal insulin practice. The label offers a fixed-dose escalation from 100 units weekly through 150, 250, and 400 units at 4-week intervals, or a flexible titration opening with a 3-fold loading dose. For patients switching from daily basal insulin, clinicians multiply the daily dose by 7, then by 3 for the first week only.

With a half-life of about 17 days, efsitora reaches steady state slowly, and omitting the loading dose can leave patients with rising CGM readings for weeks. The hosts urged close adherence to the prescribing information, which reflects titration schemes validated across the QWINT trials. U-500 and U-1000 pens deliver up to 400 units and 800 units per injection, respectively, extending weekly dosing to patients with substantial insulin resistance.

Efsitora relies on an Fc-fusion design to slow renal clearance, distinguishing it from albumin-binding icodec. The label excludes type 1 diabetes, given higher hypoglycemia rates in trials, and flags potential risk in pregnancy and lactation based on animal data. No renal dose adjustment is required, although the hosts advised slower intensification in patients with renal impairment.

Collectively, efsitora gives clinicians a second weekly basal option capable of reducing basal injections from as many as 14 per week to 1. Its uptake will likely hinge on manufacturer-supported education around loading doses, concentrated pen conversions, and coverage, areas where the hosts saw gaps after the icodec launch.

Editors’ Note: Isaacs reports disclosures with Dexcom, Abbott, Lilly, Novo Nordisk, Medtronic, Insulet, and others. Bellini reports disclosures with Abbott Diabetes Care, MannKind, Povention Bio, and others.

REFERENCES:

1. Rosenstock J, Bailey T, Connery L, et al. Weekly fixed-dose insulin efsitora in type 2 diabetes without previous insulin therapy. N Engl J Med. 2025;393(4):325-335. doi:10.1056/NEJMoa2502796
2. Philis-Tsimikas A, Bergenstal RM, Bailey TS, et al. Once-weekly insulin efsitora alfa versus once-daily insulin degludec in adults with type 2 diabetes currently treated with basal insulin (QWINT-3): a phase 3, randomised, non-inferiority trial. Lancet. 2025;405(10497):2279-2289. doi:10.1016/S0140-6736(25)01044-X
3. Blevins T, Dahl D, Pérez Manghi FC, et al. Once-weekly insulin efsitora alfa versus once-daily insulin glargine U100 in adults with type 2 diabetes treated with basal and prandial insulin (QWINT-4): a phase 3, randomised, non-inferiority trial. Lancet. 2025;405(10497):2290-2301. doi:10.1016/S0140-6736(25)01069-4