Summary: In this 13-week single-arm switch study of 49 US adults with type 1 diabetes, replacing prior usual care with inhaled technosphere insulin plus insulin degludec met its prespecified noninferiority margin for daytime time-in-range against each participant’s own baseline. Daytime TIR rose modestly from 50% to 55% (mean change 5.1%, 95% CI 0.3 to 9.8) and HbA1c fell 0.23%, with benefit concentrated in prior injection users and no gain in prior automated-insulin-delivery users.
PICO Summary
| Element | Detail |
|---|---|
| Population | 49 adults with type 1 diabetes who had completed a 17-week usual-care control period (41% on automated insulin delivery, 49% on multiple daily injections plus CGM, rest on other pumps); single-arm extension of a randomized trial, United States. |
| Intervention | Switch to inhaled technosphere insulin (Afrezza) for mealtime dosing plus once-daily insulin degludec as basal, for 13 weeks (n=49). Initial inhaled dose set at roughly twice the prior rapid-acting analog dose on a bioequivalence basis. |
| Comparison | Within-subject comparison against each participant’s own preceding 17-week baseline regimen. No concurrent parallel control arm; this is a single-arm design. |
| Outcome | Daytime TIR (70 to 180 mg/dL) rose from 50% to 55% (mean change 5.1%, 95% CI 0.3 to 9.8; noninferiority p<0.001, superiority p=0.04). HbA1c change -0.23% (95% CI -0.42 to -0.04; noninferiority p<0.001, superiority p=0.02). Reaching HbA1c <7.0% rose from 14% to 31% (p=0.02). Overnight TIR fell 15.6% in prior AID users but rose 2.0% in prior injection/sensor-augmented-pump users. Time <54 mg/dL was unchanged (0.5% to 0.7%; change 0.2%, 95% CI -0.1 to 0.5). 40% wished to continue inhaled insulin. No ARR or NNT reported. |
Inhaled Insulin in Type 1 Diabetes
Single-arm switch · type 1 diabetes · 13 weeks
Switching to inhaled mealtime insulin met noninferiority for daytime time-in-range against patients' own baseline, but the gain was small and absent in those leaving automated insulin delivery. A single-arm signal, not proof of superiority.
Expert Commentary
This study should be read as a feasibility and tolerability signal, not as proof that inhaled insulin outperforms current therapy. The design is single-arm: outcomes were measured against each participant’s own baseline rather than a concurrent control group, so the reported noninferiority and modest superiority describe change within a small switching cohort, not a head-to-head advantage. The headline effect was small, with daytime time-in-range improving five percentage points and HbA1c falling under a quarter of a percent, and the most striking finding was heterogeneity: people coming off automated insulin delivery lost meaningful overnight time-in-range, whereas those coming off injections gained. The principal limitation is therefore the absence of randomized concurrent control combined with a sample of just 49 participants, which leaves regression to the mean, expectation effects, and selection unaddressed. Can I use this with my patients? Cautiously, and only for a specific person: a motivated adult on multiple daily injections who wants to avoid a pump and prefers inhaled mealtime dosing, with close supervision through the doubled starting dose and a clear plan to monitor overnight control. It is not yet a reason to move anyone off well-functioning automated delivery. Readers should note the design is open-label and that inhaled insulin carries commercial backing, so independent randomized confirmation is needed before broader adoption.
References
Beck RW, Bailey RJ, Akturk HK, Rizvi S, Kudva Y, Blevins T, et al. A 13-Week Single-Arm Evaluation of Inhaled Technosphere Insulin Plus Insulin Degludec for Adults with Type 1 Diabetes. Diabetes Technol Ther. 2025;27(3):161-169. doi:10.1089/dia.2024.0581