Inclusion Criteria: 

• Ability to provide informed consent for study participation.
• Clinical diagnosis of T1D (per the Investigator).
• Treatment with insulin for at least 6 months prior to the collection of the baseline continuous glucose monitoring (CGM) data.
• Same treatment regimen (MDI, an AID system, or an insulin pump without automation) for the 3 months prior to screening:
  • Current (at time of screening) rapid-acting insulin analog (RAA) in use for at least 4 weeks;
  • If AID system used, automated insulin delivery must be active > 85% of the time in the 4 weeks prior to screening;
  • If MDI used, participant must be using a long-acting basal insulin plus injecting a RAA bolus for meals, per Investigator.
• Total daily insulin dose 20 to 100 units.
• Age ≥ 18 years.
• HbA1c < 11.0%:
  • Eligibility assessment based on point-of-care or local lab value and not baseline central lab value;
  • The cohort will be limited to no more than ~ 20% having a central lab HbA1c value <7.0%.
• Participant uses real-time CGM (any type of real-time CGM) on a regular basis (at least 70% of the time in the 4 weeks prior to screening):
  • Personal CGM data will be reviewed at the site but not uploaded to the study database;
  • A potential participant who is not using CGM could start CGM as part of usual care and be assessed for eligibility after 4 weeks of CGM use.
• No use of inhaled insulin in the 3 months prior to screening.
• If female of childbearing potential, willing and able to have pregnancy testing.
• Investigator believes that the participant can safely use the study treatment and will follow the protocol No medical, psychiatric, or other conditions, or medications being taken that in the Investigator’s judgement would be a safety concern for participation in the study:
  • This includes considering the potential impact of medical conditions known to be present including cardiovascular, liver, kidney disease, thyroid disease, adrenal disease, malignancies, vision difficulties, active proliferative retinopathy, and other medical conditions; psychiatric conditions including eating disorders; drug or alcohol abuse.

Exclusion Criteria:

• History of recent blood transfusions (within previous 3 months prior to randomization), hemoglobinopathies (sickle cell trait is not an exclusion), or any other medical conditions expected to significantly affect HbA1c measurement.
• Recent history of asthma (defined as using any medications to treat asthma within the last year), chronic obstructive pulmonary disease (COPD), or any other clinically important pulmonary disease (e.g., cystic fibrosis or bronchopulmonary dysplasia), or significant congenital or acquired cardiopulmonary disease.
• Exposure to any investigational product(s), including drugs or devices, in the 90 days prior to the start of screening:
  • Devices that are no longer investigational are acceptable.
• Any disease other than diabetes or current use (or anticipated use during the study) of any medication that, in the judgment of the Investigator, may impact glucose metabolism
• Current or anticipated acute uses of oral, inhaled or injectable glucocorticoids during the time period of the trial (topical glucocorticoid use is acceptable).
• Use of a non-insulin glucose-lowering medication within 3 months prior to signing informed consent.
• Smoking (includes cigarettes, cigars, pipes, marijuana, and vaping devices) within 3 months prior to screening.
• Pregnant or lactating, planning to become pregnant during the study, or is a woman of childbearing potential and not on acceptable form of birth control (acceptable includes abstinence, condoms, oral/injectable contraceptives, IUD, or implant); childbearing potential means that menstruation has started, and the participant is not surgically sterile or greater than 12 months post-menopausal).
• No known stage 4/5 renal failure or on dialysis.
• Taking Hydroxyurea medication.
• An event of severe hypoglycemia, as judged by the Investigator, within the last 90 days prior to screening.
• An episode of diabetic ketoacidosis (DKA) diagnosed at a health care facility or severe hypoglycemia event within the 90 days prior to screening.
• Employed by, or having immediate family members employed by MannKind, Corporation, or having a direct supervisor at place of employment who is also directly involved in conducting the clinical trial (as a study Investigator, coordinator, etc.); or having a first-degree relative who is directly involved in conducting the clinical trial.
• Have a history or current diagnosis of lung cancer.

Eligibility last updated 9/18/23. Questions regarding updates should be directed to the study team contact.