A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of MK-1293 Compared With a Basal Insulin in Participants With Type 1 Diabetes (MK-1293-005)

Inclusion Criteria:

- Has type 1 diabetes mellitus diagnosed at least 12 months before screening

- Subject to investigator discretion, is on a stable dose of insulin for at least 2
weeks before screening

- Has a total daily insulin dose <=1.2 units/kg

- Has a screening hemoglobin A1c <9.5%

- Has a body mass index >18.0 and <=30.0 kg/m^2

- Has a weight >=50 kg

- Female participant of reproductive potential has a serum beta-human chorionic
gonadotropin level consistent with the nongravid state and agrees to use (and/or have
her partner use) 2 acceptable methods of birth control until 2 weeks after the last
dose of study drug

- Postmenopausal female participant is without menses for >=1 year

- Surgically sterile female participant status is post hysterectomy, oophorectomy, or
tubal ligation

- Has not used nicotine or nicotine-containing products for at least 3 months before
study start or smokes less than 10 cigarettes per day and is willing to abstain
during the trial

Exclusion Criteria:

- Has a history of clinically significant gastrointestinal, cardiovascular,
hematological, hepatic, immunological, renal, respiratory, genitourinary, or major
neurological abnormalities or disease

- Has a history of clinically significant endocrine abnormalities or diseases except
type 1 diabetes mellitus

- Has had any severe hypoglycemic episodes associated with hypoglycemic seizures,
comas, or unconsciousness within the past 3 months

- Has a history of diabetic ketoacidosis within the past 6 months

- Has a history of significant multiple or severe allergies, anaphylactic reaction, or
significant intolerability to drugs or food

- Has a history of hypersensitivity to pharmacologic insulins

- Is positive for hepatitis B surface antigen, hepatitis C, or HIV

- Has had major surgery or donated or lost 1 unit of blood within 4 weeks before
screening

- Unable to refrain from use of any medication or herbal remedy from 2 weeks prior to
the first dose of study drug to until the posttrial visit. Some medications are
permitted and may be discussed with the investigators

- Vaccination within 12 weeks of start of study participation

- Consumes >3 glasses of alcoholic beverages per day. Participants consuming 4 glasses
of alcoholic beverages may be enrolled at the discretion of the investigator.

- Consumes >6 servings of caffeinated beverages per day

- Is a regular user of any illicit drugs or has a history of drug abuse (including
alcohol) within approximately 1 year

- Is on a carbohydrate-restricted diet (<100 grams carbohydrate per day); participants
who are on a carbohydrate-restricted diet may be included if they agree to a diet
consisting of >=100 grams of carbohydrate daily throughout the study

- Has a personal or family history of hypercoagulability or thromboembolic disease

- Has used systemic glucocorticoids within 3 months of screening or anticipates
treatment with systemic glucocorticoids during study participation.