A Single and Multiple-Dose Study of MK-8521 in Healthy and Obese Males (MK-8521-002)

This study will evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of MK-8521.

Part 1 primary hypothesis: Administration of single subcutaneous (SC) doses of MK-8521 is sufficiently safe and well- tolerated in healthy participants, based on assessment of clinical and laboratory adverse experiences, to permit continued clinical investigation.

Part 2: Administration of multiple once daily SC doses of MK-8521 is sufficiently safe and well-tolerated in healthy lean and obese participants, based on assessment of clinical and laboratory adverse experiences, to permit continued clinical investigation.

This was a 3 part, randomized, single and multiple ascending-dose trial that evaluated the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of MK-8521 in healthy non-obese male (Part 1-Panels A and B, Panels C, D, and E of Part 2, and Part 3 Panel H) participants between the ages of 18 and 45 years and obese male participants (Part 2, Panel F) 45 to 65 years of age. An optional Panel G in Part 2 per protocol did not occur.

Part 1 was a single rising dose study to assess the safety and pharmacokinetics of single subcutaneous (SC) doses of MK-8521. Two panels of 8 healthy young non-obese male participants were dosed in up to 3 alternating dosing periods of MK-8521 or placebo (in a 6:2 ratio). Participants had a minimum 7 day washout between dosing periods.

Part 2 was a multiple-rising dose study to assess the safety and pharmacokinetics of multiple SC doses of MK-8521. Three panels (C-E) of 8 healthy young non-obese male participants received daily SC doses of MK-8521 or placebo (in a 6:2 ratio) as a titration regimen for 10 consecutive days. One panel (Panel F) of 8 older obese male participants received daily SC doses of MK-8521 or placebo (in a 6:2 ratio) as a titration regimen for 14 consecutive days.

Part 3 was a single dose, 3-period crossover study in 12 healthy lean male participants. Participants were randomized into 6 treatment groups and received a sequence of 3 treatments (MK-8521 at 35μg, 125μg and placebo). All participants in Part 3 received MK-8521 (high dose of 125μg and low dose of 35 μg) and placebo. There was a minimum 7 day washout between each dosing period for each individual participant.

Eligibility Criteria:
Inclusion Criteria:

* Males of either 18 to 45 or 45 to 70 years of age depending on the component of the study
* Body Mass Index between either 18-25 or 30-40 kg/m\^2 depending on the component of the study
* Is in good health
* Is a non-smoker and/or has not used nicotine for at least 3 months

Exclusion Criteria:

* Is mentally or legally incapacitated, has significant emotional problems or has a history of psychiatric disorders in the past 5 years
* Has a history of the following abnormalities or diseases: endocrine, gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal, respiratory, genitourinary, or major neurological.
* History of cancer
* History of significant multiple or severe allergies or has had an anaphylactic reaction or significant intolerability to drugs or food
* Positive for hepatitis B surface antigen, hepatitis C antibodies or human immunodeficiency virus (HIV)
* Had major surgery, donated or lost 1 unit (500 mL) of blood or participated in another study within prior 4 weeks
* Has irritable bowel disease or recurrent nausea, vomiting, diarrhea or abdominal pain
* History of acute or chronic pancreatitis
* Uses 2 weeks prior to trial, or anticipates using during trial, medications, drugs or herbal remedies such as St. John's Wort
* Consumes greater than 3 glasses of alcohol per day
* Consumes greater than 6 servings of caffeinated beverages per day
* Regularly uses illicit drugs or has a history of drug (including alcohol) abuse within prior 3 months
* Has known hypersensitivity to glucagon or any glucagon like peptide 1 (GLP-1) receptor agonist
* Is unwilling/unable to consume standardized meals and/or is on a carbohydrate restricted diet
* Has history of hypersensitivity to pharmacologic insulins