• Amount of AG-881 Excreted in Urine (Aeu) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Cumulative Aeu (Cum Aeu) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Percentage of AG-881 excreted in Urine and Feces (feu and fef, Respectively) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Cumulative Percentage of AG-881 Excreted in Urine (Cum feu) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Cumulative Percentage of AG-881 Excreted in Feces (Cum fef) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Renal Clearance (CLR) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Renal Clearance Expressed as a Percentage of Total Clearance (CLR/CL) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Percentage of Total Radioactivity in Total Excreta Calculated as Cumulative Percentage of AG-881 Excreted in Urine and Feces (Cum fe) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Area Under the Concentration-time Curve from Time Zero to the Last Measurable Concentration (AUC0-last) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Area Under the Concentration-time Curve from Time Zero to 72 hours (AUC0-72) of AG-881 [ Time Frame: Up to 72 hours ]
• Partial Area Under the Concentration-time Curve from Time Zero to Common Time Point (AUC0-t) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Area Under the Concentration-time Curve from Time Zero to Infinity (AUC0-∞) of AG-881 Calculated Using the Observed Value of the Last Quantifiable Concentration [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Maximum Observed Plasma Concentration (Cmax) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Time to Maximum Observed Plasma Concentration (Tmax) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Apparent Terminal Elimination Half-life (t½) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• AUC0-∞ or AUC0-t of AG-881 in Plasma/AUC0-∞ or AUC0-t of Total Radioactivity in Plasma (AUC Plasma AG-881/Total Radioactivity Ratio) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• AUC0-∞ of Total Radioactivity in Whole Blood to AUC0-∞ of Total Radioactivity in Plasma (AUC Blood/Plasma Ratio), Calculated Using the Observed Value of the Last Quantifiable Concentration [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Total Clearance of AG-881 Following Intravenous (IV) Administration (CL) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Apparent Clearance Following Oral Administration of AG-881 (CL/F) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Volume of Distribution of AG-881 at Steady-state Following IV Administration (Vss) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Apparent Volume of Distribution During the Terminal Phase Following Oral Administration of AG-881 (Vz/F) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Absolute bioavailability (F) for AG-881 Calculated as the Ratio of Dose-normalized AUC0-∞ of Oral/Intravenous Dosing [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Metabolic Profiles of AG-881 in Plasma, Urine, and Feces, When Possible [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Structures of AG-881 Metabolites in Plasma, Urine, and, Where Possible, Feces [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]

• Amount of AG-881 Excreted in Urine (Aeu) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Cumulative Aeu (Cum Aeu) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Percentage of AG-881 excreted in Urine and Feces (feu and fef, Respectively) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Cumulative Percentage of AG-881 Excreted in Urine (Cum feu) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Cumulative Percentage of AG-881 Excreted in Feces (Cum fef) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Renal Clearance (CLR) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Renal Clearance Expressed as a Percentage of Total Clearance (CLR/CL) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Percentage of Total Radioactivity in Total Excreta Calculated as Cumulative Percentage of AG-881 Excreted in Urine and Feces (Cum fe) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Area Under the Concentration-time Curve from Time Zero to the Last Measurable Concentration (AUC0-last) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Area Under the Concentration-time Curve from Time Zero to 72 hours (AUC0-72) of AG-881 [ Time Frame: Up to 72 hours ]
• Partial Area Under the Concentration-time Curve from Time Zero to Common Time Point (AUC0-t) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Area Under the Concentration-time Curve from Time Zero to Infinity (AUC0-∞) of AG-881 Calculated Using the Observed Value of the Last Quantifiable Concentration [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Maximum Observed Plasma Concentration (Cmax) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Time to Maximum Observed Plasma Concentration (Tmax) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Apparent Terminal Elimination Half-life (t½) of AG-881 [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• AUC0-∞ or AUC0-t of AG-881 in Plasma/AUC0-∞ or AUC0-t of Total Radioactivity in Plasma (AUC Plasma AG-881/Total Radioactivity Ratio) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• AUC0-∞ of Total Radioactivity in Whole Blood to AUC0-∞ of Total Radioactivity in Plasma (AUC Blood/Plasma Ratio), Calculated Using the Observed Value of the Last Quantifiable Concentration [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Total Clearance of AG-881 Following Intravenous (IV) Administration (CL) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Apparent Clearance Following Oral Administration of AG-881 (CL/F) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Volume of Distribution of AG-881 at Steady-state Following IV Administration (Vss) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Apparent Volume of Distribution During the Terminal Phase Following Oral Administration of AG-881 (Vz/F) [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Absolute bioavailability (F) for AG-881 Calculated as the Ratio of Dose-normalized AUC0-∞ of Oral/Intravenous Dosing [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Metabolic Profiles of AG-881 in Plasma, Urine, and Feces [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]
• Structures of AG-881 Metabolites in Plasma, Urine, and, Where Possible, Feces [ Time Frame: At multiple time points daily from Day -1 to Day 14; then at 24-hour intervals until discharge (up to 29 days); then weekly up to approximately 8 weeks ]

• Percentage of Participants with Adverse Events (AEs), Graded by Severity [ Time Frame: Up to approximately 12 weeks ]
  AEs will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE; Version 4.03)
• Percentage of Participants with Laboratory Abnormalities [ Time Frame: Up to approximately 8 weeks ]
  Laboratory assessments will include parameters assessing clinical chemistry, hematology, coagulation, urinalysis, and serology.
• Percentage of Participants with Abnormalities in 12-lead Electrocardiogram (ECG) [ Time Frame: Up to approximately 8 weeks ]
• Percentage of Participants with Abnormalities in Vital Signs Measurements [ Time Frame: Up to approximately 8 weeks ]
  Vital signs will include supine blood pressure, supine pulse rate, and oral body temperature.
• Percentage of Participants with Abnormalities in Physical Examinations [ Time Frame: Up to approximately 8 weeks ]

• Drug: AG-881
  Single oral dose of approximately 50 mg AG-881 (free form) containing approximately 100 microcuries (μCi) of [14C]AG-881.
• Drug: [13C315N3]AG-881
  Single IV microdose of approximately 100 μg.

Inclusion Criteria:

• Able to comprehend and willing to sign an informed consent form (ICF) and to abide by the study restrictions, including confinement, as well as adhere to all study procedures;
• Males of any race, between 18 and 55 years of age, inclusive;
• Body mass index between 18.0 and 32.0 kilograms per meter squared (kg/m^2), inclusive, and a total body weight between 50 and 100 kg, inclusive;
• In good health, determined by no clinically significant findings from medical history, physical examination, 12-lead electrocardiogram (ECG), vital sign measurements, and clinical laboratory evaluations (congenital non-hemolytic hyperbilirubinemia [e.g., suspicion of Gilbert's syndrome based on total and direct bilirubin] is not acceptable) at Screening and/or Check-in (Day -1), as assessed by the Investigator (or designee);
• Alanine aminotransferase (ALT; at or within normal limits [WNL]), aspartate aminotransferase (AST; at or within normal limits), alkaline phosphatase (ALP; <1.5 × upper limit of normal [ULN]), bilirubin (at or below WNL). One repeat assessment allowed at each time point;
• Male participants will agree to use contraception;
• Agrees to abstain from any alcohol consumption, starting 48 hours before Check-in (Day -1) and continuing until Discharge;
• History of a minimum of one bowel movement per day;
• Adequate peripheral venous access.

Exclusion Criteria:

• Significant history or clinical manifestation of any metabolic, allergic, dermatological, hepatic, renal, hematological, pulmonary, cardiovascular, gastrointestinal, neurological, respiratory, endocrine, or psychiatric disorder, as determined by the Investigator (or designee);
• History of significant hypersensitivity, intolerance, or allergy to any drug compound, food, or other substance, unless approved by the Investigator (or designee);
• History of stomach or intestinal surgery or resection that would potentially alter absorption and/or excretion of orally administered drugs (uncomplicated appendectomy and hernia repair will be allowed);
• Has undergone any major surgical procedure within the 3 months prior to Screening;
• History of alcoholism or drug/chemical abuse within 2 years prior to Check-in (Day -1);
• History of severe and/or uncontrolled ventricular arrhythmias or other factors that increase the risk of long QT syndrome, or use, or intend to use, medications that are known to prolong the QT interval or history of unexplained syncopal events or familial history of unexplained death in young person;
• After at least 5 minutes of rest in the supine position at Screening, has a systolic blood pressure reading of ≥140 millimeters of mercury (mmHg) OR a diastolic blood pressure reading of ≥90 mmHg;
• A heart rate-corrected QT interval by Fridericia's (QTcF) method of ≥450 milliseconds (ms);
• Alcohol consumption of >21 units per week. One unit of alcohol equals 12 ounces (360 millimeters [mL]) of beer, 1½ oz (45 mL) of liquor, or 5 oz (150 mL) of wine;
• Positive urine drug screen at Screening or positive alcohol breath test result or positive urine drug screen at Check-in (Day -1);
• Positive hepatitis panel and/or positive human immunodeficiency virus test;
• Participation in a clinical study involving administration of an investigational drug (new chemical entity) in the past 30 days or 5 half-lives (whichever is longer), prior to dosing;
• Use or intend to use any medications/products known to alter drug absorption, metabolism, or elimination processes, including St. John's wort, within 30 days prior to Check-in (Day -1), unless deemed acceptable by the Investigator (or designee);
• Use or intend to use any prescription medications/products within 14 days prior to Check-in (Day -1), unless deemed acceptable by the Investigator (or designee);
• Use or intend to use slow-release medications/products considered to still be active within 30 days prior to Check-in (Day -1), unless deemed acceptable by the Investigator (or designee);
• Use or intend to use any nonprescription medications/products including vitamins, minerals, and phytotherapeutic/herbal/plant-derived preparations within 7 days prior to Check-in (Day -1), unless deemed acceptable by the Investigator (or designee);
• Use of tobacco- or nicotine-containing products within 3 months prior to Check-in (Day -1), or positive cotinine at Screening or Check-in (Day -1);
• Receipt of blood products within 2 months prior to Check-in (Day -1);
• Donation of blood from 3 months prior to Screening, plasma from 2 weeks prior to Screening, or platelets from 6 weeks prior to Screening;
• Have previously completed or withdrawn from this study or any other study investigating AG-881, and have previously received the investigational product;
• Participants with exposure to significant diagnostic or therapeutic radiation (e.g., serial X-ray, computed tomography scan, barium meal) or current employment in a job requiring radiation exposure monitoring within 12 months prior to Check-in (Day -1);
• Participants who have participated in a radiolabeled drug study where exposures are known to the Investigator within the previous 4 months prior to admission to the clinic for this study or participated in a radiolabeled drug study where exposures are not known to the Investigator within the previous 6 months prior to admission to the clinic for this study. The total 12-month exposure from this study and a maximum of 2 other previous radiolabeled studies within 4 to 12 months prior to this study will be within the Code of Federal Regulations (CFR) recommended levels considered safe, per United States (US) Title 21 CFR 361.1: less than 5,000 millirems (mrem) whole-body annual exposure with consideration given to the half-lives of the previous radiolabeled study drugs received;
• Is an employee of, or an immediate family member of an employee of, the study site or the Sponsor;
• Participants who, in the opinion of the Investigator (or designee), should not be part of this study.