This will be a Phase 1, open-label, nonrandomized, single-dose study in healthy male subjects to evaluate the Absorption, Metabolism, and Excretion of Poziotinib following a single oral dose of [14C]-poziotinib to healthy male subjects.

Potential subjects will be screened to assess their eligibility to enter the study within 28 days prior to the dose administration. Subjects will be admitted into the Clinical Research Unit (CRU) on Day -1. On the morning of Day 1, all subjects will receive a single oral dose of 8 mg (as the hydrochloride salt) containing approximately 100 μCi of [14C]-poziotinib in the fasted state.

Subjects will be confined to the CRU until at least Day 8.

Subjects will be discharged from the CRU on Day 8 if the following criteria are met:

• ≥90% mass balance recovery in combined urine and feces, and
• ≤1% of the total radioactive dose is recovered in combined excreta (urine and feces) in 2 consecutive 24-hour periods in which fecal and urine samples are obtained.

If these criteria are not met by Day 8, subjects will remain in the CRU until all discharge criteria are met up to a maximum of Day 15 in order to continue 24-hour blood, urine, and feces collections, unless otherwise agreed upon by the Sponsor and Investigator.

Key Inclusion Criteria:

• Body mass index between 18.0 and 32.0 kg/m2, inclusive
• In good health at Screening and/or at Check-in
• Subjects must be surgically sterile for at least 90 days, or when sexually active with female partners of childbearing and non-childbearing potential will be required to use a male condom with spermicide from CRU Check-in until 90 days after discharge. Subjects are required to refrain from donation of sperm from CRU Check-in until 90 days after discharge
• Able to comprehend and willing to sign an ICF and to abide by the study restrictions
• History of at least 1 bowel movement per day

Key Exclusion Criteria:

• Stomach or intestinal surgery or resection that would potentially alter absorption and/or excretion of orally administered drugs
• Swallowing difficulties or ongoing diarrhea of any etiology
• Participation in a clinical study involving an investigational drug in the past 30 days 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
• Use or intend to use any prescription medications/products within 14 days prior to Check-in
• Use or intend to use slow-release medications/products considered to still be active within 14 days prior to Check-in
• Exposure to significant diagnostic or therapeutic radiation or current employment in a job requiring radiation exposure monitoring within 12 months prior to Check-in