This is an open label, 2-period, fixed-sequence study in 15 healthy adult subjects under fed conditions. To evaluate the effect of multiple doses of lansoprazole on the absorption and pharmacokinetics (PK) of a single dose of neratinib in healthy subjects.

This is an open label, 2-period, fixed-sequence study in 15 healthy adult subjects under fed conditions. On Day 1 of Period 1 (Treatment A), a single oral dose of neratinib will be administered followed by PK sampling for 72 hours. In Period 2 (Treatment B), multiple oral doses of lansoprazole will be administered once daily for 7 consecutive days with a single oral dose of neratinib administered on Day 5. PK sampling for neratinib will be taken for 72 hours following neratinib dosing on Day 5. The washout period will be at least 14 days between each neratinib dose.

Inclusion Criteria:

Healthy, adult, men or women, 18 to 55 years of age, inclusive, at screening. Body Mass Index ≥ 18.5 and ≤ 32.0 kg/m2 at screening. Non to moderate smokers (up to 10 cigarettes a day for at least 3 months prior to screening).

Medically healthy with no clinically significant medical history, physical examination, laboratory profiles, vital signs or 12-lead electrocardiograms (ECGs), as deemed by the principal investigator (PI).

Women of childbearing potential: either be sexually inactive (abstinent) for 14 days prior to the first dose and for at least 28 days following the last dose or be using one of the protocol-specific birth control methods.

Exclusion Criteria:

Acute disease state (eg, nausea, vomiting, fever, or diarrhea) within 7 days prior to the first dose of study drug.

History or presence of alcoholism or drug abuse within the past 2 years prior to screening.

History or presence of hypersensitivity or idiosyncratic reaction to the study drugs or related compounds (eg, proton-pump inhibitors [PPIs]).

Women who are pregnant or lactating. Positive results at screening for human immunodeficiency virus, hepatitis B surface antigen, or hepatitis C virus.

Unable to refrain from or anticipates the use of:

• Any drug, including prescription and nonprescription medications, herbal remedies, or vitamin supplements (including proton-pump inhibitors) beginning 14 days prior to the first dose of study drug and throughout the study. Acetaminophen (up to 2 g per 24 hour period) and/or loperamide (up to 6 mg per 24 hours) may be permitted during the study at the direction of the PI.
• Any drugs known to be significant inducers of cytochrome p450 enzymes and/or P glycoprotein, including St. John's Wort, for 28 days prior to the first dose of study drug and throughout the study. Appropriate sources will be consulted by the PI or designee to confirm lack of PK/pharmacodynamics interaction with study drug.