This drug-drug interaction (DDI) study had been designed to investigate the effect of a moderate CYP 3A inducer efavirenz on the pharmacokinetics of maleate pyrotinib in Chinese healthy volunteers.

Inclusion Criteria:

• Sign the informed consent before the trial, and fully understand the trial content, process and possible adverse reactions;
• Ability to complete the study as required by the protocol;
• Healthy male or female subjects aged 18 to 45 (including 18 and 45) at the date of signing the informed consent;
• Body weight ≥ 50 kg for male and female, and body mass index (BMI) within the range of 19 ~ 26 kg /m2 (including 19 and 26);
• In females, documented surgical sterilization, postmenopausal status for at least 1 year (follicle stimulating hormone [FSH] > 40 mIU/mL serum at Screening), or agreement to use an approved form of contraception
• In males, agreement to avoid sperm donation for 6 months days after the dose of pyrotinib
• Liver function test results must be below the upper limit of normal.
• Participants must agree to refrain from donation of whole blood and other blood products from 90 days prior to Screening,

Exclusion Criteria:

• Loss of more than 400 mL blood during the 3 months before the trial (eg, as a blood donor)
• Allergic constitution;
• History of drug use, or drug abuse screening positive;
• Alcoholic or often drinkers;
• A smoker with 5 cigarettes per day for more than 90 days;
• Positive serology for hepatitis B surface antigen (HBsAg) and HCV (healthy participants), anti-treponema pallidum virus (TP), or antihuman immunodeficiency virus (HIV) Type 1 and Type 2 (all subjects)
• Use of any drugs or substances known to be inhibitors or inducers of CYP3A4/5 within 90 days from the first dose or 5 half-lives, if known, of the drugs or substances, whichever is greater, prior to pyrotinib administration and during the study.
• A clear medical history of important primary organ diseases such as nervous system, cardiovascular system, urinary system, digestive system, respiratory system, metabolism and musculoskeletal system.
• Abnormal clinical laboratory tests and clinical significance judged by the investigator or other clinical findings showing the following diseases, including but not limited to gastrointestinal tract, kidney, liver, nerve, blood, endocrine, tumor, lung, immune, mental or cardiovascular and cerebrovascular diseases.