Effect of Pexidartinib on the Way the Body Processes CYP3A4 and CYP2C9 Substrates (Pharmacokinetics)

Inclusion Criteria:

Is the age of majority in country of residence

Has a diagnosis of:

tenosynovial giant cell tumor (TGCT), which is associated with severe morbidity or functional limitations and for whom surgery is not an option (prior pexidartinib is permitted for TGCT patients unless ineffective or not tolerated and there has been a washout period of at least 4 weeks)
KIT-mutant tumor, including melanoma or gastrointestinal stromal tumor (GIST), for which there is no standard systemic therapy, or
other solid tumors (all comers) for which there is no standard systemic therapy and there is a rationale for use of pexidartinib at the Investigator's discretion
If a female of childbearing potential, had a negative serum pregnancy test within 14 days before enrollment, or within 72 hours before enrollment where required

Is a non-sterile male or female willing to use of one of the protocol-defined highly effective contraception methods:

intra-uterine device (nonhormonal or hormonal)
sexual abstinence (only if this is in line with the patient's current lifestyle)
barrier methods (eg, condom, diaphragm) used in combination with hormonal methods associated with inhibition of ovulation
Is a surgically sterile male or female, or is postmenopausal for at least 1 year, at least 50 years of age, with a follicle-stimulating hormone level > 40 milli-International units per mL (mIU/mL)
Has adequate hematologic, hepatic, and renal function as defined by the protocol
Is able and willing to follow all study procedures
Has provided a signed informed consent

Exclusion Criteria:

Is pregnant or breastfeeding
Is unable to swallow oral medication
Is unable to follow study procedures
Is taking or has taken any medications or therapies outside of protocol-defined parameters

Has any disease or condition that, per protocol or in the opinion of the investigator, might affect:

safety and well-being of the participant or offspring
safety of study staff
analysis of results