Study to Investigate the Effect of Rifampin and Itraconazole on the Action of Pamiparib in Participants With Cancer

Key Inclusion Criteria:

• Age ≥ 18 years
• Histologically or cytologically confirmed advanced or metastatic solid tumors that are refractory or resistant to standard therapy or for which no suitable effective standard therapy exists.
• Disease that is evaluable per RECIST Version 1.1 or Prostate Cancer Working Group-3 (PCWG-3)
• Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1
• Life expectancy ≥ 12 weeks
• Adequate hematologic and end-organ function

Key Exclusion Criteria:

• History of hypersensitivity to rifampin, any rifamycin or any of the components of the rifampin capsule (Part A).
• History of hypersensitivity to itraconazole or any of the components of the itraconazole capsule (Part B).
• Prior treatment with a poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitor at therapeutic doses is allowed, provided that such treatment was not the most recent therapy (PARP inhibitor must have been discontinued ≥ 3 months prior to the first dose of pamiparib):

• Participants who experienced prior severe toxicity to PARP inhibitors that in the opinion of the investigator precludes further treatment with PARP inhibitors should be excluded
• Diagnosis of Myelodysplastic syndrome (MDS)
• Active infection requiring systemic treatment
• Any of the following cardiovascular criteria:

• Cardiac chest pain, defined as moderate pain that limits instrumental activities of daily living, ≤ 28 days before Day 1 of pamiparib administration
• Symptomatic pulmonary embolism ≤ 28 days before Day 1 of pamiparib administration
• Any history of acute myocardial infarction ≤ 6 months before Day 1 of pamiparib administration
• Any history of heart failure meeting New York Heart Association Classification III or IV ≤ 6 months before Day 1 of pamiparib

• Participants with congestive heart failure or history of heart failure should be excluded from Part B (itraconazole)
• Any event of ventricular arrhythmia ≥ Grade 2 in severity ≤ 6 months before Day 1 of pamiparib administration
• Any history of cerebral vascular accident ≤ 6 months before Day 1 of pamiparib administration
• Previous complete gastric resection or lap-band surgery, chronic diarrhea, active inflammatory gastrointestinal disease, known diverticular disease or any other disease-causing malabsorption syndrome

• Gastroesophageal reflux disease under treatment with proton pump inhibitors is allowed
• Active bleeding disorder, including gastrointestinal bleeding, as evidenced by hematemesis, significant hemoptysis, or melena ≤ 6 months before Day 1 of pamiparib administration
• Use or anticipated need for food or drugs known to be strong or moderate CYP3A inhibitors or strong CYP3A inducers ≤ 14 days (or ≤ 5 half-lives if half-life is known) prior to Day 1 of pamiparib administration
• Known history of intolerance to the excipients of the pamiparib capsule
• Have known hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.