Drug Interaction Report

MONITOR: Immunosuppressed patients may have diminished response to diagnostic skin test antigens due to suppression of cell-mediated, delayed-type hypersensitivity. Falsely insignificant or false-negative results may occur in such patients, which may include those who have recently received or are receiving immunosuppressive agents, antilymphocyte globulins, alkylating agents, antimetabolites, radiation, some antirheumatic agents, high dosages of corticosteroids or adrenocorticotropic agents (e.g., greater than or equal to 2 mg/kg/day or 20 mg/day of prednisone or equivalent for 14 consecutive days or more), or long-term topical or inhaled corticosteroids.

MANAGEMENT: Clinicians should be aware of the potential for falsely insignificant or false-negative results when administering diagnostic skin test antigens to patients treated with immunosuppressive agents.

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of umbralisib. When a single oral dose of umbralisib was administered with a high-fat, high-calorie meal (approximately 917 calories; 171 calories from protein, 232 calories from carbohydrate, 502 calories from fat) in healthy subjects, umbralisib peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 115% and 61%, respectively, compared to administration under fasted conditions.

MANAGEMENT: Umbralisib should be administered with food at approximately the same time each day.