Drug Interaction Report

MONITOR: The concomitant use of myelosuppressive, immunosuppressive, or cytotoxic agents may potentiate and/or prolong the bone marrow toxicity associated with niraparib. Thrombocytopenia, anemia, neutropenia, and/or pancytopenia have all been observed with niraparib during clinical trials, especially during the initial phase of treatment. Additionally, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) have been reported in patients treated with niraparib. Some cases were fatal, and the duration of therapy with niraparib in patients who developed MDS/AML varied from less than 1 month to approximately 6 years. All patients had previous chemotherapy with platinum agents and/or other DNA-damaging agents, including radiotherapy.

MANAGEMENT: Caution is advised if niraparib is prescribed with other myelosuppressive, immunosuppressive, or cytotoxic agents. Do not start niraparib until patients have recovered from hematological toxicity caused by previous chemotherapy (Grade 1 or less). Complete blood counts should be monitored as recommended in the product labeling and any relevant institutional protocols. Recommendations for dose adjustments as well as treatment interruption and discontinuation can also be found in the product labeling for serious hematologic adverse reactions. If hematological toxicities have not resolved within 4 weeks after interruption, discontinue niraparib and refer the patient to a hematologist for further investigations, including bone marrow analysis and blood sample for cytogenetics. If MDS/AML is confirmed, discontinue niraparib. Patients should be advised to contact their physician if they experience pale skin, weakness, fatigue, fever, weight loss, infections, shortness of breath, unusual bleeding or bruising, or blood in urine or stool.

ADJUST DOSING INTERVAL: Food increases the systemic exposure of givinostat. An open-label, randomized, crossover, single dose food effect study conducted in 12 healthy males used givinostat liquid filled capsules. Subjects received a single oral dose of givinostat (100 mg) in the fasting state or after a high-fat standard meal, with a washout period of at least 1 week in between. The high-fat standard meal resulted in an increase in systemic exposure (AUC) and maximum plasma concentration (Cmax) of about 40% and 23%, respectively, when compared to the fasted state. Additionally, the time to maximum concentration (Tmax) was delayed slightly from 2 to 3 hours.

MANAGEMENT: Givinostat should be administered with food to increase its absorption. In the case of the oral suspension, this can also help mask its bitter taste.