population pharmacokinetic analysis indicated that creatinine clearance over the range of 36 to 130 mL/min/m2 has no effect on the clearance of temozolomide after oral administration. The pharmacokinetics of temozolomide have not been studied in patients with severely impaired renal function (CLcr <36 mL/min/m2). Caution should be exercised when TEMODAR is administered to patients with severe renal impairment [see Use in Special Populations (8.6)]. TEMODAR has not been studied in patients on dialysis.
Effect of Hepatic Impairment:
A study showed that the pharmacokinetics of temozolomide in patients with mild-to-moderate hepatic impairment (Child-Pugh Class I – II) were similar to those observed in patients with normal hepatic function. Caution should be exercised when temozolomide is administered to patients with severe hepatic impairment [see Use in Specific Populations (8.7)].
Effect of Other Drugs on Temozolomide Pharmacokinetics:
In a multiple-dose study, administration of TEMODAR Capsules with ranitidine did not change the Cmax or AUC values for temozolomide or MTIC.
A population analysis indicated that administration of valproic acid decreases the clearance of temozolomide by about 5% [see Drug Interactions (7.1)].
A population analysis did not demonstrate any influence of coadministered dexamethasone, prochlorperazine, phenytoin, carbamazepine, ondansetron, H2 -receptor antagonists, or phenobarbital on the clearance of orally administered temozolomide.
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of FertilityTemozolomide is carcinogenic in rats at doses less than the maximum recommended human dose. Temozolomide induced mammary carcinomas in both males and females at doses 0.13 to 0.63 times the maximum human dose (25–125 mg/m2) when administered orally on 5 consecutive days every 28 days for 6 cycles. Temozolomide also induced fibrosarcomas of the heart, eye, seminal vesicles, salivary glands, abdominal cavity, uterus, and prostate, carcinomas of the seminal vesicles, schwannomas of the heart, optic nerve, and harderian gland, and adenomas of the skin, lung, pituitary, and thyroid at doses 0.5 times the maximum daily dose. Mammary tumors were also induced following 3 cycles of temozolomide at the maximum recommended daily dose.
Temozolomide is a mutagen and a clastogen. In a reverse bacterial mutagenesis assay (Ames assay), temozolomide increased revertant frequency in the absence and presence of metabolic activation. Temozolomide was clastogenic in human lymphocytes in the presence and absence of metabolic activation.
Temozolomide impairs male fertility. Temozolomide caused syncytial cells/immature sperm formation at 0.25 and 0.63 times the maximum recommended human dose (50 and 125 mg/m2) in rats and dogs, respectively, and testicular atrophy in dogs at 0.63 times the maximum recommended human dose (125 mg/m2).
13.2 Animal Toxicology and/or PharmacologyToxicology studies in rats and dogs identified a low incidence of hemorrhage, degeneration, and necrosis of the retina at temozolomide doses equal to or greater than 0.63 times the maximum recommended human dose (125 mg/m2). These changes were most commonly seen at doses where mortality was observed.
14 CLINICAL STUDIES14.1 Newly Diagnosed Glioblastoma MultiformeFive hundred and seventy-three patients were randomized to receive either TEMODAR (TMZ)+Radiotherapy (RT) (n=287) or RT alone ( |
