13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis
Pegvisomant was administered subcutaneously to rats daily for 2 years at doses of 2, 8, and 20 mg/kg (about 2, 9, and 22-fold a single 30 mg dose in humans on an AUC basis). Long term treatment with pegvisomant at 8 and 20 mg/kg caused an increase in malignant fibrous histiocytoma at injection sites in males. Injection site tumors were not seen in female rats at the same doses. The increased incidence of injection site tumors was most probably caused by irritation and the high sensitivity of the rat to repeated subcutaneous injections.