[Pharmacokinetics of intratumoral interferon-gamma activity following subcutaneous administration of recombinant interferon-gamma in a patient with metastatic brain tumor derived from renal cancer].

Pharmacokinetic studies of intratumoral interferon (IFN)-gamma activity were performed 1 week and 1 month after subcutaneous (s.c.) administration of recombinant IFN-gamma (specific activity = 1 x 10(7) units/mg protein) to a patient with metastatic brain tumor in the right occipital lobe derived from primary renal cancer. The patient, a 54-year-old man, underwent total removal of the lesion on April 10, 1991, with placement of an indwelling Ommaya Reservoir in the tumor cavity. The histological diagnosis was clear-cell carcinoma. His postoperative course was uneventful. Due to detection of a new ring-like enhancing mass in the right temporal lobe on serial CT examination on May 27, radiotherapy was discontinued immediately after delivery of a total dose of 30 Gy. Recombinant IFN-gamma was then administered s.c. at a dose of 3 x 10(6) units/day for 6 weeks, and induced a partial response. During IFN-gamma therapy, IFN-gamma activity in intratumoral fluid was measured 0 min, 30 min, 90 min and 6 hours after s.c. injection of IFN-gamma. The level of IFN activity was determined by an enzyme-linked immunosorbent assay. Intra-tumoral IFN-gamma activity gradually increased, and showed the highest of measured values at 6 hours after administration, while serum IFN activity decreased rapidly with a half-life of 30 min. The patient was discharged on July 30, but died from complications of aspiration pneumonia on September 2, 1991.