Pegylated arginine deiminase treatment of patients with unresectable hepatocellular carcinoma: results from phase I/II studies.

PURPOSE: Recently, we reported that a large number of human hepatocellular cancer (HCC) cell lines were auxotrophic for arginine. Here we report the results obtained with the amino acid-degrading enzyme arginine deiminase (ADI) conjugated to polyethylene glycol (ADI-SS PEG 20,000 mw) as a means of lowering plasma arginine to treat HCC. The study was a cohort dose-escalation phase I/II study. PATIENTS AND METHODS: Pharmacodynamic studies indicated an ADI-SS PEG 20,000 mw dose level of 160 U/m(2) was sufficient to lower plasma arginine from a resting level of approximately 130 micromol/L to below the level of detection (< 2 micromol/L) for more than 7 days, a dose later defined as the optimal biologic dose. All patients were to receive three cycles at the optimum biologic dose. RESULTS: This therapy was well tolerated, even in patients who had no detectable plasma arginine for 3 continuous months of therapy. Of the 19 patients enrolled, two had a complete response, seven had a partial response, seven had stable disease, and three had progressive disease. The median survival for the 19 patients enrolled on this study was 410 days, with four patients still alive at present (> 680 days). CONCLUSION: Elimination of all detectable plasma arginine in patients with HCC was well tolerated and seemed to be effective in the treatment of some patients with HCC. Further testing of ADI-SS PEG 20,000 mw in a larger population of individuals with HCC as well as other human tumors auxotrophic for arginine is warranted.

Feasibility of adjuvant hepatic arterial infusion of chemotherapy after radiofrequency ablation with or without resection in patients with hepatic metastases from colorectal cancer.

BACKGROUND: The safety of combined hepatic artery infusion chemotherapy (HAI) and radiofrequency ablation (RFA) for liver metastases has not been assessed. We conducted a study to determine the feasibility of using HAI after RFA for colorectal cancer (CRC) liver metastases. METHODS: Between 1996 and 2001, patients with hepatic metastases from CRC were enrolled onto a prospective study of RFA plus HAI consisting of continuous-infusion floxuridine and bolus fluorouracil. Surgical complications, treatment-related toxicities, and patient outcomes were recorded. RESULTS: Fifty patients were treated with RFA and HAI with or without resection. A median of two lesions per patient, with a median greatest diameter of 2.0 cm, were treated with RFA. Postoperative complications, including 1 death, occurred in 11 of 50 patients. Toxicity from HAI was relatively mild. At 20 months' median follow-up, 32% of patients remained disease free. Ten percent of patients had recurrences at the site of RFA, 30% developed new liver metastases, and 48% developed extrahepatic disease. CONCLUSIONS: RFA of CRC liver metastases followed by HAI is feasible and is associated with acceptable complication and toxicity rates. The high rate of disease recurrence in our patients indicates that novel combinations of regional and systemic therapies are needed to improve patient outcomes.