Intra-arterial hepatic chemotherapy with pirarubicin. Preclinical and clinical studies

Intra-arterial hepatic chemotherapy (IAHC) with adriamycin (ADM) has not increased its therapeutic index. For our preclinical studies, we selected pirarubicin (THP), an ADM derivative with faster cellular uptake. In rabbits with VX2 tumor in the liver we compared plasmatic and cellular pharmacokinetics of ADM and THP after i.v. and IAH therapy. For ADM, there were no differences in plasma and heart concentrations, with only a slight increase in tumoral levels after IAH compared to i.v. administration; on the other hand, with IAH THP, there was important reduction in systemic exposure with a major increase in tumoral drug distribution. In the phase I study, involving nine patients with implanted catheters, the starting dose of THP was 30 mg/m2 with a 10 mg/m2 intrapatient escalation every 3 weeks in the absence of toxicity. Pharmacokinetics were compared for i.v. and IAH administration in seven patients. The limiting toxicity was neutropenia and the maximal tolerated dose (MTD) ranged from 50 to 110 mg/m2. Moderate nausea-vomiting (grade 1-2) and alopecia (grade 1) occurred at the MTD. No arterial occlusion, gastroduodenal ulcer, hepatitis, or sclerosing cholangitis were seen. In the phase II study, in colorectal cancer patients (CRC) with metastasis confined to the liver, patients were enrolled until June 1990. THP (40 min infusion every 3 weeks) was initiated at 60 mg/m2 with 10 mg/m2 increment until grade 2 hematotoxicity. The median MTD was 85 mg/m2 (range of 60-120 mg/m2), and the median number of cycles was 7 (range of 2-11) with cumulated doses from 180 to 1,030 mg/m2. Grade 2-4 neutropenia was reached in 15 patients. Other toxicities included two arterial occlusions, one episode of gastritis, but no hepatic toxicity and no heart failure. Antitumor effect (in 18 patients) included 1 CR, 5 PR, 3 MR, 6 NC, and 3 PD. The median survival was 18+ months and 1-year survival was 73% +/- 12%. Seven patients had extrahepatic progression at this time. In conclusion, besides 5-FU or Fudr, THP is active in IAHC (probably in relation with high local extraction) on CRC liver metastases usually unresponsive to ADM. It can be given in an outpatient setting with minimal toxicity.