Exploratory study of carboplatin plus the copper-lowering agent trientine in patients with advanced malignancies.

ABSTRACT

PURPOSE: Preclinical data showed that trientine, a copper-lowering agent, re-sensitized cancer cells to carboplatin through enhanced human copper transporter 1 (hCtr1) -mediated platinum uptake. EXPERIMENTAL DESIGN: We studied carboplatin and trientine in patients (n = 55; 45 who had failed platinum) with advanced malignancies (Phase I, modified 3 + 3 design). RESULTS: The most common cancers were head and neck (n = 13), non-small cell lung (n = 10) and epithelial ovarian (n = 8). The median number of prior regimens was four. No dose-limiting toxicity or treatment-related deaths were observed at doses up to carboplatin AUC 6 given with trientine. Eight patients achieved stable disease (SD) ≥ 6 months (six platinum failures) and one patient with platinum-resistant ovarian cancer, partial response (PR) (total SD ≥ 6 months/PR = 9, 16.4 %). The mean nadir serum copper level in the nine patients with SD ≥ 6 months/PR was 0.55 µg/mL (95 % CI, 0.34-0.75) versus 1.22 µg/mL (95 % CI, 1.02-1.42) (p < 0.001) in 38 tested patients with progression. In patients who maintained their ceruloplasmin (major copper-carrying protein) levels at 5-15 mg/dL (n = 9), the median progression-free and overall survivals were 9.2 and 15.2 months versus 1.9 (p = 0.001) and 5.7 months (p = 0.033) in patients who did not (n = 38), respectively. CONCLUSIONS: The combination of a copper-lowering agent with carboplatin was well tolerated and associated with antitumor activity, especially in patients in whom copper and/or ceruloplasmin levels were lowered. Further investigation of this strategy for reversing platinum resistance is warranted.