Background: Disulfiram inhibits hepatic aldehyde dehydrogenase causing accumulation of acetaldehyde when alcohol is ingested and is used to treat alcohol addiction. When metal ions such as copper are combined with disulfiram, key oncoproteins are bound, and inactivated. Disulfiram and copper can inhibit tumor cell growth in cell culture, and xenograft models, and induce cell killing via apoptosis. Here we determined the safety and tolerability of disulfiram when administered together with copper gluconate in patients with advanced treatment-refractory solid tumors involving the liver.

Methods: Four preselected oral doses of copper gluconate were tested (2, 4, 6, and 8 mg tid) in a standard “3+3” design. Disulfiram 250 mg was administered once daily. Patients were observed for DLTs, and pharmacodynamic studies were performed. Patients were required to refrain from alcohol consumption during the study.

Results: As of November 15, 2010, 15 patients with treatment refractory solid tumors metastatic to the liver have been enrolled. The average number of prior treatments was 7 (range 1-16). Malignancies represented included pancreatic (2), breast (4), colon (1), prostate (1), lung (1), cutaneous melanoma (2), and ocular melanoma (2). Grade 3 toxicities included dehydration (1), hyperglycemia (1), constipation (1), LFT elevations (2) and troponin elevation (1) but these were felt to be more likely related to advanced malignancy or to causes other than the study drugs. Although hepatic toxicity is a potential side effect of disulfiram, the only Grade 3 LFT elevations that occurred on treatment were in patients with disease progression in the liver suggesting that these events were not drug related. There was one reported Grade 2 disulfiram reaction due to exposure to alcohol. Other Grade 1 and 2 toxicities included changes in mental status (6), headaches (2), and dizziness (3) though many of these events corresponded to progression of the underlying malignancy. No radiographic responses to treatment have been observed. Six patients progressed within 28 days of starting treatment. One patient with advanced colon cancer achieved disease stability for 125 days. The average duration on treatment was 37 days (range 1 – 125 days). Reasons for discontinuing treatment included functional decline (4), disease progression (10), and death (1). Two remaining slots are open on the 8 mg dose cohort. Analysis of S-glutathionylation of proteins in response to treatment is ongoing.

Conclusions: Disulfiram dosed at 250 mg daily together with copper gluconate at doses of 6 mg three times daily is well tolerated in patients with advanced solid tumors involving the liver. No DLT has yet been observed.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1308. doi:10.1158/1538-7445.AM2011-1308