Gemcitabine plus CI-994 offers no advantage over gemcitabine alone in the treatment of patients with advanced pancreatic cancer: results of a phase II randomized, double-blind, placebo-controlled, multicenter study.

CI-994, an oral histone deacetylase inhibitor, has antineoplastic activity and synergism with gemcitabine preclinically. This randomized phase II trial explored whether CI-994 plus gemcitabine improves overall survival, objective response, duration of response, time to treatment failure and change in quality of life (QoL) or pain compared with gemcitabine alone. A total of 174 patients received CG (CI-994 6 mg/m(2)/day days 1-21 plus gemcitabine 1000 mg/m(2) days 1, 8 and 15 each 28-day cycle) or PG (placebo plus gemcitabine 1000 mg/m(2) days 1, 8 and 15 of each 28-day cycle days 1-21). Median survival was 194 days (CG) versus 214 days (PG) (P = 0.908). The objective response rate with CG was 12% versus 14% with PG when investigator-assessed and 1% versus 6%, respectively, when assessed centrally. Time to treatment failure did not differ between the two arms (P = 0.304). QoL scores at 2 months were worse with CG than with PG. Pain response rates were similar between the two groups. There was an increased incidence of neutropenia and thrombocytopenia with CG. Adding CI-994 to gemcitabine in advanced pancreatic carcinoma does not improve overall survival, response rate or time to progression; CG produced decreased QoL and increased hematological toxicity and appears inferior to single-agent gemcitabine.