Successful dose finding with sublingual fentanyl tablet: combined results from 2 open-label titration studies.

OBJECTIVE This analysis was conducted to determine the likelihood of identifying an effective dose of fentanyl sublingual tablet during the initial titration phase of 2 clinical trials, to characterize the actual effective dose in patients achieving successful titration, and to examine the relationship between baseline characteristics and likelihood of achieving an effective dose. METHODS Data were derived from 2 clinical trials (Study 1, n=131; Study 2, n=139) of fentanyl sublingual tablet in patients with cancer-associated breakthrough pain (BTP). Both trials comprised a 2-week titration phase and 12-month maintenance phase. The initial dose was 100 μg, titrated to an effective dose (producing effective relief of all BTP episodes on 2 consecutive days) of 100 to 800 μg. RESULTS A total of 270 patients entered the titration phase. Mean (SD) baseline BTP opioid dose was 25.7 (88.9) mg morphine equivalent, and mean baseline around-the-clock opioid dose was 196.5 (151.6) mg morphine equivalent. Using conservative criteria for determining effective dose, 174 patients (64.4%) were successfully titrated to an effective dose (mean [SD], 498.2 [234.8] μg). The most frequent (27.6%) effective dose was 800 μg, and more than 85% of patients required an effective dose ≥300 μg. There were no significant relationships between any baseline characteristics and titration success. CONCLUSION Despite stringent criteria, 64.4% of patients achieved an effective dose of fentanyl sublingual tablet within the dose range of 100 to 800 μg. Baseline characteristics were not identified to be associated with the likelihood of successful titration or with the actual effective dose of fentanyl sublingual tablet.