Efficacy and tolerability of intranasal fentanyl spray 50 to 200 microg for breakthrough pain in patients with cancer: a phase III, multinational, randomized, double-blind, placebo-controlled, crossover trial with a 10-month, open-label extension treatment period.

OBJECTIVE: This trial investigated the efficacy and long-term tolerability of intranasal fentanyl spray (INFS) 50 to 200 microg in the treatment of breakthrough pain in opioid-tolerant patients with cancer.

METHODS: This Phase III, double-blind, randomized, placebo-controlled, crossover trial was conducted at pain centers, anesthesiology departments, palliative care units, and oncology clinics in Austria, Denmark, France, Germany, and Poland. Eligible patients were adults with cancer receiving a stable dose of long-term opioid treatment for the control of background pain. Patients were treated at home with their effective dose of INFS (50, 100, or 200 microg) or inactive spray (placebo) in a randomized sequence for 3 weeks, followed by a 10-month, open-label tolerability phase during which they received their effective dose of INFS. Throughout the study, patients were allowed to use their usual rescue medication, which was recorded in patient diaries. The primary efficacy end point was the pain intensity difference at 10 minutes after study drug administration (PID(10)), as assessed using an 11-point numeric rating scale (0 = no pain to 10 = worst pain imaginable). An effect size of 0.5 for PID was considered clinically relevant. The rate of response, defined as PID(10) >2, was also assessed. Adverse events (AEs) were recorded in patient diaries during the efficacy period and reported in monthly clinic visits and follow-up weekly telephone contacts during the extension period.

RESULTS: In all, 120 patients were enrolled and achieved an effective dose; 113 were randomized and 111 were included in the intent-to-treat analysis set (56 men, 55 women; mean [SD] age, 60.6 [9.45] years; mean weight, 70.3 kg [men] and 65.3 kg [women]; white race, 107 [96.4%]; INFS 50 microg, 18; INFS 100 microg, 48; INFS 200 microg, 45; placebo, 110). PID(10) with INFS was 2-fold that with placebo (adjusted means, 2.36 vs 1.10; adjusted difference, 1.26 [greater than the clinically relevant difference of 0.5]; P < 0.001). Additional analysis revealed that the mean response rate with all 3 doses of INFS was 51.1% versus 20.9% with placebo. The prevalence of AEs was 22/111 (19.8%) during the efficacy period, during which the most frequently reported AEs were nausea (5 [4.5%]) and vertigo (2 [1.8%]). No serious AEs were considered related to the study drugs. In all, 108 patients entered the extension period, with a mean duration of exposure to INFS of 134.9 days. Progression of underlying malignant disease was the most common AE reported during this period (55 [50.9%]); this event was not considered treatment related.

CONCLUSIONS: In these opioid-tolerant patients with cancer, INFS at doses of 50, 100, and 200 microg was associated with an onset of activity at 10 minutes and effective treatment of breakthrough pain compared with placebo. All doses were generally well tolerated and clinically efficacious.