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.