A Prospective, Single-Cohort, Open, Multi-center, Observational Study of Sublingual Fentanyl for Breakthrough Cancer Pain: Effectiveness, Safety, and Tolerability in Korean Cancer Patients

Purpose Fentanyl, a highly lipophilic opioid, was developed as a sublingual fentanyl tablet (SFT) for the management of breakthrough cancer pain (BTcP), and its efficacy and safety were confirmed in a randomized, controlled study. We investigated the effectiveness and safety of SFT administered to alleviate BTcP in a real-world setting. Materials and Methods In this prospective, open, single-cohort study, conducted in 13 referral hospitals in South Korea, opioidtolerant cancer patients receiving around-the-clock opioids for persistent cancer pain were enrolled if the individual had BTcP ≥ 1 episode/day during the preceding week. The primary outcome was the SFT titration success rate. Results Among 113 patients evaluated for effectiveness, 103 patients (91.2%) had a successful titration of SFT, with an effective dose range between 100 µg and 400 µg. The most frequent dose was 100 µg, administered to 65.0%, 72.1%, and 81.8% of the patients at week 1, 4, and 12, respectively. The proportion of patients achieving the personalized pain goal assessed in the first week was 75.2%. The mean change in pain intensity measured with a numeric rating scale at 30 and 60 minutes after taking SFT was –2.57 and –3.62, respectively (p < 0.001 for both). The incidence rate of adverse events related to SFT among 133 patients included for safety evaluation was 9.0% (12/133), which included vomiting (3.0%), nausea (2.3%), and headache (1.5%). Conclusion In a real-world setting, SFT provides rapid and effective analgesia in BTcP, even at the lowest dose (100 μg), and the safety profile was acceptable.