Relationship Between Time To Onset Of Relief And Total Pain Relief Of Breakthrough Pain In Patients With Cancer Using Fentanyl Pectin Nasal Spray.

e19544 Background: Breakthrough pain in cancer (BTPc) is typified by a rapid onset of severe pain with a limited duration. Treatment for BTPc requires rapid onset of pain relief. The main purpose of this analysis was to assess the relationship between time to onset of pain relief and overall pain relief in patients treating BTPc with fentanyl pectin nasal spray (FPNS, Lazanda, PecFent). Methods: Data were pooled from FPNS-treated episodes of 2 randomized, double-blind, crossover studies assessing efficacy of FPNS in adults who experienced BTPc despite background pain that was adequately controlled with at least 60 mg/day morphine (or equivalent). Patients initially entered a dose-titration phase to establish dose of FPNS (100 to 800 mcg) to be used during the treatment phase of each study. Pain intensity (PI) was assessed at baseline and scheduled time points on an 11-point scale (0=no pain, 10=worst possible pain). This analysis assessed the relationship of time to onset of pain relief (≥1 point reduction in PI from baseline) to total pain relief (Summed Pain Intensity Difference [SPID] at 30 and 60 min postdose [SPID30 and SPID60]) by ANOVA. Responses are also provided for the placebo-treated episodes during the placebo-controlled trial. Results: There were 831 episodes of BTPc that were treated with FPNS. Mean SPID was highest when pain relief was earliest (p<0.001). When PI difference (PID) ≥1 was attained by 5, 10, and 15 min postdose, mean (SD) SPID30 scores were 13.1 (6.7), 7.6 (4.0), and 3.5 (1.8). In the placebo-controlled trial, a similar overall response (p<0.001) was observed during the 200 placebo-treated episodes: among those attaining PID ≥1 by 5, 10, and 15 min postdose, SPID30 was 12.2 (7.0), 5.3 (3.3), and 2.5 (1.0), respectively. Similarly, significant differences were observed for SPID60 with both treatments. Conclusions: Earlier time to onset of pain intensity reduction in BTPc treatment resulted in higher SPID at 30 and 60 minutes postdose of FPNS and placebo. Results suggest that early onset of relief may be associated with a greater overall degree of relief for episodes of BTPc, which emphasizes the need for rapid-acting agents in the management of breakthrough pain.