(827): Oral once-a-day AVINZA (morphine sulfate extended-release capsules) vs. twice daily OxyContin (oxycodone hydrochloride controlled-release) for the treatment of chronic moderate-to-severe low back pain; final (part I and part II) study results

Abstract

This open-label, randomized, parallel-group multicenter study evaluated the efficacy and safety of two oral SROs (once-a-day AVINZA® and twice-a-day OxyContin®) in SRO-naive subjects, age 30-70, with chronic (≥ 6 months) moderate-to-severe low back pain. During Part I of the study 392 subjects enrolled and underwent opioid dose titration (3 to 6 weeks). Opioid dose stabilization (pain score ≤4 for 3 consecutive days with ≤2 doses per day of ibuprofen for breakthrough pain) was achieved in 266 subjects (132 randomized to AVINZA and 134 to OxyContin) who then entered an 8-week evaluation period. Following completion of Part I of the study, 174 subjects (95 AVINZA and 79 OxyContin) entered a 4-month extension phase (Part II). During Part I, AVINZA achieved significantly better pain scores (p≤ 0.02) and sleep parameters (p< 0.04) than OxyContin. These improvements were achieved with a significantly lower total daily opioid dose expressed in morphine-equivalents (median of 58mg for AVINZA and 85mg for OxyContin, p=0.017). Ibuprofen doses adjusted for the number of patient-days were significantly lower in the AVINZA group (p<0.01). These clinical benefits were maintained or further improved during Part II. At the end of Part I, the mean NRS pain scores were 3.5 for AVINZA and 3.8 for OxyContin, and further decreased to 3.1 and 3.5, respectively, at Month 4, the end of Part II (p= 0.01 favoring AVINZA). Improvements in the quality of sleep were also maintained. These results were achieved with a significantly lower daily opioid dose in the AVINZA group (86mg) compared to OxyContin (119mg morphine-equivalents) with p =0.0029. The incidence and severity of elicited opioid side effects was similar in the two treatment groups during both study phases. Final results for both parts will be presented. Supported by Ligand Pharmaceuticals Inc. and Organon Pharmaceuticals USA Inc. This open-label, randomized, parallel-group multicenter study evaluated the efficacy and safety of two oral SROs (once-a-day AVINZA® and twice-a-day OxyContin®) in SRO-naive subjects, age 30-70, with chronic (≥ 6 months) moderate-to-severe low back pain. During Part I of the study 392 subjects enrolled and underwent opioid dose titration (3 to 6 weeks). Opioid dose stabilization (pain score ≤4 for 3 consecutive days with ≤2 doses per day of ibuprofen for breakthrough pain) was achieved in 266 subjects (132 randomized to AVINZA and 134 to OxyContin) who then entered an 8-week evaluation period. Following completion of Part I of the study, 174 subjects (95 AVINZA and 79 OxyContin) entered a 4-month extension phase (Part II). During Part I, AVINZA achieved significantly better pain scores (p≤ 0.02) and sleep parameters (p< 0.04) than OxyContin. These improvements were achieved with a significantly lower total daily opioid dose expressed in morphine-equivalents (median of 58mg for AVINZA and 85mg for OxyContin, p=0.017). Ibuprofen doses adjusted for the number of patient-days were significantly lower in the AVINZA group (p<0.01). These clinical benefits were maintained or further improved during Part II. At the end of Part I, the mean NRS pain scores were 3.5 for AVINZA and 3.8 for OxyContin, and further decreased to 3.1 and 3.5, respectively, at Month 4, the end of Part II (p= 0.01 favoring AVINZA). Improvements in the quality of sleep were also maintained. These results were achieved with a significantly lower daily opioid dose in the AVINZA group (86mg) compared to OxyContin (119mg morphine-equivalents) with p =0.0029. The incidence and severity of elicited opioid side effects was similar in the two treatment groups during both study phases. Final results for both parts will be presented. Supported by Ligand Pharmaceuticals Inc. and Organon Pharmaceuticals USA Inc.