Presented at the 2013 AAPM Annual Meeting « Back

Single-Entity Hydrocodone Extended Release for Chronic Low Back Pain

Richard Rauck, MD, rrauck@ccrpain.com¹, Srinivas Nalamachu, MD², James E. Wild³, George S. Walker, MD⁴, Cynthia Y. Robinson, PhD⁵, Stephen J. Farr, PhD⁵, Charles S. Davis, PhD⁶, (1) Center for Clinical Research, Winston-Salem, North Carolina, (2) International Clinical Research Institute, Inc., Overland Park, Kansas, (3) Upstate Clinical Research Associates, Williamsville, New York, (4) New Orleans, Louisiana, (5) Zogenix, Emeryville, California, (6) CSD Biostatistics, Inc., San Diego, California

Introduction/Statement of the Problem: Hydrocodone is available in combination with non-opioid analgesics, such as acetaminophen, that prevent titration of hydrocodone to therapeutic levels. Hydrocodone bitartrate extended release (HC-ER; Zogenix, Inc., San Diego, CA) lacks the dose-limiting toxicity of acetaminophen. This study examined HC-ER efficacy in opioid-experienced adults with moderate-to-severe chronic low back pain (CLBP). Materials and Methods: An open-label conversion/titration (C/T) phase (≤6 weeks) was followed by a placebo-controlled, randomized, double-blind treatment phase (12 weeks). Subjects (n=510) converted from their current opioid to HC-ER, titrated during C/T to a stabilized dose (20-100 mg twice daily). During the treatment phase, subjects (n=151 per group) received HC-ER or placebo; rescue medication was permitted. The primary efficacy endpoint was mean change in average pain intensity (PI) from baseline to day 85. Institutional review board approval was obtained. Results: The mean ± SD change in average PI score from baseline to day 85 was significantly lower in the HC-ER group versus the placebo group (0.48±1.56 vs 0.96±1.55; P=0.008). Significantly more subjects receiving HC-ER were responders compared with those receiving placebo (68% vs 31%; P<0.001). Mean total daily rescue medication use during the treatment phase was lower in the HC-ER group versus the placebo group (6.0±3.4 vs 7.5±3.9 mg). Subjects receiving HC-ER were less likely to discontinue treatment (P≤0.001) than subjects receiving placebo. Adverse events in subjects receiving HC-ER were consistent with those expected with other opioids. Conclusions: HC-ER is an effective, well-tolerated treatment for CLBP in this subject population.

Funding: This study was supported by Zogenix, Inc.