(385) Integrated efficacy and safety of gastroretentive gabapentin in treatment of patients with postherpetic neuralgia (PHN)

Abstract

For patients with PHN, the efficacy and safety of gastroretentive gabapentin (G-GR) was established in two randomized, placebo-controlled Phase 3 studies, and confirmed in an open-label, Phase 4 study. To gain further insight into the efficacy and safety of G-GR, and in how certain variables interact, data from patients who received G-GR 1800 mg once-daily in these studies were integrated and are being analyzed. The integrated dataset includes 546 patients in the efficacy population and 556 in the safety population. Efficacy evaluations in the dataset include Visual Analog Scale (VAS) and Brief Pain Inventory (BPI) completed at baseline and end of study (Week 10 for Phase 3, Week 8 for Phase 4), and Patients’/Clinical Global Impression of Change (P/CGIC) completed at end of study. Preliminary efficacy results have demonstrated a consistent, statistically significant reduction in VAS score by end of study. Further analyses will explore relationships between reduction in pain, improvements in quality of life, and baseline patient and disease characteristics. In addition, we will ascertain whether any factors are predictive of reductions in pain and improvements in quality of life.The integrated safety data show that G-GR was generally well tolerated. Seventy-two (12.9%) patients discontinued due to adverse events (AEs). The incidence of AEs decreased rapidly from 21% to 8% after 3 weeks of treatment, and reached steady low levels of 3.4% after 5 weeks of treatment. Ongoing exploratory analyses seek to identify risk factors for AE reporting and for discontinuations due to AEs. In summary, these integrated analyses are designed to validate the efficacy and safety of G-GR in treatment of PHN, and to explore in more detail the complex relationships between G-GR efficacy and safety measures. Study supported by Depomed, Inc., Newark, CA. For patients with PHN, the efficacy and safety of gastroretentive gabapentin (G-GR) was established in two randomized, placebo-controlled Phase 3 studies, and confirmed in an open-label, Phase 4 study. To gain further insight into the efficacy and safety of G-GR, and in how certain variables interact, data from patients who received G-GR 1800 mg once-daily in these studies were integrated and are being analyzed. The integrated dataset includes 546 patients in the efficacy population and 556 in the safety population. Efficacy evaluations in the dataset include Visual Analog Scale (VAS) and Brief Pain Inventory (BPI) completed at baseline and end of study (Week 10 for Phase 3, Week 8 for Phase 4), and Patients’/Clinical Global Impression of Change (P/CGIC) completed at end of study. Preliminary efficacy results have demonstrated a consistent, statistically significant reduction in VAS score by end of study. Further analyses will explore relationships between reduction in pain, improvements in quality of life, and baseline patient and disease characteristics. In addition, we will ascertain whether any factors are predictive of reductions in pain and improvements in quality of life.The integrated safety data show that G-GR was generally well tolerated. Seventy-two (12.9%) patients discontinued due to adverse events (AEs). The incidence of AEs decreased rapidly from 21% to 8% after 3 weeks of treatment, and reached steady low levels of 3.4% after 5 weeks of treatment. Ongoing exploratory analyses seek to identify risk factors for AE reporting and for discontinuations due to AEs. In summary, these integrated analyses are designed to validate the efficacy and safety of G-GR in treatment of PHN, and to explore in more detail the complex relationships between G-GR efficacy and safety measures. Study supported by Depomed, Inc., Newark, CA.