Objective: To further characterize time-to-first pain relief, effect size, correlations between various outcome measures and durability of relief for single-tablet naproxen 500 mg/esomeprazole 20 mg (NAP/ESO) given twice daily and celecoxib (CEL) (200 mg) given once daily versus placebo in knee osteoarthritis (OA).
Methods: Unpublished data from two double-blind, double-dummy, placebo-controlled trials in which patients aged ≥ 50 years with knee OA were randomized to NAP/ESO (n = 487), CEL (n = 486) or placebo (n = 246) were pooled (NCT00664560 and NCT00665431). Acute response endpoints: 1) Time to first significant pain response, 2) Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain subscale and 3) American Pain Society Patient Outcome Questionnaire (APS-POQ) scores. Sustainability endpoints: 1) Routine Assessment of Patient Index Data (RAPID3) and 2) WOMAC Stiffness, Pain and Total scores; and Patient Global Assessment (PGA) at 6 and 12 weeks. Effect sizes for all measures were calculated. Rescue pain medication use also was analyzed, as was the correlation of WOMAC to RAPID3.
Results: NAP/ESO produced statistically significant decreases in WOMAC Pain on Days 2-7 and at Weeks 6 and 12 (all p < 0.05); most APS-POQ pain assessments with NAP/ESO were significantly improved on Days 2-7 compared with placebo (all p < 0.05). A good or excellent response occurred in a median of 6 days. RAPID3 and WOMAC total/stiffness/function/PGA scores decreased significantly at Weeks 6 and 12 (all p < 0.05). Placebo-adjusted WOMAC pain effect sizes were 0.44, 0.34 and 0.25 at Day 7, week 6 and week 12, respectively. RAPID3 to WOMAC total and WOMAC pain to RAPID3: Pain scores were highly correlated at 6 and 12 weeks (correlation coefficients >0.80). No significant differences in overall responses were found between CEL and NAP/ESO.
Conclusion: Naproxen/esomeprazole produced a significant absolute moderate early pain response, which was maintained for 12 weeks. RAPID3 was found to be highly correlated with the typical OA measure (WOMAC) and might be a useful clinical tool for measuring NSAID response. NCT00664560: https://clinicaltrials.gov/ct2/show/NCT00664560, NCT00665431: https://www.clinicaltrials.gov/ct2/show/NCT00665431.
Keywords: Celecoxib; Routine Assessment of Patient Index Data; Western Ontario and McMaster Osteoarthritis Index; effect size; naproxen combination; pain.