Single and Composite Endpoints of Within-Patient Improvement in Symptoms: Pooled Tanezumab Data in Patients with Osteoarthritis

Introduction: Combining measures of key core domains (especially pain and function) into a composite endpoint that requires each patient to meet a threshold of improvement for each domain provides information on multiple aspects of osteoarthritis within individual patients. This pooled analysis of two phase 3 studies (NCT02697773, NCT02709486) explored single and composite endpoints for assessing within-patient improvement in knee or hip osteoarthritis symptoms following subcutaneous administration of tanezumab or placebo. Methods: Endpoints at week 16 included proportions of responders (C 30% improvement) in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, WOMAC Physical Function, WOMAC Pain/Function composite, and weekly average pain; and patient acceptable symptom state (PASS) composite responders, minimal clinically important improvement (MCII) composite responders
IntroductionCombining measures of key core domains (especially pain and function) into a composite endpoint that requires each patient to meet a threshold of improvement for each domain provides information on multiple aspects of osteoarthritis within individual patients. This pooled analysis of two phase 3 studies (NCT02697773, NCT02709486) explored single and composite endpoints for assessing within-patient improvement in knee or hip osteoarthritis symptoms following subcutaneous administration of tanezumab or placebo.MethodsEndpoints at week 16 included proportions of responders (≥ 30% improvement) in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, WOMAC Physical Function, WOMAC Pain/Function composite, and weekly average pain; and patient acceptable symptom state (PASS) composite responders, minimal clinically important improvement (MCII) composite responders, Outcome Measures in Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) responders, and sustained weekly average pain responders.ResultsPooled population comprised 1545 patients. Of patients who had a ≥ 30% improvement in WOMAC Pain and/or WOMAC Physical Function, 88.5% were WOMAC Pain/Function composite responders, 7.0% were WOMAC Pain (but not Function) responders, and 4.4% were WOMAC Function (but not Pain) responders. Of weekly average pain responders, 43.1% were PASS composite responders. Odds ratios (tanezumab 2.5 mg and 5 mg groups, respectively, vs placebo) were 1.75 and 1.86 (WOMAC Pain/Function composite responders), 1.41 and 1.65 (weekly average pain responders), 1.60 and 1.73 (PASS composite responders), 1.52 and 1.68 (MCII composite responders), 1.75 and 1.88 (OMERACT-OARSI responders), and 1.85 and 1.48 (sustained weekly average pain responders). Subgroup analyses suggested a greater magnitude of effect for patients with a knee index joint compared with hip on some endpoints.ConclusionResponders on single pain endpoints were in many cases also responders on function or composite endpoints. Separation of tanezumab from placebo was similar and consistent across single and composite endpoints.