Utilisation of composite endpoint outcome to assess efficacy of tocilizumab for non-infectious uveitis in the STOP-Uveitis Study

To use a composite endpoint scoring system in assessing efficacy of two doses of intravenous tocilizumab (TCZ), in eyes with non-infectious uveitis.

Data from STOP-Uveitis Study (a phase 2 multicentre, randomised, interventional clinical trial), where monthly intravenous infusions of 4 mg/kg (Group 1) or 8 mg/kg (Group 2) TCZ until month 6 (M6) were administered, were used. Efficacy was ascertained by a composite endpoint scoring system consisting of: (1) visual acuity; (2) intraocular inflammation; (3) central retinal thickness; (4) posterior segment inflammation on fluorescein angiographic and (5) steroid taper. Each component of grading system was graded as ((+1) improvement, (-1) worsening or (0) no change) based on specific criteria. The clinical response was classified as positive (improvement in at least one parameter and worsening in none), negative (worsening of any parameter) or stable (neither improvement nor worsening of any parameter). The percentage achieving various clinical responses was compared between groups.

Thirty-seven patients were analysed. At M6, 31 (83.8%) subjects demonstrated a positive clinical response (Group 1=14 (77.8%) and Group 2=17 (89.5%)). Three (8.1%) subjects (all Group 1) met the criteria for treatment failure, whereas three (8.1%) subjects showed a stable clinical response (Group 1=1 and Group 2=2). The difference in clinical responses between study groups was not significant (p>0.05).

Both doses of intravenous TCZ were effective in either improving or maintaining stability in patients using the composite endpoint scoring system. A composite scoring system as used in this study may be a better measure to assess efficacy outcomes as compared with only vitreous haze or other single outcome measures.