Off-label use judgement
The standard of evaluating whether the use of tocilizumab is off-label or on-label is based on current drug label (Roche Pharma (Schweiz) Ltd.), which is approved by the National Medical Products Administration (NMPA) in 1st January, 2018. The legally approved indications of tocilizumab are RA and sJIA up to now. The recommended dosage for the treatment of RA is 8mg/kg and administrate every four weeks intravenously while for sJIA is 12mg/kg (weight great than or equal to 30kg) and 8mg/kg (weight less than 30kg) every two weeks, intravenously. Basically, there is no obvious difference of recommended dosage of tocilizumab between China and foreign countries due to the dosage is generally based on patients’ body weight. As such, the dosage did not take account into the off-label use of tocilizumab in this study. We put more emphasis on the off-label use of tocilizumab in terms of indication. The criteria of off-label prescriptions involved is if the doctor prescribed tocilizumab for treating other indications rather RA and sJIA, and that prescription considered as off-label one.