Clinical and epidemiological research Figure 1 Study schema showing randomisation (A) and major study time points (B). week 52, patients were allowed to inject the study agent at home and were asked to return for study visits every 12 weeks. Serum samples were collected at weeks 24, 52 and 104 and assessed for the presence of antibodies to golimumab using a previously described assay.3 The protocol was reviewed and approved by the institutional review board or independent ethics committee at each site. All patients gave written informed consent. We evaluated the response to treatment by determin- ing the proportions of patients with an ASAS20 or ASAS40 response, ASAS partial remission (deﬁned as a value below 2 in each of the four ASAS domains) and at least 50% improve- ment in the Bath Ankylosing Spondylitis Disease Activity Index4 (BASDAI50 response). Changes from baseline in the Bath Ankylosing Spondylitis Functional Index (BASFI),5 Bath Ankylosing Spondylitis Metrology Index (BASMI) based on a linear method6 7 and physical and mental component summary (PCS and MCS, respectively) scores of the 36-item Short-Form Health Survey (SF-36)8 were used to assess physical function, range of motion and health-related quality of life, respectively. The proportions of patients achieving an Ankylosing Spondylitis Disease Activity Score (ASDAS)9 <1.1 (indicating inactive dis- ease) or <2.1 (indicating moderate disease activity) were also determined. This was performed as a post hoc analysis, as this measure was designed following the start of this trial. No statistical comparisons were made for efﬁcacy results after week 24 because all patients were receiving golimumab. Efﬁcacy data are presented using two approaches: 1. Intention to treat: patients who met the treatment failure cri- teria at week 141 and those who entered early escape at week 16 were considered to be non-responders at week 104. In addi- tion, patients who discontinued treatment because of an unsat- isfactory therapeutic effect after week 24 or who were missing all ASAS components were considered to be non-responders at week 104. For patients who did not meet the treatment fail- ure criteria, the missing ASAS components at week 104 were 662 replaced with the last non-missing value. Patients were categor- ised according to their original randomly assigned treatment group. Thus, group 1 consisted of patients who were originally assigned to placebo and received golimumab 50 mg at week 16 if they met the criteria for early escape or crossed over to 50 mg at week 24. Group 2 comprised patients who were initially assigned to golimumab 50 mg and received that dose through- out the study or received 100 mg at week 16 if they met the criteria for early escape. Group 3 comprised patients who were initially assigned to golimumab 100 mg and received that dose throughout the study. 2. By treatment regimen: treatment regimen 1 consisted of patients who were originally assigned to placebo at baseline and who either entered early escape at week 16 to receive golimumab 50 mg through week 104 or crossed over at week 24 to receive golimumab 50 mg through week 104. Treatment regimen 2 consisted of patients who were originally assigned to golimumab 50 mg at baseline and who either entered early escape at week 16 to receive golimumab 100 mg through week 104 or continued 50 mg through week 104. Treatment regi- men 3 consisted of patients who were originally assigned to golimumab 100 mg at baseline and who did not receive study medication adjustments. Concomitant medications were stable through week 24, but selected medications could be adjusted after week 24 (see Methods for details). Actual observed ASAS20 and ASAS40 response rates through week 104 are presented without data imputation. Patients who entered early escape were counted in the treatment regimen to which they were originally assigned. Efﬁcacy data (ASAS20; ASAS40; BASDAI50 and changes in BASDAI, BASFI, BASMI and SF-36 scores) are also presented by actual treatment received based on the early escape status (see table 1 for categories). RESULTS A total of 356 patients were randomly assigned to treatment (ﬁgure 2). Baseline disease characteristics of the study population Ann Rheum Dis 2012;71:661–667. doi:10.1136/ard.2011.154799