Outcomes of patients with diffuse systemic sclerosis eligible for autologous stem cell transplantation managed with conventional therapy.

OBJECTIVE: To determine the event-free survival of Australian patients with diffuse systemic sclerosis (dcSSc), who meet eligibility criteria for autologous stem cell transplant (ASCT) in previously published randomised controlled trials (RCTs), but were managed without ASCT.

METHODS: Patients who met inclusion criteria for the ASTIS (Autologous Stem Cell Transplantation International Scleroderma)(1) and SCOT (Scleroderma: Cyclophosphamide Or Transplantation)(2) trials were identified from the multicentre Australian Scleroderma Cohort Study (ASCS). Event-free survival (survival without cardiac, renal or pulmonary failure or death) at four years was assessed. ASCS patients who had already undergone transplantation were excluded from analysis.

RESULTS: Of the 492 dcSSc patients in ASCS, 56 met ASTIS inclusion criteria for ASCT (56/492, 11.4% of dcSSc) and 30 met SCOT inclusion criteria (30/492, 6.1%). An additional 11 patients met ASTIS or SCOT inclusion criteria, but were excluded due to severe organ manifestations. Event-free survival at four years in ASCS patients meeting ASTIS inclusion criteria was 83.3% and in ASCS patients meeting SCOT inclusion criteria was 81.2%. Event-free survival at four years in ASCS patients who met ASTIS and SCOT inclusion but also exclusion criteria was 46.7% and 45.7% respectively.

CONCLUSIONS: ASCS patients meeting ASTIS and/or SCOT inclusion criteria who were managed without ASCT have similar event-free survival (EFS) at four years than patients receiving ASCT, and better EFS than those receiving cyclophosphamide in the ASTIS and SCOT trials. This may reflect confounders unable to be controlled for, including survivor bias, but may also reflect improved standard of care for dcSSc over time.