Outcomes of Patients With Diffuse Systemic Sclerosis Eligible for Autologous Stem Cell Transplantation Treated With...

The study objective was to determine the event-free survival (EFS) of Australian patients with diffuse cutaneous systemic sclerosis (dcSSc) who met eligibility criteria for autologous stem cell transplant (ASCT) in previously published randomized controlled trials but were not treated with ASCT.

Patients who met inclusion criteria for the Autologous Stem Cell Transplantation International Scleroderma (ASTIS) and Scleroderma: Cyclophosphamide Or Transplantation (SCOT) trials were identified from the multicenter Australian Scleroderma Cohort Study (ASCS). EFS (survival without cardiac, renal, or pulmonary failure or death) at 4 years was assessed. ASCS patients who had already undergone transplantation were excluded from analysis.

Of the 492 patients with dcSSc in the ASCS, 56 met ASTIS inclusion criteria for ASCT (56 of 492 [11.4%]) and 30 met SCOT inclusion criteria (30 of 492 [6.1%]). An additional 11 patients met ASTIS or SCOT inclusion criteria, but they were excluded due to severe organ manifestations. EFS at 4 years in ASCS patients meeting ASTIS inclusion criteria was 83.3% and in ASCS patients meeting SCOT inclusion criteria was 81.2%. EFS at 4 years in ASCS patients who met ASTIS and SCOT inclusion but also exclusion criteria was 46.7% and 45.7%, respectively.

ASCS patients meeting ASTIS and/or SCOT inclusion criteria who were not treated with ASCT have similar EFS at 4 years as 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.