Outcomes of conventionally-treated systemic sclerosis patients eligible for autologous haematopoietic stem cell transplantation.

Autologous haematopoietic stem cell transplantation (HSCT) has exhibited superior efficacy compared to conventional immunosuppressives in rapidly progressive diffuse systemic sclerosis (SSc) patients, albeit still of limited availability. We examined disease outcomes of conventionally-treated real-world inception patients eligible for HSCT, according to HSCT criteria used in the ASTIS and SCOT randomised trials, and compared them to the outcomes of participants in these trials. Overall and event-free survival rates in our inception cohort were analysed at 4.5 and 7 years after HSCT criteria fulfilment and compared to those reported in HSCT and control arms of ASTIS and SCOT. Forty-five of our 142 inception cohort patients fulfilled HSCT criteria within 4 years from disease onset and had comparable baseline characteristics to SCOT/ASTIS patients. Four patients underwent HSCT. The remaining 41 were treated with conventional DMARDs: cyclophosphamide (n=24), mycophenolate mofetil (n=17), rituximab (n=2), tocilizumab (n=3), methotrexate (n=6) or combinations and their 10-year survival was 56% vs. 76% in those with diffuse SSc not fulfilling HSCT criteria. Their survival rates at the time endpoints of SCOT and ASTIS (4.5 and 7 years, respectively) were comparable to the conventionally-treated SCOT/ASTIS control groups. Extrapolating from SCOT/ASTIS results, if all our patients had undergone HSCT promptly, their overall and event-free survival rates could have increased from 73/51% to 83/72% at 4.5 years, and from 63/39% to 76/72% at 7 years, respectively. Wider availability and physician's early acknowledgement and referral of eligible patients for HSCT could significantly improve disease outcomes of rapidly progressive diffuse SSc patients.