Autologous haematopoietic stem cell transplantation for Japanese patients with systemic sclerosis: Long-term follow-up on a phase II trial and treatment-related fatal cardiomyopathy

Objectives: The objective of this study is to elucidate the efficacy and safety of autologous haematopoietic stem cell transplantation (HSCT) for Japanese patients with systemic sclerosis (SSc). Methods: A phase II clinical trial included SSc patients diagnosed within the last three years having at least one of the following clinical features: diffuse skin sclerosis with modified Rodman total thickness skin score (mRSS) ≥ 15, refractory digital ulcer or interstitial lung disease (ILD). HSCT were performed after conditioning using cyclophosphamide. Results: Fourteen patients were enrolled and underwent HSCT. Median follow-up period was 137 months. Overall survival or event-free survival rate was 93% or 40% at 10 years, respectively. Eight patients (57%) achieved more than a 50% decrease in mRSS from baseline within six months after HSCT. Six patients (43%) required additional immunosuppressive treatments due to progression of diffuse skin sclerosis and/or ILD during follow-up period. Adverse events related to HSCT occurred in six patients (43%). Severe cardiomyopathy occurred in two patients, and one of them had a fatal course. Conclusion: HSCT is a feasible treatment bringing favourable results to more than half of our patients with SSc. Careful selection of the patients is essential for whom benefited from HSCT, considering the risk-benefit balance of the treatment.