Autologous haematopoietic stem cell transplantation in non-MS neuroimmunological diseases

Central and peripheral nervous system autoimmunity has varying pathomechanisms, mandating different treatment approaches. Whilst most patients respond to standard therapy (DMT), responses may be incomplete or non-sustained. Autologous haematopoietic stem cell transplantation (aHSCT) has been reported as an immune reconstitution in refractory neuroimmunological disease. Here, we evaluate the safety and efficacy of aHSCT in patients with non-MS neuroimmunological diseases, treated at St Vincent's Hospital, Sydney. Data from a single-centre, prospective, phase II clinical trial utilising aHSCT in cases of refractory neuroimmunological diseases (non-MS) comprised 12 patients treated at St Vincent's Hospital, Sydney between May 2013 and September 2021 (HREC Ref: HREC/10/SVH/135, ACTRN12613000339752). The primary outcome was safety, defined as Day-100 transplant-related-mortality (TRM). Secondary outcomes included efficacy as determined by remission, disability scores and quality of life metrics by disease subtype. 12 patients (4 systemic lupus erythematosus (SLE)/ central nervous system (CNS) vasculitis, 3 chronic inflammatory demyelinating polyneuropathy (CIDP), 2 stiff-person syndrome (SPS), 1 Behçet's Disease (BD), 1 opsoclonus-myoclonus-ataxia syndrome (OMAS), 1 neurosarcoidosis) underwent aHSCT. TRM was 0 % and adverse effects were consistent with expected toxicities from aHSCT. Five of 12 patients were relapse-free after aHSCT at median follow up of 36 months (range 12 - 60). Five patients remained off immunosuppressive therapy at last follow-up. Clinical evidence to support the use of aHSCT in treatment-refractory neuroimmunological diseases is scant. This study highlights the experience of the largest Australian autoimmune disease transplant unit over the last decade, shedding light on which neuroimmunological conditions beyond MS, may be more likely to benefit from aHSCT.