Abstract
INTRODUCTION: Spinal muscular atrophy (SMA) is a genetic, progressive neuromuscular disease caused by pathogenic variants in the survival of motor neuron survival of motor neuron (SMN) 1 gene leading to a deficiency in SMN protein. Three disease-modifying therapies are available for the treatment of SMA, affording many with the opportunity for family planning. Fertility outcomes in patients with SMA treated with risdiplam have not been previously reported. METHODS: This study was a multicenter, non-interventional retrospective case review that included three adult male patients with SMA from three sites in Austria and the USA. The primary objective was to characterize the reproductive history and fertility journey of men with SMA who were exposed to risdiplam and whose partner had conceived. RESULTS: Three male patients aged 21-34 years with late-onset SMA were taking risdiplam during the window of conception. Of the three resultant pregnancies, two were full term and resulted in healthy babies and one was voluntarily terminated. The babies were healthy and developing normally. CONCLUSIONS: This series presents three cases of successful conception while a male patient was receiving risdiplam, a US Food and Drug Administration-approved treatment for SMA. Although there were reproductive concerns due to impairment in spermatogenesis that arose during nonclinical studies, this case series demonstrates that there was sufficient sperm production while on risdiplam to result in pregnancy. More research is needed to provide a complete understanding of the effects of risdiplam on male fertility in humans. Graphical abstract available for this article.