Understanding Spinal Muscular Atrophy
Understanding Antisense Oligonucleotides
Patients with profound hypotonia and respiratory failure at birth, a setting in which Spinraza has not been studied, may not experience a clinically meaningful benefit due to severe SMN protein deficiency. There is a risk of adverse reactions occurring as part of the lumbar puncture (e.g headache, back pain, vomiting; see section 4.8 in the SPC. Potential difficulties with the route of administration may be seen in very young patients and those with scoliosis. The use of ultrasound or other imaging techniques to assist with intrathecal administration of Spinraza can be considered at the physicians discretion.
Renal toxicity has been observed after administration of other subcutaneously and intravenously administered antisense nucleotides. If clinically indicated, urine protein testing (preferably using a first morning urine specimen) is recommended. For persistent elevated urinary protein, further evaluation should be considered.
Thrombocytopenia, coagulation abnormalities, including acute severe thrombocytopenia and renal toxicity have been observed after administration of other subcutaneously or intravenously administered antisense oligonucleotides. If clinically indicated, laboratory testing of platelet, coagulation and urine protein is recommended prior to administration of Spinraza.
There have been reports of communicating hydrocephalus not related to meningitis or bleeding in patients treated with nusinersen in the post-marketing setting. See section 4.4 in the SPC (01/2021) for further details.