Long Term Safety of Amifampridine Phosphate in Spinal Muscular Atrophy 3

This open-label outpatient extension study was designed to evaluate the long-term safety and tolerability of amifampridine in patients diagnosed with SMA Type 3. In addition, the evaluation of the effects of amifampridine on the QoL was performed. The study was planned to enroll those patients who had completed the SMA-001 study and after all final evaluations for that study had been completed, or those who demonstrated benefit after completing the dose titration period but failed to meet the randomization criteria on Day 0 of SMA-001.

The duration of participation for each patient was expected to be at least 12 months as patients could continue in the study until amifampridine was approved by Regulatory Agencies or the clinical development of amifampridine was terminated for this indication. In addition to amifampridine, patients continued to receive previous concomitant medications, as needed.