Spinal Muscular Atrophy: Benefits of Zolgensma vs Spinraza

What is SMA (Spinal Muscular Atrophy)?

(SMA) is a group of hereditary progressive diseases that destroy motor neurons—nerve cells in the brain and spinal cord. These cells are responsible for the control of essential skeletal muscle activity such as speaking, walking, breathing, and swallowing, leading to muscle weakness and atrophy. Our physiotherapist (in the video below) speaks about SMA and how it prevents children from simple movements. She explains contemporary therapeutic practices which can aid in overcoming some movement challenges in their hands and feet.

Treatment & Medication: Benefits of Zolgensma vs Spinraza

On 24th of May 2019 the U.S. Food and Drug Administration (FDA) approved Zolgensma (onasemnogene abeparvovec-xioi) the first gene therapy to treat children less than two years of age with Spinal Muscular Atrophy (SMA). Zolgensma directly addresses the root cause of the disease by providing a functional copy of the SMN gene, restoring functional SMN protein in motor neurons, preventing neuronal cell death, and halting disease progression (Al-Zaidy, SA & Mendell JR, 20019). The difference between Zolgensma and Spinraza is the frequency of given the medicine. Zolgensma is a 1-time treatment (IV infusion) as Spinraza is multiple spinal infusions each year.

A lot of research has been done to show the effectiveness of this new gene therapy. In 2019 Al Zaidy, S et all. Performed an open-label study where they included 12 genetically confirmed infants with SMA type 1 who received a one-time intravenous therapeutic dose of Zolgensma. They followed them up after 2 years. The outcome was significant; 11 children achieved sitting unassisted along with the ability to feed orally and the ability to speak, two patients were walking independently, and all children survived without the need for permanent ventilatory assistance.

The big question is: what are the costs? Zolgensma is estimated at around 2.1 million USD and Spinraza is 625,000 to 750,000 USD in the first year and ~375,000 USD every subsequent year for the rest of the child’s life. In may 2019 there was a cost-utility analysis done where both medicines were compared. They used health status based on gross motor milestones that were achieved by treated patients. The long-term value (cost-effectiveness) of Zolgensma is clear. The first two years of treatment with Spinraza cost around 50 % of one Zolgensma infusion, but Spinraza must continue for life at a cost of 375,000 dollar each year (Malone, DC. Et all. 2019).

References
Al-Zaidy SA, Mendell JR. (2019) From clinical trials to clinical practice: practical considerations for gene replacement therapy in SMA type 1. Pediatr Neurol. 100:3–11.
Al-Zaidy S, Pickard AS, Kotha K, et al. (2019) Health outcomes in spinal muscular atrophy type 1 following AVXS-101 gene replacement therapy. Pediatr Pulmonol. 179–185
Malone DC, Dean R, Arjunji R, et al. (2019) Cost-effectiveness analysis of using onasemnogene abeparvocec (AVXS-101) in spinal muscular atrophy type 1 patients. J Mark Access Health Policy.