The spinal muscular atrophy (SMA) market across the seven major markets (7MM – US, France, Germany, Italy, Spain, UK, and Japan) is forecast to grow at a compound annual growth rate (CAGR) of 1.2%, from $2.7 billion in 2023 to $3.0 billion in 2033, according to data and analytics company GlobalData.
GlobalData’s latest report, “Spinal Muscular Atrophy: Seven Market Drug Forecast and Market Analysis” reveals that a key driver of growth in this market is the anticipated launch of three myostatin inhibitors, which will together contribute $259.4 million in sales by 2033.
The 3 Myostatin Inhibitors
SMA patients have reduced levels of survival motor neuron (SMN) proteins due to SMN1 gene mutations or deletions. As such, the current pharmacological management of SMA relies on three SMN-dependent products.
The availability of disease-modifying therapies, Biogen’s Spinraza (nusinersen) and Roche’s Evrysdi (risdiplam), and gene transfer therapy Novartis’ Zolgensma (onasemnogene abeparvovec) have greatly improved disease prognosis. They allow patients to reach normal childhood development milestones.
According to Christie Wong, Managing Neurology Analyst at GlobalData:
“Rather than compete with existing therapies, Scholar Rock’s apitegromab, Roche’s RG-6237/GYM329, and Biohaven’s talditercept alfa are myostatin inhibitors being developed to improve muscle strength and function in patients with SMA. The three myostatin inhibitors are being investigated as adjunctive therapies that intend to be prescribed in combination with marketed SMN-dependent products to optimize therapeutic benefit. As such, polypharmacy in SMA patients is expected to increase over the forecast period.”
Gene Transfer Therapy
Another market driver is the potential label expansion of the intravenous formulation of Zolgensma to SMA patients weighing over 8.5kg and up to 21kg. The intrathecal formulation of Zolgensma for SMA type II patients aged two to 18 years could also be approved.
Wong continues:
“Reaching these regulatory milestones will increase the eligible population for gene transfer therapy, and sales of Zolgensma are projected to increase from $660.6 million in 2023 to $763.8 million by 2033.”
The US represents the largest market for SMA. They accounted for 56.5% of the 7MM sales in 2023. They expect to increase to 59.6% in 2033. According to Wong, the dominance of the US is due to its larger SMA population and higher drug prices.
Challenges
While the SMA market is projected to grow during the forecast period across the 7MM, it may face some challenges. Spinraza is set to lose market exclusivity in 2030 in the US and Japan, and in the 5EU in 2031.
Wong concludes:
“The loss of patent exclusivity will allow cheaper biosimilar versions of nusinersen to enter the market and result in sales erosion of Spinraza. Nonetheless, the launches of the pipeline therapies, coupled with an increase in the uptake of Zolgensma, will fuel market growth in the SMA space.”
