Treatment Expectations for Adults with SMA
Reviewed by: HU Medical Review Board | Last reviewed: August 2021
A common misconception is that spinal muscular atrophy (SMA) only affects children. However, adults make up a large portion of people living with SMA. Even still, most of the research on SMA and its treatments has focused on children.
Because of this, there are large gaps in healthcare for adults with SMA. We do not know as much about how to treat adults with SMA. We also do not yet know how beneficial disease-modifying drugs are. Plus, adults with SMA often struggle to find access to enough physical and mental healthcare.
How does SMA treatment change as an adult?
Advances in SMA treatments are changing the course of the disease for many people. However, most SMA research and advocacy focuses on children because:1,2
- Childhood types of SMA are more common and severe
- Life expectancy for common types of SMA is short
- SMA may be easier to manage in children before it has progressed
However, adults make up about one-third of the global SMA population. Adults with all types of SMA still need treatments and healthcare. Depending on the severity, they need much of the same care as children. They also need access to mental health services and palliative care to maintain their quality of life.1,2
SMA management in adulthood is mostly limited to long-term supportive care to maintain independence. We do not yet have treatments that can stop or reverse the course of SMA in adults. And we do not know as much about how the physical, mental, emotional, or social experiences of adults with SMA.1,2
Many adults with SMA currently feel that healthcare services do not meet their needs. Young adults transitioning from pediatric care face major hurdles in becoming independent. Older adults with newly diagnosed SMA may struggle to find doctors with specific knowledge about SMA. Some challenges that adults with SMA face include:1,2
- Finding specialists and clinics for adults
- Finding financial assistance for equipment
- Feeling undervalued by healthcare services
- Lack of support from society and advocacy groups
- Relying on family and friends for support
- Low access to mental health services
As new treatments increase life expectancy, more adults will be living with SMA. We need more research and training to understand the best way to help adults with SMA.
How effective are disease-modifying drugs in adults?
There are mixed results on the benefits of treatments that have been approved by the U.S. Food and Drug Administration (FDA) to treat SMA in adults. ZolgensmaⓇ (onasemnogene abeparvovec-xioi) is not yet approved for adults. SpinrazaⓇ (nusinersen) and Evrysdi™ (risdiplam) are approved for adults. However, many of the important early clinical studies only tested these drugs in children.3
Small studies have shown these drugs may be beneficial for adults but are not as life-changing as they are for children. In one study, about 40 percent of adults taking Spinraza for 14 months showed meaningful improvements in motor function. Other studies have also shown that Spinraza can stabilize or slightly reduce the severity of symptoms.4-6
However, longer and larger studies are needed to fully understand how beneficial these drugs are for adults. Ongoing clinical trials are evaluating Spinraza in adults with SMA.7
For now, Spinraza and Evrysdi are expensive. The cost of Spinraza and Evrysdi may outweigh the benefits for some adults with SMA. Many adults would prefer not to take Spinraza and instead receive those funds for wheelchairs and other adaptive equipment.8