Too Little Known About Care Needs of Adults with SMA, Study Says

A better understanding of the needs of adults with spinal muscular atrophy (SMA), best ensuring for their mental and social — as well as physical — well-being, is necessary to guide future research, care recommendations, and policy decisions, a review study states.

Among its findings was strong support for treatments that work to stabilize their disease, preventing the loss of further mobility, including control over their fingers.

The review, “Health, wellbeing and lived experiences of adults with SMA: a scoping systematic review,” was published in the Orphanet Journal of Rare Diseases.

With the approval of disease-modifying therapies in recent years, the landscape of SMA has changed dramatically, the researchers note. However, studies of these treatments focus almost exclusively on children with SMA — indeed, most SMA research centers on children.

How SMA affects adults in day-to-day life, and what therapies best help to ease disease burden in this group — which the study estimated to be more than 25% of all SMA cases worldwide — is not fully understood.

“The purpose of this scoping review was to synthesize and critically appraise the available evidence on the natural history, clinical management, physical and mental health, quality of life, and lived experiences of adults with SMA to advance future health policy, practice and research,” its researchers wrote.

They examined 95 published scientific papers, including qualitative and quantitative studies, case reports, and consensus statements on standard of care. Most of these studies involved patients with SMA types 2 and 3, and adult age was defined as 17 and older.

Nineteen studies examined the disease’s natural history, or its course in the absence of treatment. Findings showed that muscle strength and motor function tended to decline with increasing age, but this decline could be fairly slow, particularly when studies examined patients for longer than two years. There was also substantial person-to-person variability (heterogeneity) in the natural disease course.

Twenty-one studies addressed the lived experience of adults with SMA. Physically, these people reported limitations affecting their ability to independently perform such day-to-day tasks as eating and going to the restroom.

“People with SMA universally stated that maintaining stability of their current functional ability was important,” the researchers wrote. “One example was that small changes in being able to move one’s finger half an inch could be the difference between being able to operate a power wheelchair or not.”

Challenges in mental health and being socially active were also highlighted. Many adults with SMA report feelings of stigma, particularly in gatherings where accommodations for those with different levels of physical ability are lacking (e.g., wheelchair accessibility).

“The factors identified as important to psychological well-being included autonomy, competence and social participation along with resilience, determination, hope and an optimistic view of life,” the researchers wrote. “The major emotional challenges voiced by people with SMA were coping with frustration, guilt and stress alongside desire for independence.”

Forty-six studies addressed clinical care for these adults. Broadly, these studies highlighted a breadth of options for supportive care (e.g., physical therapy), but lacked a clear consensus on best care.

“It is essential for future consensus guidelines to include a specific focus on the management of adults with SMA,” the researchers wrote.

A few studies assessed a range of medications given adults with SMA; most failed to find statistically significant treatment benefits. One open-label study and seven case reports supported Spinraza (nusinersen) as safe and effective in adults with SMA. Spinraza, by Biogen, is also, at present, the only targeted treatment approved for SMA patients regardless of disease type and age.

Researchers did not specify the open-label study they were referring to, but SHINE (NCT02594124) is an ongoing Phase 3 open-label extension study in a range of SMA patients, including those with later-onset disease. All enrolled took part in previous Spinraza investigational trials, including the Phase 3 CHERISH (NCT02292537) and the earlier CS2/12 (NCT01703988). This safety and efficacy study, which opened in late 2015, is set to conclude in August 2023.

Disease heterogeneity and slow progression in adults with SMA “has contributed to the paucity of research and lack of efficacy in the limited number of trials to date,” the researchers wrote. This points to a need to identify more sensitive measures of treatment effectiveness, such as blood markers, which could be feasibly used in clinical trials over shorter periods.

Despite the importance of mental health among adults with SMA, “no literature … described mental health care for adults with SMA or evaluated transition into the adult service,” the researchers wrote, highlighting a substantial gap in knowledge and care of adults living with SMA.

“Identifying gaps in knowledge is essential to guide future clinical research, best practice care, and advance health policy with the ultimate aim of reducing the burden associated with adult SMA,” the team concluded.