In Italy, nusinersen (Spinraza®) is available for all types (from 1 to 4) of SMA, although the clinical trials which have demonstrated the efficacy of the product have concerned mostly children.
To benefit from more data on the safety and efficacy of nusinersen in adults with SMA, a retrospective Italian study was conducted in 13 adults with type 2 SMA and 103 with type 3 SMA, which were grouped into 2 categories. : those who are able to sit (but not walk) or “sitters” and those who can walk a few steps without the help of others (independently or with an aid such as a cane) or “walkers “. The median age at the first injection of nusinersen was 34 years.
Improvements in type 3 SMA
After 14 months of follow-up, the motor function (measured by HFMSE) of adults with type 3 SMA improved, more for adult « sitters » than for « walkers ». Regarding the functional capacities of the upper limbs (measured by the RULM), the improvement only concerns adult « sitters » (probably due to a ceiling effect in « walkers »). In adult « walkers », an improvement in vital capacity has also been observed.
No significant difference in type 2 SMA
For adults with type 2 SMA improvements in HFMSE or RULM are not significant. The authors explain that the small number of participants with type 2 SMA would not allow a definitive conclusion, even if a stabilization of motor function could be considered a positive effect of nusinersen in view of the natural history of the disease.
