It is currently not used due to the risk of severe side effects related to long-term use. A 2019 meta-analysis suggested that VPA may offer benefits, even without improving functional score. Hydroxycarbamide (hydroxyurea) was shown effective in mouse models and subsequently commercially researched by Novo Nordisk, Denmark, but demonstrated no effect on people with SMA in subsequent clinical trials.Compounds which increased SMN2 activity in vitro but did not make it to the clinical stage include growth hormone, various histone deacetylase inhibitors, benzamide M344, hydroxamic acids (CBHA, SBHA, entinostat, panobinostat, trichostatin A, vorinostat), prolactin as well as natural polyphenol compounds like resveratrol and curcumin. Celecoxib, a p38 pathway activator, is sometimes used off-label by people with SMA based on a single animal study but such use is not backed by clinical-stage research. SMN stabilisation
SMN stabilisation aims at stabilising the SMNΔ7 protein, the short-lived defective protein coded by the SMN2 gene, so that it is able to sustain neuronal cells.No compounds have been taken forward to the clinical stage. Aminoglycosides showed capability to increase SMN protein availability in two studies. Indoprofen offered some promise in vitro. Neuroprotection
Neuroprotective drugs aim at enabling the survival of motor neurons even with low levels of SMN protein. Olesoxime was a proprietary neuroprotective compound developed by the French company Trophos, later acquired by Hoffmann-La Roche, which showed stabilising effect in a phase-II clinical trial involving people with SMA types 2 and 3.
Other
Although the heart is not a matter of routine concern, a link between SMA and certain heart conditions has been suggested.Children with SMA do not differ from the general population in their behaviour; their cognitive development can be slightly faster, and certain aspects of their intelligence are above the average. Despite their disability, SMA-affected people report high degree of satisfaction from life.Palliative care in SMA has been standardised in the Consensus Statement for Standard of Care in Spinal Muscular Atrophy which has been recommended for standard adoption worldwide. Prognosis
In the absence of pharmacological treatment, people with SMA tend to deteriorate over time. Recently, survival has increased in severe SMA patients with aggressive and proactive supportive respiratory and nutritional support.If left untreated, the majority of children diagnosed with SMA type 0 and 1 do not reach the age of 4, recurrent respiratory problems being the primary cause of death. With proper care, milder SMA type I cases (which account for approx. 10% of all SMA1 cases) live into adulthood. Long-term survival in SMA type I is not sufficiently evidenced; however, as of 2007 advances in respiratory support seem to have brought down mortality.In untreated SMA type II, the course of the disease is slower to progress and life expectancy is less than the healthy population. Death before the age of 20 is frequent, although many people with SMA live to become parents and grandparents. SMA type III has normal or near-normal life expectancy if standards of care are followed.