OXFORD, England, Sept. 27 (UPI) -- A drug designed for patients with Duchenne muscular dystrophy was shown in a study with mice to help spinal muscular atrophy, according to new research.
The drug Pip6a-PMO significantly extended survival for mice with SMA, suggesting it could be effective at doing the same for humans in a clinical trial planned for next year, researchers report in a study published in the Proceedings of the National Academy of Sciences.
The drug reversed the effects of SMA, which is caused by a lack of the gene survival motor neuron 1, making patients unable to produce enough of the SMN protein, leading to motor neuron degeneration and progressive muscle weakness.
The main treatment for SMA is a splice-switching oligonucleotide, or SSO, which alters a similar gene, SMN2, so that it includes a part found on SMN1, though the drug must be injected into the spine and carries side effects, which were not seen in experiments with the new drug.
Related
"While Pip6a was initially designed for Duchenne muscular dystrophy, we have shown that it can also be highly effective in SMA treatment," Dr. Suzan Hammond, a researcher at the University of Oxford, said in a press release. "The survival of mice in this trial was far longer than any other treatment."
For the study, groups of mice pups with genetically engineered SMA were either injected with Pip6a-PMA or nothing, with those receiving treatment showing a response almost immediately.
Seven days after treatment, the pups were heavier and growing faster than those not treated, an effect that continued for at least 12 days. The pups treated with one dose survived a median 167 days, compared to about 12 for those not treated.
Some pups were given a second dose of Pip6a-PMA, surviving at least 200 days and a median of 457 days -- 38 times longer than untreated mice and three times longer than those receiving just one dose.
The researchers say they are planning a two-year study of the drug's efficacy in patients, and that the drug delivery technique used for SMA could be adapted for other similar diseases.
"The advantage is that it is both a central nervous system treatment and a systemic treatment for the wider body," Hammond said. "Such an approach could also work for diseases like Parkinson's, Huntingdon's and ALS, and our focus will be extending the clinical applications of Pip-PMOs."
