Genzyme Publishes SMN Gene Therapy Study
30 May 2014
The US biotech company, Genzyme, has published new results in animal models supporting the use of harmless, genetically engineered viruses to treat SMA.
Past research has shown that once administered, these viruses are able to travel around the body and target most, if not all, cells and tissues. The viruses can then potentially replace at least some of the survival motor neuron (SMN) protein lost in SMA patients.
Work from a number of different laboratories across the world has shown that delivery of the SMN viruses into SMA model mice can drastically improve symptoms and extend lifespan (for more information click here).
All of this hard work led to the initiation in the US in April 2014 of a Phase I clinical trial of a virus-mediated SMN gene therapy in Type I SMA infants (for more information click here).
As well as showing that the beneficial effects of the SMN gene therapy are dependent on the drug concentration in mice, the new research from Genzyme and collaborators indicates that the efficacy in mice can be translated into larger animal species.
Specifically, by injecting viruses engineered to produce a fluorescent signal, the researchers were able to show that the gene therapy targets up to approximately 35% and 75% of the motor neurons in the spinal cord of young pigs and non-human primates, respectively.
In SMA mice, these percentages were sufficient to positively affect the disease progression when SMN was engineered into the viruses, suggesting that the benefits observed in mice are likely to be translated into larger animals and perhaps humans.
SMN-viruses were not injected into these larger species, because established disease models are not yet available.
Pigs and non-human primates are more closely related to humans, than mice are to humans; the results from the Genzyme study therefore provide additional, continued support for the ongoing Phase I trial of SMN-producing viruses in SMA patients.