Viral vectors such as adeno-associated virus (AAV) are expected to play a pivotal role in gene therapies for neurology indications, as this vector type is the most dominant among pipeline products classified under gene therapies, according to GlobalData’s Intelligence Center.
Gene therapy for neurological disorders or injury
Of the 38 pipeline products that are currently in development stages (Phase I, II, and III), AAV-based delivery platforms account for 45% of these products. Lentiviral is the other viral-based platform and accounts for 13% of the total products. Among non-viral-based products, antisense oligonucleotides (ASOs) dominate by representing 21% of the total products.
The success of ASOs has largely been due to the mechanism of action (MOA), which has been demonstrated through the commercial success of Biogen’s Spinraza, the first-to-market drug for the treatment of spinal muscular atrophy (SMA). Therapies with similar MOAs are currently being evaluated in other indications such as Alzheimer’s disease, amyotrophic lateral sclerosis, Huntington’s disease, migraine, and multiple sclerosis. Figure 1 shows the percentage of pipeline products by type of delivery platforms.
Figure 1: Percentage of pipeline products by types of delivery platforms for neurology indications
AAV-based viral therapies recently witnessed a milestone when the FDA approved Novartis’ Zolgensma in May 2019 for treatment of children with SMA. The therapy is proposed to work as a one-off therapy to introduce the missing gene that can help in the production of the protein that is otherwise missing in patients with SMA.
As clinical efficacy of AAV-based vectors becomes more established, there is an expectation that applications of these vectors will extend to other neurology indications. Viral vectors are understood to have higher transfection efficacy compared to non-viral vectors, whereas the latter is often associated with a better safety profile. As these pipeline therapies progress through different phases of clinical development, an increased understanding of the different MOAs is expected to lead to an increase in the use of these vectors for various indications.
GlobalData (2019). Gene Therapies in Neurology – Hot Topic Report, to be published