It consists of recombinant adenovirus engineered to code for p53 protein (rAd-p53) and is manufactured by Shenzhen SiBiono GeneTech.
[3] Ad-p53 seems to act by stimulating the apoptotic pathway in tumour cells, which increases the expression of tumour suppressor genes and immune response factors (such as the ability of natural killer (NK) cells to exert "bystander" effects).
It also decreases the expression of multi-drug resistance, vascular endothelial growth factor and matrix metalloproteinase-2 genes and blocking transcriptional survival signals.
p53 mutation status of the tumour cells and response to Ad-p53 treatment are not closely correlated.
Contusugene ladenovec (Advexin), a similar gene therapy developed by Introgene that also uses adenovirus to deliver the p53 gene, was turned down by the FDA in 2008[5] and withdrawn by the maker from the EMA approval shortly after.