Abstract 5791
Background
There is a great demand for improved oncolytic viruses that selectively replicate inside cancer cells while sparing normal tissues. Here we describe a novel oncolytic adenovirus, Ixovex, that obtains a cancer selective replication phenotype by modulating the level of expression of the different alternatively spliced E1B mRNA isoforms.
Methods
In our work to probe the function of the E1B proteins we generated a virus mutant, the Ixovex virus, in which the SA1 3’ splice acceptor site sequence CAG:GA was mutated to CgG:GA. This single nucleotide point mutation (genomic location 3216) changed aa 399 in the E1B-496R protein from an arginine (AGG) to a glycine (gGG). IxoVex was validated for its viral replication (TCID-50 assay) and cytotoxicity (MTS assay) in a panel of normal and cancer cell lines. Animal studies for anti-tumour efficacy studies were performed in nude mice.
Results
Ixovex is a recombinant adenovirus that carries a single point mutation in the E1B-93R 3’ splice acceptor site that results in an overexpression of the E1B-156R splice isoform. Further, the mutation resulted in a loss of E1B-496R (E1B-55K) protein expression and as a consequence a failure of Ixovex to efficiently degrade the p53 tumour suppressor protein. Ixovex significantly inhibited tumour growth and prolonged survival of mice in an immune-deficient lung carcinoma tumour model. In complementation experiments overexpression of E1B-156R was shown to increase the oncolytic index of both Ad5wt and ONYX-015. In contrast to prior art viruses of similar type, Ixovex includes a functional E3B region for better in vivo efficacy. Ixovex virus, throughout this study has been proven to be by far the superior virus in potency compared to ONYX-015.
Conclusions
The decrease in toxicity and the inhibition of replication in normal cells indicate an astounding safety profile of Ixovex. The observation that the ONYX-015 virus replicated better in normal cells compared to Ixovex is intriguing considering that the ONYX-015 virus carries a large deletion that removes the coding sequences and splice signals needed to express the E1B-496R, E1B-93R and E1B-156R proteins. Ixovex significantly inhibit tumour growth in a human lung carcinoma animal model and that ONYX-015 does not.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
IxoGen.
Disclosure
M. Anwar: Shareholder / Stockholder / Stock options: IxoGen. G. Alusi: Shareholder / Stockholder / Stock options: IxoGen. D. Oberg: Shareholder / Stockholder / Stock options: IxoGen.
Resources from the same session
2888 - Development and validation a nomogram based on pathological microscopic features to predict survival in nasopharyngeal carcinoma and guide treatment decision
Presenter: Kuiyuan Liu
Session: Poster Display session 3
Resources:
Abstract
3607 - Deep learning in nasopharyngeal carcinoma: a retrospective cohort study of 3D convolutional neural networks on magnetic resonance imaging
Presenter: Meng Yun Qiang
Session: Poster Display session 3
Resources:
Abstract
5848 - Combined androgen blockade in patients with advanced androgen receptor–positive salivary gland carcinoma: Exploratory biomarker analyses
Presenter: Chihiro Fushimi
Session: Poster Display session 3
Resources:
Abstract
4484 - Classification of esthesioneuroblastoma (ENB) based on chromosome (chr) arm gain and loss (CNA) in the setting of a hypomutated genomic landscape
Presenter: Russell Madison
Session: Poster Display session 3
Resources:
Abstract
5753 - Trastuzumab plus docetaxel in patients with advanced HER2–positive salivary duct carcinoma: Exploratory biomarker analyses
Presenter: Hideaki Takahashi
Session: Poster Display session 3
Resources:
Abstract
3373 - Development and characterization of salivary gland cancer organoid cultures
Presenter: Wim Boxtel
Session: Poster Display session 3
Resources:
Abstract
3118 - A parent-of-origin effect of the RB1 mutations in retinoblastoma with low penetrance and variable expressivity
Presenter: Ekaterina Alekseeva
Session: Poster Display session 3
Resources:
Abstract
4512 - The humanistic burden reported by patients diagnosed with Recurrent/Metastatic Squamous Cell Carcinoma of the Head and Neck (R/M SCCHN) in Europe
Presenter: Prianka Singh
Session: Poster Display session 3
Resources:
Abstract
3961 - Concurrent Chemotherapy and External Radiation Therapy: An Open Label Non-Inferiority Phase III Randomized Controlled Trial of Weekly versus Three Weekly Cisplatin and Radical Radiotherapy in Locally Advanced Head and Neck Squamous Cell Carcinoma: CONCERT trial
Presenter: ATUL SHARMA
Session: Poster Display session 3
Resources:
Abstract
3973 - A randomized phase II study on the OPTimization of IMmunotherapy in squamous carcinoma of the head and neck (SCCHN) – OPTIM (AIO-KHT-0117)
Presenter: Viktor Grünwald
Session: Poster Display session 3
Resources:
Abstract