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
4868 - Evaluation of markers associated with efficacy of abiraterone acetate plus prednisone (AAP) in patients (pts) with castration-sensitive prostate cancer (mCSPC) from the LATITUDE study
Presenter: Kim Chi
Session: Poster Display session 3
Resources:
Abstract
4837 - LRP2, a potential new biomarker for Chinese younger aged intrahepatic cholangiocarcinoma patients
Presenter: Xiaoliang Shi
Session: Poster Display session 3
Resources:
Abstract
1286 - Reanalysis of the efficacy of molecular targeted agents (MTAs) given in the randomized trial SHIVA01 according to the ESMO ESCAT scale of actionability
Presenter: Aurelie Moreira
Session: Poster Display session 3
Resources:
Abstract
2736 - Comparison of Platforms for Determining Tumor Mutational Burden (TMB) From Blood Samples in Patients With Non-Small Cell Lung Cancer (NSCLC)
Presenter: Jonathan Baden
Session: Poster Display session 3
Resources:
Abstract
5045 - Comprehensive Pan-Cancer analysis of somatic mutations in drug transporters to reveal acquired and intrinsic drug resistance in 3149 metastatic cancer patients
Presenter: Sander Bins
Session: Poster Display session 3
Resources:
Abstract
4577 - Pan-Cancer Genomic Landscape of the Cyclin D1/FGF3,4,19 (11q13) Amplicon Including Associations with HPV Status, and ESR1 and AR Alterations
Presenter: Jennifer Johnson
Session: Poster Display session 3
Resources:
Abstract
5366 - Co-occurrence of NTRK fusions with other genomic biomarkers in cancer patients
Presenter: Xiaolong Jiao
Session: Poster Display session 3
Resources:
Abstract
4084 - Prospective comparative study of next-generation sequencing on fine needle aspirations versus core needle biopsies in cancer patients included in SHIVA02 trial
Presenter: Julien Masliah-Planchon
Session: Poster Display session 3
Resources:
Abstract
6017 - First national External Quality Assessement for the interpretation of somatic variants: assessment of 25 variants in colorectal, lung, ovarian cancers and melanoma in France
Presenter: Etienne Rouleau
Session: Poster Display session 3
Resources:
Abstract
2283 - Prospective testing of circulating tumor DNA in metastatic breast cancer facilitates clinical trial enrollment and precision oncology
Presenter: Andjelija Bujak
Session: Poster Display session 3
Resources:
Abstract