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PsiOxus Therapeutics expands clinical studies for immuno-oncolytic treatment following positive response to intravenous delivery

PsiOxus Therapeutics Ltd. (PsiOxus), an Oxford, UKbased biotechnology company developing innovative oncolytic immuno-oncologytreatments for cancer, has expanded two of its on-going phase I studies using its anti-cancer treatment candidate, enadenotucirev (EnAd), an oncolytic Ad11/Ad3 chimeric group B adenovirus. The expanded studies, introduce a number of additional cancer types into the programme, as a result of phase I data demonstrating the successful tumour delivery of EnAd through intravenous administration. The treatment was generally well tolerated with repeated dosing. PsiOxus has already enrolled its first patients in each indication of the expanded studies.

MoA study to target non-small cell lung, bladder and kidney cancer

The initial study, a phase I mechanism of action (MoA) study of intra-tumoural and
intravenous administration of EnAd in colon cancer patients, has been expanded to
include intravenous delivery to three additional tumour types, non-small cell lung,
urothelial bladder and renal cell cancer. Initial results of the MoA study in colon
cancer found that intravenous delivery was as effective as intra-tumoural delivery.
Additionally, virus replication was reported in the tumour tissue but not the
surrounding normal cells, while CD8+ T-cells were shown to have successfully
infiltrated the tumour, which is not normally seen in most colon cancers.

EVOLVE study moves to include repeat intravenous dosing

The EVOLVE (EValuating OncoLytic Vaccine Efficacy) trial has expanded to include
repeat intravenous dosing of EnAd in metastatic urothelial bladder cancer. EVOLVE
is a first in human phase I/II study to determine the dose, safety, tolerability and
potential efficacy of EnAd when delivered intravenously to patients with epithelial
cancers. It is the first clinical study to report that live replicating oncolytic virus has
been recovered directly from the blood stream of cancer patients.

Results of this dose escalation study identified a phase II dose for single and repeat
dosing of EnAd via intravenous administration. This feature of EnAd distinguishes it
from most other oncolytic viruses, where effective delivery to tumours via
intravenous administration is not seen.

Dr Christine Wilkinson-Blanc, CMO of PsiOxus, commented: “To date, convincing
clinical success with oncolytic viruses has been associated largely with intratumoural
delivery, and little evidence existed to prove that the systemic delivery of
viruses to tumour cells by intravenous administration could be successful. The
initial results of our clinical programme suggest that EnAd can target tumour cells
following intravenous administration and then replicate. This marks a significant
breakthrough in the development and utility of oncolytic viruses in cancer.”

Progress of the EnAd program is also being driven by the company’s next generation
“Armed EnAd” anti-cancer therapeutic platform, which makes it possible to further
enhance EnAd with genetic instructions for specific anti-cancer molecules such as
therapeutic antibodies, which are then produced “in situ” in the tumours. Full
details can be found on the PsiOxus website.

About PsiOxus Therapeutics, Ltd.

PsiOxus Therapeutics is an Oxford, UK-based development stage biotechnology
company with a particular focus in immune therapeutics in oncology. PsiOxus has
developed a patented platform of tumour-targeted delivery based on its oncolytic
vaccine, enadenotucirev (EnAd). EnAd’s unique design allows it to be delivered
systemically via intravenous administration. The anti-cancer scope of EnAd can be
expanded through “arming” – a process that involves addition of new genes into
EnAd. The “Armed EnAd” platform makes possible creation of a broad range of
unique oncolytic immune therapeutics, including oncolytic vaccines that express
one or more antibodies (AbEnAd), cytokines or other immune-modulatory proteins,
or nucleotide based payloads such as RNAi. The Armed EnAd platform is in
preclinical stage, while phase I/II clinical trials of the unarmed EnAd are ongoing in
different tumor types.