Imugene reveals positive imaging data for oncolytic virotherapy candidate CHECKvacc
CHECKvacc is designed to selectively kill tumour cells, while also activating the immune system to attack cancer cells.
Clinical stage immune-oncology company Imugene (ASX: IMU) has revealed what it describes as positive imaging data on its oncolytic virotherapy candidate CHECKvacc in treating metastatic triple-negative breast cancer.
City of Hope’s Dr Jamie Rand, who is Assistant Professor in the division of Breast Surgery within the Department of Surgery, presented the data at the American Association for Cancer Research Annual Meeting 2023 this week in Florida.
Initial imaging data shows CHECKvacc (also known as CF33-hNIS-antiPDL1) was “well tolerated” at all three dose levels across three cohorts in a phase one trial.
CHECKvacc is an armed chimeric vaccinia poxvirus (oncolytic virus) that has been designed to selectively kill tumour cells, while also activating the immune system.
Under the phase one trial in patients with metastatic triple negative breast cancer, CHECKvacc is targeting the PD-L1 protein and activating the local tumour microenvironment.
SPECT imaging results
Single-photon emission computerised tomography (SPECT) imaging was completed on patients with metastatic triple-negative breast cancer in the trial and this data was presented at the Florida conference.
The SPECT imaging was done on patients with this disease that had received CHECKvacc via intratumoral (IT) injection.
In this instance, 75% of the injected breast cancer lesions that received CHECKvacc via IT injection showed enhancement.
Imugene noted this suggests local viral replication with resulting human sodium iodide symporter (hNIS) expression.
hNIS allows Imugene to track where the virus is replicating via SPECT, in real time, during treatment.
SPECT imagining of these patients revealed improved enhancement in subcutaneous nodules, intramuscular nodules and lymph nodes compared to matted dermal metastasis.
Further analysis
Imugene managing director and chief executive officer Dr Leslie Chong said it is “pleasing” to confirm the safety and tolerability of CHECKvacc.
She pointed out the imaging data has revealed “several other positive outcomes” from the first in-human trial of CHECKvacc.
“We’ll complete further analysis of the data and look forward to the trial continuing, with a view to improving the prognosis of a cancer with limited options for its patients,” Dr Chong added.
CHECKvacc and oncolytic viruses
CHECKvacc came from the lab of CF33 inventor Professor Yuman Fong, who is chair of the Sangiacomo Family Chair in Surgical Oncology at City of Hope.
Professor Fong is a noted expert in the oncolytic virus field.
While also selectively killing tumour cells, oncolytic viruses activate the system to fight again the cancer cells, with both actions having the potential to improve clinical response and survival.
CHECKvacc has demonstrated “robust anti-cancer activity” during pre-clinical research in triple-negative breast cancer xenografts.
Triple-negative breast cancer
Pre-clinical trials showed CHECKvacc detected and safely killed triple-negative breast cancer at doses “several magnitudes lower” than other oncolytic viruses currently under clinical investigation.
Triple-negative breast cancer is a subtype of breast cancer – accounting for about 20% of all breast cancer cases.
It has a median survival of 12 months and there is currently no effective targeted therapy in patients where this disease has spread.
Additionally, triple-negative breast cancer rapidly develops resistance to chemotherapy.
As a result, Dr Chong says novel therapies for treating this disease are “desperately needed” to improve clinical outcomes.