Australian biopharmaceutical company Imugene (ASX: IMU) has reported “superior cancer growth inhibition” from a newly-acquired checkpoint inhibitor cancer vaccine, during preclinical trials with an existing industry-standard monoclonal antibody in validated models of colorectal (colon) cancer.
The KEY-Vaxx vaccine, acquired from Ohio State University, has been compared to industry-standard monoclonal antibody drug Keytruda, marketed by Merck and currently dominating the checkpoint inhibitor space.
Imugene’s preclinical KEY-Vaxx trial targeted PD-1, which is a key switch of the immune system’s ability to find and eliminate cancerous cells.
KEY-Vaxx aims to teach and induce the body to generate its own antibodies against PD-1-expressing cells and is the first report of treating cancer via this method.
Pre-clinically, the murine CT26 colon carcinoma line has become a platform model for evaluating the potential of drug combinations with immune checkpoint inhibitor antibodies.
Imugene said CT26 is a highly immunogenic tumor which “tends to show objective response rates to a number of commercially available checkpoint inhibitors”.
Synergies with breast cancer vaccine
Imugene’s lead product, the HER-2+ cancer immunotherapy HER-Vaxx, has entered a Phase 1b/2 clinical trial for gastric cancer.
HER-2 is a receptor which communicates molecular signals from outside to inside a cell and controls the activation of genes which in turn control cell multiplication, proliferation and tumour cell spread.
In some cancerous cells, including those present in certain types of breast and gastric cancers, HER-2 is over-expressed, causing cancer cells to reproduce uncontrollably.
While recruitment of Imugene’s HER-2+ gastric trial continues, Imugene managing director Leslie Chong said early stage pre-clinical results for KEY-Vaxx have also been promising.
“Importantly [in our trials], KEY-Vaxx not only inhibited cancer cell growth as a monotherapy, but also showed synergistic activity with the HER-2 vaccine in a second study utilising a CT26/Her-2+ cell line,” she said.
Ms Chong said the potential for combining KEY-Vaxx with HER-Vaxx in HER-2+ cancers will be investigated following an initial Phase 1 KEY-Vaxx trial.
Imugene is currently consulting with international oncology leaders and regulatory consultants regarding the clinical development of KEY-Vaxx.
The “cornerstone” of cancer therapies
The checkpoint inhibitor class of monoclonal antibody therapies have shown strong promise in the treatment of various cancers since Keytruda received approval from the Food & Drug Administration in 2014.
According to Imugene, checkpoint inhibitors have become “the cornerstone of cancer therapies”, yielding positive results in a certain percentage of cancer patients including those who did not respond to conventional treatments.
The company believes the global immune checkpoint inhibitor market will surpass US$25 billion by 2022, with checkpoint inhibitors accounting for a substantial percentage of all cancer immunotherapy revenue by 2028.
In June, Imugene announced a A$20.1 million capital raising to primarily fund the development of its clinical portfolio of cancer vaccine technologies and related intellectual property acquired from Ohio State University and the Mayo Clinic.
Proceeds will also go towards expanding Imugene’s ongoing clinical programs, notably the Phase 1 KEY-Vaxx (PD-1 checkpoint inhibitors) vaccine.
At mid-afternoon, shares in Imugene were up 4.17% to $0.025.