In 2020, Professor Shankar Siva, radiation oncologist and researcher at Peter McCallum Cancer Centre received Cancer Council Victoria’s Colebatch Fellowship to explore ideas on how to improve the effectiveness of immunotherapy.
Colebatch Fellow Prof. Shankar Siva
The $1.5m grant has provided financial security for five years to enable Prof. Siva to test the safety and efficacy of combining revolutionary stereotactic ablative body radiotherapy (SABR) with existing immunotherapy drugs to improve immune responses in patients receiving combination therapy for solid tumours.
“With the Colebatch funding, what that’s allowed me to do is to take some time from the daily clinical practice to be able to spend more time with researchers and other clinicians in designing new and novel strategies to approaching cancer,” said Prof. Siva.
Already a pioneer in SABR treatment with more than 90 per cent of his patients responding positively to the technique, Prof. Siva’s latest exploratory work has led to multiple clinical trials testing indications of SABR treatment and immunotherapy in kidney and lung cancers, as well as some breast and prostate cancers.
“SABR has a unique synergy with immunotherapy,” said Prof. Siva.
Colebatch Fellow Prof. Shankar Siva with the SABR machine
“This type of radiation therapy, in particular, works on the areas we treat to allow the immune system to recognise cancers that were otherwise escaping the surveillance that a normal immune system should perform.
“By giving these treatments, we’re eradicating areas that are resistant to immunotherapy, also allowing the immunotherapies to recognise the cancer better and to eradicate other sites of disease.”
The research enabled by the Fellowship has also revealed that the use of SABR alone can elicit responses in the bloodstream that potentially engages the immune system to target cancer elsewhere in the body.
“That in itself is an important discovery,” said Prof. Siva.
“Prof. Siva has become an internationally recognised leader in the SABR treatment of lung and kidney cancers during his tenure of the Colebatch Fellowship, embodying the legacy of Dr John Colebatch who refused to accept cancer as an unbeatable disease. Investing in innovative thinkers yields results and Cancer Council Victoria is proud to back him,” said Prof. Jeremy Millar, Chair of Cancer Council Victoria.
Looking to the future, Prof. Siva says the next step is to see if his discoveries can be translated into global studies to reach many more thousands of patients.
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