Cancer pill trialled on Victorian patients hailed as ‘game changer’

A new once-a-day pill to control cancer has been trialled on Victorian patients, with the results being hailed as a “game changer”.

Prof Jayesh Desai said most patients on the drug have some measure of disease control.

A new once-a-day cancer pill trialled with Victorian patients is being hailed a “game-changer” by researchers worldwide.

The pill, called divarasib, works by inhibiting the function of a protein called KRAS, one of the most commonly mutated proteins in cancers, that controls how cancer cells divide and survive.

Peter MacCallum Cancer Centre medical oncologist Professor Jayesh Desai said: “When the protein mutates it is always ‘switched on’ which means cells, including cancer cells, are more likely to divide uncontrollably leading to the development of tumours.”

Prof Desai is the senior author of the global study that included around a dozen Victorians.

He helped lead the trial design and the thinking behind how best to use the powerful new drug.

Biomedical animator Dr Maja Divjak shows cells with protein switched “off”.

The research has been published in the prestigious New England Journal of Medicine and has shown that divarasib is “highly effective” in treating patients with advanced or metastatic cancer linked to the KRAS-G12C mutation.

“This is precision medicine,” he said.

“We do a test, we find the cancer gene that has a mutation in it and we have confidence now we can give patients a pill and there is a high chance it will help control their cancer; not cure it, but it is a big step forward.”

Prof Desai said divarasib proved impressive in the Phase 1 trial in targeting a genetic mutation that drives solid cancers including non-small cell lung cancer and colorectal (bowel) cancer.

“There has been a major global effort in trying to target this gene for 30 years. This is a big deal,” he told the Herald Sun.

“We kept chipping away at this one, which is unique, and developing drugs that target it.”

Prof Desai said for patients with cancer caused by a gene mutation, divarasib is a game-changer.

Cells with the protein switched “on”.

“Almost all patients who get the drug get some measure of disease control.”

The drug works by irreversibly locking the protein in an inactive state, stopping tumour cells from growing.

As well as showing an impressive response in patients, the study has also confirmed it is safe and well tolerated.

In the laboratory, it was also found to be 20 times more powerful than existing drugs to treat cancers caused by the KRAS-G12C protein mutation.

The associate director of clinical research and head of early drug development trials at the Peter Mac, Prof Desai said being a senior author means he will be able to bring more of these new drug trials to patients in Australia.

“We are playing a leading role in this and that is important because it means a lot of these trials will come our way and until they come on to the Pharmaceutical Benefits Scheme, that will be the only way for Australian patients to access them,” he said.

For this study there were 137 patients globally with most having non-small cell lung cancer and colorectal (bowel) cancer, but divarasib is also being investigated for pancreatic, ovarian, breast, endometrial and gastric cancers and blood cancers such as myeloma.

“Based on these findings it is being evaluated further in clinical trials … and in combination with other treatments, across a number of cancer types,” Prof Desai said.

While he said it would be a year or two before divarasib, now being developed by Genentech/Roche for the treatment of metastatic or advanced solid tumours, is more widely available larger trials are now being recruited including at sites at the Peter Mac and The Alfred.

Originally published as Cancer pill trialled on Victorian patients hailed as ‘game changer’