Drug that saved Ron Walker could help wide range of cancer patients

A DRUG that saved Ron Walker from melanoma may also be able to save patients from 30 other types of cancer.

Ron Walker has backed a campaign to have Keytruda fast tracked for subsidised use on melanoma.

A DRUG that saved Ron Walker from melanoma may also be able to save patients from 30 other types of cancer.

Immunotherapy drug Keytruda is now showing promising results in 250 international trials, offering hope of a new treatment to thousands of desperate Australians with cancers ranging from breast, pancreatic and lung tumours, to those with leukaemia, myeloma and lymphomas.

Researchers have discovered that the same biomarker the drug aims for in melanoma cells — known as PD-L1 — is also present in many cases of the 30 other cancers.

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This means a new generation of anti-PD-1 drugs like Keytruda and Opdivo may work on cancers that are genetically similar, regardless of where they are located in a patient’s body.

Biomarker tests developed by Keytruda manufacturer MSD show between 15 and 100 per cent of some cancer types may become targets for the drugs, though Peter MacCallum Cancer Centre oncologist Prof Grant McArthur said trials are now determining how effective the treatment was for each disease.

“There is accumulating evidence on the trials of significant rates of tumour shrinkage on more than just melanoma, lung cancer, kidney cancer ... there is a growing list of cancers that do show a response to the PD-1 drugs,” Prof McArthur said.

“These drugs are active in multiple diseases. We are anticipating that these PD-1 drugs like Keytruda, Opdivo and others coming through are going to be used in multiple cancer types.”

Cancers are classified depending on where they occur in a person’s body, with different treatments required for each type.

But, because the new drugs work based on the genetic makeup of the cancer’s cells rather than their placement, they require a new set of processes to determine which patients will benefit.

US-based Dr Ken Emancipator, who developed MSD’s PD-L1 biomarker test, said being able to screen the makeup of a patient’s cancer to determine if it will respond to the medication could be the difference to gaining lie-saving treatment early.

“When the tumour expresses PD-L1 we have identified a patient that is very likely to benefit from an anti-PD-1 therapy,” Dr Emancipator said.

“We are pursuing the test in lots of other cancers. We are looking at monotherapy in 30 different tumour types.”

Ron Walker with Prof Grant McArthur at the Peter MacCallum Cancer Centre, East Melbourne.

The PD-L1 protein usually works to prevent the body attacking its own cells when inflammation occurs. But, because some inflammation-causing cancers have been found to also express PD-L1, drugs that block the protein can trick the body’s immune system into attacking and killing the cancer.

In a further boost researchers believe they may be able to alter other cancers so that they begin causing inflammation, therefore making themselves vulnerable to the new drugs.

After his life was saved as part of a clinical trial, Ron Walker backed a campaign to have MSD’s Keytruda fast tracked for subsidised use on melanoma last year, and last week the Federal Government also subsidised similar PD-1 drug Opdivo.

Dr Emancipator believes the Therapeutic Goods Administration now needs to examine approving drugs based on their effectiveness in treating cancers with similar genetic make-up, rather than classified on their location, to fast track their use.

But TGA spokeswoman Kay McNiece said the impact and safety may vary.

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