Sophia Glenn Photo: Supplied
Some bowel cancer patients are missing out on a publicly funded cancer drug because they have a specific mutation that means they need an additional drug that is not funded and their tumour is on the wrong side of their body.
Bowel Cancer New Zealand and cancer specialists are calling for the wider use of cetuximab for patients who have advanced bowel cancer with a BRAF mutation.
When Sophia Glenn found out the bowel cancer drug cetuximab was finally going to be publicly funded by the government, she was relieved.
Cetuximab was among the 13 cancer drugs the National Party campaigned on before the election and promised it would fund in June. It became available in November.
"I was pretty excited, I thought that that would be a huge saving for my family.
"And then we found out that because the tumour is not on the right side, we are not funded."
Before the cancer spread, the 41-year-old's tumour was on the right side of her bowel. She needed to have a right-sided hemicolectomy to resection the tumour out.
Pharmac only funds cetuximab if it is on the left side of a person's bowel, because the drug does not work for tumours on the right side of the bowel.
Glenn's cancer is now terminal, but her particular cancer is treatable.
That is because she has a specific mutation, called B-RAFS v600E, which can be treated with cetuximab in combination with another drug, encorafenib.
But while cetuximab by itself is publicly funded, the combination is not, so she is having to raise $80,000 for a course of treatment to extend her life.
"We're doing heaps of fundraising and a Givealittle. Everyone in my family is trying to do as much as we can. We don't just have $80,000 lying around. We are a young family, middle class."
Sophia Glenn reading to her son in the hospital. Photo: Supplied
Medical oncologist and professor of cancer medicine at the University of Otago, Chris Jackson, is among cancer specialists who have written to Pharmac, asking for cetuximab to be funded when used in combination with encorafenib.
He said studies have shown the combination is clinically effective for patients who have the specific BRAF mutation.
"Do I think the combination works? - absolutely - I don't think there's any doubt about that, would I like it to be funded? - well absolutely - is it the next best use of Pharmac's funding? Well that's really for them to decide."
Cetuximab by itself is not effective for those who just have a right-sided tumour, but if they have the BRAF mutation, and their tumour also happens to be on the right side of the body, the cetuximab and encorafenib combination will also be effective for them.
Jackson said cancer specialists are not completely sure why cetuximab does not work for patients who need to treat the right-sided tumour by itself, though it involves how someone's body develops as an embryo.
Chemotherapy is used to treat right-sided bowel cancer by itself.
However Jackson said the combination of cetuximab and encorafenib has been available to treat BRAF mutations for several years, but the manufacturers of encorafenib haven't made a funding application to Pharmac.
"I've had a number of people who have the BRAF mutation who want to access cetuximab in combination with encorafenib who do feel like they have been left out and I do understand that.
"I guess from Pharmac's point of view, just because a drug works in one situation, it doesn't mean it works as well in another. And Pharmac takes applications from drug companies for each specific clinical situation, and the people with a BRAF mutation are in a different clinical situation to people without, and the data is different and the effectiveness is different."
It is estimated about 10 percent of advanced bowel cancer patients have a BRAF mutation, according to Pharmac.
Jackson said applications for some newer treatments lag behind because Pharmac's budget had been too small for too long.
"The situation in New Zealand with drug companies is that for a very long time, Pharmac have had a small budget, and they haven't funded many cancer drugs, and there's been a big gap between what's funded in Australia and New Zealand.
"And many companies have responded to that environment by simply not turning up, and not putting applications in."
He said there is a higher chance now, with record investment in Pharmac, that an application to fund the drug could be successful.
Bowel Cancer New Zealand chief executive Peter Huskinson said hundreds of patients like Sophia Glenn are crying out for treatment.
"New Zealand does really, really badly in terms of the high number of people with advance disease, and the poor outcomes for advance disease for bowel cancer; among the worst in the world."
He said patients were relieved cetuximab was made available for use by itself last month, but the combination therapy was needed and could benefit well over 100 people in its first year of funding.
He said when the science shows a treatment works and is available overseas, it should become available for New Zealanders.
For Sophia Glenn, she said she just doesn't understand why the drug is publicly funded for some, but not others.
"It makes the last eight months difficult, it's supposed to be my last happiness, and now it's turned into a financial scramble."
In a statement, a spokesperson for Pharmac said the agency would welcome a funding application for the combination of cetuximab and encorafenib.
"We are aware that there are new studies that have been published for cetuximab used in combination with another medicine called encorafenib (a BRAF inhibitor) for people who have BRAF mutations.
"We are aware that this combination is funded overseas for BRAF mutated cancer. We have not received a funding application for cetuximab in combination with encorafenib and understand that encorafenib is not approved by Medsafe.
"We would welcome a funding application for cetuximab in combination with encorafenib, alongside a submission for Medsafe approval.
"This means we could assess these medicines and prioritise them against other funding options. We have also shared this feedback with the supplier of encorafenib."
