Australian scientist Jennifer MacDiarmid’s colleague and friend Himanshu Brahmbhatt reckons her toughness has something to do with her Scottish roots.

“They go out there in that vicious cold and they will fight to death,” says Brahmbhatt. “These are valiant fighters.”

Asked about the comment, made in upcoming SBS two-part documentary The Cancer Killers, MacDiarmid chuckles.

“He likes to think that,” she tells The New Daily. “I mean, I’m Scottish a long way back, but yeah, I am tough, I think.

“I am tough bird – and you’ve gotta be.”

In fact, MacDiarmid and Brahmbhatt – who together made a groundbreaking discovery that could revolutionise cancer treatment – have proven themselves equally determined and resilient over a 20-year roller-coaster journey to get their “magic bullet” to patients who need it.

Called EnGeneIC Dream Vector (EDV), it is described as a microscopic Trojan horse that slips inside cancer cells and destroys them from within. Unlike chemotherapy, it spares healthy cells entirely, and doesn’t have dangerous side-effects.

The Cancer Killers, filmed by production company Rymer Childs over 15 years, follows MacDiarmid and Brahmbhatt from labs and clinics to boardrooms in Australia and the US, offering an illuminating behind-the-scenes look at the struggle of bringing a revolutionary scientific discovery to market.

“The series captures not just the science, but the deeply human story – the hope, sacrifice and determination to bring new life-saving treatments to those who need them most,” says Bernadine Lim, senior SBS commissioning editor for documentaries.

The two Sydney-based molecular biologists were actually working on animal vaccines for the CSIRO in the 1990s when a colleague’s shock diagnosis of terminal cancer changed the course of their research and led to their breakthrough.

“Neither of us had been touched by anyone with cancer to that date and to see this young guy, younger than us at the time, succumb really quickly and in a horrific way, it was pretty motivating,” MacDiarmid says.

“He was 39, I think. It was lung cancer and he had no vices that would have precipitated it … he just started coughing up blood suddenly in the lab and he passed away within three months.”

When she Brahmbhatt visited their young colleague in hospital, he told them that if anyone could do something about cancer, it was them.

Jennifer MacDiarmid examines the results of a successful experiment. Photo: SBS

They began meeting at night to discuss ideas, ultimately forming their own small biopharmaceutical company, EnGeneIC – “entry of genes into cancer”. Their major breakthrough came with the discovery that a bacterial nanocell loaded with chemotherapy could be used to target cancer cells while also stimulating a robust anti-tumour immune response.

A key moment was when the treatment was tested successfully on dogs with brain cancer. Matilda, one of the four-legged patients featured in The Cancer Killers, had a brain tumour that disappeared after five weeks of EDV treatment.

But it’s a giant step going from trials involving animals to those using humans. The documentary captures MacDiarmid and Brahmbhatt’s excitement and nervousness as they waited for the initial results from world-first human trials in Melbourne in 2009

“In the film, it shows us in the motel room [next the the hospital] waiting to see that the patient was safe … there’s still that feeling of, ‘Oh my God, this person’s got end-stage cancer and they’ve put their hand up to be the first in line. Will it be OK?’,” MacDiarmid recalls.

“Of course, it was totally safe, but that was incredibly stressful.”

American cancer patient Anne Jonas went into remission after the treatment. Photo: SBS

The Cancer Killers shows the scientists dealing with a succession of challenges, including rivals trying to register copycat patents, the battle to get US Food and Drug Administration approval for human trials in America, and the need for major investment from a big pharma partner to keep EnGeneIC – and the human trials – alive.

This is where science meets business and finance, and it’s not always pretty.

When the scientists visited one venture capitalist in America, his opening gambit was: “This better be good because everyone knows nothing good comes out of Canada or Australia”. Another, MacDiarmid says, did “the thumbs up and thumbs down – like Augustus or somebody in the Colosseum”.

At one point between their meetings in the US, she bemoaned the “biotech valley of death”.

But amid the struggles, she and Brahmbhatt are buoyed by success stories – such as when Anne Jonas, an American patient with end-stage pancreatic cancer, goes into remission. She was given the EDV treatment as a compassionate case study, available to people who have run out of all other treatment options.

“There’s always an upside, a silver lining,” says MacDiarmid. “And we’re very optimistic people.”

Jennifer MacDiarmid and Himanshu Brahmbhatt have travelled to the US multiple times during their roller-coaster journey. Photo: SBS

This month, the team takes another major step forward with the launch of a six-site clinical trial across the US that will target pancreatic cancer, which has no known cure.

After their earlier successful results, the FDA granted the trial fast-track status and allowed them to open it up to “second line” patients – people who are very sick but don’t yet have end-stage cancer.

Finally, there is light at the end of the tunnel. MacDiarmid says they hope to be able to take the treatment to market in the next two to three years, offering an alternative to chemotherapy for the around one in five people who will suffer from cancer in their lifetime.

At the heart of this story – where the stakes are life and death – is the shared passion and dedication of MacDiarmid and Brahmbhatt, whose toughness has certainly been put to the test many times.

“We bounce off each other very well,” MacDiarmid says, when asked about their unique relationship.

“We don’t always see eye to eye; we have fights, but in the long run the important things are always agreed. We thrash it out until we come to a consensus … we always come to the same conclusion eventually.

“One person wouldn’t have survived this … it takes a lot of resilience and part of that is talking to someone about it who understands.”

The first episode of The Cancer Killers airs on SBS on November 4, when both episodes will also be available to screen on SBS on Demand.