Taking the toxicity out of cancer drugs

Researchers are designing implants to boost the effect of chemotherapy on tumours while minimising its toxic side effects, writes…

Researchers are designing implants to boost the effect of chemotherapy on tumours while minimising its toxic side effects, writes Claire O'Connell

Chemotherapy drugs are nasty by nature. But an Irish-owned biotech company is pioneering technology to help make toxic anti-cancer drugs more effective at tumour sites and reduce their undesirable side effects elsewhere in the body.

Researchers at Vienna-based Austrianova have designed tiny implants called Novacaps that can sit near a tumour and boost the effects of chemotherapy drugs in the bloodstream. In early trials the implants lengthened average survival times for patients with pancreatic cancer.

At any one time about 50,000 people in Europe have diagnosed cancer of the pancreas. The tenor Luciano Pavarotti and businessman Tony Ryan both died of pancreatic cancer last year, and survival time tends to be short once the disease has been identified, according to Prof Brendan Buckley of University College Cork's school of pharmacology and therapeutics.

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"Pancreatic cancer tends to present very silently, so it's often quite late on before people realise they have it," he says. "It sits and grows without interfering with much until usually it starts to encroach on the drainage of bile from the gallbladder, so people develop typically painless jaundice and they are found then to have a tumour in the pancreas."

About 80 per cent of these tumours cannot be removed through surgery, and the chemotherapy treatment currently on offer "adds very little to the duration of survival", says Buckley, who runs the European centre for clinical trials in rare diseases at UCC.

Austrianova's approach is to insert Novacaps implants in blood vessels near the tumour. The implants contain human cells that have been specially engineered to boost the effectiveness of a widely used chemotherapy agent.

"When you give somebody [the drug] by conventional means at present, through a vein, you have to have really high concentrations of it so that by the time the drug gets to the cancer there's still enough of it to affect the tumour," says Buckley.

"But that means the drug is hitting all sorts of other organs as well at a high concentration, any dividing cell is going to be affected by it."

However, if the drug-boosting implants are present, the patient needs far less of the toxic drug in their body to do the trick. "You can give a low concentration of [ the drug] so there's very little effect elsewhere in the body yet you get a relatively high concentration of the drug hitting the tumour," he adds.

A single insertion of implants can remain effective for months, says Buckley, and a small early trial in patients with pancreatic cancer saw Novacaps increase average survival times from about 25 to 40 weeks as well as reducing toxic side effects of chemotherapy.

This year UCC will organise further clinical trials of the treatment across Europe, including a site at Cork's Mercy Hospital.

"We will need around 200 and 300 patients and it will be a comparator study," explains Buckley. "So people will be randomly assigned to Novacaps or best conventional care."

Novacaps implants are designed to stop implanted cells being rejected by the body and could be engineered to help treat other cancers as well, notes Buckley. "I think it has very wide potential," he says.

It's a view echoed by Limerick pharmacist Gerard Ryan, whose company, Ryan Holdings Group, invested as the majority shareholder in Austrianova last year.

"We felt we could bring more to the party than just investment and can add skillsets like management of clinical trials and business development.

"And at Austrianova they are gifted scientists, the calibre of the people is very high. In business it's all about trust and knowing who you are dealing with," according to Ryan.