BALTIMORE (AP) – Scientists often test drugs in mice. Now some cancer patients are doing the same – with the hope of curing their own disease.
They are paying a private lab to breed mice that carry bits of their own tumours so treatments can be tried first on the customised rodents. The idea is to see which drugs might work best on a specific person’s specific cancer.
Hundreds of people in the last few years have made “mouse avatars”.
How it works – Several labs breed these mice but the main supplier to patients is Champions Oncology, a company based in New Jersey that also operates in London, Tel Aviv and Singapore. Patients have a tumour sample sent to Champions, which banks it and implants bits of it into mice kept in a Baltimore lab.
The cost – Champions charges US$1,500 to bank the tumour sample plus $2,500 for each drug tested in groups of mice. Most patients try three to five drugs and spend $10,000 to $12,000. Insurance does not cover the mouse testing; it’s considered very experimental.
The evidence – There isn’t much. Dr Andrew Gaya of Leaders in Oncology Care, a private clinic in London, looked back at how well mice performed in 70 patients whose outcomes from treatment were already known. About 70 per cent of the time, tests in the mice suggested something that turned out to have helped the patients. And if something had not worked in the mice it almost never worked in a patient.
There is no evidence that using mice is any better than care based on medical guidelines or the gene tests that many patients get now to help pick drugs.
The limits – Mouse testing has some drawbacks. It takes several months, so patients usually have to start therapy before mouse results are in. The tumour grafts are under the mouse skin – not in places where the cancer normally occurs, such as the pancreas or lungs, and therefore don’t reflect the human tumour’s environment.
The mice also have highly impaired immune systems so they can tolerate the human tumours. That means they don’t reflect how a person’s immune system would respond to a treatment and cannot be used to test immunotherapies.
The bottom line – The mice may be best for cancers that have spread widely, or that have returned after initial treatment, to help figure out what to try next. That helped Yaron Panov, a 59-year-old Toronto man diagnosed four years ago with liposarcoma, a soft-tissue cancer. No specific drugs were recommended, and “I was given six months to live,” he said.