A new breed of drugs that reduces the number of deaths from bladder cancer could also replace chemotherapy treatment for other types of cancers.
The medicines, which are known as antibody-drug conjugates (ADCs), carry out chemotherapy-like attacks on cancer cells but don’t cause side effects such as hair loss, fatigue and nausea.
The treatment is highly accurate, targeting tumours without harming healthy tissue, so doctors are able to give high doses.
Early research with the ADC drug enfortumab vedotin on bladder cancer has already shown it to cut deaths by a third – and trials are under way to test the effectiveness of the experimental therapy on breast and prostate cancer.
Professor Thomas Powles, oncologist, director of the Barts Cancer Centre and lead UK researcher for the trial, says ADCs mark ‘a new chapter’ in cancer treatment and could even lead to a cure.
The medicines, which are known as antibody-drug conjugates (ADCs), carry out chemotherapy-like attacks on cancer cells but don’t cause side effects such as hair loss, fatigue and nausea
He says: ‘Chemotherapy is something of a blunt tool. When chemotherapy drugs enter your body, they damage cancer cells but they also damage your healthy cells.
‘This causes side effects such as hair loss and nausea.
‘ADCs are able to transport cancer-killing drugs directly to the cancer cells with limited effect on the rest of the body. This treatment will allow more patients to live a relatively normal life for longer.
‘We’re still in the early days but this could eventually replace chemotherapy completely.’
ADCs are artificial antibodies – similar to those naturally produced by the immune system but designed to hunt for a particular protein found in cancer cells. They are also made to carry a ‘payload’ of chemotherapy medicine.
When they find their target, they attach themselves, delivering the dose directly into the tumour.
The technology means doctors are able to hit the cancer with larger amounts of medication without fear of seriously damaging the body.
Prof Powles says: ‘Different cancers create different proteins and ADCs can be adapted depending on the cancer. What’s more, the payload can be whatever type of cancer-killing drug you need.’
Weird science: Woman who cried tears of blood…
Tears of blood may sound like something from macabre fiction but, in fact, it’s a rare medical condition.
The British Medical Journal this month carried a report of one such bizarre case – a 25-year-old Indian woman who had attended a hospital in Chandigarh, northern India, complaining that blood was coming out of her eyes.
Doctors diagnosed vicarious menstruation.
Experts say this isn’t actual menstruation, instead it’s thought that hormonal changes in the body could weaken already thin blood vessels, causing a bleed in the vessels connected to the eye.
Doctors stopped the woman’s bleeding by prescribing the contraceptive pill.
Data published last month from Prof Powles’ trial with ADC enfortumab vedotin showed encouraging results. The trial included patients with advanced bladder cancer which had spread to other organs.
Typically, these patients would on average be likely to live no more than six months. For those on enfortumab vedotin, survival more than doubled to an average of 13 months.
The therapy is not without downsides – patients suffer skin rashes, and pins and needles are common, but this can be managed.
Every year, more than 10,000 Britons are diagnosed with bladder cancer. If the disease spreads to other organs, as is often the case, then it becomes near-on incurable – and every year, more than 5,000 Britons die from it.
Many patients undergo radical surgery to remove the bladder and other surrounding organs, before going on to a course of chemo. They may also be offered radiotherapy or immunotherapy.
But, over time, all treatments become ineffective against bladder cancer.
Patients on the ADC trial were given enfortumab vedotin after all other treatments had been exhausted. They visit hospital once a week for three out of four weeks in a month, where the drug is administered via a drip.
The treatment takes an hour. They will often stay on the treatment for as long as a year, depending on how responsive their cancer is to the drug.
One patient to undergo the treatment was Peter Smith, 74, a retired plumber from London. He was diagnosed with advanced bladder cancer four years ago after noticing blood in his urine, and it had spread through his pelvis and into his lungs.
He says: ‘I wasn’t sure how much longer I had.’
Peter was enrolled to the ADC trial and began taking enfortumab vedotin 18 months ago – and his cancer stopped growing. He says: ‘I felt a massive weight off my shoulders, knowing the cancer was under control.’
After 12 months, Peter came off the treatment and now undergoes scans every six weeks to keep an eye on the cancer.
Upcoming trials will investigate the effects of a combination of ADCs and immunotherapy.
Prof Powles says: ‘If we could use ADC to keep the cancer in check, while immunotherapy trains the body to fight the cancer on its own, we may soon be talking about a cure for this horrible cancer, and others, too.’