A ‘Trojan horse’ drug that attacks tumour cells from within may offer hope to cancer patients with few options left.
A study found the treatment – tisotumab vedotin (TV) – produced promising results in people with six advanced forms of the disease, including tumours of the cervix, bladder, ovaries and lungs.
When TV was given to these patients – who were no longer responding to standard therapies – their tumours shrunk or stopped growing.
A ‘Trojan horse’ drug that attacks tumour cells from within may offer hope to cancer patients who are failing to respond to existing treatments, research suggests (stock)
‘What is so exciting about this treatment is that its mechanism of action is completely novel,’ lead author Professor Johann de Bono – head of the division of clinical studies at the Institute of Cancer Research – said.
‘It acts like a Trojan horse to sneak into cancer cells and kill them from the inside.’
The research was a joint collaboration between the ICR and the Royal Marsden NHS Foundation Trust.
One in two people living in the UK born after 1960 will be diagnosed with some form of cancer during their lifetime, Cancer Research UK statistics reveal.
To test the effectiveness of TV, the drug was given intravenously every three weeks to 147 patients with cancer that had either relapsed, advanced or spread.
The participants were either suffering from cancer of the bladder, cervix, uterus lining (endometrial), oesophagus, lungs, ovaries or prostate.
Results revealed that more than a quarter (27 per cent) of those with bladder cancer benefited from the drug, while 26.5 per cent with the cervical form of the disease saw their tumours shrink or stop growing.
Some 13 per cent of those with oesophageal cancer or non-small cell lung cancer responded, while seven per cent with endometrial tumours benefited from the treatment.
WHAT ARE TUMOURS?
Tumours can be benign or cancerous (malignant).
Benign tumours usually grow quite slowly, do not spread and have a covering made up of normal cells.
Such growths only cause problems if:
- They become become very large
- Are painful or uncomfortable
- Are unpleasant to look at
- Press on the body’s organs
- Take up space within the skull
- Release hormones that affect how the body works
Malignant tumours typically:
- Are made up of cancer cells
- Grow faster
- Spread to surrounding tissue
- Enter other parts of the body via the bloodstream or lymph nodes
Tumours get bigger as cells continue to divide, which stimulates the development of blood vessels to ‘feed’ it oxygen and nutrients.
Such growths may move into new areas by putting pressure on surrounding regions, using enzymes to break down cells or entering via tissues.
Source: Cancer Research UK
These cancers continued to respond to TV for an average of 5.7 months, while some carried on for 9.5 months.
Patients with prostate cancer were the only ones not to benefit.
‘Our early study shows that it has the potential to treat a large number of different types of cancer, and particularly some of those with very poor survival rates,’ Professor de Bono said.
‘We saw some good responses in the patients in our trial, all of whom had late-stage cancer that had been heavily pre-treated with other drugs and who had run out of other options.’
TV is made up of a toxic drug attached to an antibody – a protein produced by the immune system to fight off invading pathogens.
It is designed to target a receptor – called tissue factor – that is found in high levels on the surface of many cancer cells.
When TV binds to the tissue factor, it is able to get inside cancer cells.
Although a ‘toxic drug’, the results of the study – published in The Lancet Oncology journal – reveal the treatment did not cause severe adverse events.
Nose bleeds were the most common side effect, impacting 69 per cent of the participants.
This was followed by fatigue (56 per cent), nausea (52 per cent) and alopecia (44 per cent).
Some of the patients also experienced eye problems, with 43 per cent developing conjunctivitis and 22 per cent dry eye.
These eye problems were reduced when the researchers adjusted the ‘trial protocol’ halfway through the study.
‘TV has manageable side effects,’ Professor de Bono said.
The drug is now being tested in other types of cancer – including bowel and pancreatic – while further trials are being carried out in cervical forms of the disease.
Biopises taken from patients at the start of the studies are also being examined to determine if they express genes for the tissue factor TV targets.
This could allow doctors to gauge whether a patient is likely to respond to the treatment ahead of time.
Professor Paul Workman, chief executive of the ICR, added: ‘We’ve seen major advances against cancer in recent decades, but many tumour types remain very difficult to treat once the cancer has begun to spread.
‘We desperately need innovative treatments like this one that can attack cancers in brand new ways, and remain effective even against tumours that have become resistant to standard therapies.’