Approximately 15-20% of breast cancer cases are described as triple-negative, meaning they do not have receptors for the hormones estrogen or progesterone, and do not overexpress the protein HER2/neu. Therefore, this type of cancer is unable to respond to therapies that target these receptors.
Patients with triple-negative breast cancer often undergo chemotherapy, combined with surgery and radiotherapy. A combination of anti-cancer drugs is usually given, but these have substantial side effects. This restricts how much drug can be given, and how often, significantly limiting the effectiveness of the treatment. Delivering these drugs at the right dose in these tumours could overcome this issue.
Image-guided drug delivery is a relatively novel concept that is starting to gain clinical relevance. Whilst the focus has often been on single drug carriers, for the first time, a team of researchers from the School of Cancer & Pharmaceutical Sciences, led by Dr Maya Thanou, have developed the technology for the co-delivery of two different anti-cancer drugs. This is valuable since multi-drug combinations often have a synergistic effect, giving much better treatment of difficult tumour types.
The nanosized drug carriers, which encapsulate the drugs in the bloodstream, not only protect the drugs, but also reduce their toxic side effects. The addition of imaging tracers allowed the team to follow their movement in the blood, as well as observe how rapidly they accumulated inside a tumour. The carriers can then be triggered to release the drugs by heating them with focused ultrasound to selectively warm the cancerous tumours without affecting other tissues.
This combination of drug carriers, imaging and ultrasound allows us to deliver several drugs to tumours at a high dosage, in a short time, in a highly localised manner. This maximises the cancer-killing effectiveness without damaging healthy organs.– Dr Maya Thanou, School of Cancer & Pharmaceutical Sciences
The remainder of the inactivated drug carriers was also found to leave the body within a few hours, which greatly reduced observed side effects. The technology is not drug-specific and could be adapted to other drug combinations according to clinical needs.
We aim to develop image-guided focused ultrasound therapies in combination with immune therapies for other cancers where there are unmet clinical needs.– Dr Maya Thanou, School of Cancer & Pharmaceutical Sciences