Researchers have made a breakthrough in more precisely targeting drugs to cancers. Using ultrasound and lipid drug carriers (liposomes), a multi-disciplinary team of biomedical engineers, oncologists, radiologists and anaesthetists at the University of Oxford have developed a new way to improve the targeting of cancer drugs to tumours.

The new technology has been used in humans for the very first time, with ultrasound remotely triggering and enhancing the delivery of a cancer drug to the tumour.

'Reaching therapeutic levels of cancer drugs within a tumour, while avoiding side effects for the rest of the body is a challenge for all cancer drugs, including small molecules, antibodies and viruses,' said Professor Constantin Coussios, Director of the Oxford Centre for Drug Delivery Devices (OxCD3) and of the Institute of Biomedical Engineering at the University of Oxford. 'Our study is the first to trial this new technique in humans, and finds that it is possible to safely trigger and target the delivery of chemotherapy deep within the body from outside the body using focussed ultrasound. Once inside the tumour, the drug is released from the carrier, supplying a higher dose of chemotherapy directly to the tumour, which may help to treat tumours more effectively for the same or a lower systemic dose of the drug.'
Published in The Lancet Oncology journal, the 10-patient phase 1 clinical trial used focussed ultrasound from outside the body to selectively heat liver tumours and trigger drug release from heat-sensitive carriers, known as thermosensitive liposomes. Building on over a decade of preclinical studies, the study demonstrated the ultrasound technique to be feasible, safe, and capable of increasing drug delivery to the tumour between two-fold and ten-fold in the majority of patients. Ongoing research worldwide is investigating the applicability of this technique to other tumour types, and future research could explore the combination of ultrasound with other drugs.

All 10 patients treated had inoperable primary or secondary tumours in the liver and had previously received chemotherapy. The procedure was carried out under general anaesthesia and patients received a single intravenous dose of 50 mg/m2 of doxorubicin encapsulated within low-temperature-sensitive liposomes (ThermoDox®, Celsion Corporation, USA). The target tumour was selectively heated to over 39.5o C using an approved ultrasound-guided focussed ultrasound device (JC200, Chongqing HAIFU, China) at the Early Phase Clinical Trials Unit at the Churchill Hospital in Oxford. In six out of 10 patients, the temperature at the target tumour was monitored using a temporarily implanted probe, whilst in the remaining four patients ultrasonic heating was carried out non-invasively.

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