Blood pressure drug boosts the effect of chemo

Scientists have discovered that a drug developed to treat high blood pressure has a powerful ‘chemo-boosting’ effect when combined with certain chemotherapeutic drugs for the treatment of angiosarcoma — a deadly form of cancer that affects the lining of blood vessels and can occur in any part of the body.

The effect of the drug, propranolol, was discovered in the Sydney laboratories of the Children’s Cancer Institute. The resulting study has since been published in the online journal EBioMedicine.

“We tested a number of drugs in our laboratory model of angiosarcoma and were excited to discover that the beta-blocker propranolol made a huge difference to the anticancer effects of a chemotherapy drug called vinblastine,” said Professor Maria Kavallaris, who worked on the project alongside colleague Dr Eddy Pasquier.

“Our earlier studies had shown that beta-blockers can work well with chemotherapy against some childhood cancers, as well as certain breast cancers. So we thought we’d see if something similar could be done with angiosarcoma.”

Once the team had shown that propranolol boosted the effects of vinblastine against angiosarcoma, Dr Pasquier worked with clinicians at the Tata Memorial Hospital in Mumbai and Aix-Marseille University in Marseilles to design a new treatment protocol. The protocol was then used in a small pilot study in Mumbai to treat seven patients with advanced and inoperable angiosarcoma.

“The results of this pilot study were quite incredible,” said Dr Pasquier. “All seven patients responded. One ended up with no clinical signs of disease at all and another two had their tumours regress to the point of almost disappearing. These are patients who had no prospects at all for survival beyond 12 months, and in whom the treatment was really just given as palliative care, so the fact that two of them are still alive today, up to 20 months later, shows just how effective this treatment is.”

Dr Pasquier said a larger trial needs to be done to confirm that the treatment can indeed improve patient outcomes and is safe to use. He and his colleagues have recently secured funding for such a trial and anticipate that, if the results prove positive, the treatment could go on to become available to angiosarcoma patients all over the world.

Professor Kavallaris noted that a big plus of the new treatment is its low toxicity, which means it could be given in an outpatient setting. It is also more efficient and more affordable than other experimental treatments for angiosarcoma, she said, “and so is far more accessible to developing countries”.

“We are really hoping it can contribute to what we call ‘a fair global oncology’,” Professor Kavallaris said. The team is also hopeful that the treatment will eventually prove useful for a number of other cancers, including difficult-to-treat cancers in children.