New cancer drug created from a Mediterranean weed

Scientists have created a new and successful cancer drug from a weed-like plant that grows naturally in the Mediterranean region.

The weed, called Thapsia garganica, naturally produces a product called thapsigargin that has been known to be toxic to animals since the time of ancient Greece. Samuel Denmeade, M.D., professor of oncology, urology, pharmacology and molecular sciences, said:

"Our goal was to try to re-engineer this very toxic natural plant product into a drug we might use to treat human cancer.”

Scientists at John Hopkins Kimmel Cancer Center have now taken the toxic substance and created an anticancer drug called G202.

G202 can move undetected by normal cells through the bloodstream until activated by specific cancer proteins. John Isaacs, Ph.D., professor of oncology, urology, chemical and biomedical engineering at Johns Hopkins said:

"The exciting thing is that the cancer itself is activating its own demise."

G202 reduced 7 out of 9 human prostate tumours in mice by more than 50 per cent in 21 days. In comparison, chemotherapy drug Docetaxel only reduced 1 out of 8 tumours by more than 50 per cent.

The study, published in the journal Science Translational Medicine, also showed that G202 produced at least 50 per cent regression in models of human breast cancer, bladder cancer and kidney cancer.

Scientists also conducted a phase I clinical trial to evaluate the safety of G202 in 29 patients with advanced cancer. Phase II trials are being planned to test the drug on patients with liver and prostate cancer.

Once the drug has been found safe and effective in clinical trials it will be licensed and marketed for use in the UK. At this stage, it will be available for patients with health insurance even before it is approved for use on the NHS.