New Generation of Drugs Targets Hard-to-Treat Cancers

Recent research has provided steps towards a new generation of oncology drugs that could improve treatment for patients with therapy-resistant cancers, according to a study conducted by the University of Kent in Germany.

The biggest cause of cancer therapies failing is drug resistance. Although there have been improvements in cancer treatments, patients who develop metastatic cancer have a 5-year survival rate below 20%.

A key resistance mechanism in cancer cells is the activity of ATP-binding cassette (ABC) transporters, which are drug pumps that behave like mechanisms in order to remove anti-cancer drugs from cancer cells.

The most important these transporters is ABCB1, also known as multi-drug resistance gene 1 (MDR1), or P-glycoprotein. Although prior attempts have been made to target ABCB1 for potential therapies, they have all failed.

The reason these attempts failed was because ABCB1 is over expressed throughout different sites in the body, especially in the gastro-intestinal barrier and the blood brain barrier.

The created agents that inhibited ABCB1 were not specific to the interaction of the anti-cancer drug with ABCB1 on the cancer cells. Instead, the agents affected the body distribution of numerous drugs and food components, which resulted in toxic side effects.

The results of the current study showed that certain inhibitors of ABCB1 would interfere with the ABCB1 mediated transport of anti-cancer drugs.

These results show progress towards developing tailored anti-cancer drug combinations and ABCB1 inhibitors that cause the accumulation of anti-cancer drugs in ABCB1 expressing cancer cells, without affecting the body distribution or other drugs or food components.