Triple attack on bowel cancer can block drug resistance, scientists say

Using a combination of drugs, as you do to treat HIV, was found to stop bowel cancer cells from becoming resistant to treatment.

Press Association
Last updated: 25 March 2019 - 12.10am

A “three-pronged attack” using a combination of drugs could overcome the challenges of resistance in bowel cancer, new research suggests.

The multi-drug approach, similar to that used to treat HIV and tuberculosis, was effective in early trials at stopping cells from evolving to develop resistance.

This could help patients with bowel cancer benefit from treatments for longer and stop tumours from beginning to grow again, according to the study published in journal Oncogene.

The researchers, from the Institute of Cancer Research (ICR), in London, said the approach could also prove effective against other cancer types.

“Cancer patients often respond very well initially to modern targeted drugs, but there is always the concern that the cancer will evolve to resist treatment,” Professor Paul Workman, study co-author and chief executive at the ICR, said.

“Our study dissected out the process by which bowel cancer cells evolve to become drug resistant, and has applied the knowledge gained to the design of a new triple combination treatment.”

The researchers examined 47 bowel cancer cell lines and found, at first, drugs cobimetinib and pictilisib worked together to stop cancer growth.

After a period of eight to 10 weeks the responsive cells developed resistance to the combination.

However, exposing the cells to a third drug called navitoclax for several weeks stopped them from becoming resistant.

Prof Workman said: “Further research is needed, but we think this triple combination of targeted drugs has the potential to help patients respond to treatment for much longer.”

“Our study shows the potential to use multiple targeted drugs together to overcome drug resistance in cancer, just as occurs in other diseases like HIV,” Dr Paul Clarke, study author from the Institute of Cancer Research, said.

“We have shown that a three-pronged attack can be effective against bowel cancer cells by blocking off their various escape routes from treatment.

“The research is still at a fairly early stage, but in principle combinations of targeted drugs could be similarly effective against many other cancer types.”

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