Diabetes Combo Therapy Attacks Melanoma

Melanoma with BRAF mutation may respond to metformin and VEGF A inhibitor

(RxWiki News) Along with breast cancer, BRAF mutations are found in certain melanoma tumors. New studies suggest that a novel combination drug therapy can keep these tumors from completing their potentially deadly mission.

Combining a commonly prescribed type 2 diabetes medication, metformin, with a targeted cancer drug has been shown in laboratory studies to deliver a one-two punch to certain melanoma tumors.

"If you notice a mole changing color or shape, have a doctor look at it."

Richard Marais, Ph.D., professor of molecular oncology and director at The Paterson Institute for Cancer Research in Manchester, England, headed the team of researchers who looked at the anti-cancer effects of metformin on melanoma.

They looked at the interaction of the diabetes drug and cells. These cells had BRAF and NMAS mutations commonly found in melanoma.

Researchers first looked at how lab-grown cells with these mutations responded to metformin. Nothing happened.

Next, mutant BRAF melanoma tumors were grown in mice. They found that the cancer cells secreted a molecule called VEGF-A that helps tumors grow by building new blood vessels. 

This discovery got the researchers to thinking that a combination of metformin and a drug that blocks or inhibits VEGF-A might be the ticket. And voila...the team approach worked.

While tumors grew faster when given metformin alone, when they had an onslaught of both the diabetes drug and a VEGF-inhibitor, tumor growth slowed by 45 percent.

When metformin was combined with bevacizumab (brand name Avastin), cancer growth was suppressed by 64 percent, compared to 34 percent when bevacizumab was given alone.

Commenting on these findings, Marais said, “Our results suggest that care should be taken when prescribing metformin to patients with BRAF-mutant melanoma as it could potentially worsen their disease."

He continues, “Most importantly, our findings regarding the effectiveness of the metformin/VEGF-A inhibitor combination could be directly tested in the clinic.” 

Marais and his team hope to conduct clinical trials to confirm these results. They want to test the combination therapy "in patients with BRAF-mutant melanoma, with the hope that this becomes an effective treatment option for people suffering from this deadly disease,”  Marais said.

Metformin is marketed under the following brand names: Fortamet, Glucophage, Glumetza and Riomet.

This study was published in the April, 2012 issue of  Cancer Discovery, a journal of the American Association for Cancer Research. 

The Association for International Cancer Research, Cancer Research U.K. and the Institute of Cancer Research funded this research.


Review Date: 
April 5, 2012