The effectiveness of melanoma treatment could be boosted if combined with a well-known drug for rheumatoid arthritis (RA), indicates early UK research.

Scientists at the University of East Anglia (UEA) found that combining the RA therapy leflunomide with the melanoma treatment selumetinib almost completely stopped the growth of a melanoma tumour in mice.

Selumetinib targets the activity of a protein called MEK, which is essential for melanoma survival. MEK inhibitors are already used in combination with BRAF inhibitors to combat resistance, but the new research suggests that adding leflunomide to the regimen could make it even more effective.

The team found that leflunomide induces cell apoptosis and seems to be effective against melanoma cells irrespective of the genetic signature of the cancer, which means that the drug’s potential utility could span all cases of the disease and not just those with BRAF mutations.

“New combination therapies are always needed and we need to identify new drugs that can be added to the arsenal of anti-melanoma therapies available for patients. It’s possible that leflunomide could play that role,” said Grant Wheeler from UEA’s School of Biological Sciences.

However, the researchers also caution that there are many questions to answer before deciding on whether the combination should be tested in clinical trials, including exploring whether melanoma can develop resistance to the regimen.

The study was published in the journal Oncotarget.