LONDON: The promise that anti-coronavirus drug treatments could beat emerging variants has fallen flat after trials that included the South African and Brazilian strains failed, scientists have said.

The drugs had high expectations amid increasing concern over the prevalence of new coronavirus variants worldwide. 

One drug, produced by Regeneron in the US, was used to treat former President Donald Trump and may have aided his recovery from COVID-19. The drug is being trialled in UK hospitals.

But scientists have said the three leading contenders among anti-COVID-19 drugs 鈥� the Regeneron, Eli Lilly and GlaxoSmithKline formulas 鈥� failed against one or more of the variants.

Nick Cammack, head of the COVID-19 therapeutics accelerator at Wellcome 鈥� a London-based charitable foundation focused on health research 鈥� told British newspaper The Guardian that the drugs offer 鈥渉uge advantages鈥� when used as treatments.

They are created from the cloning of a human white blood cell and are designed to imitate immune system effects.

But Cammack said: 鈥淭he challenge came at Christmas when these new variants appeared. The changes the virus makes in its spike proteins actually throw off these antibodies.

鈥淪o basically, most of the front-running antibody therapies for coronavirus 鈥� the great hope 鈥� lost to the South African and Brazilian variants.鈥�

GlaxoSmithKline鈥檚 formula is effective against those variants, but failed to tackle the one that emerged in the UK.

Cammack warned that the available drugs could soon be rendered ineffective given the fast-paced mutation of coronavirus. Scientists must now uncover parts of the virus that remain intact across the different variants.

鈥淚 think it鈥檚 pretty clear that while we鈥檝e seen the South African, UK and Brazilian variants, there will be others. And we need mass sequencing, genetic sequencing of the virus around the world, which will reveal where the changes are made and also reveal where the conserved regions are,鈥� Cammack said. 鈥淪o we鈥檙e somewhat back to square one, honestly.鈥�

One potential upside is that scientific data on some variants already exists in South Africa and China, while further research is expected in the coming weeks. Cammack said despite the challenges ahead, drug companies are still working together.