June 11 (Reuters) - Amgen AMGN.O said it has signed up a research firm to independently review data for its drug, Tavneos, as it seeks to prove its benefits following the U.S. health regulator's proposal to withdraw it from the market.

Tavneos was approved in October 2021 to treat a rare disease called severe active ANCA-associated vasculitis, which inflames small blood vessels and can damage organs like the kidneys and lungs.

However, the U.S. Food and Drug Administration in April proposed withdrawing its approval for Tavneos, citing a lack of proven effectiveness and false statements in its original application.

A month earlier, the agency had noted 76 cases of drug-induced liver injury with evidence suggesting a causal link to Tavneos, including eight deaths.

In a letter dated June 1 and posted in the agency's records, Amgen said Duke Clinical Research Institute began an independent, blinded review in February of data from the main late-stage trial that supported Tavneos' approval.

The drugmaker said it plans to submit detailed data to the FDA by June 29, adding that it believes Tavneos' benefits outweigh its risks and that withdrawing the drug would not be in the best interest of patients.

The company did not immediately respond to a Reuters request for comment on its letter.

Amgen acquired Tavneos through its $3.7 billion purchase of ChemoCentryx in 2022.

About 20 deaths linked to serious liver dysfunction have been reported in Japan in patients treated with the drug, according to a safety notice ‌issued by partner Kissei Pharmaceutical in May.

Bloomberg News first reported the development earlier in the day.