Tokyo - Fujifilm Holdings Corp has ended development of its anti-influenza drug Avigan to treat COVID-19, the firm said on Friday, after more than two years of work on a pill once hailed as Japan's biggest contribution to the global coronavirus fight.

In March, Fujifilm had cut short enrolment in a Phase III trial, saying the emergence of the Omicron variant made it tough to measure the drug's effectiveness in preventing severe symptoms.

Subsequent analysis of data from 84 people enrolled in the trial showed no significant results, the company said in a statement on Friday.

During the first few months of the pandemic, Japan had ordered Fujifilm to triple national stockpiles of the drug, originally approved as an emergency flu treatment.

At the time, Prime Minister Shinzo Abe had hoped for early approval of the drug and pledged to donate it to needy countries. Abe, who left office in 2020, was assassinated in July during a political rally.

The drug, known generically as favipiravir, was approved in India and Russia after early studies showed it eased symptoms and cut hospital stays.

But studies in Japan were inconclusive, leading domestic regulators to hold off on approval, partly because data from animal studies showed it could lead to birth defects.

(Reporting by Kantaro Komiya and Rocky Swift; Editing by Chang-Ran Kim)