SINGAPORE, June 29 (Reuters) - The governments of Australia, New Zealand, Taiwan and Singapore have bought GlaxoSmithKline's (GSK.L) Relenza flu treatment since the H1N1 outbreak began in April, a top GSK official said on Monday.
GSK Asia Pacific director Christophe Weber told Reuters the firm had advised governments to keep the inhaled Relenza drug at 30-50 percent of their overall flu drug stockpiles, which mainly comprise the Tamiflu capsule made by competitor Roche ROG.VX.
"There have been some publications showing that there is some level of resistance developed for Tamiflu," Weber said on the sidelines of a GSK media seminar in Singapore.
"In case there will be more resistance to Tamiflu, and Relenza will be a good alternative," he said.
Weber declined to say amount or value of orders by the four countries, saying he would rather those governments disclosed their orders themselves.
Glaxo's partner Biota Holdings BTA.AX, which originally developed the medicine and earns a 10 percent royalty on Australian sales, said in May that Canberra had bought an additional 1.6 million courses at A$43 million ($33.7 million).
On completion of the supply contract, the Australian National Medical Stockpile will hold 3.4 million courses of Relenza, or 33 percent of the country's total stockpile of antiviral flu drugs.
The World Health Organisation (WHO) declared the first 21st century flu pandemic this month and advised governments to prepare for a long battle against the new H1N1 flu virus.
As of June 26, it had killed 306 worldwide with the number of confirmed cases of H1N1 at least 67,072.
The flu has spread widely after emerging in April in Mexico and the United States. The WHO warned the pandemic could last a year or two. (Reporting by Nopporn Wong-Anan; Editing by Alex Richardson)