A malaria drug made by India's Cipla has been pre-qualified by the World Health Organization (WHO), an important step towards its roll-out across Asia, where millions of people are infected with the mosquito-borne disease every year.

The drug, which has already been used to treat 18,000 adults in India, is intended as the first-line treatment in a number of South East Asian countries, Cipla and the Drugs for Neglected Diseases Initiative said in a joint statement on Wednesday.

"It addresses an important public health need in the region as it forms part of the malaria treatment arsenal necessary to control the disease," said Bernard Pecoul, Executive Director of DNDi, a not-for profit research and development organization.

There are an estimated 25 million cases of the disease, which can be deadly, in the western Pacific and South Asia region each year, a spokeswoman for the Geneva-based DNDi said.

Pre-qualification means a drug meets WHO standards of quality, safety and efficacy and makes it eligible to tenders for quick procurement by aid agencies which buy in bulk, including the U.N. Children's Fund (UNICEF) and Global Fund to Fight AIDS, Tuberculosis and Malaria.

The drug's combination of artesunate and mefloquine is one of five artemisinin combination therapies (ACTs) recommended by the WHO for treatment of uncomplicated plasmodium falciparum malaria. It is the first of the five to be pre-qualified as a fixed-dose combination of those two molecules.

A fixed-dose combination - a single daily dose of one or two tablets over three days - is easier for patients, as it ensures both drugs are taken together and in correct proportions.

The advantage over so-called monotherapy is that it increases patient compliance and helps reduce the risk of drug-resistance developing, the statement said.

The artesunate-mefloquine fixed-dose combination was developed by DNDi and the Brazilian government-owned drugmaker Farmanguinhos Fiocruz in 2008. The Brazilian maker transferred the technology two years later to Cipla, India's fifth-largest drugmaker by sales, for use in Asia, the statement said.

Cipla made headlines in 2001 by producing antiretroviral drugs to treat AIDS in Africa for under $1 per day.