Johannesburg: Africa's biggest generic drug maker Aspen will market Tibotec Pharmaceutical's anti-AIDS drug prezista in sub-Saharan Africa, and may manufacture it if demand increases, Aspen said on Wednesday.

Under the deal with Ireland's Tibotec, a unit of U.S. Johnson&Johnson (J&J), there will be a single co-branded product named prezista, distributed by South Africa's Aspen and sold at a an ex-factory price that should not exceed $3 a day. Prezista is J&J's first AIDS drug launched last year, and last month received conditional marketing approval in the European Union for all member states.

Aspen said in a statement 20 countries will be targeted, subject to regulatory approvals. Prezista is an advanced treatment for AIDS meant for patients who have not improved from earlier drug cocktails.

Resistance is becoming a problem because the virus can mutate, particularly if patients fail to rigorously follow complicated drug regimens. "More and more patients in Sub-Saharan Africa are in need of access to new therapies when their existing regimens fail," said Julie McHugh, Group Chairman, Virology, Tibotec.

Aspen, which has pioneered drug treatments for AIDS in Africa, has businesses in Australia, India, South Africa, the United Kingdom and the United States.

The AIDS virus infects around 40 million people worldwide, two-thirds of them in sub-Saharan Africa, according to UNAIDS.