US pharmaceutical giant Gilead Sciences and an NGO called the Medicines Patent Pool announced a deal on Tuesday aimed at boosting access to HIV drugs in poorer countries through generic manufacturing.

The HIV medicines tenofovir and emtricitabine, as well as two drugs that are still in clinical development, cobicistat and elvitegravir, will be made in low-cost copycat form under the licensing agreement.

Included too is a combination of these drugs in a hoped-for single pill known as the Quad.

The Medicines Patent Pool, founded by AIDS campaign group UNITAID in 2010, seeks to widen access to HIV drugs through voluntary licences with Big Pharma.

The new deal is unusual because pharmaceutical companies very rarely allow licensing of drugs for public health while the product is still in clinical development.

"Today marks a milestone in managing patents for public health. The licence agreement with Gilead Sciences will help make medicines available at a lower cost and in easier-to-use formulations without delays," said Ellen 't Hoen, executive director of the Medicines Patent Pool.

"(...) People in developing countries often have to wait for years before they can access new health technologies. Today's agreement changed that."

Gilead will pick up royalties of three to five percent of generic sales, but will waive royalties for any formulations of the drug that are used for children.

Generic drugs have been essential in the effort to cast a lifeline to the millions of people in poor countries who are badly infected by the human immunodeficiency virus (HIV).

Thanks to generics, the cost of the least expensive first-generation HIV treatment has dropped to less than $86 a patient annually from $10,000 in 2000.

However, doctors need alternatives to these front-line drugs because some patients fail to respond to the treatment. In addition, the AIDS virus mutates, posing a long-term resistance problem.

It is the first agreement between the Medicine Patents Pool and a pharmaceutical company.

UNITAID, headed by former French foreign minister Philippe Douste-Blazy, was set up in September 2006 to boost funding to fight AIDS, tuberculosis and malaria. Its funding derives from a solidarity levy on airline tickets sold in 15 countries.