New Delhi. Hundreds of Indian activists protested in New Delhi on Monday against a challenge to the country's patent law by Swiss pharmaceutical giant Novartis. India produces affordable medicines that are vital to many people living in developing countries. Over half the medicines currently used for AIDS treatment in developing countries come from India and such medicines are used to treat over 80% of the 80,000 AIDS patients in MSF projects. If Novartis is successful in its challenge against the Indian government and its patent law, more medicines are likely to be patented in India, making it very difficult for generic producers to make affordable versions of them. This could affect millions of people around the world who depend on medicines produced in India.