From Africa's crowded AIDS clinics to the malarial jungles of Southeast Asia, the lives of millions of ill people in the developing world are hanging in the balance ahead of a legal ruling that will determine whether India's drug companies can continue to provide cheap versions of many life-saving medicines.

The case — involving Swiss drug maker Novartis AG's cancer drug Glivec — pits aid groups that argue India plays a vital role as the pharmacy to the poor against drug companies that insist they need strong patents to make drug development profitable. A ruling by India's Supreme Court is expected in early 2013.

"The implications of this case reach far beyond India, and far beyond this particular cancer drug," said Leena Menghaney, from the aid group Doctors Without Borders. "Across the world, there is a heavy dependence on India to supply affordable versions of expensive patented medicines."

With no costs for developing new drugs or conducting expensive trials, India's $26 billion generics industry is able to sell medicine for as little as one-tenth the price of the companies that developed them, making India the second-largest source of medicines distributed by UNICEF in its global programs.

Indian pharmaceutical companies such as Cipla, Cadila Laboratories and Lupin have emerged over the past decade as major sources of generic cancer, malaria, tuberculosis and AIDS drugs for poor countries that can't afford to pay Western prices.