The market for antimalarial drugs consists of the 2.8 billion (2.8x10(9)) people living in malaria endemic areas and about 20-30 million people, mainly Europeans and North Americans, who travel or live in malarious areas, and the wealthy elite of malarious developing countries. Some of the largest markets include China, India, and Indonesia with a total of 1.9 billion people exposed; Latin America, with 119 million; and sub-Saharan Africa with 400 million. An estimated 200 million clinical cases occur each year, with around 2 million deaths annually, primarily in African children. Antimalarial drugs are distributed through several different networks and are purchased by governments and private individuals. At present the world market is dominated by chloroquine by virtue of its safety, wide availability and low price. Approximately 20% of the total production of chloroquine was distributed through national control programmes and 80% through other channels; chloroquine is probably the second or third most widely consumed drug in the world. The global market for antimalarial drugs is likely to be of the order of US$100-120 million, with chloroquine making up about US$64-80 m, sulfadoxine/pyrimethamine about US$20 m, and other drugs making up US$10-20 m. Chloroquine is rapidly losing its effectiveness against the malaria parasite, and a safe, effective, cheap replacement is urgently needed. Another product which was found to be safe and effective against malaria, with a price per treatment held at or near the present price of chloroquine, could quickly replace chloroquine as the first-line treatment against malaria. However, most purchasers of chloroquine are very price sensitive, and governments in particular have to balance the number of treatments they can buy with a limited budget against the potentially greater effectiveness of a more expensive drug. Sales of the 2 newest widely available antimalarial drugs, mefloquine and halofantrine, are virtually limited to the travellers' market because of their high price. Since there is no cheap, safe, and effective alternative ready to take the place of chloroquine in the treatment of some 200 million cases of clinical malaria which occur each year, conditions are optimal for further development of promising compounds which might fulfill this major therapeutic gap. The rewards, both financial and in terms of public recognition, are likely to be great, and the risks of marketing such a product appear to be manageable.
