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Background on malaria
Malaria, one of the three most important diseases in Africa according to WHO 1, is a major cause of morbidity and mortality worldwide, especially in developing countries where it has serious economic and social costs. The disease is present in over 100 countries and threatens half of the world’s population. 2
Every year, 350 to 500 million cases of malaria occur worldwide, with over 1 million deaths, affecting mostly children in sub-Saharan Africa. The child death rate from malaria doubled between 1990 and 2002 3. Malaria remains the single largest cause of death for children under five in Africa, where it kills one child every 30 seconds – this translates to the deaths of approximately 3,000 children every day 4.
Malaria is caused by a parasite, called Plasmodium, that is transmitted from man to man by the bite of anopheline mosquitoes. Four species of the parasite are involved: Plasmodium falciparum, P. malariae, P. vivax and P. ovale. The most common and most dangerous species is P. falciparum.
Malaria and poverty
Malaria and poverty are interrelated in a vicious circle:
- Malaria thrives where uncontrolled water spots and warm temperatures enable Anopheles mosquitoes to breed, and where infected patients act as parasite reservoirs. These conditions - which once existed in the United States, Australia and Southern Europe - are common in many parts of the developing world.
- Malaria deepens poverty: patients are often bedridden and incapable of carrying out normal daily activities. Malaria is thought to slow annual economic growth by 1,3% in African countries with high prevalence of malaria 5. The economic cost of malaria in Africa is estimated at $12 billion every year 6.
Treatments for malaria
Treatments exist but, in recent decades, drugs such as chloroquine or sulphadoxine-pyrimethamine have become increasingly ineffective due to drug resistance.
Resistance to chloroquine now reaches over 90% in many parts of Africa. The spread of resistance is a serious threat to global public health (see map below).
Source: WHO 2006
As a response to increasing levels of resistance to antimalarial medicines the World Health Organization (WHO) since 2001 has actively encouraged malaria-endemic countries to use combination therapies, preferably those containing artemisinin derivatives (ACTs – artemisinin-based combination therapies), and to fixed-dose combinations when possible.
Why the need for fixed-dose combinations?
Compliance to treatment is essential to ensure treatment effectiveness and to prevent future resistance to ACT. But when combinations are provided as two separate drugs, patients might take only of one the two drugs or fail to complete the whole course. Taking one drug without the other increases the risk of resistance. Fixed-dose combinations (FDC’s) combine two drugs into one tablet, instead of separate tablets, to ensure that the patients take both drugs in the right dose.
What is the current state of drug R&D for malaria?
Between 1975 and 2004, only 7 of 1393 new chemical entities (NCE’s) approved were targeted at malaria 7.
Worldwide, several compounds are at various stages of antimalarial drug development around the world, with the Medicines for Malaria Venture (MMV) being a key partner in many of these projects. Sanofi-aventis currently has several active projects. The most advanced one is ferroquine, a compound that is active against chloroquine-resistant falciparum and currently in phase II clinical development.
The immediate availability of ASAQ represents a key development in the efforts to roll back malaria by reducing the likelihood of resistance, thereby contributing to the efforts to make available a number of ACTs for the management of malaria in the future.
1. Data on the Roll Back Malaria website – WHO: http://www.rbm.who.int/ consulted in September 2006.
2. World Health Organization. World Malaria Report. Geneva: WHO ; 2005, Introduction.
3. Global Forum for Health Research. Monitoring Financial Flows for Health Research. Geneva: 2005, p. 59.
4. Global Forum for Health Research. Monitoring Financial Flows for Health Research. Geneva: 2006, p. 91.
5. Gallup J and Sachs JD. The economic burden of malaria. Am J Trop Med Hyg 2001 ; 64: 85-96, p. 19.
6. Sachs J and Malaney P. The economic and social burden of malaria. Nature 2002 ; 415: 680-5.
7. Chirac P, Torreele E. Global framework on essential health R&D. Lancet. 2006 ; 367 : p. 1560.
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