International Strategies for Tropical Disease Treatments - Experiences with Praziquantel - EDM Research Series No. 026
(1998; 113 pages) View the PDF document
Table of Contents
View the documentAbstract
View the documentAcknowledgments
View the documentInformation on authors
View the documentExchange rates used in the report
Close this folderChapter 1: Policies for praziquantel*
View the documentObjectives of this report
View the documentStructure of the report
View the documentLessons learned
View the documentReferences
Open this folder and view contentsChapter 2: Bayer & E. Merck: Discovery and development of praziquantel*
Open this folder and view contentsChapter 3: Shin Poong Pharmaceutical Co.: Process development in the Republic of Korea*
Open this folder and view contentsChapter 4: The Egyptian International Pharmaceutical Industries Co.: Praziquantel formulation*
Open this folder and view contentsChapter 5: The international supply of praziquantel*
Open this folder and view contentsChapter 6: Demand for praziquantel and national distribution*
Open this folder and view contentsChapter 7: Prices and production costs of praziquantel*
View the documentOther documents in the DAP Research Series
View the documentDAP Research Series No. 26

Objectives of this report

The development of new drugs for tropical diseases occurs within a complex political and economic context. While the discovery of an effective compound represents scientific success, it also initiates a new round of negotiation and struggle over how the technological innovation should be made available to the sufferers of the disease. This social process becomes especially problematic when the disease sufferers are people who cannot pay for the product on their own. The search for an AIDS treatment or an AIDS vaccine highlights the economic, ethical, and political dimensions of these problems (Grady, 1995).

Similar issues have existed for a long time for pharmaceutical products that treat tropical diseases and where the disease sufferers are predominantly poor people in poor countries. This report explores the policies that evolved for one such product - praziquantel - for the treatment of schistosomiasis, a parasitic disease of major global public health importance. The discovery of praziquantel represents the most important development in recent decades in the treatment of schistosomiasis. This parasitic disease, involving five species of schistosome worms (Schistosoma mansoni, S. haematobium, S. japonicum, S. intercalatum, and S. mekongi), is estimated to infect 200 million people in 74 countries, with an exposed population of about 600 million people. The parasitic infection is transmitted through freshwater snail vectors (Biomphalaria and Bulinus species). The spread of schistosomiasis is often associated with water resource development projects (dams and irrigation schemes) that create new habitats for the snails through ecosystem changes and alter human behaviour patterns in ways that increase exposure to the parasite (Hunter et al., 1993). Praziquantel is effective treatment for all five species of schistosomes, and for both major types of morbidity (urinary lesions for S. haematobium, and hepatic lesions for the other species).

Praziquantel was the first anthelminthic drug to fulfill WHO’s requirements for population-based chemotherapy of a broad range of parasitic infections. The chemical entity was discovered in 1972, and was developed first for the veterinary market and then for human treatment of schistosomiasis. By 1985, approximately one million persons had been treated with praziquantel. Today, praziquantel remains the drug of choice for all forms of schistosomiasis occurring in humans, because of its high efficacy, its low toxicity, and its ease of single, oral administration (compared to the two other major drugs currently available for treatment of schistosomiasis: metrifonate and oxamniquine). From these perspectives, the development of praziquantel can be considered a case of successful drug development for tropical diseases, involving various forms of public-private cooperation.

On the other hand, major problems persisted in praziquantel’s availability throughout the 1980s, especially because of the product’s price in countries with endemic schistosomiasis. Organizations around the world adopted different strategies to cope with the drug’s initial high price set by the originating companies, Bayer and E. Merck of Germany. We seek to understand the origins of the pricing decisions, and how different organizations confronted those problems. But price was not the sole obstacle to availability. Even in the early 1990s, with significant price reductions in praziquantel, the product remained unavailable in many countries with endemic schistosomiasis, especially in sub-Saharan Africa. We explore some of the non-price factors that have affected the availability of this product in a number of countries.

This report places the production and pricing issues of praziquantel within the political and economic contexts of several national governments (Egypt, Germany and the Republic of Korea) and also within the activities of three international agencies (World Health Organization, UNICEF, and the World Bank). Using the case of praziquantel, the report raises broader issues of new drug development for tropical diseases, including the role of international agencies, the international patent system, and public/private sector interactions. Our analysis gives particular attention to the interactions among four actors: pharmaceutical producers, international agencies, non-governmental organizations (NGOs), and developing country governments. For praziquantel, the strategies of these four groups shaped the prices and the distribution mechanisms that determined whether the sufferers of schistosomiasis (and which sufferers) would receive the new treatment.

The experiences with praziquantel illustrate basic conflicts between private business and public health in the development of new drugs. The producers of tropical disease products include both originating companies and follow-on companies. The “research-oriented” pharmaceutical companies invest substantial resources in discovering and developing new drugs, and they expect significant returns for the risks involved. Those risks occur not only in the discovery phase, but also in the marketing and sales phase for new products, as companies face difficult pricing and distribution decisions. For tropical disease products, companies confront a basic dilemma: the ultimate consumers are usually very poor people in the world’s poorest countries. The follow-on companies, which have operated in national legal environments without product patent protection, have had opportunities in “copying” new products that others have discovered, especially if they could discover an alternative production process that was patentable. This report examines how praziquantel was developed by both originating and follow-on firms in Egypt, Germany and the Republic of Korea, how it was priced in different markets and market segments, and how these development and pricing strategies affected the product’s availability in different countries.

International agencies are concerned with the availability of new drugs for tropical diseases for multiple reasons. Some agencies, such as the World Health Organization, have a mandate to improve global health, and new drugs for tropical diseases can offer an effective means to achieve health improvements. Other international bodies, such as the World Bank, seek primarily to promote economic growth and development, and new drugs for tropical diseases can provide a mechanism for dealing with unwanted side-effects of growth (such as water-borne diseases associated with water resource development projects) and for raising the productivity of workers, as well as improving overall social welfare. And UNICEF seeks to expand access to those pharmaceutical products that can improve the health condition of specific populations (especially mothers and children). The policy measures to achieve these diverse organizational goals also differ among the international agencies. For praziquantel, this report analyzes the different strategies adopted by these three international agencies and compares their impacts.

NGOs have, in some instances, served as viable alternatives to both the public and the private sectors in health care delivery by reaching under-served populations in developing countries. Using the example of praziquantel, this report examines the role of NGOs in the development and distribution of drugs for tropical diseases.

Finally, developing country governments seek access to new drugs for tropical diseases because those products can improve the welfare of their people. Many governments, however, have confronted extremely difficult financial situations in the 1980s and 1990s, with limited foreign exchange reserves, poorly performing economies, and external pressures to adjust their economic policies. Structural adjustment programmes sought to reduce government expenditures, which often restricted funds available for purchasing medicines. Governments that could not afford to spend major portions of their medication budget on new products either sought external aid, purchased old drugs, or directed patients to the private market. But in many poor countries, new pharmaceutical products are often not available in the private market, or are priced far beyond the means of the majority of the people. For praziquantel, this report examines the experiences of availability and distribution in a number of countries.

In sum, this report seeks to identify national and international policies that have facilitated or hindered the availability of praziquantel, especially for the world’s poorest countries in Africa where schistosomiasis is endemic. Our analysis of praziquantel illustrates more general problems in the design of national and international policies for tropical disease products, and suggests strategies for future research and action. This study of praziquantel’s production and pricing involved an international team of policy analysts, with expertise in economics, political science, management, business policy, and tropical diseases, based in Egypt, Germany, the Republic of Korea and the United States of America.

to previous section
to next section
The WHO Essential Medicines and Health Products Information Portal was designed and is maintained by Human Info NGO. Last updated: December 6, 2017