An end to neglect: fighting parasitic diseases

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Pf looks at how the pharmaceutical industry is working with WHO to transform the developing world by defeating neglected diseases such as sleeping sickness and river blindness.

 In January 2012, the World Health Organisation (WHO) launched a roadmap to defeat 10 key neglected tropical diseases, with support from 13 major pharmaceutical companies. The campaign targets diseases that are widespread only in the developing world and form major barriers to the economic development of the affected countries. The companies pledged to work in partnership with WHO, governments and health and finance organisations to strengthen their drug donation programmes, support drug distribution and implementation, and increase R&D in this disease area.  

Trojan horses
Most neglected tropical diseases (NTDs) are carried by parasites (such as tsetse flies) or are parasites (such as flatworms), which makes them difficult to treat as parasites are well adapted to the biology of the host. The parasite often acts as a ‘Trojan horse’ introducing disease into the human body. While preventative measures such as sanitation are important for controlling infection, only effective drug treatment can strike at the lethal team of parasite and micro-organism. The challenge is not only to develop effective drugs, bu to ensure they reach the populations affected by the disease.

In the ‘London Declaration on Neglected Tropical Diseases’, WHO and 13 drug companies committed to these objectives for 2020: to eradicate guinea worm disease; make progress towards eliminating lymphatic filariasis, blinding trachoma, sleeping sickness and leprosy; and achieve control of schistosomiasis, river blindness, Chagas disease, visceral leishmaniasis, and soil-transmitted helminthes. The companies involved are Abbott, AstraZeneca, Bayer, Bristol-Myers Squibb, Eisai, Gilead, GSK, Johnson & Johnson, Merck KGaA, Merck Sharp & Dohme (MSD), Novartis, Pfizer and Sanofi.

Margaret Chan, Director General of WHO, said: “The efforts of WHO, researchers, partners, and the contributions of industry have changed the face of NTDs. These ancient diseases are now being brought to their knees with stunning speed. I am confident almost all of these diseases can be eliminated or controlled by the end of this decade.” For some of the world’s poorest nations, that means an end to a crippling burden of endemic disease.

As a Sanofi video commented, NTDs are neglected because the populations they affect are neglected. For the pharma industry, offering drug donation, training and education to defeat these diseases is an opportunity to put down roots in important future markets, as well as boosting the industry’s public image through concrete achievements. Despite the current global economic crisis, funding for neglected disease R&D has increased significantly since 2007. Corporate social responsibility is a key aspect of any global drug company’s strategy – especially for companies based in Europe
and the US, where reputation can be a difficult issue.

In May 2012, Dr Margaret Chan commented on work to fight schistosomiasis in Africa: “These Cinderella diseases, long ignored and underappreciated, are a rags-to-riches story. We can blanket this part of the world with medicines that rid every schoolchild of worms and eggs, parasites that interfere with their learning, impair cognitive development, and compromise their nutritional status.” Such achievements, which depend on the pharmaceutical industry, are of historic importance on the world stage.

River blindness
Onchocerciasis (river blindness) causes an estimated 270,000 people each year in Africa and elsewhere to lose their sight. Its biological audit trail is complex: a nematode worm enters the body through the bite of a blackfly; the worms spread through the body, carrying symbiotic bacteria; when the worms die, the bacteria trigger the human immune system, causing severe itching and damaging eye tissue. Some 37 million people are infected with river blindness.

The most successful treatment is MSD’s Mectizan (ivermectin), an oral medication that kills the parasite in its larval stage. On 11 October 2012 (World Sight Day), MSD celebrated 25 years of its programme to donate Mectizan for treatment of river blindness. Through this programme, progress has been made towards eliminating the disease in Nigeria, Uganda, Senegal, Mali and Sudan. MSD is committed to maintaining drug donations until the disease is eliminated.

The Mectizan Donation Programme has influenced the development of other initiatives to fight NDTs in two ways: its multi-sector partnership model and its use of community-directed intervention (CDI). Stakeholders working with MSD to build the programme include WHO, the World Bank, governments, NGOs and communities. The CDI strategy, whereby communities plan their own means of delivering treatment, has enabled Mectizan to be delivered to 75 million people in Africa each year.

Former US President Jimmy Carter commented: “In Africa, where it was once thought river blindness could only be controlled, strides are being made to completely eliminate the disease from a number of countries. Thanks to MSD, the commitment of endemic communities, and strong partnerships, we can now envision a world someday free of river blindness.”

A leading distributor of Mectizan in Africa is Sightsavers, an NGO committed to preventing blindness. Simon Bush, Sightsavers’ Director for NTDs, told Pf: “Sightsavers will, through its support to river blindness programmes in Africa, treat over 25 million people this year as well as playing our part in supporting a network of about one million community-directed distributors.

“We have also the proof of the elimination of transmission of the disease in Kaduna state in Nigeria, which shows that elimination of the disease can be achieved in Africa through treatment with Mectizan alone.” 
The contribution of MSD has been “vital”, Bush said: “Sightsavers would not be able to support the elimination of river blindness and blinding trachoma if it were not for the drug donation programmes. We would not have been able to go to scale.” The supply chain reaching from a major pharmaceutical company to a network of community-directed distributors, reaching through society and across the world, is expected to eliminate transmission of the disease in the targeted countries by 2021.

Blood fluke
Schistosomiasis (blood fluke) is a parasitic flatworm infestation. The larvae enter the body from fresh water sources, mature in the liver and travel through the blood vessels, laying eggs that trigger destructive immune reactions. The disease is estimated to affect 200 million people in Africa and to cause 200,000 deaths each year.

The only medicine with which all forms of schistosomiasis can be treated is Cesol (praziquantel) from Merck Serono (a division of Merck KGaA). In 2007, the company committed to donate 200 million Cesol tablets to WHO for distribution to school-age children primarily in Africa, and to support an awareness programme in schools. In January 2012, Merck Serono doubled its annual donation of tablets to 50 million, to be maintained until the disease is eliminated. It has committed to work with partners to develop a pre-school version of the drug.

Seven million children were treated with Cesol in 2012, bringing the total to 28 million. At the end of November, Merck Serono symbolically donated the 100 millionth Cesol table to WHO, and announced a new programme to distribute the medicine throughout Kenya.

The company’s CEO, Stefan Oschmann, said: “Merck Serono is committed to more effectively fighting neglected tropical diseases.” He added that partnership is the essence of the campaign: “The closer we co-ordinate the donation activities, research and development of new drugs, as well as the supply and distribution of drugs with each other, the more effectively we’ll be able to fight these diseases.”

Sleeping sickness
Trypanosomiasis (sleeping sickness) is one of the tropical world’s most feared diseases. It is spread by the bite of the tsetse fly and affects the brain, causing sleepiness, coma and death. Almost always fatal if untreated, sleeping sickness may be the real basis of the ‘zombie’ myth. But now, according to Dr Margaret Chan, “the stage is set for the elimination of sleeping sickness, a prospect that was unthinkable a decade ago”. For over ten years, Sanofi has worked with WHO to provide drugs and develop treatment protocols for the disease via the campaign ‘Human African Trypanosomiasis – Not Neglected by Sanofi’.

In 2011, Sanofi renewed its commitment to fighting sleeping sickness through a $25m donation, extending its partnership with WHO by another five years. The company donates three of the five drugs used to treat the disease. In January 2012, Sanofi announced a global partnership with Eisai and the Bill & Melinda Gates Foundation to eliminate five NTDs including sleeping sickness and lymphatic filariasis. In July, it noted that the sleeping sickness treatment programme had saved 170,000 lives and reduced the number of new cases from 30,000 in 2001 to 6,500 in 2011. By 2020, WHO has said, Africa may be clear of the disease.

Sanofi’s video from Chad illustrates the methods used to implement treatment. By funding mobile medical teams working in towns and villages, the campaign has brought daily drug therapy to people unable to travel long distances to the city hospitals. Seeing the effects of treatment within the community encourages other patients to be treated there. Sanofi is committed to providing the drugs and supporting their implementation until sleeping sickness is eliminated.