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In infants, data show for the first time that the vaccine candidate can beadministered as part of existing African national immunization programs. Inchildren aged 5 to 17 months, the candidate RTS,S/AS01 reduced the risk ofclinical episodes of malaria by 53 percent over an eight-month follow-upperiod and was shown to have a promising safety profile. The studies wereconducted in Kenya and Tanzania and were presented today at the AmericanSociety for Tropical Medicine and Hygiene (ASTMH) annual meeting.
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RTS,S/AS is the leading candidate in a global effort coordinated by thePATH Malaria Vaccine Initiative (MVI) to develop a malaria vaccine. Malariakills almost one million people each year -- most of them infants and youngchildren in Africa, the intended recipients for this vaccine candidate(3).
"Today's study results strongly show that our investments in developingmalaria vaccines are beginning to pay dividends," said Christian Loucq, MVIdirector. "We are closer than ever before to developing a malaria vaccine forchildren in Africa. History has shown that vaccines are the most powerful toolto control and eliminate infectious diseases. Clearly, the world urgentlyneeds a safe and effective vaccine to win the war against this terribledisease."
The studies published today build on previous findings indicating theefficacy of RTS,S/AS, including a phase 2 trial, published in The Lancet in2007, that demonstrated "proof of concept" that RTS,S/AS could prevent malariainfection in infants(4).
"The vaccine works alongside standard infant vaccines of WHO's ExpandedProgram of Immunization (EPI), has a favorable safety profile, and hasconsistently shown a significant efficacy level. We can begin to foresee thedifference this scientific breakthrough could make in the lives of millions ofAfrican children who suffer and die from this disease year after year," saidJoe Cohen, a co-inventor of the vaccine and vice-president of Research &Development, Emerging Diseases & HIV at GSK Biologicals. "The energy andmotivation levels are at an all-time high, as the partnership finalizespreparations to launch the historic phase III trial early next year."
Infant Study: Effective Co-Administration with EPI Vaccines(1)
The infant study enrolled 340 infants under 12 months of age in Tanzaniaand found that RTS,S/AS02, when administered at 8, 12, and 16 weeks of agewith a commonly used childhood vaccine, did not interfere with the protectiveimmune responses to each of the vaccine components. The childhood vaccinecontained antigens for Diphtheria (D), Tetanus (T), whole-cell pertussis (Pw)and haemophilus influenzae B (Hib). In countries where a malaria vaccine isneeded most, the current immunization schedule for infants, called the WHOExpanded Program on Immunization (EPI), would provide an optimal deliveryplatform.
Researchers evaluated the safety and immune responses when administeringthe RTS,S/AS02 vaccine in conjunction with an EPI schedule. It was arandomized double-blind trial with participants simultaneously receivingeither RTS,S/AS02 and DTP w/Hib as well as oral polio vaccine; or a hepatitisB vaccine and DTP w/Hib as well as oral polio vaccine.
Additionally, the study reported 65 percent reduction against firstinfection from malaria in those infants who received three doses of theRTS,S/AS02 vaccine and were followed over a six-month period. This studybuilds upon results published in October 2007 in The Lancet, which found asimilar level of efficacy for RTS,S/AS02 when it was given in a staggeredfashion with the administration of DTPw/Hib vaccine(4).
"This finding has a very strong implication for protecting infants:RTS,S/AS efficacy data are very encouraging when administered alongside thechildhood vaccines now widely in use and those vaccines maintain their desiredefficacy alongside RTS,S," said Salim Abdulla of the Ifakara Health Instituteof the Tanzanian Ministry of Health. Abdulla led a team that includedresearchers from the Swiss Tropical Institute and the London School of Hygieneand Tropical Medicine, GSK Biologicals, and MVI.
Child Study: 53% Efficacy Against Clinical Malaria in Children(2)
The other trial enrolled 894 children 5-17 months old in both Kenya andTanzania. It was designed to evaluate the safety and efficacy of the RTS,S/AS,combined with another GSK's proprietary Adjuvant System, coded AS01. The studywas a double-blind randomized clinical trial in which children received eitherthree doses of the RTS,S/AS01 vaccine candidate or a rabies vaccine.
It found that the RTS,S/AS01 formulation reduces clinical malaria episodesby 53 percent for up to an average of eight months. Earlier studies inMozambique using RTS,S formulated with a different GSK Adjuvant System (AS02)demonstrated 35 percent efficacy against clinical disease for 18 months amongchildren 1-4 years old. Researchers concluded that these study results supportthe use of RTS,S/AS01 for upcoming Phase 3 trials.
"These findings build a solid case for phase III testing, which thepartners in this endeavor are looking forward to starting in the near future,"said Philip Bejon of Kenya Medical Research Institute (KEMRI)-WellcomeCollaborative Research Programme and the Centre for Tropical Medicine,University of Oxford, the study's lead author.
The team for the efficacy trial of RTS,S/AS01 in young children comprisedresearchers from the KEMRI-Wellcome Collaborative Research Programme (Kilifi,Kenya), the National Institute for Medical Research (Tanzania), the JointMalaria Programme (Korogwe, Tanzania), and other institutions in collaborationwith GSK and the MVI.
About RTS,S/AS
GSK and the PATH Malaria Vaccine Initiative signed a public-privatepartnership agreement in 2001 to pursue pediatric clinical development ofRTS,S/AS in Africa. To advance the development program, African researchcenters in five countries, and collaborating institutions, joined with thepartnership.
Pending approvals by national regulatory agencies and ethics committees, amulti-center phase III efficacy trial is on track to start in early 2009. Thetrial will seek to confirm and evaluate with precision the vaccine's efficacy,including duration, and will continue to closely monitor safety.
The vaccine was invented, developed and manufactured in laboratories atGSK Biologicals' headquarters in Belgium in the late 1980s and initiallytested in US volunteers as part of a collaboration with the US Walter ReedArmy Institute of Research.
Funding for the development of this vaccine candidate has been madepossible through a US$107.6 million grant from the Bill & Melinda GatesFoundation to the PATH Malaria Vaccine Initiative. GSK has investedapproximately $300 million to date and expects to invest another $50-100million before the completion of the project.
The clinical development of RTS,S/AS is led by the Clinical TrialPartnership Committee, a collaboration of leading African research institutes,Northern academic partners, MVI and GSK with support from the Malaria ClinicalTrial Alliance.
About KEMRI-Wellcome Research Programme
The KEMRI-Wellcome Research Programme is an internationally renownedresearch centre tackling malaria and other important diseases in Kenya.Safeguarding the health of young African children and their families is theprimary motivation of research. The Programme is fully integrated into theKenyan research infrastructure, through its close relationship with KEMRI(Kenya Medical Research Institute). In Kilifi, the Programme is embeddedwithin Kilifi District Hospital, building its research programmes around localmedical infrastructure and contributing to healthcare delivery. Researchersare also committed to engaging with the local community, to discuss theirresearch and why it is being carried out. The Programme is located at sites inKilifi, an hour's drive north of Mombasa on the coast of Kenya, and in thecapital Nairobi. For more information, please visithttp://www.kemri-wellcome.org.
About the Joint Malaria Programme, Tanzania
The Joint Malaria Programme (JMP) is a joint collaborative link betweenthe National Institute for Medical Research (NIMR) in Tanzania, KilimanjaroChristian Medical Centre (KCMC) in Tanzania, London School of Hygiene andTropical Medicine (LSHTM) in the UK, and the Centre for Medical Parasitology(CMP) at the University of Copenhagen in Denmark. Its mission is to conducthealth research to alleviate disease burden in Tanzania. The Korogwe trialsite, established in 2002 under NIMR Tanga Centre, has a staff of around 70.The site aims to be a center of excellence in clinical and biomedicalresearch. Korogwe is located in the Tanga region of Tanzania, an area that hasseen a recent decline in malaria rates. Korogwe has a Demographic SurveillanceSystem (DSS) under NIMR Tanga Centre for malaria intervention trials. For moreinformation, please visit http://196.45.36.203/Pages/projects/about.html.
About the Bagamoyo Branch of the Ifakara Health Institute
The Ifakara Health Institute (IHI), formerly IHRDC, is an autonomous,non-profit, district-based health research and resource instituteheadquartered in Ifakara, Tanzania. The Bagamoyo unit was established as anextension of the Ifakara Health Institute in 2005. It is dedicated topromoting effective solutions to important public health issues throughresearch, training and service support for community development. It hasdistinguished itself in a short time period as a leading clinical trial siteand has made a significant positive impact on the community through theimprovements it has brought to the Bagamoyo District Hospital and theperipheral health facilities in the vicinity of the hospital. IHI wasregistered as a Tanzanian Trust in 1996 under the leadership of the Board ofTrustees chaired by Ministry of Health. Other members of the Board includeNational Institute for Medical Research, Swiss Agency for Development andCooperation, Swiss Tropical Institute, Commission for Science and Technology,Regional Medical Officer for Morogoro, Managing Trustee of African MalariaIntervention Network, Muhimbili University College of Health Sciences,Economic and Social Research Foundation, INDEPTH, Representatives of RegionalAdministration and Local Government. For more information, please visithttp://www.ihi.or.tz.
About GSK Biologicals
GlaxoSmithKline -- one of the world's leading research-basedpharmaceutical and healthcare companies -- is committed to improving thequality of human life by enabling people to do more, feel better and livelonger. For company information, please visit http://www.gsk.com/media.
GSK Biologicals (GSK Bio), one of the world's leading vaccinemanufacturers, is headquartered in Rixensart, Belgium, where the majority ofGlaxoSmithKline's activities in the field of vaccine research, development andproduction are conducted. In 2006, GSK Bio distributed more than 1.1 billiondoses of vaccines to 169 countries. Of these doses, seventy-five percent ofthese went to the developing world. Approximately 136 million were doses ofcombination pediatric vaccines which protect the world's children from up tosix diseases in one vaccine.
About the PATH Malaria Vaccine Initiative (MVI)
The PATH Malaria Vaccine Initiative (MVI) is a global program establishedat PATH through an initial grant from the Bill & Melinda Gates Foundation.MVI's mission is to accelerate the development of malaria vaccines and ensuretheir availability and accessibility in the developing world. MVI's vision isa world free from malaria. For more information, please visithttp://www.malariavaccine.org. Founded in 1977, PATH is an international,nonprofit organization that creates sustainable, culturally relevantsolutions, enabling communities worldwide to break longstanding cycles of poorhealth. By collaborating with diverse public- and private-sector partners,PATH helps provide appropriate health technologies and vital strategies thatchange the way people think and act. PATH's work improves global health andwell-being. For more information, please visit http://www.path.org.
(1) Abdulla S, Oberholzer R, Juma O, et al. Safety and immunogenicity ofRTS,S/AS02D malaria vaccine in infants. N Engl J Med 2008;359:2533-44.
(2) Bejon P, Lusingu J, Olotu A, et al. Efficacy of RTS,S/AS01E: clinicalmalaria in 5 to 17 month old children. N Engl J Med 2008;359:
(3) World Health Organization. World Malaria Report 2008, Sept 2008.http://malaria.who.int/wmr2008. Last accessed: Nov 2008
(4) Aponte JJ, Aide P, Renom M, et al. Safety of the RTS,S/AS02D candidatemalaria vaccine in infants living in a highly endemic area of Mozambique: adouble blind randomized controlled phase I/IIb trial. Lancet 2007 Nov3;370(9598):1543-51. Epub 2007 Oct 18.
SOURCE PATH Malaria Vaccine Initiative
