24 July 2015
Issued:
London, UK
- WHO will now assess how the
world’s first malaria candidate vaccine might be used alongside other
tools to prevent malaria
GSK
announced today that the Committee for Medicinal Products for Human Use (CHMP)
of the European Medicines Agency (EMA) has adopted a positive scientific
opinion for its malaria candidate vaccine MosquirixTM, also known as
RTS,S, in children aged 6 weeks to 17 months. Following this decision, the
World Health Organization (WHO) will now formulate a policy recommendation on
use of the vaccine in national immunisation programmes once approved by
national regulatory authorities.
RTS,S,
which was developed in partnership with the PATH Malaria Vaccine Initiative
(MVI), is the first candidate vaccine for the prevention of malaria to reach
this milestone. While other vaccines tackle viruses or bacteria, RTS,S has been
designed to prevent malaria caused by the Plasmodium falciparum parasite, which
is most prevalent in sub-Saharan Africa (SSA). In 2013, there were an estimated
584,000 deaths from malaria with around 90% of these occurring in SSA, and 83%
in children under the age of five in SSA.1
The
CHMP scientific opinion is a key step in the regulatory process toward making
RTS,S available alongside existing tools currently recommended for malaria
prevention. The positive opinion for young children was based on the review of
data assessing the candidate vaccine’s safety, efficacy and quality. Clinical
data submitted for CHMP assessment were mainly from a phase III clinical trial
programme involving more than 16,000 young children that was conducted by 13
African research centres in eight African countries (Burkina Faso, Gabon,
Ghana, Kenya, Malawi, Mozambique, Nigeria, and Tanzania).
Data
from this trial programme demonstrate that over the first 18 months following
three doses of RTS,S, malaria cases were reduced by almost half in children
aged 5-17 months at the time of first vaccination and by 27% in infants aged
6-12 weeks. At study end, four doses of RTS,S reduced malaria cases by 39% over
four years of follow-up in children, and by 27% over three years of follow-up
in infants.2 In areas of the highest malaria burden, more
than 6,000 clinical malaria cases were prevented over the study period for
every 1,000 children vaccinated.2 The efficacy of RTS,S was
evaluated in addition to existing malaria control measures, such as insecticide
treated bed nets, which were used by approximately 80% of the children and
infants in the trial.
Sir
Andrew Witty, CEO of GSK said:
“Today’s scientific opinion represents a further important step towards making
available for young children the world's first malaria vaccine. While RTS,S on
its own is not the complete answer to malaria, its use alongside those
interventions currently available such as bed nets and insecticides, would
provide a very meaningful contribution to controlling the impact of malaria on
children in those African communities that need it the most. The work doesn’t
stop here and GSK remains committed to investing in R&D for malaria
vaccines and treatments to find more ways to tackle this devastating disease.”
Dr
David C. Kaslow, Vice President of Product Development at PATH said: “Today marks a significant scientific milestone for the
long-standing partnership to develop a vaccine, yet several more steps remain
before a malaria vaccine might reach the young children in Africa who most need
protection against this deadly human parasite. PATH will continue to work with
GSK and other partners to ensure that the evidence is available, as soon as
possible, to support informed decision-making on those remaining steps.”
GSK
has committed to a not-for-profit price for RTS,S so that, if approved, the
price of RTS,S would cover the cost of manufacturing the vaccine together with
a small return of around five per cent that will be reinvested in research and
development for second-generation malaria vaccines, or vaccines against other
neglected tropical diseases.
Next
steps
Following
the CHMP positive scientific opinion, two of the WHO’s independent advisory
groups, the Strategic Advisory Group of Experts (SAGE) on Immunization and the
Malaria Policy Advisory Committee (MPAC) will now jointly review the evidence
base for RTS,S and make a joint policy recommendation for how it might be used
alongside other tools to prevent malaria in the event the vaccine candidate is
approved by national regulatory authorities in SSA. The WHO has indicated that
such a policy recommendation may be possible by end of this year.
Following
the WHO policy recommendation, GSK will also submit an application to the WHO
for pre-qualification of RTS,S. WHO pre-qualification involves a scientific
assessment of the quality, safety and efficacy of any new vaccine proposed for
introduction in WHO Expanded Programme on Immunization. A pre-qualification
decision is used by the United Nations agencies and other large scale public
procurement agencies to help inform vaccine purchasing decisions.
Once
a WHO pre-qualification is granted, GSK would then apply for marketing
authorisation in countries in sub-Saharan Africa on a country-by-country basis.
These regulatory and policy decisions would, if positive, enable countries to
begin implementation of RTS,S through their universal immunisation programmes.
Both
a WHO policy recommendation and WHO pre-qualification are requirements for
Gavi, the Vaccine Alliance, to support eligible African countries introducing
RTS,S into local immunisation programmes supported by UNICEF.
Notes
to Editors
- Mosquirix is the brand name given
to this malaria candidate vaccine. Its scientific name, RTS,S, reflects
the composition. RTS,S also contains the AS01 adjuvant system.[i]
- RTS,S aims to trigger the
body’s immune system to defend against the Plasmodium falciparum malaria
parasite when it first enters the human host’s bloodstream and/or when the
parasite infects liver cells. It is designed to prevent the parasite from
infecting, maturing and multiplying in the liver, after which time the
parasite would re-enter the bloodstream and infect red blood cells,
leading to disease symptoms.
- The safety and efficacy of
RTS,S has been evaluated in a large-scale phase III trial, in which it was
administered in three doses, one month apart, with an additional fourth
dose given 18 months later. Results from this trial have consistently
demonstrated that RTS,S can help to protect children against malaria in
endemic countries, when used in addition to other malaria control measures
such as bed nets.
- RTS,S is the most advanced
malaria vaccine candidate in development globally. It was created in 1987
by scientists working at GSK laboratories. Early clinical development was
done in collaboration with the Walter Reed Army Institute for Research. In
January 2001, GSK and PATH, with grant monies from the Bill & Melinda
Gates Foundation to PATH, entered into a public-private partnership to
develop an RTS,S-based vaccine for infants and young children living in
malaria-endemic regions in sub-Saharan Africa.
- GSK has invested more than $365
million to date and expects to invest a further $200 to $250 million until
development is completed. Between 2001 and the end of 2014, the MVI,
supported by grants from Bill & Melinda Gates Foundation, invested
more than $200 million to advance the RTS,S project.
- The EMA’s CHMP opinion is a
final stage in the Article 58 procedure initiated in July 2014, by which
the CHMP gives a scientific opinion, in co-operation with the World Health
Organization (WHO), on a medicinal product for human use that is intended
exclusively for markets outside of the European Union (EU). This
assessment requires medicinal products to meet the same standards as those
intended for use in the EU.
References
1.
http://www.who.int/malaria/media/world_malaria_report_2014/en/
2.
RTS,S Clinical Trials Partnership,
The Lancet. 2015; 386 (9988): 31–45.
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