INTERVIEW: ASEAN Preps For First Dengue Vaccine
This article was originally published in PharmAsia News
Executive Summary
As the first vaccine against the dengue virus moves towards initial regulatory filings, experts have met in Asia to consider the potential impact of the product and issues related to its availability.
The 3rd Association of Southeast Asian Nations (ASEAN) Member States Dengue Vaccination Policy (ADVA) regional workshop was held in Chiang Mai, Thailand earlier this month and brought together representatives of government, academia, industry and funding organizations.
While the form of broad regional collaboration for the prevention and control of dengue by ASEAN's 10 member states was discussed, much of the work is still at the planning stage, and this time focuses on mathematical modeling of the impact of the introduction of the dengue vaccine, and support strategies following this.
Dr. Ira Longini, professor and co-director, Center for Statistics and Quantitative Infectious Disease, Emerging Pathogens Institute of the University of Florida in the U.S., told PharmAsia News that the ADVA meeting was looking at questions such as "how should the vaccine be used, in who, and how should early stocks be evaluated for safety and effectiveness?"
Sanofi Pasteur's live, attenuated chimeric CYD-TDV vaccine is the furthest along in development, and the first approval applications for the product are expected in the first half of this year.
In Asian trial results reported last year, the vaccine showed efficacy of 57% against virologically-confirmed dengue, ranging from 35% to 78% depending on each of the four dengue serotypes and statistically significant except for serotype 2.
A Latin American trial it showed overall efficacy of 60.8%, and in both regional trials, hospitalizations were reduced by more than 60%. The global development program includes around 40,000 volunteers, and Sanofi is also planning an Indian clinical study (Also see "Sanofi Eyes India For Phase III Dengue Vaccine Study" - Scrip, 13 Nov, 2014.).
Dr. Longini said that ADVA, among others, is "looking at best strategy and modeling the expected impact on dengue. Will it prevent severe [hemorrhagic] disease and hospitalization?"
While formal recommendations from the ADVA meeting have yet to be released, the main aims are for an early roll-out in countries on a limited basis, but logistical issues such as cold chain supplies and co-ordination remain to be finalized, he noted.
Dr. Longini said: "We now have a very impressive blueprint to measure the impact and a year from now, large quantities of the vaccine should be available."
The French firm has indicated that priority countries for its vaccine in Asia may include Singapore and Malaysia, along with several Latin American countries, although nothing firm has been decided. It has also suggested that pricing may be decided country-by-country depending on health budgets (Also see "Southeast Asia, Latin America Public Health Budgets In Focus For Dengue Vaccine" - Scrip, 10 Sep, 2014.).
A JP Morgan study last September calculated that if Sanofi could price the vaccine at $10 per dose in endemic regions, Southeast Asia and parts of Latin America, it could generate a recurring revenue opportunity of EUR1.2 billion.
The company has already completed a dedicated EUR300 million production facility in France with an initial annual capacity of 100 million doses.
Pressing Health Need
Dengue is a major health issue in Asia, which accounts for around 75% of the global disease burden, costing the Southeast Asian region an estimated $1 billion annually, according to the World Health Organization.
1.8 billion of the 2.5 billion people at risk globally are in Asia. Indonesia and Vietnam reported the second- and third-highest number of cases among the 30 most endemic countries worldwide.
Thailand had its worst epidemic in more than two decades in 2013, with 150,454 reported cases and 133 fatalities, although there was a sharp decline last year. Incidence varies with the effect of environmental factors on the mosquito vector, and although mosquito control is seen as a key complementary strategy to a vaccine, by itself it has not been broadly successful in curbing the disease.
The WHO is looking to reduce global dengue mortality by 50% and morbidity by 25% by 2020.
ADVA Value
Dr. Usa Thisyakorn, professor of pediatrics at Chulalongkorn University in Thailand, pointed to the value of the ADVA initiative, which in Chiang Mai concluded that surveillance and information would be important in ensuring the success of the vaccine.
"ADVA has been valuable and successful in presenting a united front against dengue and promoting a joint effort in the entire region," Dr. Longini added.
As for the vaccine, "We see it as a very important breakthrough, particularly in helping to reduce the burden and avoid hospitalization and possible deaths," Dr. Thisyakorn told PharmAsia News.
While funding is still something that is being worked out, she noted "there is a very big range of country economic status but some support from international agencies is expected."
Dr. Longini suggested that this might come from the GAVI vaccine alliance and would also be helped by WHO prequalification of the Sanofi vaccine, which would allow supply of the quality-assured product through WHO-related agencies.
Sanofi Pasteur has been been providing an unrestricted educational grant to the ADVA workshop program since 2011 and also supports ASEAN Dengue Day (on June 15) to raise awareness of the disease and support collaboration.
Other companies working on vaccine candidates include Takeda Pharmaceutical Co. Ltd./Inviragen Inc., which is taking its DENVax vaccine into Phase III trials, Merck & Co. Inc. and Vical Inc.