Missing In Action: China’s Best Shot In Ebola Vaccine Race
Executive Summary
As the Congo grapples with the latest outbreak of Ebola, China has approved its first domestically developed vaccine in record time, hailing it a national innovation champion. But as the World Health Organization starts vaccinations in Africa, can China make the cut and compete with global players including Merck & Co?
Hailing it as a national priority, the China FDA has approved its first home grown Ebola vaccine in record-breaking time, but it has yet to be used in an ongoing new outbreak in Africa.
Located thousands of miles away from the affected area, China believes the approval is not only important but an urgent task, as given its 1.3 billion population, the country sees it as only a matter of time before the next epidemic could hit the nation.
So right after the abatement of the last major Ebola outbreak in 2014, which hit West Africa hard causing over 11,000 deaths, China decided to have own vaccines ready before the next wave.
Developed by China’s Academy of Military Medical Sciences, along with CanSino Biotech, the new vaccine is based on the Zaire string of the virus, the same used in the one being shipped to affected Congo regions, provided by Merck & Co. Inc..
The Chinese vaccine, despite having obtained CFDA approval, has yet to be assessed in a Phase III trial as the approval was given on the condition that this be conducted. This was also the first conditional approval to be granted under China’s regulatory reforms to accelerate new drugs and biologics approvals.
Record Approval Times
The vaccine developed in China, using an adenovirus (AAV) carrier, obtained a priority review in February 2015 and in just 10 work days the CFDA granted clinical trial approval (CTA).
In 79 work days, the agency officially approved the product last October, setting a new record for an NDA approval time. Comparatively, the standard time frames for a CTA is 90 work days and 150 for an NDA.
“To defend public well-being amid a public health crisis, we don’t hesitate to stand by scientists and push forward the vaccine to the market,” said Xu Jiaqi, director of the Center for Drug Evaluation (CDE), the new drug review arm of the CFDA.
To that end, eight reviewers working at the CDE’s biologics division were divided into two groups and worked on the Ebola vaccine simultaneously. Given the limited reviewer resources - about 120 compared to over 1,000 at the US FDA - the agency was mustering all available effort towards the approval.
Phase III Data Lacking
Responding to questions from Scrip, World Health Organization spokesman Tarik Jaseravic said the Merck vaccine is the only one that has shown efficacy in a Phase III study, out of 12 candidates. (Also see "Ebola Outbreak In DR Congo: Where Are The Vaccines In Development?" - Scrip, 16 May, 2018.)
“Twelve candidate Ebola vaccines (including monovalent, bivalent and multivalent candidates) have undergone or are currently undergoing clinical development at different trial phases. The Phase 3 trial for an rVSV-vectored candidate vaccine (rVSVΔG-ZEBOV-GP), undertaken in Guinea, is the only study that has reported clinical efficacy and effectiveness for any candidate Ebola vaccine,” he noted.
But compared to the Merck product and one approved in Russia, the Chinese vaccine shows great potential, noted the CFDA.
“The sponsor completed three clinical studies, including a randomized, double-blind Phase I study using placebo on 120 Chinese people, and a Phase 2 on 61 Africans residing in Hangzhou, as well as a Phase 2 on 500 people in Sierra Leone,” noted the agency in a statement.
In comparison, the Merck vaccine has completed a Phase III study in 7,000 people in Guinea, while the locally approved Russian vaccine has only completed a Phase I program in 24 people and Phase II in 59 patients.
“Although our vaccine can produce higher levels of antibody inside a human body, due to the lack of Phase 3 study data, the antibody level’s association with effectiveness of disease prevention is unknown,” recognized the CFDA in granting the conditional approval, which also specifies only emergency use amid a public health crisis.
A freeze-dried dry power formulation, the vaccine is said to be easier to store and ship in the conditions of Africa, added the agency.
Funding/Supply Channels
So far, the new Chinese vaccine's manufacturer, CanSino, in January cleared the EU’s Qualified Person’s Good Manufacturing Practice rules. The company didn’t disclose the current production situation, but it is expected to make stockpiles for emergency use.
Merck meanwhile has donated doses of its vaccine to the WHO, the operation to administrate these being underwritten by donations from the Vaccine Alliance, GAVI, and others, noted the WHO.
GAVI had previously entered an advanced procurement agreement for 300,000 doses of the Merck vaccine, and has approved additional funding for a global stockpile of one or more vaccines if they are licensed and recommended by the WHO.
Given the ready funding and China's desire to make domestically developed Ebola vaccines work, the path to possible global supplies should be clear. But so far, China's National Health Commission hasn't publicly disclosed any plans to send any of the Chinese product to the affected Congo regions.
Earlier this week, the WHO opened its annual meeting during which Director-General, Tedros Adhanom Ghebreysus said: “It’s concerning that we now have cases of Ebola in an urban center, but we’re much better placed to deal with this outbreak than we were in 2014. I am pleased to say that vaccination is starting as we speak today.”
Participating Chinese Health Commissioner Ma Xiaowei told the meeting that China is willing to share its experiences with the world.
From the editors of PharmAsia News.