China Clears First Coronavirus Vaccine Trial
Executive Summary
Leveraging its Ebola vaccine success, Tianjin-based CanSino is looking to launch China’s first vaccine for COVID-19 as it secures permission to start local clinical trials.
Using adeno-associated virus vector technology, Tianjin CanSino Biotechnology Inc. has secured the first clearance in China to start a clinical trial with a potential vaccine for the new coronavirus. The company's candidate, Ad5-nCoV, has been jointly developed with the China Institute of Military Medical Science (IMMS).
The race to develop the first vaccine is heating up and after US firm Moderna Inc. dosed the first patient in its US trial, China cleared the way to its first clinical study. CanSino's vaccine is based on an AAV serotype 5 vector encoding the spike protein of the SARS-CoV-2 virus, a structure seen as key to its cell entry and spread. “This technology enabled us to translate our [previously developed] globally innovative Ebola virus vaccine from a concept to an approved product in only three years,” noted CanSino.
The company will start the trial in healthy people in Wuhan, the original epicenter of the now global outbreak. Preclinical results for Ad5-nCoV show that the candidate can induce a strong immune response and has a good safety profile, said the company. The AAV5 vector has been used widely after a patent held by the US National Health Institute expired, and there are several trials for products using the vector, including BioMarin Pharmaceutical Inc.’s Factor VIII gene therapy for hemophilia.
Ke Wu, the chief executive official of another Chinese vaccine developer, Wuhan-based Bravovax, told the Pink Sheet that the CanSino vaccine uses technology different to that of Moderna's product, which uses messenger RNA. The AAV vector is comparatively slower to develop, but speed does not necessarily mean success, Wu noted.
Bravovax has teamed up with Geovax to develop its own vaccine against the coronavirus. (Also see "China Rallies Behind Coronavirus Vaccines But Small Players May Have Best Shot" - Scrip, 4 Mar, 2020.)
Ebola Regulatory Precedent Relevant?
CanSino said it is aiming to leverage the AAV technology "to launch the vaccine candidate as soon as possible with no compromise on quality and safety." Its prior experience with the Ebola vaccine suggests that development timescales can be substantially compressed in times of health crisis.
In 2017, China approved the company's Ebola vaccine, also developed with IMMS, in record time. The product obtained a priority review in just 10 work days after the then China FDA granted clinical trial clearance. In less than four months, the agency in late 2017 granted an official approval, setting a record for a new drug. The standard time frames at the time were usually 90 work days for clinical trial approvals and 150 days for NDAs.
CanSino's Ebola vaccine used the same Zaire string of the virus as Merck & Co. Inc.'s approved product, but lacked a Phase III study. “The sponsor completed three clinical studies...including a randomized, double-blind Phase I study using placebo in 120 Chinese people and a Phase II in 61 Africans residing in Hangzhou, as well as a Phase II on 500 people in Sierra Leone,” noted Chinese regulators at the time. Merck had completed a Phase III study in 7,000 people in Guinea.
“Although [CanSino's] vaccine can produce higher levels of antibody inside a human body, due to the lack of Phase III study data, the antibody level’s association with effectiveness of disease prevention is unknown,” the CFDA conceded in granting the conditional approval, which also specified emergency use only in the public health crisis.
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(The Pink Sheet's coverage of the coronavirus outbreak and the biopharma industry's response is aggregated here.)