China's CanSino Bio advances COVID-19 vaccine into phase 2 on preliminary safety data

by Angus Liu | Apr 10, 2020 6:56am

In the global race to develop an effective vaccine to protect people against the novel coronavirus, China’s CanSino Bio has leapt ahead.

CanSino and its collaborators at the Academy of Military Medical Sciences’ Institute of Biotechnology plan to move their adenovirus type-5 vector-based recombinant COVID-19 vaccine, Ad5-nCoV, into phase 2 clinical trial in China “soon,” the company said in a disclosure (PDF) to the Hong Kong Stock Exchange on Thursday.

The company said the partnership made the decision “[b]ased on the preliminary safety data of the phase 1 clinical trial,” detailed results of which have not been shared.

In fact, virtual enrollment of the phase 2 study where interested individuals can sign up via a QR code has already started, putting CanSino ahead of all the others on a long list of COVID-19 vaccine developers.

It was only in mid-March when CanSino kicked off the first-in-human trial of Ad5-nCoV in healthy volunteers in the city of Wuhan, then the epicenter of the outbreak. Moving a vaccine from phase 1 into phase 2 in just three weeks is super fast, if not unprecedented, even with all the urgency around an ongoing pandemic, making the process look more like a phase 1/2 paradigm.

Per the phase 1 trial design, 108 subjects are supposed to be followed for up to six months for analyses of safety as well as T-cell and antibody responses. The study’s primary endpoint was set to look at adverse reactions seven days post injection, data CanSino likely already have.

According to the phase 2 protocol CanSino’s partner posted Friday on China’s clinical trial registry, the new study will again be conducted in Wuhan and will enroll 500 healthy participants. It’s worth noting that the investigators have abandoned the highest dose used in the phase 1 trial. This time, 250 people will get the middle dose, and the remaining 250 will be split up to receive either the low dose or placebo.

The randomized study has three primary endpoints, which will examine adverse reactions within the first 14 days of vaccination as well as serum levels of anti-SARS-CoV-2 neutralizing antibody and antibody against the coronavirus’s spike protein at day 28. Again, all participants will be followed for up to six months.

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