- Coronavirus vaccine developers, working against the clock to quickly prove their experimental candidates, are preparing for late-stage clinical trials that would enroll tens of thousands of people in the U.S., Europe and, potentially, other regions as the pandemic's heaviest impact begins to shift to the Southern Hemisphere.
- So far, early safety studies of coronavirus vaccines have involved several dozens to hundreds of healthy volunteers. But establishing the safety and effectiveness of a treatment that could potentially be given to tens of millions of people globally will require massive trials spanning many countries.
- A Phase 2 study of a vaccine being developed by the University of Oxford and AstraZeneca, which started last week, aims to recruit 10,260 adults and children in the U.K. The British drugmaker is already planning a Phase 3 trial in the U.S. of some 30,000 people.
At least 10 experimental coronavirus vaccines are in human testing, mostly smaller Phase 1 studies designed to give preliminary evidence of safety and to help select a dose for larger trials.
Three of those vaccines, from the University of Oxford, the U.S. biotech Moderna and China's CanSino Biologics, have already progressed through initial study phases and have been advanced, or are about to be advanced, into the next stage of testing.
Whereas previously trial phases would be staggered over multiple years, developers and regulators are compressing typical development timelines to allow vaccine candidates to quickly move into evaluations across larger groups of people. The accelerated approach is necessary to meet the exceedingly ambitious goal set out by the U.S. government and others of obtaining a vaccine within 12 to 18 months, or even sooner.
Company plans to accomplish that task are starting to come into focus, and would result in a enormous effort to recruit, enroll and treat tens of thousands of adults and children in just a few months.
AstraZenca plans to start its 30,000-person Phase 3 trial in July. Pfizer CEO Albert Bourla, speaking on a conference call hosted by the drugmaker trade group IFPMA Thursday, said the company is planning for a study of its vaccine candidate that would enroll 20,000 or 30,000 participants.
Johnson & Johnson, the first major drugmaker to begin a coronavirus vaccine program, is anticipating running two "large" Phase 3 trials, the company's chief scientific officer Paul Stoffels said on the call Thursday.
Trials testing tens of thousands of participants are fairly typical in vaccine development, but it's unusual for several involving so many people to begin within months of each other.
J&J hopes to begin human testing of its candidate in September, with first supply available as early as the beginning of next year. AstraZeneca has committed to providing the U.K. and the U.S. with doses of its vaccine starting in September and October, respectively.
And Pfizer hopes to have enough evidence to support early use of its candidate by this fall.
"If things go well and the stars are aligned, we will have enough evidence of safety and efficacy so that we can feel comfortable, and FDA will feel comfortable, and EMA will feel comfortable to have a vaccine around the end of October," said Bourla on the call, referring to the Food and Drug Administration and the European Medicines Agency.
All three companies, as well as others like Moderna, will be challenged to complete their testing while cases of coronavirus infection are still prevalent. While declining case numbers is unquestionably a welcome development, conducting clinical trials in regions like Europe and the U.S. could become more difficult
"We're running against time," said AstraZeneca CEO Pascal Soriot on the call. "We see already in Europe, the disease is declining. It's still going in the U.K., because the U.K. started later, still going in the U.S., but very soon the disease intensity will be low and it will become difficult."
J&J is planning to run its trials in the Northern Hemisphere, Stoffels said, but the company could move testing to the countries in Africa and South America if the pandemic's burden shifts further. Infections and deaths in Brazil, in particular, have risen dramatically.
Already, Chinese drugmakers are looking outside their country to run studies of their vaccine candidates. CanSino Biologics, the furthest along, recently secured approval for Canadian regulators to begin testing there, for instance.