Fosun Pharma has stopped development of BioNTech’s first COVID-19 vaccine, following the lead of its German partner by picking BNT162b2 as the candidate to take to market.

BioNTech signed up to work with Fosun to bring a COVID-19 vaccine to China in March. The deal, which is worth up to $135 million, led to Fosun registering a phase 1 trial of mRNA vaccine BNT162b1 with the Chinese authorities in July. Less than one week later, BioNTech and its global partner Pfizer selected BNT162b2 as the candidate to take forward into phase 2/3.

Now, Fosun Chief Medical Officer Aimin Hui has told Reuters that BNT162b2 is also the preferred shot for the Chinese market. Fosun has opted against further development of BNT162b1, choosing instead to run a bridging study that may enable it to use global BNT162b2 data to support approval in China.


Chinese authorities have become more accepting of data generated overseas in recent years. If all goes to plan, the bridging study will enable Fosun to show the safety and efficacy seen in the global program is applicable to the Chinese population and win approval “around the same time” as the vaccine is authorized in other countries.

The switch to BNT162b2 could provide benefits. BioNTech and Pfizer selected the vaccine as their phase 2/3 candidate, despite it entering the clinic second, after linking it to a lower rate of adverse events than BNT162b1.

In a phase 1/2 trial, 17% of 18- to 55-year-olds who received 30 μg of BNT162b2 reported related adverse events. The comparable adverse event rate for BNT162b1 was 50%. BioNTech and Pfizer also linked BNT162b1 to a higher rate of adverse events in 65- to 85-year-olds. Fewer people who received BNT162b2 suffered systemic events, and those that did reported milder events.

The immune responses linked to the two vaccines were similar, leading BioNTech and Pfizer to pick the more tolerable candidate for late-phase development. Given the potential for the vaccine to be given to hundreds of millions of people as well as face intense scrutiny and, in some quarters, skepticism, tolerability could be an important enabler of successful mass immunization programs.

It remains unclear when those immunization programs will start. Last week, Pfizer said its trial was yet to see the 32 COVID-19 cases that will trigger the first look at the late-phase data.

Pfizer Inc on Monday said its experimental vaccine was more than 90% effective in preventing Covid-19 based on initial data from a large study, a major victory in the fight against a pandemic that has killed over 1 million people, roiled the world's economy and upended daily life.

Pfizer and German partner BioNTech SE are the first drugmakers to show successful data from a large-scale clinical trial of a coronavirus vaccine. The companies said they have so far found no serious safety concerns and expect to seek US emergency use authorisation later this month.

If authorised, the number of vaccine doses will initially be limited. Many questions also remain including how long the vaccine will provide protection. However the news provides hope that other vaccines in development against the novel coronavirus may also prove effective.

"Today is a great day for science and humanity," Albert Bourla, Pfizer's chairman and chief executive, said in a statement. "We are reaching this critical milestone in our vaccine development program at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen."

Pfizer expects to seek broad US emergency use authorisation of the vaccine for people aged 16 to 85. To do so, it will need to have collected two months of safety data on around half of the study's roughly 44,000 participants, expected in late November.

"I'm near ecstatic," Bill Gruber, one of Pfizer's top vaccine scientists, said in an interview. "This is a great day for public health and for the potential to get us all out of the circumstances we're now in."

Pfizer said the interim analysis was conducted after 94 participants in the trial developed COVID-19, examining how many of them received the vaccine versus a placebo.

The company did not break down exactly how many of those who fell ill received the vaccine. Still, over 90% effectiveness implies that no more than 8 of the 94 people who caught Covid-19 had been given the vaccine, which was administered in two shots about three weeks apart.

The efficacy rate is well above the 50% effectiveness required by the U.S. Food and Drug Administration for a coronavirus vaccine.

To confirm its efficacy rate, Pfizer said it will continue the trial until there are 164 Covid-19 cases among participants. Given the recent spike in US infection rates, that number could be reached by early December, Gruber said.

The data have yet to be peer-reviewed or published in a medical journal. Pfizer said it would do so once it has results from the entire trial.

Pfizer and BioNTech have a $1.95 billion contract with the U.S. government to deliver 100 million vaccine doses beginning this year. They have also reached supply agreements with the European Union, the UK, Canada and Japan.

To save time, the companies began manufacturing the vaccine before they knew whether it would be effective. They now expect to produce up to 50 million doses or enough vaccine to protect 25 million people this year.

Pfizer said it expects to produce up to 1.3 billion doses of the vaccine in 2021.