Sanofi and GSK delay COVID-19 vaccine, marking a setback for the worldwide struggle

© Reuters. FILE PHOTO: A Sanofi logo is displayed during the company's annual results press conference in Paris, France

By Matthias Blamont

PARIS (Reuters) – Sanofi (NASDAQ 🙂 and GlaxoSmithKline (NYSE 🙂 said clinical trials of their COVID-19 vaccine showed inadequate immune responses in the elderly, delaying start-up until the end of next year, and marking a setback in the global fight against the pandemic.

Friday's announcement, highlighting the challenges of developing record-breaking shots, hampers efforts to develop the multiple options experts say the world needs to tackle a disease that has killed over 1.5 million people .

The news, which came on the same day that Australia suspended a domestic vaccine project, is also a blow to many governments that have booked hundreds of millions of doses of the shot, including the European Union, the United States and the UK.

Sanofi's shares in France fell 2.8% around 0910 GMT while those of GSK in the UK rose 0.2%.

The two companies said they wanted to start another study this coming February in hopes of developing a more effective vaccine by the end of 2021.

The setback affects one of the most established technologies in vaccines – used against human papillomavirus, hepatitis B, and pertussis, among others – which aims to introduce laboratory-made proteins into the body in order to get the immune system to target it Defend against the novel to develop coronavirus.

It cemented the lead of newer vaccine approaches like Pfizer-BioNTech and Moderna (NASDAQ 🙂 that use mRNA genetic engineering to induce the body to produce these proteins. Both shots were found to be 95% effective in successful large-scale trials.

Delays and additional attempts are not uncommon, but the Sanofi / GSK announcement underscores the unique challenges drug makers are facing in multitasking science, speed, and logistics during a pandemic that has battered the global economy.

It also highlights why governments spread their bets by getting shots from various developers.

Australia, meanwhile, stopped manufacturing a COVID-19 vaccine developed by the University of Queensland and used an adjuvant from biotech company CSL (OTC 🙂 after studies showed it could interfere with HIV diagnosis.

"Science can't just be about getting positive results. Negative results will and must happen," said Diego Silva, an expert at the University of Sydney's School of Public Health.

"Negative results are just as important as success in science because they too are part of the evidence base for future research."


Sanofi said the results of Friday's Phase I / II studies showed "an immune response comparable to patients who have recovered from COVID-19 in adults ages 18 to 49, but a low immune response in older adults , probably due to an insufficient concentration of the antigen ". .

"With this type of vaccine, the result is not a surprise. We know that older patients need more antigen. However, in phases I and II, drug manufacturers test tolerance and you cannot test high doses," said Jean-Daniel Lelievre. Head of the Department of Immunology and Infectious Diseases at the Henri Mondor Hospital in Creteil, France.

"I would think Sanofi and GSK can improve their vaccine."

Phase III trials should begin this month. However, Sanofi said it would instead start a Phase 2b trial in February.

"The study will include a proposed comparison with an approved COVID-19 vaccine," the company said, declining to provide further details.

"If the data are positive, a global phase III study could begin in the second quarter of 2021. Positive results from this study would lead to regulatory filings in the second half of 2021 and thus the potential availability of the vaccine from mid-2021 through the fourth quarter Delay 2021. "

The two companies said they "updated governments and the European Commission when they entered into a contractual obligation to purchase the vaccine".

Britain leaps ahead

The vaccine uses the same recombinant protein-based technology as one of Sanofi's seasonal influenza vaccines. It is coupled with an adjuvant, a substance that acts as a booster for the vaccine manufactured by GSK.

Sanofi and GSK have expanded production to be ready to produce up to one billion doses of their vaccine by 2021. GSK said the goal of producing 1 billion doses of adjuvants by 2021, some of which are expected to be shipped to other partners, remained in place but has been reviewed.

The phase I / II study tested the safety, tolerability and immune response of the vaccine in 440 healthy adults at 11 trial sites in the United States.

This week the UK started using the Pfizer BioNTech vaccine, ahead of the rest of the world in the race.

Canada also gave the go-ahead for the shot, while a group of outside advisors to the U.S. Food and Drug Administration voted Thursday to approve the emergency clearance.

The UK's AstraZeneca (NASDAQ 🙂 Plc and Oxford University have also reported data for their late-stage COVID-19 uptake, showing an average success rate of around 70%.

Sanofi is working on another COVID-19 vaccine candidate with Translate Bio (NASDAQ :), a US company that uses mRNA technology. Phase I trials are expected to begin this month.

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