Covid Vaccine Setbacks Temper Optimism After Upbeat News
(Bloomberg) -- Vaccine makers, including two of the biggest in the world, suffered setbacks in the push to get more Covid-19 shots across the line, tempering a run of positive news.
Sanofi and GlaxoSmithKline Plc delayed advanced trials of their experimental Covid-19 shot after it failed to produce a strong enough response in older people, pushing its potential availability to the end of next year. In another blow, trials of a vaccine being developed by CSL Ltd. and the University of Queensland in Australia ran into difficulties.
Sanofi and its U.K. partner will begin a new second-phase study with a more concentrated antigen in February after they said the current dosage failed to generate a good immune response in people 50 years and older. Younger adults showed a response similar to patients who have recovered from the disease.
The problem arose after two different reagents used to measure vaccine formulations provided inaccurate information about the concentration of antigens, Sanofi said in an emailed statement. The companies notified U.S. officials about the matter.
The delay underscores the difficulties and uncertainties companies face in developing shots in record time against a disease that’s already claimed more than 1.5 million lives. It’s also a blow for governments that were counting on supplies from the two vaccine giants amid expectations the world will need multiple inoculations to stop the spread of the pathogen.
Australia meanwhile canceled an order for 51 million doses of a Covid shot being developed by CSL and the Australian university. A component of the vaccine comes from the human immunodeficiency virus, and while that posed no risk of infection, some trial participants had false positive tests for HIV.
The announcements temper some of the optimism following positive trial results from Pfizer Inc. and Moderna Inc. Another inoculation from AstraZeneca Plc and the University of Oxford looks promising, too, despite questions about its effectiveness in older adults. The U.K. and Canada have already approved a shot from Pfizer and partner BioNTech SE that employs messenger RNA technology, and the U.S. and Europe may do so soon. China and Russia have already begun administering their own vaccinations.
Sanofi fell as much as 3.3% Friday in Paris, while Glaxo was little changed in London.
The delay to the Sanofi-GSK vaccine means it may not reach the market until the fourth quarter of 2021 rather than the middle of the year. A study using an improved antigen mix, exposing monkeys to the virus, showed a rapid clearance of the pathogen from the nose and lungs.
The companies are planning a new trial that could include a head-to-head comparison with an approved Covid-19 vaccine to speed research. The companies haven’t disclosed how many people will be included. Advanced-stage tests could start in the second quarter of next year.
“We want our vaccine to protect everyone, including populations most vulnerable to Covid-19,” Sanofi said. “Therefore, we need to refine our candidate’s antigen formulation to provide high-level of protection across all age adults.”
This particular candidate relies on recombinant DNA technology Sanofi uses to make influenza shots, along with Glaxo’s adjuvants, which enhance the body’s immune response. The companies previously said they expected to produce as many as 1 billion doses in 2021.
Sanofi has another mRNA shot for Covid in development and GSK is involved in a handful of other collaborations for Covid.
The recombinant DNA approach received approval in the U.S. for combating the flu in 2013. It’s a synthetic process that aims to produce an exact genetic match of proteins found on the surface of the virus.
What Bloomberg Intelligence Says
“This development may increase the odds of an approval for AstraZeneca’s vaccine despite unanswered questions over its trial and data.”
-- Sam Fazeli, senior pharmaceutical analyst
Glaxo-Sanofi Covid-19 Vaccine Delay Is a Boost for Astra, Others
The delay highlights the challenges a number of second generation Covid-19 vaccines could face now that the first shots are being approved. One potential benefit of a comparator trial arm with another Covid-19 vaccine will be recruitment. With as many as three approved vaccines possibly available in the coming weeks, studies for those further back in the development process may need to rethink incentives to keep enrollment up.
The biggest orders for the vaccine include the European Union, which has agreed to buy 300 million doses, and the U.S., which is purchasing 100 million with an option for more. Sanofi and GSK have intended to provide 200 million doses of their vaccine to the Covax program, which is aimed at distributing shots equitably all over the world.
Glaxo is also developing vaccines with Sichuan Clover Biopharmaceuticals Inc. of China, which reported last week that the shot had induced neutralizing antibodies in early-stage trials. The U.K. company has also begun late-stage trials for a vaccine with Canada’s Medicago Inc.
©2020 Bloomberg L.P.