UPDATE 2-Sanofi, GSK kick off Phase III trial for COVID-19 shot

(Adds details, quote)

By Dominique Vidalon

PARIS, May 27 (Reuters) - France's Sanofi and Britain's
GlaxoSmithKline launched a late-stage human trial for a
recombinant COVID-19 vaccine candidate on Thursday which they
hope to get approved by the end of 2021.

The study initiated by Sanofi and GSK is
one of the first late stage trials that combines tests for
boosters and variants, as drugmakers adapt their strategies to
deal with an evolving coronavirus.

The two drugmakers, which earlier this month reported
positive interim results, confirmed their double-blind,
placebo-controlled, phase III study would include more than
35,000 adults in the United States, Asia, Africa, and Latin
America.

"In a two-stage approach, the study will initially
investigate the efficacy of a vaccine formulation targeting the
original virus, while a second stage will evaluate a second
formulation targeting the B.1.351 virus," Sanofi said.

The virus lineage known as B.1.351 was first detected in
South Africa.

"Recent scientific evidence shows that antibodies created
against the B.1.351 variant may provide broad cross-protection
against other more transmissible variants," Sanofi said.

"The design of the Phase III, conducted across a broad
diversity of geographies, also allows evaluation of the efficacy
of the candidate against a variety of circulating variants," the
French drugmaker added in a statement.

Sanofi also confirmed it would begin clinical studies in the
coming weeks to assess the efficacy of the vaccine as a booster,
regardless of what vaccine a subject may have received first.

Pending a positive phase III outcome, the vaccine could be
approved in the fourth quarter after it was initially targeted
for the first half of the year before a setback.

Sanofi and GSK were forced to restart their trial in
December when the vaccine showed a low immune response in older
adults as a result of a weak antigen formulation.
(Reporting by Dominique Vidalon; Writing by Matthias Blamont;
Editing by Subhranshu Sahu and Alexander Smith)