UPDATE 2-GSK says tests indicate antibody drug works against Omicron

* Sotrovimab, developed with Vir, tested in lab and on
hamsters

* Key Omicron mutations did not elude drug activity in study

* Tests continuing on further mutations
(Adds background on rival drugs)

By Ludwig Burger

Dec 2 (Reuters) - Laboratory analysis of the antibody-based
COVID-19 therapy GlaxoSmithKline (GSK) is developing
with U.S. partner Vir has indicated the drug is
effective against the new Omicron variant, the British drugmaker
said on Thursday.

A GSK statement said that lab tests and a study on hamsters
have demonstrated the sotrovimab antibody cocktail to work
against viruses that were bio-engineered to carry a number of
hallmark mutations of the Omicron variant.

The tests are continuing to confirm the results against all
of the Omicron mutations, with an update expected by the end of
the year, it added.

The antibody is designed to latch on to the spike protein on
the surface of the coronavirus, but Omicron has been found to
have an unusually high amount of mutations on that protein.

“Sotrovimab was deliberately designed with a mutating virus
in mind," said Vir Chief Executive George Scangos, adding that
the drug was targeting a region of the spike protein that was
highly unlikely to mutate.

Separately, Britain's drug regulator on Thursday approved
sotrovimab, also known under the brand name Xevudy, for people
with mild to moderate COVID-19 and who are at high risk of
developing severe disease.

The Medicines and Healthcare products Regulatory Agency
(MHRA) recommended use of Xevudy as soon as possible and within
five days of the onset of symptoms.

Sotrovimab is based on monoclonal antibodies, which are
lab-made versions of the natural antibodies the body generates
to fight off an infection. Similar products are offered or being
developed by Eli Lilly, Regeneron and
AstraZeneca.

Regeneron on Tuesday said that lab tests and computer
modelling suggest that COVID-19 antibody drugs including
Regeneron's would have reduced efficacy against the Omicron
variant.

(Reporting by Ludwig Burger
Editing by David Goodman)