UPDATE 2-China's Clover ends COVID-19 vaccine partnership with GSK

(Adds Dynavax share movement)

BEIJING, Feb 1 (Reuters) - Clover Biopharmaceuticals has ended its partnership with GlaxoSmithKline Plc to develop a COVID-19 vaccine using its adjuvant, the Chinese drugmaker said on Monday, as it will stick with a vaccine booster from U.S.-based Dynavax instead.

The decision marks a further setback to GSK which said in December that clinical trials of a rival COVID-19 vaccine developed with partner Sanofi showed an insufficient immune response in older people and they decided to delay its launch.

Clover has been testing two COVID-19 vaccine candidates, one containing an adjuvant, typically designed to boost the efficacy of vaccines, from GSK, and the other from Dynavax Technologies Corp.

While both candidates induced high levels of neutralizing antibodies, Clover said it decided to initiate Phase II and III studies of the candidate using the Dynavax adjuvant after taking into account “scale-up manufacturing considerations.”

“Having fully evaluated all available data, and based on our discussions with Clover and CEPI, we will not progress this collaboration using GSK’s pandemic adjuvant,” a GSK representative said in an emailed response to Reuters.

The Coalition for Epidemic Preparedness Innovations (CEPI), a global epidemic response group, is funding the Phase II/III trial of Clover’s vaccine.

CEPI separately on Monday agreed to provide Dynavax funding of up to $99 million to manufacture its adjuvant or vaccine booster for COVID-19 vaccine developers that CEPI has funded.

Shares of Dynavax rose nearly 15% before the trading bell.

A Clover representative said GSK and the company will “move forward with other collaborations that they believe will be able to maximize their respective and overall impacts against the COVID-19 pandemic.”

The mid-to-late stage trial of its candidate with the Dynavax’s adjuvant will start in the first half of this year, with interim analysis of its efficacy expected around in the middle of 2021, Clover said. (Reporting by Roxanne Liu and Tony Monroe in Beijing, additional reporting by Manas Mishra in Bengaluru; Editing by Miyoung Kim, Louise Heavens and Shinjini Ganguli)