BioNTech plans to spend up to about 1 billion euros ($1.1 billion) more on research and development and buy back up to $500 million more of its shares this year, drawing on more than 21 billion euros from the now waning commercial success of its COVID-19 vaccine.

In a statement on Monday, Germany's BioNTech, Pfizer's partner on the Comirnaty vaccine, said it plans to spend 2.4 to 2.6 billion euros on research and development (R&D) in 2023, up from 1.54 billion euros last year.

"We plan to continue investing in our transformation with a focus on building commercial capabilities in oncology and working towards registrational trials," said Chief Executive and Co-Founder Ugur Sahin.

The company said it expects to authorise new share buybacks worth up to $500 million this year, having already spent $1.3 billion on own shares through March 17.

Thanks to its COVID-vaccine market lead in the Western world, BioNTech ended the year 2022 with a cash balance of 13.9 billion euros plus receivables, or cash it stands to receive, of 7.14 billion euros.

Commercial revenues from the shot slipped 9% to 17.2 billion euros last year and are expected to drop further to about 5 billion euros in 2023, the company added.

Driving the increase in development costs, BioNTech has started testing four new infectious-disease vaccines on humans over the past few months, targeting influenza and COVID-19 in a combination shot and also herpes, malaria as well as shingles.

It will also continue with its traditional focus on oncology, seeking to use its mRNA technology to help the human immune system to attack tumours.

It said "multiple trials" that could potentially support a request for regulatory approval would be initiated in 2023 and 2024. ($1 = 0.9289 euros) (Reporting by Ludwig Burger and Patricia Weiss, Editing by Rachel More and Jane Merriman)