FRANKFURT (Reuters) – BioNTech said Singapore’s Temasek and other investors are injecting $250 million into the German biotech firm through a private placement, reflecting heightened investor appetite for promising developers’ vaccines against the coronavirus.

The company, which went public on the U.S. Nasdaq in October last year, said the investors would purchase about $139 million in ordinary shares and $112 million in 4-year mandatory convertible notes.

The investors are in for an early reckoning because BioNTech has said it expects first clinical data on its COVID-19 vaccine development programme known as BNT162 this month or in July.

The transaction would increase the number of shares outstanding by 2.6 million from 226.8 million shares as per end of March, resulting in a combined stake of 1.1% for the investor group once all notes are converted.

BioNTech, which is also working on personalised cancer vaccines, would not say how much of the total is attributed to Singapore state investment company Temasek.

BioNTech and its partner Pfizer launched testing programmes involving humans in April and May.

Domestic rival vaccine developer CureVac, in which the German government is taking a 23% stake, is planning an initial public offering in the United States next month. U.S. peer Translate Bio has attracted France’s Sanofi as an investor in a deal worth as much as $2 billion.

BioNTech, which awarded the rights to BNT162 in China to Shanghai Fosun under a March collaboration deal, is competing with CureVac as well as U.S. biotech firms Moderna and Translate Bio in the race to develop messenger-RNA vaccines.

These molecules act as recipes designed to instruct human cells to produce antigen proteins. That would allow the immune system to develop an arsenal against future coronavirus infections.

(Reporting by Ludwig Burger; editing by Thomas Seythal and Emelia Sithole-Matarise)