BioNTech SE agreed to buy former Covid vaccine rival CureVac NV for about $1.25 billion in an all-stock transaction that will boost its growing oncology business.

CureVac’s U.S. listed shares rose 30.71% in premarket trading.

CureVac investors will get approximately $5.46 in BioNTech shares for each CureVac one, the companies said Thursday. The price represents a 34% premium to CureVac’s closing share price on Wednesday. CureVac shareholders will own between 4% and 6% of BioNTech once the deal closes.

The deal caps decades of rivalry between the two companies that came to a head during the race to develop a Covid vaccine. BioNTech won the race with its partner Pfizer Inc., transforming into one of Europe’s leading biotechs. CureVac’s shot never made it to market after proving less effective in clinical trials.

CureVac has since pivoted away from infectious disease work, focusing instead on cancer immunotherapies. Oncology is a key area for BioNTech as well, and the takeover will bring together “complementary capabilities” to boost BioNTech’s capacity in cancer, Chief Executive Officer Ugur Sahin said in a statement.

The deal also represents an exit for the German government, which holds 13.3% of CureVac after taking a stake during the pandemic. It will get about $163 million in BioNTech shares under the terms of the deal. The government has a positive view of the transaction, according to BioNTech.

BioNTech expects to have contractual commitments to support the deal from slightly more than half of CureVac’s shareholders, including its main investor Dietmar Hopp, the German billionaire who co-founded software giant SAP SE.

The takeover is the latest in a series of steps by BioNTech to leverage its Covid billions into its growing cancer portfolio. Earlier this month the company licensed a next-generation cancer drug to Bristol-Myers Squibb Co. for as much as $11.1 billion.

The transaction is subject to certain caps on how many shares would be exchanged if BioNTech’s share price hits certain levels five days before the deal closes, a so-called collar mechanism. Both boards endorsed it.