Shares of Halozyme Therapeutics (NASDAQ:HALO) added ~12% in the premarket on Friday after the drug delivery technology company withdrew its non-binding proposal to acquire German drugmaker Evotec SE (NASDAQ:EVO). The U.S. biotech cited Evotec's (NASDAQ:EVO) reluctance to engage in takeover discussions as the reason for the decision.

"We continue to believe that a combination of Halozyme and Evotec would create a leading, differentiated, global pharma services company, benefitting shareholders, patients, and employees," said Halozyme's (NASDAQ:HALO) CEO, Helen Torley.

"Evotec has been unwilling to engage with us to explore a potential combination, and a company spokesperson has publicly commented that its goal is to remain an independent company," Torley added.

Last week, shares of Evotec (EVO) rose after confirming buyout interest from Halozyme (HALO), which had placed its non-binding all-cash bid at €11 per share for a total value of €2B, including debt.