Astellas Pharma has extended its $52-per share offer to acquire OSI Pharmaceuticals to May 17, though the latter’s shareholders are showing little desire to offer up their stakes.

This is the second time that the Japanese company has extended the deadline for its offer, as it was due to expire on April 23. That had been put back from an original date of March 31, two weeks after OSI’s board turned down Astellas’ hostile $3.5 billion takeover bid and said it is contacting other potential purchasers.

It looks as though investors share the OSI boards concerns as Astellas noted that as of April 22, around 42,200 shares had been tendered, representing less than a 1% stake in the company. The Tokyo-headquartered company has been pursuing OSI for over a year but said last week that it has no intention of upping its bid, though analysts believe a $60 per share offer would swing the deal.

OSI is feeling the heat, however, and no other bidders have yet shown their hand. The US firm also announced at the end of last week that first-quarter net income shrank 70.1% to $4.9 million, hit by costs of $11 million in connection with the Astellas offer.