US-based Halozyme Therapeutics will buy specialty pharmaceutical firm Antares Pharma in a $960 million all-cash deal, the companies said on Wednesday. Halozyme will pay $5.6 for each share of Antares Pharma, a premium of 49.7% to the company's last closing price. "The addition of Antares...further strengthens our position as a leading drug delivery company," Halozyme CEO Helen Torley said.