Pfizer admitted it had seen a £58.8 billion offer for London-listed Astra turned down in January, and said chairman Ian Read had attempted to open new talks over the weekend.
Astra “again declined to engage”, Pfizer said, adding that it was considering its options. It insisted that a deal would represent a “highly compelling opportunity” to Astra investors and said any offer would include a “substantial” cash payment as well as the chance to become significant shareholders in the combined company.
The transaction would be expected to result in a combination of the two firms under a UK-incorporated holding company, with management on both sides of the Atlantic and head offices in New York, where it would be listed on Wall Street.
Pfizer, best known for its Viagra anti-impotence treatment, said: “We have great respect for AstraZeneca and its proud heritage as an innovation-driven biopharmaceutical business with a rich science-based foundation in both the United Kingdom and Sweden.
“In addition, the United Kingdom has created attractive incentives for companies to manufacture products and maintain and protect intellectual property, and we have seen that capital and jobs have followed these types of incentives.
“We believe patients all over the globe would benefit from our shared commitment to R&D, which is critical to the future success of the pharmaceutical industry, in the form of potential new therapies that help to fight some of the world’s most feared diseases, such as cancer.”
Pfizer’s January proposal offered a premium of 30 per cent over Astra’s share price at the time, but the stock has gained about a quarter in value since news of the takeover interest began to circulate last week, and closed up 586.5p, or 14.4 per cent, at 4,666.5p last night.
Astra said it had considered the latest request for talks, but “without a specific and attractive proposal”, it had deemed it inappropriate to engage in discussions with Pfizer, adding that the US group’s offer “very significantly” undervalued the company and its prospects.
It said: “The board remains confident in the ongoing execution of AstraZeneca’s strategy as an independent company and that its successful delivery will create significant value for shareholders.”
If accepted, the move would be expected to mark the biggest-ever foreign takeover of a UK business, but unions and MPs have voiced concerns about the potential impact on jobs and manufacturing exports from any deal.
It comes as Astra moves its research centre to Cambridge where it recently announced the launch of a joint facility with the Medical Research Council.
The company was itself formed through the merger of Sweden’s Astra and Britain’s Zeneca in 1999. It is one of the world’s biggest pharmaceutical companies and produces a large range of medicines including cancer and diabetes drugs. It employs more than 50,000 people around the world, including 6,700 in the UK.
Revenues were down 6 per cent to £15.3bn last year, reflecting the loss of exclusivity on a number of drugs it had developed as patents ran out.
Pfizer’s revenues of $51.6bn (£30.7bn) for 2013 were also down on the previous year. A takeover of AstraZeneca would dwarf its previous deal to buy rival Wyeth for $68bn (£48bn) in 2009.