The London-listed firm said the financial and other terms of the proposal were “inadequate, substantially undervalue AstraZeneca and are not a basis on which to engage with Pfizer”.
Pfizer’s offer was higher than its previous £46.61 bid, made on 5 January and revealed at the end of last month, and represented a 39 per cent premium on Astra’s closing share price on 3 January.
But AstraZeneca chairman Leif Johansson said he rejected it with no hesitation.
He said: “AstraZeneca continues to invest significantly in research, development and manufacturing in the UK, Sweden and the US.
“We are showing strong momentum as an independent company, in particular with our exciting, rapidly progressing pipeline, which the Board believes will deliver significant value for shareholders.
“Pfizer’s proposal would dramatically dilute AstraZeneca shareholders’ exposure to our unique pipeline and would create risks around its delivery. As such, the board has no hesitation in rejecting the proposal.”
Earlier in the day, Ian Read, Pfizer’s Scots-born chairman and chief executive, had said there was “a highly compelling strategic, business and financial rationale” for combining the businesses, with “significant benefits for shareholders and stakeholders of both companies”.
Read also revealed that he has written to Prime Minister David Cameron in a bid to allay fears over UK jobs. He pledged to complete AstraZeneca’s proposed research and development hub in Cambridge and said 20 per cent of the combined company’s R&D workforce will be in the UK.