Anglo-Swedish drugmaker AstraZeneca has gained control of 96% of stock in US group MedImmune, providing a free run to complete its acquisition on or around June 18.

“This has been a terrifically successful tender,” a company spokesman told PharmaTimes UK News, “but we have extended the offer period by three days to see if anymore shareholders will sell,” he added.

AstraZeneca announced its intention to buy MedImmune for $15.6 billion in April, but reaction to the deal was mixed. At the time, the group explained the move extended its R&D science base "to allow it to address novel drug targets through three key technological approaches - small molecules, biologics and, for the first time, vaccines."

Purchase price too high?

But some analysts felt that it was unlikely to fill the major gaps in the company's R&D portfolio, and there were complaints that the purchase price was far too high for a maturing blockbuster franchise in the respiratory treatment Synagis (palivizumab), an unprofitable flu vaccine and a pipeline still in early-stage development.

And although the move went down well with most shareholders in MedImmune, Charles Larson filed a class-action lawsuit against the company just days after the merger was announced, claiming that the board breached its duties of "loyalty, due care, independence, candour, good faith and fair dealing" in doing the deal. But at the end of May the court said it would not stand in the way of the merger, after Larson failed to prove how many MedImmune shares he owned, according to media reports.