Not surprisingly, the board at Genzyme Corp has voted unanimously to reject the unsolicited $69.00 per share offer made by Sanofi-Aventis and urged stockholders not tender their shares to the French drugmaker.

Sanofi went in with a hostile bid that values Genzyme at around $18.50 billion earlier this week but the latter says the offer is based on "identical financial terms" to two previous unsolicited proposals", both of which were rejected by the board. The US biotech has repeated its view that Sanofi's offer is "inadequate and opportunistic" and "substantially undervalues the company".

Genzyme spoke of its "valuable late-stage pipeline, which includes "three breakthrough products that are expected to be launched by the end of 2013", notably alemtuzumab, "a potentially transformative therapy for multiple sclerosis". Phase III results for the drug will be available in the middle of next year.

More surprising is a filing to the US Securities and Exchange Commission which gives a version of a meeting between Genzyme chief executive Henri Termeer and his counterpart at Sanofi,Chris Viehbacher, which the French firm does not share. Genzyme says a price range of $69 to $80 per share was discussed, with Mr Viehbacher allegedly saying that the range was "manageable," although he disputed the higher end based on his understanding of the company's business.

Sanofi does not remember the meeting in the same way and spokesman Jean-Marc Podvin told Reuters that "we strongly disagree with Genzyme's characterisation of the September 20 meeting between the CEOs". He went on to say that "at that meeting we made a variety of efforts to move the process forwards, including discussing the merits of our $69 per share offer and we tried to understand if media reports about Genzyme's price expectations were accurate".

Genzyme added that it is initiating a programme to communicate with shareholders "regarding the intrinsic value of the company". It will also hold an analyst and investor meeting in New York "to provide a financial outlook and other pertinent information" in the near future.