Astellas Pharma has made public a $1 billion bid it submitted for CV Therapeutics which was rejected at the end of last year and has reiterated its desire to push ahead with a potential acquisition of the US firm.

The Japanese drugmaker said that initially it offered $16.00 per share in cash on November 14 and a week later CVT rejected it. However that offer is on the table and Astellas noted that the proposal represents a 41% premium to the closing share price of CVT on January 26, and up 69% on its 60-day average.

Astellas is keen to get its hands on the anti-angina drug Ranexa (ranolazine) which recently received the thumbs-up in the USA for a new first line indication (for chronic angina). Astellas, which already markets CVT’s Lexiscan (regadenoson), an A2A adenosine receptor agonist used as a pharmacologic stress agent, has been looking to reduce its reliance on the immunosuppressant Prograf (tacrolimus).

However it appears that relations between the two firms have cooled since the initial bid and Astellas said that CVT “has subsequently declined to engage…in any meaningful discussions regarding a transaction”. The Tokyo-based company’s chief executive Masafumi Nogimori said the firm is “disappointed that the CVT board of directors has rejected outright what we believe is a very compelling all-cash proposal”.

He claimed that a link-up would deliver stockholders “significant immediate value that we believe far exceeds what CVT can achieve as a standalone company”. Mr Nogimori added that “our established infrastructure and proven track record in drug development and commercialisation provide an ideal platform to increase the value inherent in CVT”.

In a letter to CVT chief executive Louis Lange, Mr Nogimori said that “we remain prepared to meet immediately with you and your advisors to discuss our proposal”. He added that due diligence and a definitive agreement is achievable within three to four weeks “and we look forward to your prompt response”.

CVT has not yet responded to Astellas’ aggressive stance but while the company is biding its time, investors dived into the stock, pushing it up 35.9% to $15.42.