Shares in Actelion leapt yesterday after the Swiss biotech, which is thought to be a takeover target for Amgen, said it is talking to other drugmakers.

Actelion has been at the centre of speculation for many months now, with a number of potential buyers being mentioned such as Shire and GlaxoSmithKline. This week, Amgen entered the frame, following a report by Bloomberg that cited two unnamed sources with knowledge of the matter.

The news agency's article had claimed that as a defensive measure, Actelion chief executive Jean-Paul Clozel has considered asking Roche, Johnson & Johnson and Bristol-Myers Squibb to consider taking a minority stake in the firm, which is home to the pulmonary arterial hypertension blockbuster Tracleer.

Against this background, Actelion has taken the somewhat surprising step of releasing a one-line statement saying that "as part of its ordinary course of business, the company is in regular dialogue with other industry participants". Possible price tags that have been bandied about are in the region of 8 billion Swiss francs.

Dr Clozel has spoken in the past of his desire for the Allschwil-based group to remain independent. However, it has suffered a number of clinical setbacks, notably safety concerns from a late-stage trial of its investigational GSK-partnered insomnia drug almorexant and the failure of clazosentan in a Phase III study of patients with brain haemorrhage.

Investors have been concerned for a long time that Actelion is too reliant on Tracleer which loses patent protection in 2015. The company's confirmation that talks of some sort are happening went down well, therefore, and shares were up 9.1% to 54.60 francs.