Pfizer has hit the acquisition trail again and has agreed to pay $164 million for Coley Pharmaceutical Group, which specialises in vaccine adjuvant technology and a new class of immunomodulatory drug candidates.

Under the terms of the purchase, Pfizer is paying $8.00 per share in a cash tender offer, quite a premium on Coley’s closing price of $3.00 the day before the deal was agreed. However, after the tie-up with the world’s largest drugmaker was announced, Coley’s shares shot up over 160% to $7.81.

Coley is working on TLR vaccines and therapeutics which work by stimulating or blocking toll-like receptors which, in turn, direct the immune system to fight disease, Pfizer noted. The latter’s chief executive, Jeffrey Kindler, said that Coley’s product candidate portfolio and technology “have the potential to significantly enhance future vaccine and immunotherapeutic approaches to a broad range of diseases”, including Alzheimer’s, asthma, infectious disease and oncology. The acquisition is expected to close early in 2008.

The firms have been partners before and suffered a major blow just a few months ago when the New York-based drugs giant discontinued a development programme in advanced non-small cell lung cancer for PF-3512676, a toll-like receptor 9 (TLR9) agonist, in combination with cytotoxic chemotherapy. This included two Phase III and two Phase III trials of the drug, previously called ProMune, which Pfizer licensed from Coley in March 2005.