Pfizer’s late-stage pipeline has suffered another blow with the news that the firm has terminated trials of an experimental lung cancer treatment.

The New York-based drugs giant said that it has discontinued a development programme in advanced non-small cell lung cancer for PF-3512676 in combination with cytotoxic chemotherapy. This includes two Phase III and two Phase III trials of the drug, previously called ProMune, which Pfizer licensed from Coley Pharmaceutical Group in March 2005.

A scheduled interim analysis of the Phase III clinical trials by an independent data safety monitoring committee showed that there was no evidence that PF-3512676 produced additional clinical efficacy over that achieved with the standard cytotoxic chemotherapy regimen alone. The DSMC concluded that the risk-benefit profile did not justify continuation of the trials and Pfizer agrees.

Charles Baum, vice president of Pfizer's R&D, was upbeat despite the disappointing news and said that “while these results show the challenge of bringing new therapies to patients with cancer,” the company is still determined to continue trying to become a force in oncology. It is conducting over 200 clinical trials of 16 new medicines in immunotherapy, signal transduction inhibition and angiogenesis inhibition, he noted.

However the halting of the trials has hit Coley very hard indeed and its share price slumped almost 60% to end the day at $3.46. PF-3512676, a toll-like receptor 9 (TLR9) agonist delivered by subcutaneous injection, was the firm’s only drug in late-stage trials and chief executive Robert Bratzler said that the news is surprising based on the signs of clinical activity observed in Coley's Phase II randomised clinical trial. “We are disappointed with this setback in the programme," he said, but added that the firm remains focused on advancing its portfolio of TLR candidates for the treatment of cancer, allergy and asthma, lupus and rheumatoid arthritis.

The original deal could have been worth up to $455 million, though Pfizer made an initial payment of just $50 million and did not return calls from PharmaTimes World News asking whether it had paid out much more than that. However the real cost to the firm is that PF-3512676 represents yet another Phase III failure.

Pfizer's near-term pipeline of new drugs is looking extremely bare and this setback comes after the abrupt termination of Pfizer's high-density lipoprotein booster torcetrapib at the end of last year, news which wiped over $21 billion off the value of the firm. Since then, observers to muse about how the company was going to plug the gaping hole in its pipeline and in its future earnings once Lipitor (atorvastatin) comes off-patent around 2011.

A major acquisition has been touted as a possibility and as the rumour mill goes into overdrive about whether Bristol-Myers Squibb is going to be taken over, Pfizer’s name is rising ever closer to the top of the list of potential bidders. By Kevin Grogan