Pfizer investigator questions cause of deaths in tofacitinib trial

When news broke recently that four patients died during Pfizer's late-stage study of tofacitinib--a rheumatoid arthritis drug widely billed as one of the brightest prospects in the company's pipeline--the pharma giant wasted little time in rushing out a reassuring statement that only one of the four deaths was actually linked to the drug. Now the lead investigator in the trial tells Reuters' veteran reporter Ben Hirschler that a second death could be tied to tofacitinib. And he doesn't sound 100 percent certain about the other two, either.

"It's unlikely that two of the four were associated (with tofacitinib). It's possible that the other two of the four were associated, but based upon the information I have it's impossible to say with absolute certainty," Joel Kremer of Albany Medical College told Reuters. To be sure, Kremer also noted that four deaths in an RA study like this is in no way unusual. And later today Pfizer is unveiling the specific trial data on tofacitinib, which it heralded as a solid winner on a key score of statistical significance.

Rheumatologist Paul Emery, president of  the European League Against Rheumatism, gave the drug a solid endorsement today and discounted any safety fears. "It's a very impressive drug," he said to Reuters and others. "The way it is priced will have the biggest influence on its market penetration."

Pfizer has a tremendous amount of credibility on the line here. Its R&D operation hasn't delivered a blockbuster in more than a decade, despite spending more on drug research than any other company in the business. Tofacitinib and the cancer drug crizotinib are both billed as potential game changers in the clinic, with the RA drug poised to offer a new oral alternative for a multibillion-dollar market for injectables.

Before it gets an approval, though, investigators will be expected to review the trial deaths. In particular Kremer raised questions about a Russian patient who died from a respiratory illness 42 days after discontinuing a low dose of the drug.

- here's the story from Reuters
- here's the follow-up story with Emery's remarks