Pfizer spearheads push to get pain drugs back on blockbuster track

Can Pfizer get its derailed program for the arthritis pain drug tanezumab back on track? Two years ago Pfizer put their well advanced anti-nerve growth factor drug on ice after regulators learned that a number of patients taking the drug had been forced to undergo joint replacement surgery. And that news quickly forced the hands of J&J, Regeneron and AstraZeneca, which also shelved their own pain studies as investigators puzzled out indications of bone tissue death.

Now, though, a federal advisory panel is being asked to weigh in on the question of whether new osteoarthritis studies are warranted, or whether the investigative path should be limited to certain conditions which can't be effectively treated with existing medications. And the experts will have to consider again why some patients had to undergo joint replacement surgery, including the question of whether the pain drug masked the symptoms of pain so effectively that they were spurred to heightened levels of physical activity.

A spokesperson for J&J tells FierceBiotech this morning that it still has an "active pain program and are recruiting patients for fulranumab cancer trial where FDA lifted hold." But its arthritis work is still in limbo with the class hold.

Pfizer wants the arthritis drugs advisory committee to consider the full potential for osteoarthritis, offering new safety clauses that would suspend the use of the drug in patients who aren't responding, or perhaps using a lower dose to help safeguard patients' health. The treatment works by blocking the nerve growth factor protein, which triggers pain sensations.

For regulators, there's little question that the treatments are linked to joint damage. But they have also noted that the damage is not evident at lower doses.

It's a tantalizing field. Analysts had pegged the total potential market for these drugs as high as $11 billion, offering mega-blockbuster returns for any developer which could get to the regulatory finish line. But even if the panel gives them a green light to reopen blocked development paths, they would face a daunting list of challenges for safety data.

- get the report from Dow Jones
- here's the AP's report