Pfizer can add one more promising experimental drug that has been hobbled by unexpected safety issues. The pharma giant says it has been forced to suspend an ambitious slate of trials of its experimental pain drug tanezumab after patients taking the therapy for osteoarthritis saw their condition worsen to the point they required joint replacement surgery. Pfizer, which only days ago touted "extraordinary" late-stage data for the drug, says that at the request of the FDA its researchers have stopped enrolling patients or providing the drug in all of its osteoarthritis trials.
"Patient safety is a top priority for Pfizer," a Pfizer spokesperson told Bloomberg in an e-mail. "We are coordinating closely with regulatory authorities and investigators to implement the clinical hold in the osteoarthritis studies and for patients with co-morbid osteoarthritis in the chronic pain program."
Tanezumab, an infused biologic which is designed to block pain by inhibiting nerve growth factor, moved into late-stage testing a year ago. And Pfizer execs had high hopes that the therapy could go on to become the first biotech therapy approved for pain. A Bloomberg analyst survey concluded that the drug had the potential to earn $260 million a year by 2013. Instead, the drug company faces a fresh round of criticism for its plague of development problems despite an annual R&D budget of $7 billion.
In addition to osteoarthritis Pfizer was studying tanezumab for cancer pain, lower back pain and other types of pain. "I don't think it's definitely over for this product, but this is a potential big red flag for some of those other indications," Morningstar analyst Damien Conover told Reuters.