Pfizer is waiting for the Food and Drug Administration to approve its new pill for rheumatoid arthritis (RA) - the first oral biologic for treating this ailment.
In reviewing the drug, which is called tofacitinib, FDA medical staff note several issues and have overall written in the 168-page briefing documents that there are “serious safety concerns.” These include increased risks of serious infections and malignancies, as well as a higher chance of lymphoma.
The FDA panel also says that X-rays were analyzed and scored, but outcomes did not always provide evidence the pill slowed the progression of structural damage in RA patients. “One conundrum associated with the assessment of efficacy in RA is the possible dissociation between clinical and radiographic outcomes. Radiographic progression may occur in people who have very low apparent disease activity and patients with clinical disease activity may have no evidence of radiographic progression,” the agency staff write.
Beyond the panel meeting, though, Pfizer may have to work hard to convince doctors and payers, as well. A recent survey of 100 rheumatologists and insurers found that 55 percent of these doctors say the Pfizer pill would not replace a med they are currently prescribing. And 96 percent of the payers say tofacitinib would not replace a drug that is currently offered in their plans.
Nonetheless, 85 percent of rheumatologists and 60 percent of payers have a favorable impression of the pill. And 27 percent of the rheumatologists say that they would be willing to regularly prescribe a small RA molecule, with another 46 percent reporting that they would do so within the first year of availability.
The FDA staff said the drug appeared to reduce swollen and tender joints during clinical trials. The review comes ahead of a vote on Wednesday by an FDA advisory panel that will decide whether to recommend the drug as a treatment for people who have not had success with at least one other type of drug for RA. The FDA will make a final decision in August, taking into account the panel's recommendations.
Analysts see tofacitinib as a potential blockbuster medicine, with peak sales of $2 billion to $3 billion a year, if its benefits are deemed to outweigh its risks.
Mark Schoenebaum, an analyst at ISI Group, said in a research note that the increase in malignancy risk was a new piece of information about tofacitinib. Some other drugs for RA have also had this side effect, he said. “We continue to expect a positive panel outcome, after extensive discussions of the issues mentioned above,” said Michael Tong, analyst at Wells Fargo, in a research note. “We also note that FDA briefing (documents) are typically negative in tone.”
RA and related diseases have been one of the most lucrative areas for drugmakers, with more than $20 billion in annual sales. An estimated 1.3 million Americans suffer from RA, according to the Arthritis Foundation. About 1 percent of the world's adult population has the disease.