Rheumatoid arthritis treatment Xeljanz, while expected to grow into a big seller for Pfizer ($PFE), hasn't had a fast start. The company hoped adding a psoriasis indication for the drug, also known as tofacitinib, might give sales a jolt. But mixed trial results suggest that approval won't arrive anytime soon--and if it does, demand could be slim.
According to Pfizer ($PFE), a high 10-milligram dose of tofacitinib proved as effective as Amgen's ($AMGN) popular treatment Enbrel at treating adults with moderate-to-severe psoriasis in a late-stage study. The thing is, researchers studied the drug at that dosage level when testing it for rheumatoid arthritis, and it ultimately garnered approval only for the lower 5-milligram dose due to concerns over elevated safety risks.
At the 5-milligram dose, tofacitinib proved less effective than Enbrel, and even then, the drug produced "serious side effects" in mid-stage trials, according to one analyst. Cardiovascular events, elevated cholesterol and decreases in hemoglobin were present at all dosage levels, Citi's Yaron Werber wrote in a research report seen by Reuters. "Based on our doctor checks, the safety of tofacitinib is not clean enough to garner broad use by the risk-averse dermatology community," Werber said.
Separately, Pfizer said Wednesday that tofacitinib met its primary effectiveness goal in a study of the treatment versus placebo. But overall, it's not great news for Pfizer, which hoped to capitalize on a patient pool estimated at 125 million people worldwide, including 7.5 million in the U.S. Xeljanz, approved last November as a treatment for RA, posted second-quarter sales of $22 million. But analysts deemed that a slow start, considering that many expect the drug to post blockbuster numbers annually.
A few factors have complicated that goal for Xeljanz, with stiff competition being the most obvious. In addition to Enbrel, which also boasts an RA indication, Xeljanz is up against a host of other strong players--including AbbVie's ($ABBV) Humira, which took over the title for the world's best-selling drug when Lipitor went off patent. And though Pfizer touts Xeljanz's oral delivery method as an advantage over its injectable peers, company exec Geno Germano has admitted that getting doctors to switch their patients can prove a difficult task.
Pfizer has also struggled with European regulators, who in June denied the company's appeal after recommending against approval of the drug. In its rejection, the EMA's Committee for Medicinal Products for Human Use (CHMP) acknowledged that the drug improved arthritis symptoms and patients' fuctions, but it determined Xeljanz didn't sufficiently thwart the advance of the disease or damage to joints.
And a June study of a generic cocktail could complicate things for Xeljanz even further. Data showed that a combination of methotrexate and two other generics worked as well as Enbrel at a fraction of the price--about $1,000 a year, compared with the $25,000 Pfizer charges for Xeljanz treatment.
Special Report: Top 10 rheumatoid arthritis drugs 2013