Pfizer Inc.’s experimental pill for rheumatoid arthritis was as effective as Humira from Abbott Laboratories and showed no new side effects in study results the company plans to submit for U.S. approval this year.
Nine study summaries were released today and will be presented at the American College of Rheumatology conference in Chicago in November. In one trial, both doses of Pfizer’s drug, called tofacitinib, were slightly more effective than Humira across six categories of improvement in symptoms and patient mobility, though the study wasn’t big enough to establish the pill’s superiority.
Pfizer, the world’s biggest drugmaker, designed tofacitinib to compete with injectable drugs that dominate the market, led by Humira from Abbott Park, Illinois-based Abbott, Johnson & Johnson’s Remicade and Amgen Inc.’s Enbrel, which New York-based Pfizer shares. The new drug may bring in more than $2.6 billion a year, said Catherine Arnold, an analyst at Credit Suisse Group AG in New York.
“This is a game-changing drug,” Arnold said. “Our peak sales of $2.6 billion are likely conservative.”
Humira will reach peak sales of about $8.5 billion in 2013 before sales decline as doctors grow comfortable with tofacitinib and other new drugs, said Arnold, who has an “outperform” rating on Pfizer’s stock and a “neutral” rating for Abbott.
Pfizer fell 19 cents, or 1 percent, to $18.82 at 4 p.m. in New York Stock Exchange composite trading. Abbott declined 86 cents, or 1.6 percent, to $51.44.
“Pfizer believes the risk-benefit profile supports regulatory submission for both the 5- and 10-milligram dose,” Victoria Davis, a spokeswoman for Pfizer, said in an e-mail. “We are looking forward to filing in the U.S., EU and Japan by the end of the year.”
Tofacitinib is the most-advanced pill in a family of experimental drugs to target a protein, called JAK, which leads to joint destruction in 1.3 million Americans with rheumatoid arthritis. Three biotechnology companies are trying to catch up to Pfizer with similar treatments: Rigel Pharmaceuticals Inc., Incyte Corp. and Vertex Pharmaceuticals Inc. Pfizer’s pill is the only one to complete the third and final stage of tests generally needed for U.S. regulatory approval.
Humira performed unexpectedly poorly in the study, which may not represent the true effectiveness of the drug, said Elizabeth Hoff, a spokeswoman for Abbott. The proportion of Humira patients showing a 20 percent improvement after six months was 47 percent, compared with a typical proportion of 65 percent of patients with such improvement. Patients with 50 improvement only accounted for 28 percent of those studied, compared with past studies showing 52 percent of patients.
“Looking at the scores, this isn’t what we typically see,” Hoff said today in a telephone interview. “These are very similar patient populations. You see a pretty significant difference.”
The safety of tofacitinib was similar to what was seen in previous studies, and deaths and side effects were toward the lower end of a range of results from similar drugs, the company reported. Much of the data from the individual studies was reported previously.
Twelve deaths were reported among 3,030 patients who took the drug, compared with 1 death among 681 taking a placebo and 1 death among 204 patients on Humira across the Phase 3 studies completed by Pfizer. Patients spent more time on tofacitinib than Humira or placebo and deaths per amount of time spent on the drugs were statistically similar.
Patients taking tofacitinib were more likely to have serious infections compared with Humira or placebo. There were 0.029 infectious for every year a patient was taking the Pfizer pill, compared with 0.015 infections for placebo and 0.017 on Humira. In at least one trial, infection rates were greater for those taking the higher of two possible doses of tofacitinib.
Rheumatoid arthritis is a chronic disease in which the immune system mistakenly attacks healthy tissue, causing inflammation in and around joints. Treatments suppress the immune system and can increase vulnerability to infection.
Shots known as anti-TNF therapy are standard care for the 80 percent of patients who don’t respond to methotrexate, a generic drug that can block cell growth in people with certain cancers and immune disorders.
Tofacitinib would add to Pfizer’s recently expanded offerings in pain and inflammation. The company gained the arthritis remedy Enbrel in the $68 billion purchase of Wyeth in 2009. The medicine was Pfizer’s second-best seller last year with $3.3 billion in revenue. The drugmaker bought King Pharmaceuticals Inc. last year for about $3.3 billion to add additional painkillers to its range of products.
Pfizer is counting on revenue from its arthritis pill to help offset losses when its top-selling Lipitor cholesterol drug, with $10.7 billion in annual sales, faces competition beginning in November from cheaper copies in the U.S.