Pfizer, Inc. recently filed a Xeljanz lawsuit accusing a generic drug maker of infringing on its patents for the blockbuster rheumatoid arthritis (RA) medication.
In February, Ajanta Pharma submitted an Abbreviated New Drug Application to the U.S. Food & Drug Administration (FDA) requesting approval to market a generic version of the 5 mg Xeljanz (tofacitinib) tablets. That application included a “Detailed Statement” asserting that Pfizer’s Xeljanz patents are invalid.
Pfizer filed its Xeljanz lawsuit last month in Delaware federal court, disputing that assertion and claiming that its patents would not begin to expire for several more years. Among other things, the company is seeking a permanent injunction to prevent Ajanta from selling its generic medication. (Case No. 1:19-cv-00517-UNA)
Xeljanz is one of Pfizer’s top-selling drugs, so it’s understandable that the drug maker would want to hold off generic competition as long as possible. In fact, the company made about $1.7 billion from Xeljanz sales in 2018.
The FDA initially approved 5 mg Xeljanz tablets to treat adults with RA in 2012. The twice-daily medication works by blocking an enzyme called “Janus kinases” that contributes to RA inflammation. The agency subsequently approved Xeljanz XR, an 11 mg, once daily, extended release tablet, in 2016.
The FDA expanded the approved indications for Xeljanz and Xeljanz XR to include adult patients with active psoriatic arthritis in 2017. And just last year, the agency cleared 10 mg twice daily Xeljanz to treat ulcerative colitis.
Despite its popularity, Xeljanz can cause some very serious side effects. In fact, when the FDA first approved the medication, it ordered Pfizer to conduct post-market studies to better assess the the risk of heart-related events, cancer, and opportunistic infections among RA patients treated at one of two doses (10 mg twice daily and 5 mg twice daily).
Earlier this year, the safety monitoring board for one of those trials discovered participants on the high-dose Xeljanz regimen had a “statistically and clinically important difference” in the rate of pulmonary embolism (a life-threatening blood clot in the lungs) and overall death compared those taking the 5 mg dose or another drug called a tumor necrosis factor inhibitor.
The study in question was investigating the risk of heart and circulatory problems among Xeljanz patients 50 years of age or older who already faced a higher risk of these events. Because of the worrisome findings, Pfizer transitioned all patients in the study’s 10 mg Xeljanz arm to the 5 mg dose.
In a February 25th Drug Safety Communication, the FDA reiterated that the twice-daily 10 mg Xeljanz dose is only approved for ulcerative colitis.
“This trial will continue and is expected to be completed by the end of 2019,” the agency said. “We are working with the manufacturer to evaluate other currently available safety information for tofacitinib and will update the public with any new information based on our ongoing review.”
After the FDA published that communication, attorneys around the country began to investigate potential Xeljanz lawsuit filings involving pulmonary embolism (PE), deep vein thrombosis (DVT blood clot), heart attack, stroke, or cardiovascular death.
A pulmonary embolism occurs when a DVT blood clot breaks free and travels to the lungs. Because of their life-threatening nature, patients taking Xeljanz should seek immediate for any pulmonary embolism symptoms, including.
From 2013 to 2018, the FDA received 52 reports of DVT and 79 reports of pulmonary embolism related to Xeljanz. Fifteen of these patients died. There is no way to confirm if Xeljanz actually caused any of these injuries. However, it’s also possible that many additional cases were never reported to the FDA.