MATTHEW PERRONE AP Business Writer WASHINGTON (AP) — Belgian drugmaker UCB said Wednesday it received federal approval for an injectable drug to treat arthritis, entering a competitive market dominated by some of the largest U.S. pharmaceutical companies. The FDA approved the drug Cimzia for patients with moderate to severe rheumatoid arthritis. The injectable medication was previously approved to treat gastrointestinal Crohn's disease last April. Cimzia is the fourth in a class of drugs known as tumor necrosis factor blockers approved in the U.S. The three other products are each multibillion-dollar blockbusters: Abbott Laboratories' Humira, Johnson & Johnson's Remicade and Wyeth and Amgen's Enbrel. Enbrel was the biggest seller of the group last year with sales of $3.4 billion. The drugs all work by targeting and neutralizing a protein that, when overproduced, causes inflammation and damage to bones, cartilage and other tissue. UCB hopes that a syringe specially designed for arthritis patients will give Cimzia an edge over competitors. A collaboration with consumer product maker OXO Products, the prefilled syringe has oversized finger grips and a rounded needle cap, designed to make it easier for patients to uncap and inject the drug. OXO President Alex Lee said the collaboration was natural, since many arthritis patients are already drawn to the company's ergonomically designed kitchenware. "The idea of universal design is designing products that are easy and comfortable to use for the largest spectrum of users possible," said Lee in an interview. "That means including people with dexterity issues, but not overtly targeting them." OXO is a division of El Paso, Texas-based Helen of Troy Ltd. FDA approved Cimzia based on four studies involving more than 2,300 patients that showed Cimzia alongside the immune-system suppressing drug methotrexate significantly reduced arthritis symptoms after six months. The drug combination also slowed progression of joint damage, the company said. Dr. Roy Fleischmann, who helped conduct trials of Cimzia, said the new drug could be useful for patients who develop resistance to older drugs like Humira. He also noted the drug's flexible dosing schedule, which permits injection every two or four weeks. "It's the same dose, but you can do it monthly or every two weeks, and from my experience patients respond equally well," said Fleischmann, who is co-medical director of Metroplex Clinical Research Center in Dallas. Older drugs like Enbrel and Humira are generally injected every one or two weeks. Despite its relative advantage over those medicines, Cimzia will also have to compete with a new drug from J&J called Simponi, the follow-up to Remicade, which is injected monthly. The FDA approved the drug late last month. Cimzia is critical to UCB's business outlook as the company continues to lose revenue from expiring patents on older medicines. Last fall, generic drug maker Mylan launched a low-cost version of the company's main product, anti-epileptic drug Keppra. Earlier in the year Brussels-based UCB announced plans to cut costs by laying off 2,000 workers worldwide, or nearly a fifth of its work force.