Drug switch may benefit arthritis patients

By David Douglas

NEW YORK (Reuters Health) - Patients with rheumatoid arthritis who fail to respond to one of the biological drugs will often have a better response to a second drug within the same class, Danish researchers report in the Annals of the Rheumatic Diseases.

"Our data show that patients with rheumatoid arthritis benefit from switching to a second biologic drug," lead investigator Dr. Elisabeth Hjardem told Reuters Health. The order in which the drugs were given did not seem to matter, she added.

Hjardem, of Copenhagen University Hospital, Hvidovre, and colleagues note that

About 30 percent of patients treated with drugs within the class of tumor necrosis factor (TNF)-alpha blockers will require a switch because of poor response or adverse events. TNF-alpha is involved in systemic inflammation and regulation of cells in the immune system. Overproduction or dysregulation of TNF-alpha can result in a variety of disorders, such as rheumatoid arthritis.

In their current study, the researchers investigated the effects of drugs designed to block TNF-alpha function. The most common initial drug was infliximab (Remicade), and second-line agents were usually adalimumab (Humira) or etanercept (Enbrel).

To evaluate what impact this might have, the researchers examined a national biological treatment database with 1,021 patients and identified 235 who switched to a second TNF-alpha blocker after the initial drug failed.

The main reason for the switch was lack of efficacy, reported by 109 patients. Adverse events prompted the change in 72 patients. Switchers were more likely to be younger, to have used higher doses of methotrexate and to have a higher level of disease activity.

Three months after the switch, the average Disease Activity Score 28 (DAS28) improved by 1.6 points, and the majority had a good or moderate response using European League against Rheumatology (EULAR) guidelines.

Of the patients who changed drugs because of adverse effects, only 15 percent continued to experience adverse effects and the drug remained still effective.

The second drug's effects lasted up to 92 weeks compared with 37 weeks with the first. However, write the investigators, "it was not quite as high as for the non-switching rheumatoid arthritis patients."

The overall improvement "applies both to patients with lack of efficacy and with adverse events," Hjardem said.

The study was nationwide and represented common clinical practice, making these results "applicable to rheumatoid arthritis patients in general," she concluded.

SOURCE: Annals of the Rheumatic Diseases, September, 2007.