WASHINGTON — Patients with active rheumatoid arthritis preferred the adalimumab autoinjection pen device to the prefilled syringe in an Abbott-sponsored study, Dr. Martin Okun reported in a poster presentation at the annual meeting of the American Academy of Dermatology.
Adalimumab, a fully human IgG monoclonal anti-tumor necrosis factor, is approved for the treatment of adults with rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis. It can be administered via subcutaneous injection with a prefilled syringe or by an autoinjection pen, which was developed to facilitate self-injection by patients with physically limiting autoimmune diseases, noted Dr. Okun of Abbott Laboratory's department of medical affairs.
The investigators evaluated existing data from an earlier open-label phase II study that was done in pursuit of the original Food and Drug Administration approval of 52 patients with active RA who self-administered 40 mg adalimumab subcutaneously with the syringe at visit 1, followed by the same dose via the pen at visits 2 (at week 2) and 3 (week 4). The patients chose the site—either thigh or abdomen—and maintained the same site for all three injections.
The patients had a mean age of 54 years and a mean RA duration of 8 years. Two-thirds were women, and the majority (88.5%) were white. They had been injecting adalimumab via syringe for a mean of 15 months.
On the 10-point visual analog scale, with 0 being “no pain” and 10 being “as bad as it could be,” the patients rated their pain immediately following injection as a mean of 3.7 with the syringe at visit 1, compared with 2.3 and 2.0, respectively, for the pen at visits 2 and 3.
Overall, 40 patients (77%) deemed the pen to be less painful than the syringe, while 4 patients (8%) found the syringe less painful and 8 (15%) had no preference. Significant reductions in injection-site pain were observed at 15–30 minutes post injection with the pen, Dr. Okun reported.
Overall impressions of the injection experience with the pen were rated “favorable” or “extremely favorable” by 86.5% at visit 2 and 88.5% at visit 3, compared with just 32.6% for the syringe at visit 1. Overall preference was 88.5% for the pen compared with 5.8% for the syringe and 5.8% with no preference.
Reasons listed for preferring the pen included ease of use, convenience, time to inject (about 10 seconds versus 30 seconds for the syringe), safety, and “less pain.” More than 94% of the patients said they would likely use the pen if it were available at the same cost as the syringe, and the same proportion said they would recommend the pen to another patient, Dr. Okun reported.
Poster session moderator Dr. Craig Leonardi, a dermatologist at St. Louis University, cautioned that patients must be trained to use the pen. “It's not sufficient to just prescribe the pen. You have to show patients how to use it. Otherwise they make mistakes.”