An open-label, multicenter study to evaluate the safe and effective use of the single-use autoinjector with an Avonex.sup.[R] .sup.prefilled syringe in multiple sclerosis subjects

Background The ability to self-inject in patients with multiple sclerosis (MS) has been associated with a reduced risk of missed injections and drug discontinuation, and a beneficial effect on patients' independence. However, injection anxiety, needle phobia and disease-related disability are major barriers to a patient's ability to self-administer treatment. Use of an autoinjector may improve patients' ability to self-inject. This study evaluated the safe and effective use of Avonex Pen[TM] (prefilled pen), a single use autoinjector, for intramuscular delivery of interferon beta-1a (IM IFN[beta]-1a, Avonex) in MS patients. Methods This was a Phase IIIb, open-label, single-country, multicenter trial in MS patients currently using IM IFN[beta]-1a prefilled syringes. Patients received weekly 30 mcg IM IFN[beta]-1a treatment over 4 weeks. On Day 1, patients self-administered IM IFN[beta]-1a using a prefilled syringe at the clinic. On Day 8, patients received training on the prefilled pen and self-administered IM IFN[beta]-1a using the device. On Day 15, patients self-administered IM IFN[beta]-1a at home using the prefilled pen. A final injection occurred at the clinic on Day 22 when patients self-administered IM IFN[beta]-1a using the prefilled pen while clinic staff observed and completed a detailed questionnaire documenting patients' ability to self-inject with the device. Serum neopterin levels were evaluated pre and post-injection on Days 1 and 8. Adverse events were monitored throughout. Results Seventy-one (96%) patients completed the study. The overall success rate in safely and effectively using the prefilled pen was 89%. No device malfunctions occurred. One unsuccessful administration occurred at Day 22 due to patient error; no patient injury resulted. Patients gave the prefilled pen high ratings (8.7-9.3) on a 10-point scale for ease of use (0 = extremely difficult, 10 = extremely easy). Ninety-four percent of patients preferred the prefilled pen over the prefilled syringe. Induction of serum neopterin levels, serving as a biomarker for type 1 interferon action, was similar to that of the prefilled syringe. The prefilled pen demonstrated a safety profile comparable to the prefilled syringe. Conclusions The prefilled pen is a safe and effective device for administration of IM IFN[beta]-1a and represents an alternative method for self-injection for MS patients using this therapy. Trial registration This study is registered at clinicaltrials.gov, ident