Autoinjector Pen Helps Multiple Sclerosis Patients

A pen-type intramuscular injector allows multiple sclerosis (MS) patients to self-administer interferon-beta-1a (Avonex).

The Avonex Pen is an autoinjector system and titration regimen for patients receiving once-a-week treatment with Avonex for relapsing forms of MS. The device integrates a prefilled syringe and a small, 25 gauge, 15-mm-long needle, and it is intended to reduce anxiety about self-injection. An optional titration regimen at the start of therapy calls for gradual dosage escalation over a four-week period, starting at 7.5 µg and increasing in 7-µg increments each week until the regular dose of 30 µg is reached. A clinical trial in healthy volunteers indicated that the severity of flu-like adverse symptoms was reduced by 76% by titration, compared with starting treatment at the full dosage of 30 µg per week.


During titration, patients must use the conventional prefilled syringes fitted with a special kit for delivering the reduced doses. Once the full dose is reached, patients may then switch to the new autoinjector pen. According to the prescribing information, Avonex should be used with caution in patients with depression or mood disorders or seizures. Patients should also be monitored for signs of hepatic injury, and those with cardiac disease should be closely monitored. Routine periodic blood chemistry and hematology tests are recommended during treatment. The Avonex Pen is a product of Biogen Idec (Weston, MA, USA), and has been approved by the US Food and Drug Administration (FDA).

“Interferon has been an effective treatment for multiple sclerosis for more than 15 years,” said Douglas Williams, PhD, executive vice president of research and development at Biogen Idec. “Data have shown it to have the highest adherence rate among currently marketed injectable therapies; however, anxiety around administration and the potential for flu-like symptoms can be a barrier for some patients.”

Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms. Disease onset usually occurs in young adults, and it is more common in women. The name multiple sclerosis refers to scleroses (scars), particularly in the white matter of the brain and spinal cord, which is mainly composed of myelin.

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