Plegridy® (peginterferon beta-1a)


Plegridy® is pegylated interferon beta-1a. Pegylation is a common technology that can increase the circulating life of a molecule in the body (in this case, interferon beta-1a), to prolong the duration of effect of the product.

Interferons are proteins produced naturally in the human body to help fight infections and regulate the immune system. Some beta interferons have been shown to slow down activity and disease progression in MS. They do this by helping regulate the immune system, reducing attacks on myelin or nerves.

During clinical trials, Plegridy has been shown to have comparable effectiveness to the currently available interferon beta agents. Additional data from the trial also suggested a significant reduction in the number of brain lesions seen on magnetic resonance imaging (MRI).

Plegridy® is a subcutaneous (under the skin) injectable therapy that is pegylated to extend its half-life in the body. This means it needs to be injected only once every two weeks rather than more regularly as compared with other interferon beta agents. The treatment comes in the form of a single-use, prefilled injection pen.

It is usually recommended that the dose is gradually increased when first starting to use Plegridy® to help your body become used to the medication and keep side effects to a minimum. You will receive a month’s supply in a pack, which will consist of two pens. The initiation pack contains a 63 microgram (orange) pen for your first injection and a 94 microgram (blue) pen for your second injection 14 days later. For subsequent injections, you will need to obtain the continuation pack that contains two 125 microgram (grey) pens.

Plegridy® helps most people with MS, but may have side effects in some people. All medications have side effects. It is important to notify your health professional if you experience any side effects or are feeling unwell.

The most common side effects of Plegridy® are flu-like symptoms, such as headache, tiredness, muscle aches, joint pain, shivering and fever. Potential serious side effects may include yellowing of your skin or the whites of your eyes (jaundice); itching all over; feeling sick, nausea and vomiting, easy bruising of the skin, loss of appetite, tiredness, confusion, bleeding more easily than normal, dark coloured urine, and pale stools.

Your neurologist will assist you to assess the risks and the expected benefit of treatment with Plegridy® prior to starting therapy and over the course of treatment. Your health professional can provide comprehensive information on the use of Plegridy®, including precautions and side effects.

Plegridy® is suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects.

If you are currently pregnant or trying to become pregnant, please discuss your individual circumstances and treatment options with your neurologist or healthcare team.

Although no information is available on peginterferon beta-1a in breastmilk, the levels of conventional interferon beta-1a in breastmilk are minuscule. In addition, because interferon is poorly absorbed orally, it is not likely to reach the bloodstream of the infant.

If you are currently breastfeeding, please discuss your individual circumstances and treatment options with your neurologist or healthcare team.

Plegridy® has been approved by the Therapeutic Goods Administration (TGA) for the treatment of patients with relapsing remitting MS and is available through the Pharmaceutical Benefits Scheme (PBS). Your neurologist will need to obtain an authority to prescribe the medication for you.

For details of the criteria required to receive a prescription for Plegridy® treatment through the PBS, please visit the official PBS website at: – 63 & 94 microgram pens – 125 microgram pens

You will need to click on the red Authority Required (STREAMLINED) link.

If you are eligible for medications through the PBS, you will need to pay a contribution fee each time your prescription is dispensed. The Federal Government pays for the remaining cost. The amount of the contribution fee depends upon whether or not you have a pension or concession card. The amount of this fee is set each year by the Federal Government.

Further information about the PBS, your entitlements and details regarding the PBS safety net (which protects patients and their families requiring a large number of PBS items) is available through the Medicare Australia website at:

If you are not eligible for Plegridy® through the PBS, for example if you are a visitor from overseas, your neurologist may write a private prescription. In this instance you will have to pay the full cost to the pharmacy that dispenses your medication. You will need to request a quote from your pharmacist for the price of any medication which is not subsidised by the PBS.

Plegridy® (peginterferon beta-1a)

Forms of MS used for:
Relapsing forms of MS
Administration route:
Subcutaneous injection (injection under skin)
Dosage and frequency:
Every two weeks
Refrigerate 2-8°C
TGA approval date:
November 2014
Available on PBS:

General Information and Assistance

Most pharmacies do not keep Plegridy® in stock. It is therefore important to let your pharmacist know a few days before you need the medication so that they can order it in for you.

Plegridy® pre-filled injection pens should be stored in the closed original carton to protect from light until ready for injection. Store in a refrigerator between 2 to 8°C. Do not freeze. Discard if frozen. When no refrigerator is available, Plegridy® may be stored protected from light between 2°C to 25°C for a maximum of 30 days in total. If the outside temperature is warm it is a good idea to take your medication home in an ice cooler. Your pharmacist may be able to assist with this.

Biogen runs a Patient Support Program called MS Alliance. The website for MS Alliance is and the toll-free helpline is 1800 286 639.

For more information

Speak to your neurologist about what treatment best suits your individual circumstances.

MS Nurses can also provide information, training and ongoing support in managing your immunotherapy.

MS Australia does not recommend any specific disease-modifying treatment for people living with MS. Decisions about any treatments, taking into consideration the potential benefits and side effects for each individual’s circumstances, should be made in careful consultation with the person’s neurologist.

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Plegridy®(Interferon beta-1a)