Guselkumab

Guselkumab is used to treat inflammatory types of arthritis, such as psoriatic arthritis (PsA).

For the treatment of PsA, guselkumab may be used alone or in combination with DMARD therapy, such as methotrexate (MTX). It is also used for treatment of moderate to severe psoriasis and in some countries, it is approved in the treatment of ulcerative colitis.

For patients with PsA, guselkumab is administered via subcutaneous (s.c.) injection (meaning injection with a needle in the fatty layer of tissue just under the skin) every 8 weeks as a maintenance dose.  When started the first two doses are administered 4 weeks apart. Subcutaneous injections can be administered at home either by the patient themselves or by a caregiver. 

When given by s.c. injection, the recommended dose is 100 mg at week 0 and at week 4, then every 8 weeks thereafter. The medication may come as a single-use pre-filled syringe or autoinjector for administration. 

In some people with inflammatory conditions such as arthritis or psoriatic arthritis, signalling proteins called Interleukin-23 (IL-23) are involved in the body’s inflammatory response where it attacks the body’s own tissues. Guselkumab works by suppressing the body’s immune system; specifically, it blocks IL-23 and prevents it from causing inflammation. By doing this, guselkumab can help to reduce pain and swelling in the joints, improve day-to-day function, and prevent long term damage to the joints. 

Like all the biologics, you will not feel the effects of guselkumab right away. Some people begin to feel the effects of guselkumab within a few weeks; however, it may take three to six months to feel the full effect. It is important to be patient and keep taking your medication.

Guselkumab can make it more difficult for your body to fight infections. People with active infections should not take guselkumab. If you have a fever, think you have an infection or have been prescribed an antibiotic, contact your healthcare provider. People who have had frequent infections in the past or a history of tuberculosis should discuss the use of guselkumab with their prescriber.

Also contact your healthcare provider if you are having surgery as you may need to stop guselkumab until you are healed and there is no sign of infection.

Guselkumab has not been studied in pregnant people or lactating parents so its effect(s) on pregnant people or nursing babies are unknown. You should tell your doctor if you are pregnant or are planning to become pregnant. Because of the potential for adverse reactions in nursing infants, a decision should be made on whether or not to discontinue nursing or the medication, taking into account the importance of the drug to the lactating parent.

Anyone who has had a previous allergic reaction to guselkumab should avoid the medication.  
If you have a history of cancer or active cancer, you should discuss this with your healthcare provider prior to taking guselkumab. Tell your healthcare provider if you notice any unusual changes to your skin or health status while taking guselkumab. 

Before starting this medication, you will likely be tested for inactive (“latent”) tuberculosis (TB) because guselkumab can dampen the immune system and cause TB to become active.

Ideally, your vaccinations should be up to date prior to starting guselkumab. If you have already started therapy with guselkumab, your healthcare provider will likely recommend most inactive vaccines (e.g., influenza, pneumococcal). Live vaccines are not recommended due to risk of causing infection. Before receiving any vaccinations while taking guselkumab, you should speak with your healthcare provider. 

Like all medications, taking guselkumab carries some risk of side effects, which must be balanced with the potential benefits. In general, the risk of joint damage and permanent disability resulting from arthritis is much greater than the risks of side effects from guselkumab. When monitored properly, the vast majority of side effects are rare. Most improve over time and are reversible. 

Guselkumab can increase your risk of infections. The most commonly reported side effect with guselkumab is symptoms of a cold (sore throat, stuffy nose). You should take precautions to minimize your risk of being infected by common contagious infections such as COVID-19, influenzae, pneumonia, and the common cold.
People have also commonly reported experiencing headaches and diarrhea. Talk to your healthcare provider if any of these symptoms affect you severely.

Guselkumab can rarely cause a reaction (redness, pain, and itching) at the injection site. Talk to your healthcare provider if these symptoms become severe.

Take your guselkumab as prescribed and contact your healthcare provider if you have any concerns while taking the medication.

To avoid injection reactions, injection sites should be rotated and avoid areas where the skin is tender, bruised, red and/or hard.

Blood tests are not routinely required while you are taking guselkumab. Your healthcare provider may order periodic blood tests to check your blood count and follow the activity of your arthritis.

Guselkumab must be refrigerated at 2 to 8 degrees Celsius until you are ready to use it. Keep the product in the original package and out of the light. 

Guselkumab must be kept cool while travelling. Ask your pharmacist for a cool carrier if you are not able to put the drug in your refrigerator right away.

The patient support program for TREMFYA is called “Janssen BioAdvance®”. Their phone number is 1-833-972-2420.