Biologics are injectable medications that pharmaceutical companies make from living cells in a lab or through a biological process. They change or stop specific cytokine activities inside immune cells that cause inflammation in psoriasis.

As biologics target specific parts of the immune system, they can be safer than broad-spectrum medications that suppress the entire immune system.

In a person with psoriasis, biologics modulate or block the activity of specific cytokines inside immune cells that cause the inflammation relating to the condition.

As we continue to gain knowledge about the specific causes of psoriasis, better and safer biologics will continue to come onto the market.

Four classes of biologics are currently available:

  • blockers of tumor necrosis factor-alpha (TNF-alpha)
  • interleukin 12 and 23 (IL-12/23) inhibitors
  • IL-17 inhibitors
  • IL-23 inhibitors

Each of these molecules is a specific messenger in the immune system involved in the development of psoriasis. The dosing regimen and side effects differ, depending on the drug.

TNF-alpha blockers include adalimumab (Humira), etanercept (Enbrel), and certolizumab pegol (Cimzia).

They all have approval to treat both psoriasis and psoriatic arthritis. Depending on the drug, people will need a dose every week or every other week.

Additionally, these biologics are the most broad-acting medications, as TNF-alpha is an upstream mediator of inflammation. The further downstream the target, the more specific the biologic is, and potentially, the fewer side effects it has.

The only IL-12/23 inhibitor available is ustekinumab (Stelara). It can treat both psoriasis and psoriatic arthritis, and a person receives a dose during the first week of treatment, week 4 of treatment, and then every 12 weeks.

The IL-17 inhibitors include secukinumab (Cosentyx) and ixekizumab (Taltz). They treat both psoriasis and psoriatic arthritis, and the dosing schedule is every 2–4 weeks.

The IL-23 inhibitors are the newest class of biologics to come onto the market. They include risankizumab-rzaa (Skyrizi), guselkumab (Tremfya), and tildrakizumab (Ilumya). Each has approval to treat psoriasis. Depending on the drug, a person receives a dose every 8–12 weeks.

Psoriasis occurs due to overactivity of the immune system, resulting in skin inflammation.

By blocking specific steps in the immune pathway that cause this inflammation, biologics can minimize the inflammation and stop the immune attack on the skin and joints.

Without inflammation, the skin can return to its original healthy state, but joint damage can be permanent. This is why it is so important to receive a diagnosis and start treatment as early in the course of the disease as possible.

Biologics are appropriate for people with moderate to severe psoriasis. In some cases, this refers to psoriasis that affects more than 10% of the body’s surface area.

People with psoriasis that affects less of the skin may still receive biologics. The affected areas may be unique and significant. For example, psoriasis affecting the hands can be debilitating, even though it only covers a small percentage of the total body surface area.

People who should not receive biologics include those with active cancer, an active infection (including untreated tuberculosis), and individuals who are systemically unwell in general.

The main side effects that biologics can cause include infections and malignancies.

While reducing inflammation in the skin is positive for psoriasis treatment, blocking the immune system — which defends the body from infections and combats cancerous cells — can potentially lead to adverse effects.

If the immune system does not protect the body from infections and cannot recognize and fight off atypical cells as well as usual, a person may have a greater risk of infections and malignancies.

Besides these risks, TNF blockers have links to the development of multiple sclerosis, or MS.

Also, IL-17 blockers have an additional warning about a potential increased risk of inflammatory bowel disease, or IBD.

While the potential adverse effects may cause concerns, they are extremely rare. With regular follow-up visits to a dermatologist, these drugs are safe to use.

The dermatologist will examine the person’s skin, assess their medical history for potentially concerning symptoms, and perform blood monitoring.

A person can self-inject most biologics on the market in the comfort of their own home. Many companies also provide nursing support, which involves a nurse visiting the person’s home to teach them to self-administer injections.

People can administer most of the medications using auto-injector pens rather than traditional syringes to ease the process. In some cases, a person can still visit their doctor’s office for the injections if they are not comfortable administering them at home.

The first step is to clean the hands and the injection site thoroughly. An injection should only take place in an area that psoriasis has not affected.

A person then places the auto-injector flush to the skin and presses the releaser to deliver the medication. They should avoid lifting the auto-injector from the skin until the device has fully administered the dose.

Then, the individual can clean the skin again if there is blood and apply an adhesive bandage.

Below are some answers to common questions about biologics for psoriasis.

What steps should someone take if a biologic is ineffective or stops working?

Many people have experienced benefits from biologics for several years. But in some cases, the response lessens over time.

This may result from the person’s body developing antibodies against the medication, neutralizing its effect. In some cases, a particular class of biologics may not be effective at all.

If an individual does not respond to a biologic after several weeks of continuous use, or if someone is no longer responding to one, the dermatologist may change the medication to another in the same or different class.

Can biologics cure psoriasis permanently?

While researchers are currently evaluating new biologics, it will be several years before they become available.

The good news is that the options available are yielding safe and effective results. Current medications can lead to a favorable reduction in PASI scores in people with psoriasis.

How long does a person stay on biologics for psoriasis?

A person can take biologics for psoriasis on a long-term basis, and the medication will remain safe and effective.

However, for some people, biologics will become less effective over time. This can also happen if a person stops and starts a biologic. In this instance, another biologic may work.

Are biologics for psoriasis worth the risk?

A dermatologist will carefully screen people with psoriasis and weigh up the risks before prescribing biologics.

The risk of developing a serious infection remains the biggest concern with biologics. This risk is higher in people who are older, have diabetes, smoke or chew tobacco, or have a history of infections.

However, biologics can offer an extremely safe and effective treatment for many people with moderate to severe psoriasis or psoriatic arthritis.

Joshua Zeichner, MD, is the Director of Cosmetic and Clinical Research in Dermatology at Mount Sinai Hospital in New York City. He actively lectures to international audiences and is involved in the daily teaching of residents and medical students. His expert opinion is commonly called upon by the media, and he is regularly quoted in national newspapers and magazines, such as The New York Times, Allure, Women’s Health, Cosmopolitan, Marie Claire, and more. Dr. Zeichner has been consistently voted by his peers to the Castle Connolly list of New York City’s best doctors.