Psoriasis is a chronic, immune-mediated skin disorder that affects millions of people worldwide, often manifesting as red, scaly plaques that can be both physically uncomfortable and emotionally distressing. Traditional therapies such as topical treatments, phototherapy, and systemic medications remain important, but for individuals with moderate to severe disease, newer targeted treatments called biological agents have revolutionized psoriasis care.

Biological agents, also known as biologics, are advanced therapies derived from living organisms such as plants, microorganisms, or animal cells. Unlike broad immunosuppressants that dampen the immune system as a whole, biologics are designed to selectively block specific pathways of the immune response that drive psoriasis. Because of this precision, biologics can deliver highly effective results while minimizing many of the systemic side effects associated with older treatments.

How Biological Agents Work

Psoriasis develops when the immune system becomes overactive, with T-cells releasing cytokines that fuel chronic inflammation and trigger the rapid overproduction of skin cells. Biologics disrupt this cycle by targeting key inflammatory mediators. Tumor necrosis factor-alpha (TNFα) inhibitors such as infliximab, etanercept, and adalimumab were the first widely used biologics, and they remain important options. Later generations of biologics expanded treatment possibilities, targeting interleukin-12, interleukin-23, and interleukin-17 pathways. For example, ustekinumab blocks IL-12 and IL-23, guselkumab and risankizumab specifically target IL-23, while secukinumab, ixekizumab, and brodalumab focus on IL-17.

These therapies are typically administered at defined intervals, either through self-injected subcutaneous doses or hospital-based intravenous infusions. Infliximab, for instance, requires infusions at carefully scheduled intervals in a clinical setting, while adalimumab or etanercept may be injected at home. Some patients may continue to use topical agents or systemic medications alongside biologics to enhance outcomes.

Effectiveness and Safety

Biological agents have dramatically improved the quality of life for patients with psoriasis, often achieving clear or nearly clear skin within weeks of treatment. However, responses can vary, and some patients may experience a gradual decline in effectiveness over time, known as secondary treatment failure. In these cases, switching to another biologic with a different target pathway can restore results.

The treatment with biologics is the most advanced treatment and may include modification of different pathways involved in the development of psoriasis:

TNF-α inhibitors

• Adalimumab (Humira) — plus multiple biosimilars (e.g., Amgevita, Hadlima, Hyrimoz, Idacio, Hulio, Yuflyma).

• Etanercept (Enbrel) — biosimilars: Brenzys, Erelzi

• Infliximab (Remicade) — IV; biosimilars: Inflectra, Renflexis, Avsola.

• Certolizumab pegol (Cimzia).

IL-12/23 (p40) inhibitor

• Ustekinumab (Stelara).

IL-23 (p19) inhibitors

• Guselkumab (Tremfya).

• Risankizumab (Skyrizi).

• Tildrakizumab (Ilumya).

IL-17 pathway

• Secukinumab (Cosentyx).

• Ixekizumab (Taltz).

• Brodalumab (Siliq) — IL-17RA.

• Bimekizumab (Bimzelx) — IL-17A/F.

Special type (GPP)

• Spesolimab (Spevigo) — generalized pustular psoriasis (GPP) only; not for chronic plaque psoriasis

Safety is an important consideration. While biologics are generally well tolerated, they are still immunomodulatory and can increase susceptibility to infections such as tuberculosis or certain bacterial illnesses. Careful screening for latent infections is essential before starting therapy, and patients require ongoing monitoring with blood tests.  A number of  studies suggest that biologics also reduce cardiovascular risks associated with severe psoriasis.

Vaccination status is another key consideration. Live vaccines should be avoided during treatment with biologics, and annual flu shots are recommended. Patients should discuss any vaccination needs with their dermatologist before beginning therapy.

When to Consider Biologics

Because biologics are costly and highly specialized, they are typically reserved for individuals with moderate to severe psoriasis that has not responded to other treatments, or for those who cannot tolerate traditional therapies due to side effects or underlying health conditions. Dermatologists determine candidacy based on factors such as disease severity, impact on quality of life, comorbid conditions like psoriatic arthritis, and previous treatment history.

The Centre for Medical and Surgical Dermatology in Pickering, led by board-certified dermatologist Dr. Breslavets, provides a comprehensive range of treatment options for psoriasis, from basic topical therapies to advanced biologic and phototherapy services. Every patient receives a thorough assessment that considers not only the type and severity of their psoriasis but also its broader impact on quality of life. This individualized evaluation allows Dr. Breslavets to design highly tailored treatment plans that may incorporate topical medications, phototherapy, systemic agents, and—when indicated—biological therapies.

Biological agents represent one of the most advanced approaches available today, offering targeted relief for patients with moderate to severe psoriasis that has not responded adequately to other treatments.By combining these cutting-edge therapies with supportive lifestyle and preventive guidance, the clinic empowers patients to achieve long-term relief, improve their skin health, and regain confidence.