Biologics have transformed how moderate to severe psoriasis is treated, offering people with the chronic autoimmune condition a level of skin clearance and long-term control that wasn’t possible with older therapies.
Unlike older medications like methotrexate and cyclosporine, which affect the immune system more broadly, these new biologic therapies target specific drivers of psoriasis, often leading to clearer skin and fewer side effects.
Most biologics approved for psoriasis block a single inflammatory pathway. A newer option, bimekizumab (Bimzelx), takes a different approach, targeting two pathways at once. But does this dual approach translate into significantly better results for people with psoriasis?
Biologics used for psoriasis are a class of drugs known as monoclonal antibodies. These lab-made proteins block specific immune signals that drive inflammation.
“I often explain to patients that psoriasis is driven by an immune response. Biologics work by selectively blocking specific cytokines, such as IL-23 and IL-17, that signal to the skin to cause inflammation and rapid cell turnover,” says Marisa Garshick, MD, a dermatologist in New York and New Jersey, and a clinical assistant professor of dermatology at NewYork-Presbyterian Weill Cornell Medicine.
Much of that inflammation runs along what’s known as the IL-23/IL-17 axis, the primary highway of inflammation in plaque psoriasis.
“The IL-23/IL-17 axis is important, because IL-23 helps promote the cells that produce IL-17, which is a key driver in psoriasis,” Dr. Garshick says.
Most established biologics for psoriasis — drugs like secukinumab (Cosentyx), adalimumab (Humira), and risankizumab (Skyrizi) — target a single inflammatory signal at a time, such as IL-17, IL-23, or TNF-alpha.
Bimekizumab is the only approved biologic for psoriasis that blocks both IL-17A and IL-17F.
“IL-17A is considered the more potent inflammatory signal, while IL-17F is present in higher amounts in psoriatic skin,” says Garshick. “By targeting both, medications like bimekizumab may offer greater suppression of inflammation, which may translate to improved clinical outcomes for some patients, compared with blocking IL-17A alone.”
Research suggests that blocking IL-17A and IL-17F together may be more effective than solely neutralizing IL-17A in treating psoriasis.
“It’s about achieving a more complete blockage of the inflammatory signals behind psoriasis,” says Lawrence Green, MD, a clinical professor of dermatology at the George Washington University School of Medicine in Washington, DC.
Think of it as an inflammatory cascade — a chain reaction of immune signals that trigger inflammation in the skin.
Some biologics work higher up in the cascade, such as IL-23 inhibitors, which act earlier in the disease process and may offer more gradual and potentially longer-lasting control. Others, like IL-17 inhibitors, act further downstream, closer to where inflammation is actively driving symptoms in the skin.
“Psoriasis isn’t driven by just one signal,” Dr. Green says. “So when you block more than one, like IL-17A and IL-17F, you’re casting a wider net on the inflammation.”
As newer biologics raise the bar for psoriasis treatment, researchers are looking at whether targeting more than one inflammatory pathway can push results even further.
In a clinical trial in which researchers compared secukinumab with bimekizumab in more than 700 adults with moderate to severe plaque psoriasis, after 48 weeks of treatment, about 67 percent of those taking bimekizumab achieved complete skin clearance versus about 46 percent of those taking secukinumab.
Other clinical trials have shown similar results: Compared with adalimumab and ustekinumab, bimekizumab had higher rates of efficacy, with roughly 10 to 20 percent more patients achieving near or complete skin clearance.
“They do consider it superior in efficacy, but you’re splitting hairs at that point, because all these agents are so effective,” says Chris Adigun, MD, a board-certified dermatologist in private practice in Chapel Hill, North Carolina.
It shows how far psoriasis treatment has come. When Dr. Adigun was training, ”we never even hoped for” that level of skin clearance, she says, adding, “Now we’re aiming for completely clear skin.”
Dual inhibitors may have an edge in speed and durability in maintaining results over time, Garshick says. Clinical trials “suggest that dual inhibitors such as bimekizumab can offer high rates of skin clearance, with some patients achieving results more quickly,” she says. Long-term data suggests that skin clearance results can last for years.
One common question with biologic therapy is whether blocking two inflammatory pathways increases risk.
Overall, evidence suggests that the safety profile of dual inhibitors is comparable to other biologics. They’re generally well tolerated and quite similar to their single-inhibitor counterparts, Garshick says.
One notable difference is a higher incidence of oral candidiasis, or
thrush. It’s one of the most common side effects of bimekizumab.
It’s a “slightly increased risk,” Garshick says. “This is typically mild and manageable when it occurs.”
Other side effects include headache, cough, joint pain, muscle aches, and feeling tired.
Dual inhibitors may sound promising for people looking for very high levels of skin clearance, but they’re not automatically the best choice for everyone.
Choosing a biologic is a decision that patients make with their dermatologist, taking into account factors like disease severity, prior treatment response, comorbidities, and practical considerations like insurance coverage, Garshick says.
In some cases, the nature of the psoriasis itself can help guide that decision.
For people with psoriasis that is more inflammatory, “it’s more red, more active, more revved up — that’s where I’m more likely to think about something like bimekizumab,” Green says.
It’s not necessarily about defaulting to the newest drug, especially given how effective biologics are overall. “I don’t need to use something that is shiny and new,” Adigun says. “As we get more options, it becomes less about which drug is better overall and more about which one is the right fit for that patient.”
