Clears psoriasis sits at the center of this dementia and brain health question.
The drug that clears psoriasis in over 90 percent of patients is bimekizumab, sold under the brand name Bimzelx. In the BE READY Phase 3 clinical trial, 91 percent of patients achieved PASI 90 — meaning 90 percent skin clearance — at week 16, compared to just 1 percent on placebo. The FDA approved bimekizumab on October 17, 2023, as the first dual IL-17A and IL-17F inhibitor for moderate-to-severe plaque psoriasis in adults, and it has since become the biologic with the highest short-term clearance rate on the market. But bimekizumab is not the only drug pushing toward that 90 percent threshold. Risankizumab, marketed as Skyrizi, reaches 85 to 90 percent PASI 90 rates with continued treatment and has remarkable five-year durability data.
Meanwhile, zasocitinib, an oral pill still in development from Takeda, is showing promise as a non-injectable option that could reshape how psoriasis is treated. This article examines how these drugs work, what they cost, what side effects patients should expect, and how to think about choosing between them — particularly for older adults managing multiple health conditions. For readers of this site, the connection between chronic inflammatory conditions like psoriasis and brain health is worth noting. Systemic inflammation is increasingly recognized as a contributor to cognitive decline, and the same inflammatory pathways targeted by these drugs are subjects of active research in neurodegenerative disease. Managing psoriasis aggressively may have implications beyond skin health.
Table of Contents
- What Is the Drug That Clears Psoriasis in Over 90 Percent of Patients, and How Does It Work?
- The Cost of 90 Percent Clearance and Who Actually Pays It
- Skyrizi and the Case for Long-Term Durability Over Peak Clearance
- Side Effects and Tradeoffs — What Patients Need to Know Before Starting
- The Promise and Limitations of Zasocitinib, the Oral Option
- Psoriasis, Systemic Inflammation, and the Brain Health Connection
- What Comes Next in Psoriasis Treatment
- Conclusion
- Frequently Asked Questions
What Is the Drug That Clears Psoriasis in Over 90 Percent of Patients, and How Does It Work?
Bimekizumab works by blocking two related proteins, interleukin-17A and interleukin-17F, that drive the inflammatory cascade responsible for the rapid skin cell turnover seen in psoriasis. Older biologics targeted only IL-17A, which helped considerably but left IL-17F free to continue promoting inflammation on its own. By shutting down both pathways simultaneously, bimekizumab achieves clearance rates that prior-generation drugs could not match. In head-to-head Phase 3 trials, it outperformed adalimumab, secukinumab, and ustekinumab for both PASI 90 and PASI 100 outcomes. The numbers are striking even beyond that 91 percent headline figure. Between 59 and 68 percent of patients across bimekizumab trials achieved PASI 100, which represents complete skin clearance — not a reduction, but the total absence of visible plaques.
For people who have spent years cycling through topical steroids, phototherapy, and older systemic medications, that kind of result can feel almost unbelievable. It is worth understanding, however, that clinical trial populations are carefully selected and monitored. Real-world results, while generally strong, may not always replicate the precision of a controlled study. The practical experience of taking bimekizumab involves subcutaneous injections. The drug is administered by the patient at home after initial loading doses, similar to other biologics. For older adults or those with dexterity issues — common among people also dealing with psoriatic arthritis — the self-injection process is manageable but worth discussing with a healthcare provider before starting.
The Cost of 90 Percent Clearance and Who Actually Pays It
Bimekizumab carries a list price of approximately $7,200 per syringe, a figure that can cause immediate sticker shock. However, the list price of a biologic and the amount a patient actually pays are often very different numbers. UCB, the manufacturer, offers patient assistance programs through which commercially insured patients may pay as little as $5 per dose. Medicare patients, unfortunately, do not typically qualify for manufacturer copay cards, and their out-of-pocket costs under Part D can be substantially higher. this pricing reality creates a two-tier access problem that disproportionately affects older adults.
Someone on a commercial insurance plan through an employer may find bimekizumab essentially free after assistance programs. A 67-year-old on Medicare with moderate-to-severe plaque psoriasis may face thousands of dollars in annual copays for the same drug. If you are in that situation or helping a family member navigate it, specialty pharmacies and nonprofit foundations like the Patient Access Network Foundation sometimes bridge the gap. However, coverage is not guaranteed and varies year to year. It is also worth knowing that Skyrizi has similar assistance programs and may be covered differently by a given insurance plan, making a cost comparison between biologics an essential part of the treatment decision.
Skyrizi and the Case for Long-Term Durability Over Peak Clearance
Skyrizi, the brand name for risankizumab, takes a different pharmacological approach by targeting interleukin-23 rather than IL-17. Its initial clearance rates are slightly lower than bimekizumab’s — about 75 percent of patients achieve PASI 90 at week 16. But the longer-term picture tells a different story. In the LIMMitless extension trial, 85.1 percent of patients maintained PASI 90 at five years, and 52.3 percent maintained complete clearance at that same time point. Those are extraordinary durability numbers for any medication, let alone one treating a chronic autoimmune condition.
In the IMMerge head-to-head trial against secukinumab, Skyrizi delivered 87 percent PASI 90 at week 52 compared to secukinumab’s 57 percent. A Phase 2 trial using a high-induction dosing strategy pushed risankizumab’s PASI 90 rate to 94.4 percent at week 28, suggesting that with optimized dosing, this drug can match or approach bimekizumab’s peak performance. For patients and clinicians who prioritize sustained control over years rather than the fastest possible initial response, Skyrizi represents a compelling alternative — especially because its side effect profile differs meaningfully from bimekizumab’s. The distinction matters for older patients and those with compromised immune systems. A drug you will take for five or ten years needs to be evaluated differently than one measured only at week 16. Skyrizi’s track record of maintaining high clearance rates over years, combined with its every-12-week dosing after the loading period, makes it particularly practical for people who want fewer injections and a proven long-term safety record.
Side Effects and Tradeoffs — What Patients Need to Know Before Starting
The most notable side effect of bimekizumab is candidiasis, a fungal infection that occurs in roughly 15 to 20 percent of patients. Most cases are oral thrush rather than systemic or invasive candidiasis, and they are generally manageable with antifungal treatment. But this is not a trivial consideration. For older adults, particularly those who wear dentures or take other immunosuppressive medications, oral candidiasis can be persistent and uncomfortable. It is a known biological consequence of blocking both IL-17A and IL-17F, since these cytokines play a role in the body’s natural defense against fungal infections.
Skyrizi, by contrast, does not carry the same elevated candidiasis risk because it targets a different part of the immune system. Its most common side effects in trials were upper respiratory infections and headaches, which are also seen with many other biologics. This difference in side effect profiles creates a genuine clinical tradeoff: bimekizumab offers the highest initial clearance rates but comes with a specific and relatively common side effect that some patients will find unacceptable, while Skyrizi offers slightly lower initial clearance with potentially better tolerability and proven staying power. For someone helping an elderly parent or spouse weigh these options, the conversation with a dermatologist should not focus solely on which drug clears skin fastest. It should include questions about the patient’s history of fungal infections, their comfort with managing a potential side effect, how many other medications they take, and whether they have the support system to handle complications if they arise.
The Promise and Limitations of Zasocitinib, the Oral Option
Not everyone wants injections, and not everyone can tolerate biologics. Zasocitinib, a once-daily oral TYK2 inhibitor being developed by Takeda, represents a fundamentally different approach. In Phase 3 results released in December 2025, more than 50 percent of patients achieved PASI 90 and approximately 30 percent achieved PASI 100 at week 16, with continued improvement through week 24. The drug met all 44 ranked secondary endpoints compared to both placebo and apremilast, and Takeda has announced plans for an FDA filing in fiscal year 2026. Those numbers are lower than bimekizumab’s or Skyrizi’s, which is an important caveat.
An oral pill that clears skin in half of patients is a meaningful advance over older oral options, but it does not match the performance of the best injectable biologics. The value proposition of zasocitinib lies in convenience, patient preference, and access — a daily pill with no injection training, no cold-chain storage requirements, and potentially different insurance coverage dynamics. For the subset of patients who refuse injections or who have had adverse reactions to biologics, zasocitinib could be the drug that finally gets them adequate treatment. However, the drug is not yet approved, and Phase 3 data, while encouraging, requires scrutiny of long-term safety data that simply does not exist yet for this molecule. Patients and families should track this development with cautious optimism rather than treating it as an imminent solution.
Psoriasis, Systemic Inflammation, and the Brain Health Connection
Chronic psoriasis is not just a skin disease. It is a systemic inflammatory condition, and the same inflammatory mediators that drive plaque formation have been implicated in cardiovascular disease, metabolic syndrome, and emerging research suggests, neurodegenerative processes. Several population-level studies have found associations between severe psoriasis and increased risk of cognitive impairment later in life, though the mechanisms are still being investigated.
This does not mean that treating psoriasis will prevent dementia. But it does mean that uncontrolled, long-term systemic inflammation is not benign, and that achieving high clearance rates with modern biologics may have benefits beyond what is visible on the skin. For families already navigating dementia care or brain health concerns, understanding that inflammatory conditions deserve aggressive treatment — not dismissal as “just a skin thing” — is part of a broader approach to reducing modifiable risk factors.
What Comes Next in Psoriasis Treatment
The trajectory of psoriasis treatment over the past decade has been remarkable. A disease that once left many patients with persistent, painful plaques despite treatment now has multiple drugs capable of near-complete or complete clearance. Bimekizumab raised the bar to 91 percent PASI 90 in 2023. Skyrizi demonstrated that those results can be sustained over five years.
Zasocitinib may soon offer an oral alternative for patients who cannot or will not use injections. Looking ahead, the field is moving toward personalized treatment selection based on individual patient characteristics, combination approaches, and potentially even shorter treatment courses for patients who achieve sustained remission. The additional FDA approvals for bimekizumab in 2024 — covering psoriatic arthritis, ankylosing spondylitis, and non-radiographic axial spondyloarthritis — suggest that these drugs will increasingly be used to treat the full spectrum of inflammatory disease rather than isolated symptoms. For patients and caregivers, staying informed about these options means being prepared to have specific, evidence-based conversations with dermatologists and rheumatologists rather than accepting older treatments out of inertia.
Conclusion
Bimekizumab is currently the drug most associated with clearing psoriasis in over 90 percent of patients, achieving 91 percent PASI 90 in its pivotal trial and offering 59 to 68 percent complete clearance rates. It is not the only option approaching that threshold — Skyrizi delivers comparable results over longer timeframes with a different side effect profile, and zasocitinib may soon provide an oral alternative for patients who need one. The choice between these drugs involves weighing speed of clearance against long-term durability, injectable versus oral administration, candidiasis risk versus other side effects, and the realities of insurance coverage and cost.
For older adults and those managing multiple health conditions, including cognitive concerns, the decision deserves a thorough conversation with a specialist rather than a default to whichever drug has the most impressive headline number. The goal is sustained clearance with manageable side effects over years, not just a dramatic response at week 16. These drugs have transformed what is possible in psoriasis treatment, and patients who have been undertreated with older therapies owe it to themselves to revisit what modern options can achieve.
Frequently Asked Questions
What does PASI 90 mean, and why is it the standard for measuring psoriasis clearance?
PASI 90 means a 90 percent reduction in the Psoriasis Area and Severity Index, which measures the extent and severity of plaques across the body. It has become the benchmark because earlier standards like PASI 75 are now achievable by multiple drugs, and PASI 90 better reflects what patients consider a meaningful quality-of-life improvement — near-complete clearance of visible disease.
Is bimekizumab safe for older adults or people with other health conditions?
Bimekizumab was studied primarily in adults with moderate-to-severe plaque psoriasis, and clinical trials included a range of ages. However, the 15 to 20 percent candidiasis rate is a specific concern for older adults, who may already be more susceptible to fungal infections. Anyone considering this drug should discuss their full medical history, including other immunosuppressive medications, with their dermatologist.
How much does bimekizumab actually cost out of pocket?
The list price is approximately $7,200 per syringe, but commercially insured patients may pay as little as $5 per dose through UCB’s patient assistance program. Medicare patients generally cannot use manufacturer copay cards and may face significantly higher costs. Specialty pharmacies and nonprofit foundations can sometimes help bridge the gap.
Can psoriasis drugs reduce the risk of cognitive decline?
There is no direct clinical evidence that psoriasis biologics prevent dementia or cognitive decline. However, chronic systemic inflammation is increasingly recognized as a contributor to neurodegenerative processes, and controlling inflammation through effective psoriasis treatment may be one component of reducing modifiable risk factors. This is an active area of research without definitive answers.
What if I cannot tolerate injections — are there oral alternatives?
Currently approved oral options for psoriasis include apremilast and deucravacitinib, though their clearance rates are lower than injectable biologics. Zasocitinib, a once-daily oral TYK2 inhibitor, showed more than 50 percent PASI 90 in Phase 3 trials and is expected to be filed with the FDA in fiscal year 2026. It may offer a stronger oral alternative, though it still does not match biologic-level clearance rates.
How long do patients need to stay on these drugs?
Psoriasis is a chronic condition, and most patients on biologics continue treatment indefinitely to maintain clearance. Stopping treatment typically leads to disease recurrence. Skyrizi’s five-year data from the LIMMitless trial showed that 85.1 percent of patients maintained PASI 90 at week 256, suggesting that long-term treatment sustains results. Some researchers are exploring whether drug holidays or dose reductions are feasible for patients in deep remission, but this is not yet standard practice.
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