Plaque psoriasis is the most common form of psoriasis, characterized as an autoimmune condition where the body's immune cells mistakenly attack healthy cells. In individuals with plaque psoriasis, this immune system overactivity leads to inflammation and the rapid production of skin cells. This results in the formation of raised, discolored patches on the skin known as "plaques," often covered with a silvery-white scale. These plaques can be itchy and uncomfortable, typically appearing on the scalp, elbows, knees, and lower back, though they may occur elsewhere on the body.
People with plaque psoriasis experience "flare-ups," periods when their symptoms are most pronounced and can last for weeks or even months. Various triggers can exacerbate psoriasis or initiate a flare-up, including certain medications, infections (like colds or flu), dry or cold weather, stress, skin injuries, smoking, and excessive alcohol consumption.
While many individuals manage plaque psoriasis symptoms with topical treatments applied directly to the skin, some with moderate to severe plaque psoriasis may not achieve sufficient relief. For these individuals, oral or injected medications that target the immune system may be necessary. Skyrizi (risankizumab-rzaa) is one such medication, approved in 2019 for the treatment of moderate to severe plaque psoriasis. Clinical research suggests that Skyrizi, an injectable medicine, may offer greater efficacy compared to some previously approved injectable treatments for the same condition.
Understanding How Skyrizi Works
The active ingredient in Skyrizi is risankizumab, a medicine administered via injection that targets and blocks the action of a substance called interleukin-23 (IL-23). In individuals with plaque psoriasis, elevated levels of IL-23 contribute to inflammation. By inhibiting IL-23, Skyrizi effectively reduces the inflammation and, consequently, the symptoms associated with plaque psoriasis.
For many, topical prescription medications are sufficient for managing plaque psoriasis. However, individuals with moderate to severe plaque psoriasis might consider other therapeutic avenues, including oral or injected medications, or light therapy. If topical treatments do not adequately control symptoms, Skyrizi is a potential option to discuss with a healthcare provider.
Clinical Studies and Efficacy of Skyrizi
The safety and efficacy of Skyrizi for plaque psoriasis were evaluated in four clinical studies involving participants aged 18 and older with moderate to severe plaque psoriasis. The average age of participants was approximately 48 years, with 70% being male. The demographic breakdown included 80% White, 16% Asian, and 2.5% Black individuals; the race of other participants was not specified.
A significant portion of study participants had previously tried non-topical treatments, including light therapy (over two-thirds), oral medications (about half), and injectable medicines (about two-fifths).
The studies employed various comparative designs:
- One study compared Skyrizi against a placebo, with neither participants nor researchers knowing who received which treatment.
- Another study pitted Skyrizi against adalimumab (Humira), an injectable medication approved for plaque psoriasis that works by blocking tumor necrosis factor (TNF). Blinding was maintained in this study.
- Two studies compared Skyrizi against either a placebo or ustekinumab (Stelara), another injectable medication approved for plaque psoriasis that targets multiple substances in the body.
Effectiveness was measured in two primary ways:
- The percentage of participants who achieved at least a 90% improvement in their symptoms.
- The percentage of participants who achieved clear or almost clear skin, as assessed by the Static Physician’s Global Assessment (sPGA). The sPGA scale ranges from 0 (completely clear) to 5 (severe symptoms).
Key Findings on Symptom Improvement
After four months of treatment, a significantly higher proportion of participants using Skyrizi experienced at least a 90% improvement in their symptoms compared to those receiving other treatments:
- Skyrizi: 72%-75%
- Adalimumab: 47%
- Ustekinumab: 42%
- Placebo: 2%-5%
This indicates that Skyrizi demonstrated superior efficacy in symptom improvement compared to adalimumab, ustekinumab, and placebo. Furthermore, in a study where participants using adalimumab who did not achieve a 90% symptom improvement were switched to Skyrizi, approximately two-thirds experienced at least a 90% improvement after four months, suggesting Skyrizi's potential benefit for those with residual symptoms.
Clear or Almost Clear Skin Rates
Regarding achieving clear or almost clear skin (sPGA score of 0 or 1), Skyrizi also showed significant results:
- Skyrizi: 84%-88%
- Adalimumab: 60%
- Ustekinumab: 63%
- Placebo: 7%-8%
These findings highlight Skyrizi's effectiveness in achieving clearer skin compared to the other treatment options studied.
How to Administer Skyrizi
Skyrizi is administered as a liquid injection beneath the skin. The initial dosing regimen involves an injection every 4 weeks for the first two doses, followed by injections every 12 weeks thereafter. The injection can be administered into the thigh, abdomen, or the outer area of the upper arm.
Skyrizi is available in two forms: a prefilled device designed for subcutaneous injection, eliminating the need for separate syringes and needles, and a prefilled syringe with a needle. Healthcare providers will demonstrate the proper injection technique before the first use. The medication should be stored in the refrigerator and can be allowed to reach room temperature before injection to enhance comfort.
It is crucial to follow the "Instructions for Use" provided with the prescription for correct preparation and administration. If there are any uncertainties regarding the use of Skyrizi, consult a pharmacist or healthcare provider.
Expected Results and When to Seek Medical Advice
Symptom improvement with Skyrizi typically begins within the first 2-3 months of treatment, with the most significant changes often observed during the second and third months. Some individuals may continue to experience improvement into the fourth month.
It is important not to discontinue Skyrizi or any other plaque psoriasis medication without consulting a healthcare provider, even if symptoms improve, as this can lead to a recurrence or worsening of symptoms. If symptoms do not show improvement after approximately 2-3 months of Skyrizi treatment, a healthcare provider should be consulted to discuss alternative treatment options.
Potential Side Effects and Precautions
Skyrizi can cause reactions at the injection site, such as redness, pain, itching, or swelling. To minimize this risk, avoid injecting into a psoriasis plaque or any skin that is already tender, damaged, bruised, or scarred.
Individuals using Skyrizi may have an increased risk of infections, particularly respiratory tract infections, including common cold symptoms, sore throat, or nasal/throat infections. Preventive measures include frequent hand washing, avoiding close contact with sick individuals, and staying up-to-date with vaccinations, such as the annual flu vaccine. Discuss any necessary vaccinations with your healthcare provider before starting Skyrizi.
Serious Hypersensitivity Reactions: SKYRIZI is contraindicated in patients with a history of serious hypersensitivity reaction to risankizumab-rzaa or any of its excipients. Serious hypersensitivity reactions, including anaphylaxis, have been reported with its use.
Risk of Infection: SKYRIZI may increase the risk of infections. In patients with a chronic or recurrent infection, the risks and benefits of prescribing SKYRIZI should be carefully considered. Patients should seek medical advice if they experience signs or symptoms of a clinically important infection.
Tuberculosis (TB) Screening: Prior to initiating SKYRIZI treatment, patients should be evaluated for TB infection. Treatment for latent or active TB should be considered for patients for whom an adequate course of treatment cannot be confirmed. Patients should be monitored for signs and symptoms of active TB during and after SKYRIZI treatment.
Live Vaccines: The use of live vaccines is not recommended in patients treated with SKYRIZI. Medications that affect the immune system can increase the risk of infection following the administration of live vaccines.
Liver Problems: While primarily noted in the context of Crohn's disease or ulcerative colitis treatment, liver problems have been observed, including changes in liver blood tests accompanied by a rash leading to hospitalization in one case. Healthcare providers will monitor liver function through blood tests before, during, and for at least 12 weeks after treatment, and may discontinue SKYRIZI if liver problems develop.
Pregnancy and Breastfeeding: Women who are pregnant, plan to become pregnant, or are breastfeeding should discuss these circumstances with their healthcare provider. A Pregnancy Registry is available to collect information about the health of mothers and babies exposed to SKYRIZI during pregnancy.
It is essential to inform your healthcare provider about all prescription or over-the-counter medications, vitamins, herbal products, or supplements you are taking, as well as any recent or upcoming immunizations.
Use of IL-23 Inhibitors to Treat Plaque Psoriasis
Specialty Pharmacy and Financial Assistance
SKYRIZI is considered a "specialty" medicine, meaning it can typically only be obtained from a specialty pharmacy. Your insurance company may require prior authorization before dispensing the medication.
The manufacturer offers a savings coupon program that may reduce out-of-pocket costs to as little as $0, depending on your prescription insurance coverage and type.