The U.S. Food and Drug Administration that it has approved Siliq (brodalumab) as treatment for adults diagnosed with moderate-to-severe plaque psoriasis.
An injectable biologic, Siliq is designed for patients who have stopped responding or failed to respond in the first place to systemic therapy or phytotherapy. Moderate-to-severe cases of plaque psoriasis cause significant discomfort and skin irritation for patients and Siliq's approval offers another option to address that, said Dr. Julie Beitz, director for the FDA's Office of Drug Evaluation III at the agency's Center for Drug Evaluation and Research.
"Patients and their health care providers should discuss the benefits and risks of Siliq before considering treatment," she added, referring to the drug warnings attached with the approval.
Siliq As Psoriasis Treatment
Plaque psoriasis is the most common form of psoriasis characterized by flaky, silver-white scales on thick, red skin. Siliq works by targeting a cytokine called interleukin-17, a key driver for the disease. With it blocked, inflammatory response related to psoriasis is kept at bay.
Results from three randomized clinical trials controlled with placebo were used to establish that Siliq was safe and effective to use. These clinical trials involved 4,373 adults with moderate-to-severe psoriasis. Based on the results, more of the patients who received Siliq had clear or nearly clear skin compared to those who were given placebo. These results were assessed using a scoring system that took into consideration the severity, nature, and extent of psoriatic skin changes.
Though effective, Siliq still caused adverse reactions in some patients, which included joint pain, fatigue, headache, diarrhea, nausea, throat pain, muscle pain, injection site irritation, low white blood cell count, fungal infections, and influenza.
Additionally, Siliq use led to increased suicidal behavior and ideation, including completed suicides, during the clinical trials in patients with histories of suicidal tendencies or depression. Because of this, the drug comes with a Boxed Warning and will only be made available with restrictions through the Siliq Risk Evaluation and Mitigation Strategy Program.
In line with these restrictions, patients must sign an agreement form that they have been made aware of the risks Siliq comes with and that they understand the importance of seeking medical attention should suicidal thoughts and other mood changes crop up or worsen.
Siliq will be affecting the immune system so patients are also warned of increased risks of getting infections or allergic conditions. Health care providers are advised that the drug is not to be administered to anyone with active tuberculosis infections and that those given Siliq should avoid live vaccine immunizations.
As an autoimmune disorder, psoriasis most commonly manifests in patients aged 15 to 35. According to the American Academy of Dermatology, about 7.5 million people have the condition in the United States, with about 80 percent of patients diagnosed with mild to moderate cases while the remaining 20 percent have to deal with moderate-to-severe psoriasis. A case is defined as moderate to severe when psoriasis affects more than 5 percent of the surface area of the body.
In 2013, it was estimated that the total direct treatment cost associated with psoriasis was at $51.7 billion to $63.2 billion.