Biologics represent a modern class of medications derived from living organisms, such as cells or microorganisms, rather than being chemically synthesized. These complex molecules, including proteins and genetic materials, are manufactured through biotechnological processes. Unlike traditional small-molecule drugs, which have a defined chemical structure, biologics are larger and more complex. Risankizumab and ustekinumab are two examples of such biologic medications. These drugs are utilized in the management of various chronic inflammatory conditions, offering targeted benefits to patients.
Understanding Risankizumab and Ustekinumab
Risankizumab, known by its brand name Skyrizi, is a biologic medication. It is approved to treat several immune-mediated inflammatory conditions. Risankizumab is used for adults with moderate to severe plaque psoriasis, active psoriatic arthritis, and moderately to severely active Crohn’s disease. It also received approval for treating moderately to severely active ulcerative colitis.
Ustekinumab, marketed as Stelara, is another biologic drug. This medication is approved for a similar range of chronic inflammatory conditions. Ustekinumab is indicated for adults and pediatric patients six years and older with moderate to severe plaque psoriasis, active psoriatic arthritis, and moderately to severely active Crohn’s disease. It is also approved for the treatment of adult patients with moderately to severely active ulcerative colitis.
How Risankizumab and Ustekinumab Target Disease
Risankizumab works by targeting a protein called interleukin-23 (IL-23). It binds to the p19 subunit of IL-23, a key component of this inflammatory pathway. By blocking IL-23, risankizumab helps reduce the inflammation associated with conditions like psoriasis, psoriatic arthritis, and inflammatory bowel diseases.
Ustekinumab, in contrast, has a dual mechanism of action, targeting two different proteins. It binds to the p40 subunit, which is common to both interleukin-12 (IL-12) and interleukin-23 (IL-23). This broader blockade interferes with inflammatory processes mediated by both IL-12 and IL-23, which are involved in the pathogenesis of various inflammatory conditions.
Clinical Outcomes and Side Effects
Clinical trials have provided comparative data on the effectiveness of risankizumab and ustekinumab in conditions like plaque psoriasis and Crohn’s disease. In studies of plaque psoriasis, risankizumab has demonstrated high rates of skin clearance, often achieving 90% improvement in the Psoriasis Area and Severity Index (PASI 90) in many patients. Ustekinumab also achieves PASI 75 or PASI 90 responses, though risankizumab often shows higher rates of skin clearance.
In Crohn’s disease, both medications aim for clinical remission and endoscopic improvement. Risankizumab’s induction studies showed clinical response and remission as early as week 4, with sustained results at week 12 and week 52 for endoscopic response and clinical remission. Ustekinumab has also shown effectiveness in achieving and maintaining remission in Crohn’s disease patients. Specific rates of remission can vary between trials and patient populations.
Regarding safety, both risankizumab and ustekinumab, as biologics, carry a warning about an increased risk of infections due to their immunosuppressive effects. Common side effects for risankizumab include upper respiratory infections, fatigue, fungal skin infections, headache, and injection site reactions. For inflammatory bowel diseases, additional common side effects can include joint pain, abdominal pain, anemia, fever, back pain, and urinary tract infections.
Ustekinumab’s common side effects include upper respiratory infections, headache, and injection site reactions. While rare, ustekinumab has been associated with a nervous system condition called reversible posterior leukoencephalopathy syndrome (RPLS). Both drugs require careful monitoring for signs of infection and other adverse events. Individual patient responses to these medications can differ due to individual factors.
Administration and Treatment Considerations
Risankizumab is administered through different methods depending on the condition treated. For plaque psoriasis and psoriatic arthritis, it is typically given as a subcutaneous injection at Week 0, Week 4, and then every 12 weeks after that. For Crohn’s disease and ulcerative colitis, treatment begins with an intravenous infusion at Week 0, Week 4, and Week 8, followed by subcutaneous injections every 8 weeks.
Ustekinumab also has varying administration routes and frequencies. For plaque psoriasis and psoriatic arthritis, the initial two doses are given subcutaneously 4 weeks apart, followed by an injection every 12 weeks. In Crohn’s disease and ulcerative colitis, ustekinumab treatment starts with a single intravenous dose based on body weight, with the first subcutaneous dose given 8 weeks after the intravenous dose, and subsequent subcutaneous doses every 8 to 12 weeks.
The choice between risankizumab and ustekinumab involves patient-specific factors, including patient preference for injection frequency or the need for intravenous infusions. The specific characteristics of the disease, such as severity and previous responses to other therapies, also play a role. Insurance coverage and costs are practical considerations for accessibility. Co-existing medical conditions and potential drug interactions are also reviewed by healthcare providers. Both medications necessitate ongoing medical monitoring and patient education for safe and effective use.