INTRODUCTION
Psoriasis and psoriatic arthritis are chronic immune-mediated diseases that impose significant burdens on patients’ physical and psychological well-being. Conventional treatment modalities, including phototherapy and systemic therapies, frequently prove insufficient in achieving high levels of disease control necessary to enhance quality of life, particularly in severe cases. Development of targeted biologics (which includes guselkumab) was possible thanks to the identification of specific cytokines that play a pivotal role in the pathogenesis of psoriasis and psoriatic arthritis, particularly interleukin (IL)-23. This monoclonal antibody selectively binds to the p19 subunit of IL-23, a key cytokine implicated in the inflammatory cascade that drives the proliferation of pathogenic T cells, including Th17 cells, which in turn produce IL-17 and other inflammatory mediators. Guselkumab successfully reduces inflammatory cytokine production through inhibition of IL-23. This directly correlates with improvements in skin and joint symptoms in affected patients [1–3]. The results of clinical trials such as VOYAGE 1, VOYAGE 2, and NAVIGATE have provided compelling evidence for the efficacy of guselkumab in the treatment of plaque psoriasis, with a significant proportion of patients achieving a Psoriasis Area and Severity Index (PASI) PASI 90 or PASI 100 response. It is noteworthy that these studies have demonstrated that the effects of guselkumab are not only rapid but also durable, with treatment benefits extending up to 2 years. Moreover, the DISCOVER-1 and DISCOVER-2 trials, which examined guselkumab in patients with active psoriatic arthritis, demonstrate its efficacy in alleviating joint symptoms and skin manifestations, thereby supporting its dual efficacy in managing these related conditions. Importantly, for patients who have not responded adequately to other biologics, including TNF inhibitors and ustekinumab, guselkumab represents a viable therapeutic alternative with robust outcomes [4, 5]. The objective of this study is to provide a comprehensive analysis of the efficacy, safety, and impact on the quality of life of guselkumab in patients with moderate-to-severe plaque psoriasis and psoriatic arthritis, based exclusively on verified clinical findings. This work, through focusing on real-world data and primary studies, aims to clarify guselkumab position in current treatment frameworks and its potential to address gaps left by other therapeutic options. Through the synthesis of pivotal trial outcomes, including PASI response rates, quality-of-life measures, and adverse event profiles, this review provides a comprehensive perspective on guselkumab’s clinical value for both dermatologists and rheumatologists seeking effective, patient-centered treatment strategies.
EFFICACY, SAFETY, AND IMPACT ON THE QUALITY OF LIFE OF GUSELKUMAB IN THE TREATMENT OF MODERATE-TO-SEVERE PLAQUE PSORIASIS AND PSORIATIC ARTHRITIS
Guselkumab is a human monoclonal antibody. It works through targeting the p19 subunit of the IL-23 allowing for selective inhibition of its pathway. As a result, reduction of inflammatory processes and keratinocyte proliferation is achieved, which are major processes in the formation of psoriatic lesions. Thanks to that, effective management of moderate-to-severe plaque psoriasis is possible. In contrast to earlier biologics, which targeted both IL-12 and IL-23, guselkumab’s selective inhibition minimizes off-target effects, focusing its action precisely on the IL-23/Th17 axis that is critical in psoriatic pathophysiology. By selectively targeting this pathway, guselkumab has been demonstrated to elicit rapid and clinically meaningful improvements, including substantial reductions in PASI score, underscoring its capacity to attenuate key inflammatory mechanisms underlying the disease. Furthermore, guselkumab consistently outperforms conventional therapies such as adalimumab, achieving higher PASI response rates across multiple rigorously conducted clinical trials. In the VOYAGE 1 and VOYAGE 2 trials, guselkumab was associated with significantly higher rates of PASI 75, PASI 90, and PASI 100 responses, with more than 70% of patients achieving PASI 90 by week 16, a therapeutic milestone that was sustained over a 2-year follow-up period. These studies demonstrate that the benefits of guselkumab extend across diverse anatomical regions and are not confined to particular body sites. They further highlight the agent’s effectiveness in long-term disease management, characterized by rapid disease control and durable remission. Notably, the scalp and nails, areas traditionally considered difficult to treat due to resistance to other therapies, also responded favorably to guselkumab. In patients with active psoriatic arthritis, the DISCOVER-1 and DISCOVER-2 studies confirmed guselkumab’s efficacy in improving both cutaneous manifestations and joint symptoms. These studies included biologic-naive patients and patients previously treated with TNF inhibitors, demonstrating the applicability of guselkumab in a variety of patient backgrounds. Aforementioned studies proved significant improvements in the American College of Rheumatology response criteria (ACR20, ACR50, ACR70) at week 24, joint inflammation and progression of joint damage was reduced through the usage of the drug. Skin symptoms were also reduced. The drug achieved PASI 90 in a major part of participants. It qualified guselkumab as a versatile treatment for both manifestations of psoriatic disease [6]. The NAVIGATE study further investigated the efficacy of guselkumab in patients with an inadequate response to ustekinumab, another IL-23 inhibitor that targets both IL-12 and IL-23 via the p40 subunit. Guselkumab showed much better clinical response through achieving PASI 90 and PASI 100 as well as reducing disease activity, which was measured by the Investigator Global Assessment (IGA) score. This suggests that guselkumab may be a superior option for patients who fail to respond to broader IL-12/23 inhibitors, providing an effective alternative that capitalizes on its specific IL-23 p19 blockade. In terms of safety, guselkumab has shown a favorable profile with adverse events comparable to placebo and other biologics. Common adverse events include nasopharyngitis, headache and injection site reactions, which are generally mild and well tolerated by patients. Serious adverse events, such as infections and malignancies, occur at low rates, confirming the safety of guselkumab even with long-term use. Guselkumab’s position in terms of patient safety is highlighted through lower occurrence of serious infections. That distinguishes guselkumab from other IL-17 inhibitors that are associated with a higher risk of inflammatory bowel disease and candidiasis. The impact of guselkumab on patients’ quality of life was also demonstrated by significant improvements in Dermatology Life Quality Index (DLQI) and Psoriasis Symptoms and Signs Diary (PSSD) scores. These improvements reflect reductions in symptom severity, including itching, discomfort and psychological distress, which are critical to improving daily functioning and overall well-being. In VOYAGE 2, patients reported DLQI scores indicating minimal or no impact of psoriasis on their lives which were maintained over two years of treatment, underscoring the durability of guselkumab’s therapeutic effects on the quality of life [7]. The pharmacokinetics of guselkumab support a convenient dosing regimen, administered at weeks 0 and 4 and then every 8 weeks. This dosing frequency improves adherence, an important consideration in chronic disease management, by reducing the burden of frequent injections. Pharmacokinetic data indicate that steady-state concentrations are achieved by week 20, providing consistent drug exposure consistent with sustained clinical effects. This dosing advantage, combined with the robust efficacy of guselkumab, makes it an optimal choice for patients requiring long-term treatment of moderate-to-severe plaque psoriasis. In conclusion, guselkumab represents a significant advance in the treatment of psoriasis and psoriatic arthritis, particularly for patients with an inadequate response to previous biologics. Its precise targeting of IL-23 not only achieves high levels of skin clearance but also reduces joint symptoms in psoriatic arthritis, establishing it as a comprehensive therapeutic option.
A wide range of biologic treatment options is currently available for patients with psoriasis and psoriatic arthritis. Although this paper focuses on guselkumab, the comparative table summarizes not only its strengths but also its limitations relative to other agents, particularly with respect to PASI effectiveness (Table 1).
Table 1
Efficacy of guselkumab compared with other biologics across key clinical endpoints in psoriasis and psoriatic arthritis
[i] % Responders (Guselkumab/Comparator) – Absolute response rates: (number of patients achieving the stated endpoint ÷ number assessed) × 100. Effect – Absolute difference in response rates in percentage points (pp), calculated as Guselkumab % – Comparator %. Positive value (+) → guselkumab outperforms the comparator. Negative value (–) → comparator outperforms guselkumab. RR (risk ratio) is shown instead of pp when a study reports only relative effect measures; RR > 1 favors guselkumab, RR < 1 favors the comparator. Endpoints follow trial definitions (e.g., PASI 90/100 for skin clearance, ACR 20 for joint response) and the stated assessment time-point (week 4, 12, 52, etc.), PsO – psoriasis, PsA – psoriatic arthritis.
Ixekizumab, as a highly selective interleukin 17A inhibitor, has a very rapid onset of action and exceptionally high clinical efficacy. In clinical trials, impressive response rates of PASI 90 and PASI 100 were achieved in the first 12 weeks of treatment. In direct comparisons and network meta-analyses, ixekizumab outperforms guselkumab in terms of both the percentage of patients who achieve deep remission (PASI 100) and the speed of action. Compared to other interleukin inhibitors, it is clearly more effective than ustekinumab, as confirmed by data from comparative studies (including VOYAGE 1 and 2). Guselkumab, as an IL-23 inhibitor, targets the pathogenesis of psoriasis more selectively than ustekinumab (an IL-12/23 inhibitor), resulting in better disease control and longer maintenance of remission. When compared with adalimumab and brodalumab, guselkumab also compares favorably, achieving higher response rates of PASI 90 and PASI 100, and providing longer maintenance of therapeutic effects, while having a better tolerability profile and a lower risk of developing neutralizing antibodies [8–11].
In conclusion, ixekizumab provides a deeper and faster therapeutic response than guselkumab, making it the more potent option overall. Guselkumab, however, remains one of the most effective and safest IL-23 inhibitors, outperforming agents such as ustekinumab, adalimumab, and brodalumab. In routine clinical practice, treatment choice should balance efficacy with the patient’s clinical profile, dosing preferences, and risk of adverse effects.