The course of chronic plaque-type psoriasis in placebo groups of randomized controlled studies

Assessment of cytochrome P450 1A1 gene polymorphism and vitamin A serum level in psoriasis vulgaris

Psoriasis is characterized by cutaneous hyperproliferation, secondary to immune system dysregulation. Vitamin A regulates the immune response and sustains epithelial tissue hemostasis. The CYP1A1 gene, has many biological actions, including vitamin A metabolism. To evaluate CYP1A1 gene polymorphism and serum vitamin A level in patients with psoriasis vulgaris, a case-control study involving two groups was conducted: group 1 (45 patients with psoriasis vulgaris) served as the cased group and group 2 (45 healthy participants who were sex and age matched) acted as the control group. CYP1A1 (rs1048943) gene polymorphism and vitamin A serum level were assessed by TaqMan allelic discrimination (PCR) and ELISA, respectively. AG genotype was present only in cases (22.2%), while AA genotype was present in all controls (P=.001). Vitamin A levels were lower in cases than in controls (32.0 ± 7.41 vs. 46.2 ± 15.7 μg/ml, respectively) (P<.001). AG genotype was associated with a lower vitamin A level (P=.001). The detected genotype difference between psoriasis patients and controls, which was associated with a lower serum vitamin A level and was also lower in more severe cases, suggests a role of the CYP1A1 gene and vitamin A in disease pathogenesis and prognosis.

Efficacy and safety of netakimab, a novel anti-IL-17 monoclonal antibody, in patients with moderate to severe plaque psoriasis. Results of a 54-week randomized double-blind placebo-controlled PLANETA clinical trial

Background. Netakimab (NTK), an original humanized anti-interleukin-17 monoclonal antibody, showed therapeutic efficacy in moderate to severe plaque psoriasis in a phase 2 clinical study. Herein we report the results of 54 weeks of a phase 3 trial. Aim. To evaluate the efficacy and safety of two NTK regimens vs. placebo in moderate to severe plaque psoriasis. Methods. PLANETA is the ongoing randomized double-blind placebo-controlled clinical trial. 213 patients with moderate to severe plaque psoriasis were randomly assigned to receive NTK 120 mg once every 2 weeks (NTK Q2W), NTK 120 mg once every 4 weeks (NTK Q4W) or placebo. During the first 3 weeks, patients received subcutaneous injections of NTK or placebo (according to the allocation) once a week. Patients in the NTK Q2W group then received NTK at weeks 4, 6, 8, and 10. Subjects in the NTK Q4W group received NTK at weeks 6 and 10 and placebo at weeks 4 and 8. Patients in the placebo group received placebo injections at weeks 4, 6, 8, and 10. Treatment was unblinded at week 12. During the open-label phase, patients in both NTK groups continued to receive NTK Q4W. The primary efficacy endpoint was the proportion of patients in each group who achieved a 75% or greater reduction from baseline in psoriasis area and severity index (PASI 75) at week 12. Results. A total of 77.7%, 83.3%, and 0% of patients had a PASI 75 response at week 12 in the NTK Q2W, NTK Q4W, and placebo groups, respectively (P 0.0001, Fishers exact test, ITT). The effect was maintained throughout the 1-year treatment. NTK showed a good safety profile and low immunogenicity. Conclusion. Treatment with NTK results in high rates of sustained clinical response in patients with moderate to severe plaque psoriasis. The study is ongoing; thus, long-term use efficacy and safety data are forthcoming.

Efficacy and Safety of Netakimab, A Novel Anti-IL-17 Monoclonal Antibody, in Patients with Moderate to Severe Plaque Psoriasis. Results of A 54-Week Randomized Double-Blind Placebo-Controlled PLANETA Clinical Trial

INTRODUCTION

Netakimab (NTK), an original humanized anti-interleukin-17 monoclonal antibody, showed therapeutic efficacy in moderate-to-severe plaque psoriasis in a phase 2 clinical study. Herein we report the results of 54 weeks of a phase 3 PLANETA trial aimed to evaluate the efficacy and safety of two NTK regimens vs. placebo.

METHODS

Two hundred thirteen patients with moderate-to-severe plaque psoriasis were randomly assigned to receive NTK 120 mg once every 2 weeks (NTK Q2W), NTK 120 mg once every 4 weeks (NTK Q4W) or placebo. During the first 3 weeks, patients received subcutaneous injections of NTK or placebo (according to the allocation) once a week. Patients in the NTK Q2W group then received NTK at weeks 4, 6, 8 and 10. Subjects in the NTK Q4W group received NTK at weeks 6 and 10 and placebo at weeks 4 and 8. Patients in the placebo group received placebo injections at weeks 4, 6, 8 and 10. Treatment was unblinded at week 12. During the open-label phase, patients in both NTK groups continued to receive NTK Q4W. The primary efficacy endpoint was the proportion of patients in each group who achieved a ≥ 75% reduction from baseline in psoriasis area and severity index (PASI 75) at week 12.

RESULTS

A total of 77.7%, 83.3% and 0% of patients had a PASI 75 response at week 12 in the NTK Q2W, NTK Q4W and placebo groups, respectively (P < 0.0001, Fisher's exact test, ITT). The effect was maintained throughout the 1-year treatment. NTK showed a good safety profile and low immunogenicity.

CONCLUSION

Treatment with NTK results in high rates of sustained clinical response in patients with moderate-to-severe plaque psoriasis. The study is ongoing; thus, long-term use efficacy and safety data are forthcoming.

CLINICAL TRIAL REGISTRATION

The trial is registered at the US National Institutes of Health (ClinicalTrials.gov; NCT03390101).

Humanized anti-CD2 monoclonal antibody treatment of plaque psoriasis: efficacy and pharmacodynamic results of two randomized, double-blind, placebo-controlled studies of intravenous and subcutaneous siplizumab

New biologic therapies focused primarily on cytokine pathways, some targeting T cell-mediated immune responses, are being developed for the treatment of psoriasis. Siplizumab is a humanized anti-CD2 monoclonal antibody that interferes with costimulation necessary for T cell activation and proliferation. We assessed the biological activity, serum concentrations, and pharmacodynamic effects of siplizumab in patients with plaque psoriasis. Two multicenter, phase II randomized, double-blind, placebo-controlled studies were conducted: one study randomized 124 patients to one of two intravenous (IV) doses (0.012 and 0.04 mg/kg) of siplizumab, given every 2 weeks x 8 doses; the other study randomized 420 patients to one of three subcutaneous (SC) dose regimens of siplizumab given weekly (5 mg for 12 weeks, 5 mg for 6 weeks, and 7 mg for 4 weeks) or placebo for 12 weeks. Adults with plaque psoriasis involving > or =10% of the body surface area and who were not receiving psoriasis therapy were eligible. Treatment with siplizumab resulted in reductions in psoriasis severity, but most of the effects were not statistically significant compared with placebo. Statistically significant differences among IV siplizumab-treated and placebo groups were observed at study day 28, with greater psoriasis area and severity index (PASI) score reductions from baseline in the siplizumab groups. The difference in PASI50 response rates between the 0.04 mg/kg siplizumab and placebo groups was also statistically significant at day 28. A trend toward clinical improvement was observed in SC siplizumab-treated groups. Significant reductions in circulating absolute lymphocyte counts and CD2+ (CD3+, CD8+, and CD16+/56+), but not CD2- (CD19+ and CD14+), lymphocyte populations were observed. These changes were not accompanied by concomitant reductions in infiltrating CD3+ lymphocytes in psoriatic lesions, epidermal thickness, or keratin 16 (K16) and intercellular adhesion molecule (ICAM) expression. The effect of siplizumab did not differentially affect CD45RO+ and CD45RA+ lymphocytes. Low or undetectable mean trough serum concentrations of siplizumab following IV or SC treatment were observed. Pharmacokinetic data coupled with higher-than-expected placebo clinical response rates may partly explain siplizumab's marginal clinical activity. Higher doses of siplizumab may be required to detect significant improvements in psoriasis; however, further development of this agent was not planned.

Relapse, rebound, and psoriasis adverse events: An advisory group report

Psoriasis is a chronic disease, the severity of which varies among patients and changes unpredictably over time in individual patients. Psoriasis can be exacerbated during treatment by infection, endocrine factors, hypocalcemia, medications, psychologic stress, skin trauma, or other factors. Patients who discontinue treatments may experience a return of disease--relapse--or worsening of disease--rebound. The National Psoriasis Foundation (NPF) proposed standardized definitions of relapse and rebound. Efalizumab, a recombinant humanized immunoglobulin G-1 monoclonal antibody, is approved for the management of psoriasis. During efalizumab clinical trials, a small percentage of patients experienced protocol-defined adverse events related to psoriasis. After publication of the NPF definition of rebound, post hoc exploratory analyses of the efalizumab clinical trial data were performed. The efalizumab clinical trial investigators discussed their observations, the analyses, and their individual approaches to the treatment of patients receiving or discontinuing efalizumab therapy, the conclusions of which are described herein.

A reappraisal of the concept of suppressive versus remittive psoriasis treatments

Among the ways to characterize the many treatments for psoriasis is to distinguish suppressive from remittive therapies. Remittive therapies are thought to be treatments that result in a prolonged period of disease remission even after stopping the drug, while suppressive treatments are thought to work only during the treatment period. However, apparent differences in remittive and suppressive properties may be due to the remitting and relapsing nature of psoriasis and the order in which treatments are used in patients. Few clinical trials have compared the suppressive versus remittive properties of different treatments. Given the adverse events and expense associated with many psoriasis therapies, a major implication is that psoriasis patients who have cleared on therapy should probably be tested at intervals to see if they can be tapered off their medication without loss of control of their disease.