Based on the Maui Derm 2018 presentation by Joel M. Gelfand MD, MSCE, FAAD, from University of Pennsylvania Perelman School of Medicine, Philadelphia Pennsylvania

Article by Jo Ann LeQuang and the Journal of Clinical and Aesthetic Dermatology

Medical literature on the topic of psoriasis comorbidities has been rapidly expanding since around the turn of the century. There is a strong body of evidence that patients with psoriasis are at increased risk for developing psoriatic arthritis, cardiovascular disease (e.g., myocardial infarction, stroke), Crohn’s disease, diabetes, metabolic syndrome, mood disorders (e.g., anxiety, depression, suicide), and a much rarer condition, T-cell lymphoma.^7–14 Genes and loci associated with psoriasis overlap with those associated with other conditions, such as diabetes and cardiovascular diseases (PSORS2/3/4, CDKAL1, ApoE4, TNFAIP32), with the potential contribution of environmental risk factors such as obesity and smoking.

The pathophysiology of psoriasis includes an increased presence of antigens, activation of T-cells and T-helper cell Types 1 and 17 cytokines (Th1 and Th17), and possibly higher levels of C-reactive proteins. These immunological conditions make patients vulnerable to other diseases associated with inflammatory processes.^7–13 Chronic inflammation has been associated with numerous conditions, such as atherosclerosis and thrombosis.⁹ Epidermal proliferation associated with psoriasis plaques can increase uric acid and exacerbate oxidative stress.⁷ Patients under treatment for psoriasis might be exposed to varying risks and benefits associated with drug therapies.¹¹ Finally, psoriasis in and of itself is associated with an adverse psychosocial impact owing to its disfiguring nature and chronic persistence.¹⁴ All of these factors combine such that psoriasis is comorbid with numerous conditions.

Cardiometabolic diseases. In a four-year, population-based cohort study from the United Kingdom (n=8,124 patients with psoriasis and 76,599 controls),¹⁵ patients with psoriasis had a hazard ratio for development of Type II diabetes mellitus of 1.64 (95% CI, 1.23– 2.18) if more than 10 percent of their BSA was affected. For each 10-percent increase in BSA affected by psoriasis, there was a 20-percent increase in risk for developing diabetes. This is not trivial: about 125,650 new cases of diabetes every year can be directly linked to psoriasis.¹⁵

Cardiovascular diseases. A prospective database study (n=130,976 patients with psoriasis and 556,995 control patients) of 5.4 years duration found patients with psoriasis had a higher rate of myocardial infarction than controls and exhibited a dose-response effect, in that those with the most severe psoriasis had the highest rate of myocardial infarction.⁷ A cohort study using the General Practice Research Database (N=3,603 patients with psoriasis) found that patients with severe psoriasis were at increased risk for cardiovascular death, independent of the traditional cardiovascular risk factors.¹⁶ Recent studies suggest that elevated risk for cardiovascular conditions might be attributed to arterial stiffness, an early independent predictor of adverse cardiovascular events. Arterial stiffness occurs frequently among psoriasis patients.¹⁷

Stroke. Stroke is a major cause of morbidity and mortality, and its associations with diabetes, hypertension, atrial fibrillation, transient ischemic attacks, and smoking are well known.¹⁸ In a population-based cohort study, it was found that severe psoriasis increased an individual’s chance of having a stroke by 44 percent. There is an elevated risk for stroke for all patients with psoriasis, but the risk for patients with mild psoriasis was deemed modest.⁹

Cancer. Patients with psoriasis are at an increased risk of cancer, particularly, but not exclusively, NMSC. It remains unclear whether new psoriasis treatments targeting interleukin (IL) 12 and 23 affect the patient’s risk for cancer.¹⁹ IL-12 and IL-23 play a role in the cellular responses and inflammatory processes associated with psoriasis but they are also involved in the immune response to tumors and infections. A systematic review and meta-analysis found that individuals with a history of cancer who developed psoriasis (or other immune-related disorders such as rheumatoid arthritis and inflammatory bowel disease) and were treated with TNF inhibition did not show an elevated risk for cancer recurrence or a new cancer.²⁰ A review of cancer rates among patients with various immune-mediated diseases found that there was not an increased rate of cancer among patients with psoriasis in general or among patients with psoriasis who were on TNF inhibition therapy.²¹

Liver disease. Patients with psoriasis are at increased risk for all liver disease, nonalcoholic fatty liver disease (NAFLD), and cirrhosis. The prevalence of liver disease and cirrhosis was shown to increase in proportion to the BSA affected by psoriasis.²² The prevalence of NAFLD is estimated to be 20 to 60 percent among patients with plaque psoriasis.^23–27 Nonalcoholic steatohepatitis (NASH) is a progressive form of fatty liver disease with an incidence of about 22 percent among patients with psoriasis.²⁶ This area warrants further study.

Emerging comorbidities. Infections. A new area of research explores the risk of serious infection and opportunistic infection in patients with psoriasis.²⁸ The risks of opportunistic infections and herpes zoster have been shown to be elevated among patients with moderate-to-severe psoriasis and could be statistically associated with immunosuppressive therapy.²⁹

Sleep disorders. Psoriasis adversely affects sleep and has been associated with comorbid obstructive sleep apnea.³⁰ It is thought that intermittent hypoxia caused by sleep apnea along with sleep deprivation creates a chronic inflammatory state that can set the stage for autoimmune disorders such as psoriasis.³¹

Chronic obstructive pulmonary disease (COPD). COPD shares some risk factors with psoriasis, including obesity, smoking, a sedentary lifestyle, and an association with metabolic syndrome, as well as potentially shared biological pathways such as Th17 driven inflammation.³² Patients with psoriasis have increased risk for impaired pulmonary function compared with control patients, as evidenced on spirometry.³³ Patients with psoriasis also have a greater risk of developing COPD, compared with the general population, with an OR of 1.90 (95% CI, 1.36–2.65), and this risk increases with the severity of the psoriasis (2.15 for severe psoriasis, 95% CI, 1.26–3.67).³⁴

Chronic kidney disease and end-stage renal disease (ESRD). Chronic kidney disease and ESRD have also been associated with psoriasis, according to a systematic review and meta-analysis (n=199,808), with an estimated pooled risk ratio for patients with psoriasis and chronic kidney disease of 1.34 (95% CI, 1.14–1.57) and psoriasis and ESRD of 1.29 (95% CI, 1.05–1.60).³⁵ Severe psoriasis confers a greater risk than milder forms of psoriasis, with an adjusted hazard ratio of 1.90 (95% CI, 1.33–2.70) for chronic kidney disease and 2.97 (95% CI, 1.72–5.11) for ESRD.³⁶

Peptic ulcer disease. Patients with psoriasis are at a greater risk than patients without psoriasis for developing peptic ulcer disease (adjusted OR 1.27, 95% CI, 1.03–1.58).³⁷

Sexual dysfunction. Patients with psoriasis are more likely than the general population to experience sexual dysfunction, in particular erectile dysfunction (ED).³⁸ According to one study,³⁹ prevalence of ED was much higher in male patients with psoriasis (n=135, 61.5%) compared with controls (n=201, 48.3%), (p=0.001).

Drug therapies. TNF inhibitors. The systemic inflammation associated with psoriasis, psoriatic arthritis, and rheumatoid arthritis accelerates atherosclerosis and, in this way, might promote cardiovascular disorders. This risk exists even in patients with psoriasis who have no other cardiovascular risks, and cardiovascular disorders are especially prevalent in those with psoriasis and other cardiovascular risk factors. Thus, treatment of the underlying inflammation has been proposed to mitigate the cardiovascular risk.⁴⁰ In a systematic review on rheumatoid arthritis,⁴¹ TNF inhibitors, such as infliximab, etanercept, and adalimumab, have been shown to be cardioprotective. In a meta-analysis of studies assessing the effect of TNF inhibitors on adverse cardiovascular events in patients with psoriasis, with or without psoriatic arthritis (n=49,795, 5 studies),⁴² the risk for a cardiovascular adverse event was significantly lower when patients were treated with TNF inhibitors compared with topical treatments or phototherapy (risk ratio 0.58, 95% CI, 0.43–0.77, p<0.001). In this meta-analysis,⁴² 278 patients in the TNF inhibitor group and 1,063 in the control group had suffered myocardial infarctions. TNF inhibitors appeared to significantly reduce cardiovascular adverse events compared with methotrexate (risk ratio 0.67, 95% CI, 0.52–0.88, p=0.003). The risk for myocardial infarction specifically was significantly decreased, compared with topical therapy or phototherapy, among patients treated with TNF inhibition (risk ratio 0.73, 95% CI, 0.59–0.90, p=0.003) or with methotrexate (risk ratio 0.65, 95% CI, 0.48–0.89, p=0.007). The role of TNF inhibitors compared with other treatments for all-cause mortality and stroke remains to be elucidated. It must be noted that TNF inhibitors do not reduce the rate of heart failure and, in fact, might worsen it.^43–45

Biologic therapies. In a systematic review and meta-analysis of 38 randomized clinical trials of adults with plaque psoriasis (n=18,024),⁴⁶ the use of biologic therapies overall was not associated with any significant differences in the risk for major adverse cardiovascular events (MACEs), with an OR of 1.45 and 95-percent CI of 0.34–6.24. Specifically, for TNF alpha inhibitors (adalimumab, etanercept, infliximab), the OR was 0.67 (95% CI, 0.10–4.63); for anti-IL-17A agents (secukinumab and ixekizumab), the OR was 1.00 (95% CI, 0.09–11.09), and ustekinumab had an OR of 4.48 (95% CI,
0.24–84.77). There were no statistically significant differences among these various agents at approved doses compared with placebo.⁴⁶

In light of what we know now, how should psoriasis be treated? People with psoriasis face a greater mortality burden compared with the general population.⁴⁷ In a study from Noe and colleagues,⁴⁸ BSA affected by psoriasis conferred a mortality risk such that patients with more than 10-percent affected BSA had a higher risk of all-cause death than those with less than three-percent BSA involvement.⁴⁸ For many conditions, the more severe the psoriasis, the greater the comorbid risk to the patient. Thus, moderate and severe cases of psoriasis warrant special consideration.

Since patients with psoriasis are at increased risk for a number of cardiovascular conditions, dermatologists should educate these patients with psoriasis about the increased risk for cardiovascular disease and screen them according to standard guidelines for hypertension, diabetes, and hyperlipidemia. At present, fewer than half of all dermatologists ever conduct such screenings, but it is important since these patients might not be seeing other physicians or these other physicians might be unaware of a patient’s psoriasis and the risk it poses.^49–51 Thirty-seven percent of newly screened patients with psoriasis were found to be at high risk for cardiovascular disease, and almost half of them (46%) were not optimally managed for these risk factors.^49–51 The question that emerges from our growing knowledge of psoriasis comorbidities is whether more aggressive treatment of psoriasis would lower the risk of cardiovascular disease, cardiometabolic disorders, and overall mortality. Moreover, which type(s) of pharmacological therapy would be most helpful in reducing the risk of MACE and cardiovascular mortality? Early observational data suggest that methotrexate^52,53 and TNF inhibitors^54–56 are able to lower the risk of certain cardiovascular events (but not heart failure). Data are not yet available on whether phototherapy, topical treatments, and specific drugs such as apremilast, ustekinumab, secukinumab, ixekizumab, and guselkumab confer any cardioprotective benefits to patients with psoriasis. Randomized, controlled clinical studies and further systematic reviews and meta-analyses are needed to guide prescribers with more definitive evidence.

Treatment of atherosclerosis focuses mainly on reducing plasma lipid levels, but biomarkers for inflammation (high-sensitivity C-reactive protein and IL-6) have likewise been associated with an elevated risk for cardiovascular events independent of cholesterol level. Since statin drugs reduce both cholesterol levels and inflammation, it is unclear whether the reduction of vascular inflammation alone (without concomitant reduction of lipids) can reduce cardiovascular events associated with atherosclerosis. Canakinumab is a fully human monoclonal antibody that targets IL-1 beta and has known anti-inflammatory effects. The Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS)⁵⁷ was a randomized, double-blind, placebo-controlled clinical trial enrolling 10,061 patients with a prior myocardial infarction in order to determine if canakinumab could prevent recurrent vascular events in patients with a high-sensitivity C-reactive protein level of 2mg/L or greater. At 48 months, the median reduction from baseline in C-reactive protein levels was 26-percent, 37-percent, and 41-percent greater in patients who received 50, 150, or 300mg of canakinumab, respectively, compared with placebo.⁵⁷ IL-6 levels also decreased, measured at 12 months. Canakinumab had no significant effect on either low-density lipoproteins (LDL) or high-density lipoproteins (HDL) cholesterol levels and resulted in a median of about five-percent elevation in triglycerides. The primary endpoint of the study was a composite endpoint of nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death; the composite endpoint occurred significantly less often among the 150mg canakinumab group compared with placebo (p=0.0275). Patients in the canakinumab group were more likely to experience neutropenia than those in the placebo group, and the pooled canakinumab group had significantly higher mortality attributable to infection or sepsis (incidence rate was 0.31 compared to 0.18 per 100 person-years, p=0.02).55 IL-1 beta inhibition appears to be an important anti-inflammatory pathway that might offer a degree of cardioprotection, but it is associated with its own risks for infection.⁵⁷

Other studies are ongoing in evaluating the role of vascular inflammation and lipid metabolism in moderate-to-severe psoriasis. The Cardiovascular Inflammation Reduction Trial (CIRT)⁵⁸ will evaluate methotrexate’s role in the possible reduction of major vascular events in a population without psoriasis but with a history of myocardial infarction, diabetes, or metabolic syndrome. TNF inhibition does not appear to reduce vascular inflammation compared with placebo at 16 weeks.⁵⁹ The PSOLAR data do not show that biologics reduce the risk of MACE in patients with moderate-to-severe psoriasis.⁶⁰

The association between psoriasis and cancer exists but remains to be more fully elucidated. As a precautionary measure, patients with psoriasis should be advised to stay current with all age-appropriate cancer screenings (e.g., colon, cervical breast, prostate, and lung). The incidence of smoking is higher among patients with psoriasis than the general population, so low-dose computed tomography (CT) screenings for lung cancer might be appropriate for patients 55 to 80 years of age with a history of smoking 30 or more packs of cigarettes per year as well as for current smokers and smokers who have quit in the last 15 years. Since psoriasis is associated with sexual dysfunction, clinicians might wish to ask patients about their sexual health.⁶¹ Lesions in the genital area can be particularly distressing and should be discussed with patients.⁶² Since over 45 percent of patients with genital-area psoriasis never discuss the problem with a clinician, the dermatologist might need to initiate such conversations.⁶³ Patients with psoriasis are at increased risk for infections, so patients with guttate flares should be screened for possible streptococcal infection. Patients with severe psoriasis should also be screened for human immunodeficiency virus (HIV). Patients with psoriasis should be regularly vaccinated for influenza, pneumonia, hepatitis B, human papilloma virus (ages 9– 26 years), and shingles (>50 years of age).⁶⁴

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Based on the Maui Derm 2018 presentation by Andrew Blauvelt, MD, MBA, Oregon Medical Research Center, Portland, Oregon

Article by Jo Ann LeQuang and the Journal of Clinical and Aesthetic Dermatology

Psoriasis is caused by the complex interplay of four factors: autoantigens, environmental antigens, genetics, and the immune system. Autoinflammation, an inflammatory state not mediated by circulating autoantibodies and autoreactive T-cells, has recently been implicated as well.⁶⁵ Genetics remains the key to better understanding the immune system and the pathogeneses of all autoimmune disorders, including psoriasis. Better understanding of the pathogenesis of psoriasis will allow for more accurate mapping of psoriasis pathways and improved ability to identify therapeutic targets, which, in turn, will lead to safer and more effective treatments.

The genetics of psoriasis. Psoriasis has strong heritability, and over 70 susceptibility loci/genes associated with psoriasis have been identified to date.⁶⁶ In monozygotic twins, there is approximately a 70-percent genetic concordance, and 10 percent of the children of parents with psoriasis will develop psoriasis themselves (a 4- to 5-fold increase over general population). In the 1970s, psoriasis was found to be associated with the HLA Class I antigens, with associations between psoriasis and HLA-C (HLA-Cw6 in particular) and HLA-B alleles.⁶⁷ The most common and dominant gene association is HLA-C*0602, but only 41 percent of people with psoriasis are HLA-C*0602-positive.⁶⁸ In fact, the HLA-C*0602 gene, in and of itself, is neither necessary nor sufficient to develop psoriasis. About 20 percent of the population are carriers of the HLA-C*0602 gene, and about 10 percent of carriers develop psoriasis.⁶⁶

Autoantigens. Antigens are molecules that induce an immune response in a host organism, and antibodies are the body’s method to target these antigens. Antigens are typically peptides, polysaccharides, and lipids that originate endogenously or exogenously. Autoantigens are endogenous antigens that are produced by normal cell metabolism or as a result of a viral or bacterial infection. The major histocompatibility (MHC) Class I antigen pathway serves to alert the immune system of the presence of a cell with a viral infection. MHC molecules are expressed on nucleated cells and platelets. In humans, HLA-A, HLA-B, and HLA-C correspond to MHC Class I, while HLA-DP, HLA-DM, HLA-DOA, HLA-DOB, HLA-DQ, and HLA-DR correspond to MHC Class II. Thus, autoantigens are endogenous proteins that can be attacked by the immune system, which is the reason they are associated with autoimmune disorders.

HLA-C*0602 is an MHC Class I molecule that normally presents autoantigens to CD8 T-cells. The autoantigens are ADAMTSL5 and LL-37. ADAMTSL5 is a peptide derived from the protein ADAMTSL5 and produced by melanocytes that can bind to HLA-C*0602 and stimulate psoriatic CD8+ T-cells. LL-37 is an antimicrobial peptide produced by keratinocytes, and it contains a VRSRRCLRL-like peptide that stimulates psoriatic T-cells.⁶⁶

Environmental antigens also play a role in psoriasis. Streptococcal M proteins contain peptides that overlap with hyperproliferative keratin (K16/K17) peptides; these Streptococcal M proteins can stimulate psoriatic T-cells and have been implicated in certain cases of guttate psoriasis as environmental antigens. Yeast proteins are known to contain a VRSRRCLRL-like peptide that can stimulate psoriatic T-cells, and these exogenous antigens have been implicated in cases of beer-exacerbated psoriasis.⁶⁶

The psoriasis pathways: targets and mechanisms of actions. Psoriasis can be defined as a T-cell-mediated disease mainly driven by pathogenic T-cells that produce high levels IL-17 in response to IL-23. Greater understanding of the IL-23/T-17 axis, identified as the main pathway for psoriasis, has revolutionized the way psoriasis is treated today by offering important targets for pharmacotherapeutic interventions.⁶⁹ Broadly blocking this pathway (e.g., with methotrexate) might work, but it might not be as safe or effective as a narrower blockade (e.g., TNF inhibition), which targets inflammation more specifically and results in greater efficacy and greater patient safety. However, if the target could be even more narrowly considered—that is, targeting psoriatic inflammation specifically along the IL-23, IL-17A, and IL17RA pathways—this should, in theory at least, allow for even greater safety and better effectiveness. Selective IL-23 blockers include guselkumab, tildrakizumab, and risankizumab. Selective IL-17A blockers include secukinumab, ixekizumab, and bimeizumab. Brodalumab blocks IL-17RA. Thus, pharmacological targets can be viewed as a continuum, with IL-23 the most upstream target and IL-22 and IL-17A downstream. While all of these points represent pharmacologically sound therapeutic targets, there are clinical differences among the inhibitors for these targets (Table 3).^69,70

Not all of the cells that produce IL-17A are regulated by IL-23. Some cells, like Th17, depend on IL-23 in order to produce IL-17A, but others produce IL-17A independently of IL-23. This means that IL-23 inhibition will affect some IL-17A producers (those that depend on IL-23) but not the IL-23-independent IL-17A producers. Furthermore, it is thought that some of the IL-17A produced by cells other than Th17 in the skin and the gut might protect the body from candidiasis and inflammatory bowel disease. This would explain the association of candidiasis and inflammatory bowel disorder with IL-17 but not IL-23.⁶⁹

As a general rule, the pharmacodynamic effects of a drug greatly exceed its pharmacokinetic effects, with the result being that a drug might have an impact on the underlying disease long after it has been eliminated from the body. For example, IL-23 inhibition might also cause the death of pathogenic skin-resident memory T17 cells, which depend on IL-23 for survival. Thus, the prolonged drug effect in destroying these T17 cells might lead to more durable psoriasis control.⁶⁹

In a study evaluating clinically resolved psoriatic lesions,⁷¹ it was found that the lesions contained psoriasis-specific IL-17-producing alpha beta T-cell clones. Healed psoriatic skin (treated with phototherapy and etanercept) showed oligoclonal populations of T-cells, which produce IL-17. This observation might explain why new psoriatic lesions tend to recur at the same site as healed lesions.⁷¹

References

66. Elder JT. The quest for psoriasis autoantigens: genetics meets immunology in the melanocyte. J Invest Dermatol. 2017 Oct;137(10):2042–2045.

67. Chandran V. Genetics of psoriasis and psoriatic arthritis. Indian J Dermatol 2010;55(2):151–156.

68. Okada Y, Han B, Tsoi L, et al. Fine mapping of major histocompatibility complex associations in psoriasis and its clinical subtypes. Am J Hum Genet. 2014 Aug 7;95(2):162–72.

69. Hawkes JE, Chan TC, Krueger JG. Psoriasis pathogenesis and the development of novel targeted immune therapies. J Allergy Clin Immunol. 2017;140(3):645–653

70. Maxwell JR, Zhang Y, Brown WA, et al. Differential roles for interleukin-23 and interleukin-17 in intestinal immunoregulation. Immunity. 2015;43(4):739–750.

71. Matos TR, O’Malley JT, Lowry EL, et al. Clinically resolved psoriatic lesions contain psoriasis-specific IL-17-producing alphabeta T cell clones. J Clin Invest. 2017;127(11):4031–4041.

Based on the Maui Derm 2018 presentation by Bruce E. Strober, MD, PhD, Professor and Chair, University of Connecticut Health Center, Department of Dermatology, Farmington, Connecticut

Article by Jo Ann LeQuang and the Journal of Clinical and Aesthetic Dermatology

Four significant studies emerge when perusing the new data from 2017, all of which can help guide clinical care of patients with psoriasis. The first involves treating psoriasis in pregnant and lactating women. Treating psoriasis in any special population can pose clinical challenges, but new and encouraging answers are available for certolizumab pegol. Second, the prevalent and distressing condition of genital psoriasis has always been difficult for patients and prescribers. New 2017 data on ixekizumab as a potential course of treatment holds promise. Third, novel treatments for psoriasis seem to abound but the issue of durability of results is relevant to patients and prescribers. This year, long-term data on secukinumab durability are available to help guide clinical decision-making. Finally, the risk of non-melanoma skin cancer (NMSC) and other cutaneous malignancies has been further studied in order to better understand what contributory role biologics might play in their development.

Certolizumab pegol in pregnancy. Pregnant women represent an important special population in which inflammatory diseases can be particularly difficult to treat due to the risk of transference to the child in utero. CRIB was a prospective, multicenter, post-market, pharmacokinetic study that evaluated the placental transfer of certolizumab pegol (CZP).¹ Sixteen pregnant women were entered into and completed the study. The patients had to be at least 30 weeks pregnant, with a diagnosis of an approved CZP indication—psoriatic arthritis, rheumatoid arthritis, Crohn’s disease, or ankylosing spondylitis—and receive the last dose of CZP 35 days or less before delivery. Blood samples for measurement of CZP plasma concentration were taken from mothers, umbilical cords, and neonates at delivery; blood was drawn again from the infants at four and eight weeks post-delivery. At delivery, maternal CZP plasma levels from the 16 patients fell within the anticipated therapeutic range (24.4µg/mL, range 5.0– 49.4). Sixteen neonates were included in the study, but two were excluded from per-protocol datasets, one because of missing data at birth, the other because of implausible pharmacokinetic data. Of the 14 neonates in the per-protocol study, there was no quantifiable level of plasma CZP in 13 infants (<0.032µg/mL) and a minimal level in one (0.042µg/mL). At Weeks 4 and 8, none of the infants had quantifiable plasma levels of CZP. Umbilical cord samples were taken from the 16 patients but one was excluded due to missing data; of the 15 included umbilical cords, three had quantifiable levels of CZP, the highest of which was 0.048µg/mL. Thus, the CRIB clinical trial demonstrated that there was little to no CZP transfer from mother to child and that there was no fetal exposure to CZP during the third trimester of pregnancy. These findings suggest that CZP can be safely administered to pregnant women, when appropriate, without the risk of placental transfer.

Ixekizumab in genital psoriasis. Genital psoriasis affects up to 63 percent of all patients with psoriaris² and can be difficult to treat. A recent randomized, double-blind, placebo-controlled Phase IIIb study (IXORA-Q)³ evaluated the potential of ixekizumab for the treatment of genital psoriasis. A total of 149 patients with moderate-to-severe genital psoriasis with body surface area (BSA) greater than one percent were randomized to receive either placebo (n=74) or ixekizumab at recommended doses (n=75). Moderate-to-severe genital psoriasis was defined by the Physician’s Global Assessment of Genitalia (sPGA-G) as having a score of three or higher. The primary endpoints were patients who score zero or one on the sPGA-G, the overall sPGA score, a three-point or more improvement over baseline on the itching numeric rating scale, and response to Item 2 on the Genital Psoriasis Sexual Frequency Questionnaire (GenPs-SFQ), which asked if genital psoriasis limited sexual activity (Table 1). The ixekizumab group received the United States Food and Drug Administration (FDA)-approved psoriasis dosing of 160mg of ixekizumab at Week 0, then 80mg every two weeks through Week 12; the placebo group received placebo on the same schedule. After 12 weeks, patients entered an open-label treatment phase for a total of 52 weeks. Most of the IXORA-Q patients were male (75.8%). The mean age of patients was 43.7± 2.7 years and mean weight was 93.5±24.7kg. Among the participants, 52.3 percent had previously used non-biologic systemic therapies, and19.5 percent had previously used biologic systemic therapies to treat their psoriasis. By Week 12, significantly more patients in the ixekizumab group had clear or almost clear genital-area skin compared to placebo (73.3% vs. 8.1%, p<0.001). Fifty-six percent of ixekizumab patients had completely clear genital-area skin at 12 weeks compared to placebo (5.4%), p<0.001. Patients also reported at Week 12 a clinically meaningful relief from itchiness over baseline with ixekizumab versus placebo (59.7% vs. 8.3%, p<0.001), with a statistically significant difference emerging at Week 2. Item 2 on the GenPs-SFQ (Table 1) found that significantly more patients in the ixekizumab group reported that genital psoriasis never or rarely limited sexual activity at Week 12 versus placebo (78.4% vs. 21,4%, p<0.001) with the difference achieving statistical significance by Week 1 (21.6% vs. 4.8%, p=0.036). Treatment-emergent adverse events (TEAEs) were more frequent with ixekizumab than placebo; most were mild to moderate. The most commonly reported TEAEs with ixekizumab were respiratory tract infection, injection site reactions, oropharyngeal pain, pruritus, back pain, eczema, and hypertension. Severe TEAEs occurred more frequently among the placebo group than the ixekizumab group (4.1% placebo vs. 1.3% ixekizumab). Six patients discontinued the study (6.8% of placebo group and 1.3% of ixekizumab group) because of adverse effects.³

Secukinumab durability. In 2014, the results of two Phase III studies, Efficacy of Response and Safety of Two Fixed Secukinumab Regimens in Psoriasis (ERASURE, N=738) and Full-year Investigative Examination of Secukinumab vs. Etanercept Using Two Dosing Regimens to Determine Efficacy in Psoriasis (FIXTURE, N=1,306) were published.⁴ Patients with moderate-to-severe plaque psoriasis were recruited. Patients in the FIXTURE study were randomized to receive subcutaneous secukinumab 300mg or 100mg once a week for five weeks, then every four weeks thereafter; etanercept 50mg twice a week for 12 weeks, then weekly thereafter; or placebo. The study objective was to show the superiority of secukinumab over placebo at 12 weeks (defined as Psoriasis Area and Severity Index Score [PASI] of at least 75 percent over baseline [PASI75] and a score of “clear” or “almost clear,” that is, 0 or 1, on a five-point PGA). More patients in the secukinumab group at both doses achieved PASI75 at 12 weeks compared to patients in the placebo group or etanercept group ( Table 2).

The ERASURE and FIXTURE studies were then extended to evaluate long-term control of moderate-to-severe psoriasis following the withdrawal of secukinumab.⁴ PASI75 responders in the secukinumab 300mg and 150mg groups entered the study and were randomized to be treated for two years with secukinumab (same dose as original study) or placebo. Patients were monitored monthly and could not use any other psoriasis medications. Relapse in placebo patients, defined as greater than 50-percent loss of the previous gain in PASI score reduction, was treated by switching the patients to the secukinumab group. Among the placebo patients, 14 percent and 21 percent of the patients in the previous secukinumab 150mg and 300mg groups, respectively, did not relapse in the first year without medication; in the second year, six percent and 10 percent of the placebo patients who had previously been treated with secukinumab 150mg and 300mg, respectively, did not relapse. The meaning of these data is controversial and should not be interpreted to mean that the typical patient treated with secukinumab will achieve “remitted” control of his or her skin disease. In fact, without an active control group, it is impossible to know if this type of response is typical of many different therapies for psoriasis.

Risk of non-melanoma skin cancer (NMSC) with biologics versus methotrexate. The Psoriasis Longitudinal Assessment and Registry (PSOLAR) database was evaluated to determine the potential risk of NMSC in patients who used biologic therapy compared to those who were eligible for biologic treatment but took methotrexate instead.⁵ Collection of data was cut stopped on August 23, 2015, and was pooled from 12,090 patients representing 48,870 patient-years of follow-up. Within this group, 6,350 patients used biologics and 432 used methotrexate. Most of the patients in this registry study were Caucasian. This was a well-performed analysis with a comparator group. There were 72 new diagnoses of NMSC (48 basal cell carcinoma [BCC], 24 squamous cell carcinoma [SCC]). This signals a declining rate of BCC with ustekinumab and a trend toward increasing rates of SCC with TNF-inhibitors. That said, the risk of skin cancer with all biologic drugs remains very low, and targeted monitoring of high-risk patients remains the sensible approach.

Risk of malignancy with systemic psoriasis treatment. Using the PSOLAR data, a retrospective, nested case-control analysis⁶ was conducted on the risk of malignancy for individuals who received systemic psoriasis treatment; this analysis was based on 12,090 registry participants who were followed for 4.2 years, with a maximum follow-up period of 8.2 years. The analysis included patients with newly diagnosed malignancies (other than NMSC) and excluded those with a history of cancer (other than NMSC). Four randomly chosen control patients were matched with each case by age at index date (±6 months), sex, geographical region, and date of enrollment. For the purposes of this study, “exposure” was defined as having received a dose of the study therapy within one year of the index date and stratified by the duration of therapy into three discreet categories: greater than 0 and less than three months; three months to less than 12 months; and 12 months or longer. A total of 252 malignancy cases were found and matched to a total of 1,008 controls. Treatment of psoriasis using methotrexate or ustekinumab for any of the three discreet time periods was not associated with an increased risk of malignancy compared with no exposure to these drugs. However, TNF inhibitors, when used longer term (12 months or longer) were associated with an increased risk of cancer (odds ratio [OR]1.54, 95% confidence interval [CI], range 1.10– 2.15, p=0.01). This risk for TNF inhibitors disappeared when the analysis solely focused on patients receiving these agents as monotherapy. Also, the use of TNF inhibitors for shorter exposure periods (<12 months) was not associated with an increased risk of malignancy.⁶

References

1. Mariette X, Förger F, Abraham B, et al. Lack of placental transfer of certolizumab pegol during pregnancy: results from CRIB, a prospective, postmarketing, pharmacokinetic study. Ann Rheum Dis. 2018;77(2): 228–233.

2. 1Ryan C, Sadlier M, De Vol E, et al. Genital psoriasis is associated with significant impairment in quality of life and sexual functioning. J American Acad Dermatol. 2015;72(6):978–983.

3. Ryan C, Menter A, Guenther L, et al. Efficacy and safety of ixekizumab in a randomized, double-blinded, placebo-controlled Phase 3b study of patients with moderate-to-severe genital psoriasis. Br J Dermatol. 2018 May 10. doi: 10.1111/bjd.16736. [Epub ahead of print].

4. Langley RG, Elewski BE, Lebwohl M, et al. Secukinumab in plaque psoriasis—results of two phase 3 trials. N Engl J Med. 2014;371(4):326–338.

5. Fiorentino D, Ho V, Lebwohl M, et al. Risk of malignancy associated with biologic therapy and methotrexate (MTX) in the Psoriasis Longitudinal Assessment and Registry (PSOLAR). Poster Abstract B221. Presented at the American Academy of Dermatology. Orlando, Florida. 3–7 March 2017. J Am Acad Dermatol. 2017;76:(6 Suppl).

6. Fiorentino D, Ho V, Lebwohl MG, et al. Risk of malignancy with systemic psoriasis treatment in the Psoriasis Longitudinal Assessment Registry. J Am Acad Dermatol. 2017;77(5):845–854.e845.