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Archive

Winter 2019, Vol. 27 No. 4

Hong Kong J. Dermatol. Venereol. (2019) 27, 163-164


Editorial

Biologics for psoriasis: more studies in Chinese patients required

CK Ho 何正綱

Psoriasis is a chronic inflammatory dermatological condition that affects all races. Worldwide, 2 to 3 percent of the population is affected by psoriasis although there is racial variation.1 The prevalence of psoriasis in Chinese has been reported to be 0.23 percent in Taiwan, and 0.123 to 0.35 percent in China in contrast to a prevalence of 2.6 percent in Caucasians and 8.5 percent in Norway.1 With advances in our understanding of the pathogenesis of psoriasis, newer agents that target different cytokines in the inflammatory pathway of psoriasis have become available and have offered new hope for many psoriasis patients. There are now 11 biologics for psoriasis, of which the latest are tildrakizumab, risankizumab and guselkumab which target interleukin 23 (IL-23).

Biologics have become available for over a decade and new agents targeting different cytokines of the inflammatory pathway continue to be developed. As a result, continued surveillance is required on the long-term effects of suppression of the immune system by these therapies.

Studies confirming the efficacy of etanercept for psoriasis and its side effects have been available for over a decade,2 and as we accumulate experience on etanercept we are becoming more familiar with its long-term side effects. However, current literature on the use of biologics is mainly based on Caucasian patients. We cannot be sure whether this data can be completely extrapolated to Asian patients. In the current issue, Choi et al provide valuable data on of this agent in Chinese patients. To date, there are only a few studies of biologics in Chinese or Asian patients and this study provides valuable information for clinicians when deciding on which biologic to use when managing psoriasis.

More data for biologics in Chinese psoriasis patients needed. Compared to Caucasian patients, Chinese have higher incidence of hepatitis B, TB and tuberculosis. The reported seroprevalence of HBsAg in Hong Kong is 7.8 percent which, despite universal vaccination, remains higher than the estimated global prevalence of 3.9 percent.3,4

The incidence of tuberculosis in Hong Kong is 67 per 100,000 population compared to 8 per 100,000 population in the United Kingdom.5 Whether this will affect the incidence of side effects and whether there are any other implications when using biologics is unclear. Apart from this, data on whether there are there racial differences in efficacy with biologics are still lacking.

Serious infection, re-activation of hepatitis B, malignancy, and exacerbation of heart failure are just some of the listed side effects of etanercept. Without further studies, we do not have an idea of the true frequency of these side effects in this agent or any of the other biologics. This information is important both when counselling our patients and when deciding which agent to use. Hence these studies are important. With the increasing use of biologics, continued research and accumulation of experience, in particular for Asian or Chinese patients with psoriasis are important for the optimal use of these agents in our locality. This applies to each biologic, especially the newer agents as it is only through continual surveillance, can we truly understand the long-term effects of these treatments.

CK Ho
何正綱

References

1. Parisi R, Symmons DP, Griffiths CE, Ashcroft DM; Identification and Management of Psoriasis and Associated ComorbidiTy (IMPACT) project team. Global epidemiology of psoriasis: a systematic review of incidence and prevalence. J Invest Dermatol 2013;133:377-85.

2. Tyring S, Gordon KB, Poulin Y, Langley RG, Gottlieb AB, Dunn M, et al. Long-term Safety and Efficacy of 50 mg of Etanercept Twice Weekly in Patients With Psoriasis. Arch Dermatol 2007;143:719-26.

3. Liu KSH, Seto WK, Lau EHY, Wong DK, Lam YF, et al. A Territorywide Prevalence Study on Blood-Borne and Enteric Viral Hepatitis in Hong Kong. J Infect Dis 2019 May 24;219:1924-33.

4. The Polaris Observatory Collaborators. Global prevalence, treatment and prevention of hepatitis B virus infection in 2016; a modelling study. Lancet Gastroenterol Hepatol. 2018;3:383-403.

5. WHO Global tuberculosis report 2019.