As a new weapon in the treatment of psoriasis, biological agents have the advantages of high specificity, quick effect, good curative effect and few side effects, representing the latest progress in the field of psoriasis treatment. Biological agents already on the market for the treatment of psoriasis include etanercep, Infliximab, adamumab and usnuumab. These biological agents with different characteristics have shown good efficacy and application prospects in preclinical and clinical studies, which has brought good news for the treatment of psoriasis, especially severe psoriasis.

The inherent shortcomings of traditional treatments for psoriasis have led us to explore new treatments. Theoretically, locus of regulation can be found in every link of the pathogenesis of psoriasis, so that the occurrence and development of psoriasis can be partially blocked. Biological agents are biological protein molecules with certain pharmacological activity that are extracted from animal tissues or synthesized on a large scale by using recombinant DNA technology. Their mechanism of action is to block their biological activity and play a therapeutic role by simulating or interfering with the functions of certain cytokines in vivo.

The principle of biological agents is different from that of traditional treatment methods, and biological agents have no obvious hepatotoxicity, neurotoxicity or bone marrow suppression compared with traditional drugs such as methotrexate and cyclosporin, so they can be safely combined with traditional treatment methods. Biological agents for the treatment of psoriasis started later in China than in developed countries. At present, biological agents for the treatment of psoriasis have been officially approved, including isepp and Infliximab, the former is a similar domestic product of etanercep. In addition, there are other biological agents that have completed registered clinical trials in China, including Usunumab and adamumab. Preliminary statistical results show that the therapeutic effect on psoriasis is similar to the data of foreign clinical trials. Clinical studies showed that after 12 weeks of treatment with isepp for plaque psoriasis, 65%, 45%, and 12% of the patients reached ACR20, ACR50, and ACR70 (an evaluation system of efficacy), respectively, and 85% of the patients reached the effective response standard for joint psoriasis, which was significantly superior to traditional treatments such as methotrexate and cyclosporin. However, the accumulated case data of biologic therapy for severe psoriasis in China are still few. Although partial efficacy has been preliminarily shown, the overall efficacy is not satisfactory, and the safety needs to be further evaluated.

Biological agents are mainly suitable for patients with moderate or severe psoriasis or poor therapeutic effect of traditional medicine. In addition to (a) : severe psoriasis, the patient must also meet one of (b).

(a) In the case of severe psoriasis, the index of lesion area and severity of psoriasis ≥ 10%, and the index of dermatological quality of life ≥ 10. In exceptional cases, special areas that seriously affect physical and mental health, such as external genitalia or body exposure, may also be used in (a), although they do not meet the criteria previously described.

Subparagraph (b) meets at least one of the following:

(1) There is a higher risk of serious side effects after standard systemic treatment;

(2) Unable to tolerate standard systemic treatment;

(3) Poor efficacy of standard systemic treatment;

(4) Patients with comorbidities are unable to use standard systemic treatment;

(5) The disease is life-threatening.

It is worth noting that biological agents can increase the incidence of infection, such as pneumonia, hepatitis B recurrence, tuberculosis recurrence, etc. Therefore, the constitution is particularly weak patients or patients with infection, not suitable for the use of biological agents. At the same time, patients with congestive heart failure and malignant tumors should not use biological agents. Second liver virus carrier or tuberculosis recessive infection person, when applying biological preparation, need special caution. For some special groups, such as children, pregnancy, breastfeeding, perioperative patients, although there have been a few reports of application, most of the studies tend to be conservative, generally advocating strict control or cautious use.

Due to its high price, short clinical application time and the need to further observe its long-term application safety, the promotion of biological agents in clinical practice has been limited. In the future, the research and development of more efficient and safe biological agents with independent intellectual property rights will be our direction of efforts.