Biologics – The Future of Dermatology?

Dr. Sadiya Khan

Resident Medical Officer, Bangalore

Over the last decade, the use of biologics has transformed the world of dermatology. For those who are wondering what these molecules are – biologics are a large group of substances obtained by genetic engineering including hormones and immunoreactive compounds that act at a cellular level. These molecules are used in the treatment and prevention of various chronic diseases.

In dermatology, 3 types of biologics are commonly used – recombinant human cytokines, monoclonal antibodies and fusion proteins. What’s unique about these biologics is that they are designed to specifically interfere with, or block an individual step in the immunopathological pathway of the disease, unlike conventional drugs which don’t target a particular disease. Because of their specific action, they are presumed to have fewer side effects compared to traditional immunosuppressants.

Biologics are proving their worth as a treatment modality for those who failed to respond to approved therapeutic options. They have shown increased efficacy in the treatment of inflammatory diseases not just limited to the skin, mainly rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, IBD, Psoriasis, and more recently the pemphigus group of diseases.  Biologics are divided into 3 major groups:

1. Monoclonal antibodies target specific cell surface receptors and interrupt the inflammatory cascade. Some of the commonly used monoclonal antibodies known to date are:
2. Anti TNF Alpha – infliximab, adalimumab, and certolizumab. These are used in a variety of skin disorders like plaque psoriasis, atopic dermatitis, and Hidradenitis Suppurativa (HS). 
3. Anti CD 20- Rituximab. They are used in patients with lymphoma, SLE and refractory pemphigus.
4. Anti IL12 and Anti-IL 23 – Ustekinumab (Used in refractory plaque psoriasis)
5. Anti-IgE – Omalizumab (Used in chronic urticaria and atopic dermatitis)
6. Anti Phosphodiesterase 4 – Apremilast.

2. Fusion antibody proteins are created by the fusion of the receptor domain of a human protein with the constant region of human IgG. The resultant protein binds specifically to a ligand or co-receptor. The most commonly used ones are Alefacept, Abatacept and Etanercept.

They are also used for treating recalcitrant psoriasis, alopecia areata and pyoderma gangrenosum.

3. Recombinant human cytokines and growth factors – cytokines are released in response to any immune stimulus. Recombinant cytokines are used as immunomodulators. The principal ones used in dermatology are:
4. Interferons – produced by virus-infected cells, exhibit anti-proliferative, anti-neoplastic functions.
5. Granulocyte-macrophage colony-stimulating factor( GM CSF) – promotes wound healing in leg ulcers and melanoma treatment
6. Platelet-derived growth factor (PDGF) – promotes granulation tissue formation, re-epithelialisation and wound angiogenesis.

Though they come with their advantages, treatment can be expensive and their immunosuppressive properties come with some adverse effects like- allergic reactions, acute flu-like symptoms, mild transient injection site reactions, reactivation of tuberculosis, and risk of thrombocytopenia in some cases. Hence patients must undergo a thorough evaluation before being put on biologics and should be monitored by regular follow-ups and relevant investigations.

Hence biologics have offered a ray of hope to patients with chronic skin conditions by producing remission and improving their quality of life. They are important components of the drugs of the future and will continue to flourish however further research about their long-term safety profile and cost effectiveness will be necessary for the same.

References:

1.             Sehgal V, Khurana A, Pandhi D. Biologics in dermatology: An integrated review. Indian J Dermatol [Internet]. 2014 [cited 2023 Aug 10];59(5):425. Available from: http://dx.doi.org/10.4103/0019-5154.139859
2.              Biologics in dermatology: A brief review [Internet]. Bjmp.org. [cited 2023 Aug 10]. Available from: https://www.bjmp.org/content/biologics-dermatology-brief-review
3.              Coondoo A. Biologics in dermatologic therapy – An update. Indian J Dermatol [Internet]. 2009 [cited 2023 Aug 10];54(3):211. Available from: http://dx.doi.org/10.4103/0019-5154.55627
4.              Chopra A, Mitra D, Saraswat N, Mitra B, Talukdar K, Agarwal R. Biologics in dermatology: Off-label indications. Indian Dermatol Online J [Internet]. 2020 [cited 2023 Aug 10];11(3):319. Available from: https://journals.lww.com/idoj/Fulltext/2020/11030/Biologics_in_Dermatology__Off_Label_Indications.3.aspx