Ask The Expert
June 7, 2018
Omalizumab in Chronic Spontaneous Urticaria
Question
For how long should we use omalizumab in chronic spontaneous urticaria?
Answer
By Luis Felipe Ensina, MD, MSc, PhD
Reviewed by Margarida Gonçalo, MD, PhD and Ricardo Cardona Villa, MD
Omalizumab is a monoclonal anti-IgE antibody that has been approved for the treatment of refractory chronic spontaneous urticaria (CSU) in many parts of the world since 2013 (1). With its use in clinical practice, several questions have arisen, especially regarding the duration of treatment. There are three different situations where we should consider stop omalizumab treatment: side effects, lack of efficacy and disease remission.
Phase III clinical trials with omalizumab showed that the drug has an excellent safety profile. The most common side effects were nasopharyngitis, sinusitis, upper respiratory tract infection, viral upper respiratory tract infection, headache, and cough. Rates of treatment discontinuation due to adverse events were higher in the placebo group. Anaphylaxis or other conditions that could limit its use were not reported in the three key clinical trials. However, some case reports in asthma, and one in CSU have been published (2). Despite the low risk, if a patient presents symptoms suggesting anaphylaxis related to omalizumab injection, the treatment must be stopped until a complete investigation is performed.
Omalizumab recommended dose is 300mg every four weeks. In pivotal clinical trials, 52-58% of patients improved with this treatment regimen, 33-40% with complete control of symptoms (2). The number of responders is even higher in real-life studies, with rates around 80% (3).
The urticaria activity score (UAS) and urticaria control test (UCT) are disease measurement tools that can be used for defining response (4). The UAS works as a prospective, daily diary focusing on the two key urticaria symptoms wheals and pruritus, with a score ranging from 0 to 42 in 7 days (UAS7). Lower scores indicate less activity. The UCT is a retrospective tool to be used at the time of consultation. It is a four-question instrument, with five answer options (0 to 4 points). The higher the score (ranges from 0 to 16), the higher the level of disease control (disease is controlled when ≥12) (5).
There are two categories of responders to omalizumab in CSU. Fast responders improve their symptoms in up to 6 weeks, and slow responders may require more than three doses to respond (6). In this way, stopping treatment before three months may be too early and we would miss an opportunity to control the disease. A patient is considered non-responder when there is no response after six months of treatment. For the non-responders, omalizumab should be discontinued and alternative therapy considered (4).
When there is a response, the patient should continue treatment “until the disease is gone” (7). In pivotal clinical trials patients were treated for up to six months (2). Because of that, health systems in different countries recommend stopping the treatment after this period, and start over if there is a recurrence. There is substantial evidence that retreatment is effective and could be done in these cases (8). On the other hand, in countries where there is no pre-determined treatment schedule, recommendations are to reduce the doses and/or increase the dose intervals to assess for spontaneous remission at regular intervals (4). There is now evidence for safety and efficacy in long-term treatment of chronic urticaria in patients that still need the drug after several years (9-10).
Omalizumab is a “game changer” in CSU treatment. It should be indicated according to the guidelines (7). An individualized approach must be considered when considering treatment discontinuation.
References
1. Larenas-Linnemann DES, Parisi CAS, Ritchie C, Cardona-Villa R, Cherrez-Ojeda I, Cherrez A, et al. Update on Omalizumab for Urticaria: What's New in the Literature from Mechanisms to Clinic. Curr Allergy Asthma Rep. 2018;18:33.
2. Giménez-Arnau AM. Omalizumab for treating chronic spontaneous urticaria: an expert review on efficacy and safety. Expert Opin Biol Ther. 2017;17:375–85.
3. Zuberbier T, Maurer M. Omalizumab for the treatment of chronic urticaria. Expert Rev Clin Immunol. 2015;11:171–80.
4. Ferrer M, Boccon-Gibod I, Gonçalo M, İnalöz HS, Knulst A, Lapeere H, et al. Expert opinion: defining response to omalizumab in patients with chronic spontaneous urticaria. Eur J Dermatol. 2017;27:455–63.
5. Weller K, Zuberbier T, Maurer M. Clinically relevant outcome measures for assessing disease activity, disease control and quality of life impairment in patients with chronic spontaneous urticaria and recurrent angioedema. Current Opinion in Allergy and Clinical Immunology. 2015;15:220–6.
6. Kaplan A, Ferrer M, Bernstein JA, Antonova E, Trzaskoma B, Raimundo K, et al. Timing and duration of omalizumab response in patients with chronic idiopathic/spontaneous urticaria. J Allergy Clin Immunol. 2016;137:474–81.
7. Zuberbier T, Aberer W, Asero R, Abdul Latiff AH, Baker D, Ballmer-Weber B, et al. The EAACI/GA²LEN/EDF/WAO Guideline for the Definition, Classification, Diagnosis and Management of Urticaria. The 2017 Revision and Update. Allergy. 2018. Epub ahead of print.
8. Sussman G, Hebert J, Gulliver W, Lynde CW, Yang WH, Chambenoit O, et al. Omalizumab retreatment of patients with chronic idiopathic urticaria / chronic spontaneous urticaria following return of symptoms: primary results of the optima study. Allergy. 2017;72(S103):147–346.
9. Pinto-Gouveia et al. Long‐term management of chronic spontaneous urticaria with omalizumab. Clin Exp Dermatol. 2017;42(7):735-42.
10. Maurer et al. The XTEND-CIU study: Long-term use of omalizumab in chronic idiopathic urticaria. JACI 2018;14(3):1138.
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