In the present issue of Allergologia et Immunopathologia a first meta-analysis on the effect of Omalizumab in chronic spontaneous urticaria is published.1 The team of Prof Dirceu Solé, from the Federal University of Sao Paulo, have made a very interesting and necessary job collecting all the evidence and summarizing it as several meta-analyses.
This is not the first time that Allergologia et Immunopathologia publishes a report on the efficacy of Omalizumab on the management of chronic spontaneous urticaria, but it is the first occasion in which that efficacy is put so clearly. The work of the writing team has been considerable as they retrieved more than 800 papers which had to be assessed using the abstract. However, only 13 of them needed further evaluation in order to decide whether they were included in the analyses. Only 6 of them were, in the end, included in the meta-analyses.
If the paper is scrutinised further on, it is easy to realize that the number of clinical trials per dose of Omalizumab is quite low (just four for the highest dose of 300mg associated to antihistamines vs antihistamines associated to placebo where the more numerous trials are). Here, the Urticaria Activity Score for 7 days (UAS7) less or equal to 6 was clearly lower in the Omalizumab group: the number of events with UAS7 score ≤ 6 was about four times less in the active group. With lower doses of Omalizumab the results were also favourable, but less dramatic.
The probability of complete remission of symptoms (UAS7=0) was six times higher when Omalizumab was associated to the antihistamine than when placebo was associated to it. Again, 300mg of Omalizumab as compared to 150mg or 75mg had quite better effect. Similarly, quality of life achieved during the treatment period was significantly better in the Omalizumab-treated group of patients. Again, 300mg achieved better results than 150mg or 75mg.
It should be noted that it is in the group of 300mg where the most numerous group of trials are, and they include a total of about 1000 patients in each group (active and control), meaning that the results are quite robust.2–5 It is also of interest that in the three analyses and for the three treatment regimes, heterogeneity is extremely low both for UAS7≤ 6 and UAS7=0. In fact, a quick look at the graphs show that all trials obtain very similar results.
With respect to the improvement of quality of life (according to Dermatology Life Quality Index), heterogeneity was also very low and, again, the graph indicates a very uniform effect across all trials at the three dose regimes. Again 300mg is the one with a higher efficacy, lowering almost 4 points the quality score as compared to the control group.
Taking all this data into account it is perfectly reasonable that Omalizumab has included the indication of chronic spontaneous urticaria added to that of asthma in many countries.
This is definitely a very timely review summarising the up-to-date evidence on this important issue, which suggests that Omalizumab might be a first line treatment associated to antihistamines, the only limitation (not trivial) being the cost of the drug.
