Therapeutic alternatives for chronic urticaria: additional reports on omalizumab

Therapy of antihistamine-resistant chronic spontaneous urticaria

INTRODUCTION

Chronic urticaria affects up to 1-3% of the general population and contributes to significant direct and indirect medical costs as well as decreased quality of life, which has a significant economic impact on our health care system. Areas covered: Given the prevalence of this condition on a large sector of the population, finding lasting relief for refractory cases is essential and is the focus of this review. Expert commentary: The choice of appropriate therapy in chronic refractory urticaria is not a 'one-size fits all' approach. Treatment should take multiple factors into consideration including the chronicity of hives, presence of physical urticaria, type of cellular infiltrate on skin histopathology, patient age, concomitant comorbid conditions, as well as patient preference and cost.

Omalizumab for difficult-to-treat dermatological conditions: clinical and immunological features from a retrospective real-life experience

BACKGROUND

Omalizumab, a therapeutic monoclonal antibody specific for human IgE, has thus far been used as add-on therapy for moderate-to-severe allergic asthma in adults and children.

OBJECTIVE

The objective of this study was to test omalizumab efficacy in other conditions in which the IgE-mast cell axis is supposed to play a role.

METHODS

Nine patients with dermatological manifestations possibly related to activation of the IgE-mast cell axis (six chronic spontaneous urticaria and three atopic dermatitis patients) were administered off-label omalizumab because of refractoriness to standard therapy. All patients were subjected to strict clinical, laboratoristic, and imaging follow-up to monitor for possible adverse effects. In addition, to further assess the role of omalizumab on T cells, mast cells, and eosinophils, T-cell immune polarisation as well as eosinophil cationic protein and tryptase serum levels were determined before and during omalizumab administration.

RESULTS

Therapy was effective in seven out of nine patients (six complete responses, one partial response, and two no responses). Interestingly, omalizumab appeared to induce lymphocyte polarisation toward a type 2 immune response and to be able to quench eosinophil-mediated inflammation, particularly in atopic dermatitis patients. Tryptase serum levels were generally low and remained unchanged during omalizumab treatment. Despite treatment spanning over several years in most of the patients, no adverse effects nor new ensuing medical conditions have thus far been observed (median follow-up: 42 months).

CONCLUSIONS

Off-label omalizumab was safe and effective in our patients. The novel immunologic features recorded in our patients add further complexity to the mechanism of action of omalizumab.

A randomized, placebo-controlled, dose-ranging study of single-dose omalizumab in patients with H1-antihistamine-refractory chronic idiopathic urticaria

BACKGROUND

Proof-of-concept studies with omalizumab in patients with chronic idiopathic urticaria (CIU) have shown significant decreases in mean urticaria activity scores (UASs).

OBJECTIVE

We sought to evaluate the efficacy and safety of omalizumab in patients with CIU who remain symptomatic despite concomitant H(1)-antihistamine therapy.

METHODS

This phase II, prospective, double-blind, placebo-controlled, dose-ranging study investigated omalizumab in patients aged 12 to 75 years in the United States and 18 to 75 years in Germany with a UAS over 7 days (UAS7) of 12 or greater despite antihistamine therapy. Patients were randomized 1:1:1:1 to receive a single subcutaneous dose of 75, 300, or 600 mg of omalizumab or placebo added to a stable dose of H(1)-antihistamine. The primary efficacy outcome was change from baseline to week 4 in UAS7. Patients were followed for an additional 12 weeks to monitor safety.

RESULTS

Ninety patients from the United States or Germany were enrolled. Both the 300-mg omalizumab group (-19.9 vs -6.9, P < .001) and the 600-mg omalizumab group (-14.6 vs -6.9, P = .047) showed greater improvement versus the placebo group in UAS7. No meaningful difference was observed for the 75-mg omalizumab group. Similar results were seen for key secondary end points of weekly hive and itch scores. Onset of effect occurred after 1 to 2 weeks. Omalizumab was well tolerated, and the incidence of adverse events was similar across treatment groups.

CONCLUSION

This study demonstrated that a fixed dose of 300 or 600 mg of omalizumab provides rapid and effective treatment of CIU in patients who are symptomatic despite treatment with H(1)-antihistamines.

Unmet clinical needs in chronic spontaneous urticaria. A GA²LEN task force report

Chronic spontaneous urticaria, formerly also known as chronic idiopathic urticaria and chronic urticaria (CU), is more common than previously thought. At any time, 0.5-1% of the population suffers from the disease (point prevalence). Although all age groups can be affected, the peak incidence is seen between 20 and 40 years of age. The duration of the disease is generally 1-5 years but is likely to be longer in more severe cases, cases with concurrent angioedema, in combination with physical urticaria or with a positive autologous serum skin test (autoreactivity). Chronic spontaneous urticaria has major detrimental effects on quality of life, with sleep deprivation and psychiatric comorbidity being frequent. It also has a large impact on society in terms of direct and indirect health care costs as well as reduced performance at work and in private life. In the majority of patients, an underlying cause cannot be identified making a causal and/or curative treatment difficult. Nonsedating H₁-antihistamines are the mainstay of symptomatic therapy, but treatment with licensed doses relieves symptoms effectively in < 50% of patients. Although guideline-recommended updosing up to fourfold increases symptom control in many patients, a substantial number of patients have only little benefit from H₁ -antihistamines. Consequently, there is a great need for new therapeutic strategies.

[Therapeutic alternatives for antihistamine-refractory urticaria]

Patients with chronic spontaneous urticaria, the most frequent non-acute form of urticaria, generally exhibit a clinical picture of persistent disease, a high degree of disease activity, considerable impairment of quality of life, and poor response to treatment. More than half of the patients continue to develop symptoms despite standard therapy with non-sedating antihistamines. In these cases, the antihistamine dose should be increased (up to four times the daily dose). If this approach also does not result in symptom control, the high-dose antihistamine should be combined with a leukotriene antagonist and if necessary an H2 blocker. If the patient does not respond to this combination therapy, cyclosporin A, dapsone, or omalizumab should be administered.

Monoclonal antibodies and other biologic agents in the treatment of asthma

Asthma represents a syndrome of airway inflammatory diseases with complex pathology. The immunologic pathogenesis is being increasingly revealed and provides opportunity for targeted biological intervention. Current experience with immunomodulators as targeted therapy in asthma is described in this literature review. Targeted therapies have included strategies to activate dendritic cells through the TLR-9 receptors, to interrupt the action of T(H)2 cytokines with cytokine blockers and monoclonal antibodies, to promote development of T(H)1 responses, to block IgE mediated pathways and to block TNFalpha. Omalizumab is the only biological therapy that has an approved indication in asthma at this time. An improved understanding of the heterogeneity of asthma should allow for specific targeting of different disease phenotypes specific therapies including immunomodulators.