Omalizumab Outperforms HCQ as Add-on Treatment for Chronic Spontaneous Urticaria

Use of omalizumab as an add-on treatment in patients with chronic spontaneous urticaria (CSU) not controlled by antihistamines is significantly more likely to be associated with alleviation of urticaria than use of hydroxychloroquine (HCQ). This was among study findings published in The Journal of Allergy and Clinical Immunology: In Practice.

Investigators aimed to evaluate the real-world effectiveness of add-on treatments used by patients with refractory CSU at 2 large clinical practices. Toward that end, they conducted a retrospective chart review of 264 patients (83% women; mean age at first encounter 44 years, range 3 to 80 years) with refractory CSU not adequately controlled for 6 weeks or more using optimized doses of second-generation histamine-1 blockers. Exclusion criteria included patients with nonidiopathic chronic urticaria. Outcomes evaluated included 3 levels of treatment response: (1) complete response: absent or infrequent urticaria and patient satisfaction with treatment; (2) sustained response: complete response to an add-on therapy for 1 year or longer; and (3) partial response: a reduction in hives that still required a second add-on therapy.

The most frequently prescribed initial add-on medications were omalizumab (51%) 300 mg subcutaneous monthly and HCQ (42%) 200 mg orally twice daily. Other add-on treatments used by patients (7%) included colchicine, cyclosporine, sulfasalazine, and dapsone. After discovering that the most common add-on treatments were omalizumab and HCQ, the researchers focused their study on comparing the treatment response yielded by these 2 add-on therapies. Notably, patients receiving omalizumab or HCQ had no significant differences in baseline characteristics.

The analysis of treatment response showed that a greater proportion of patients receiving omalizumab had a complete response at 3 months of treatment (82%) than those treated with HCQ (38%); mean time to complete response was also lower in those using omalizumab vs HCQ (2.15 vs 2.54 months, respectively). Sustained response was found to be significantly greater among patients using omalizumab (82%) vs those using HCQ (66%) (P <.01). Partial response at 3 months was achieved by 15% of those using omalizumab vs 45% of those using HCQ.

Among patients receiving HCQ as first add-on treatment, 43% required rescue bursts of oral corticosteroids after 3 months of therapy vs 32% of patients who started on omalizumab.

Researchers noted that the real-world choice of treatment would likely be influenced by patient preference for oral vs injection delivery and cost to patient. Also, although omalizumab has proven efficacy and safety for refractory CSU, not as much data exist in these areas for HCQ.

In further analyses, the investigators found that patients with incomplete responses to first add-on interventions (N=45) subsequently showed complete responses to omalizumab (65%) and HCQ (62%). Patients with thyroid disease history were less likely to experience complete response (45%) to any add-on treatments vs those without thyroid disease history (63%) (P =.03). No significant associations were noted between complete response to first add-on intervention and sex, age, or duration of CSU. There was no discontinuation of treatment by either group due to adverse events most of which were brief, including headache, fatigue, and injection site pain.

Study limitations included: the retrospective observational design; use of global physician assessments instead of validated symptom scales to determine clinical response outcomes; and lack of a placebo treatment arm.

Overall, investigators found that “Omalizumab add-on treatment was significantly more likely to be associated with a complete response vs hydroxychloroquine.” However, they further noted that “Hydroxychloroquine is an acceptable alternative to omalizumab.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.