Safety of omalizumab therapy in patients with resistant urticaria during SARS-CoV- 2 pandemic

ABSTRACT

Background: The 2021 EAACI Biological Guidelines note safety of omalizumab use during rhinovirus infections, but data on initiation of this biologic therapy for patients with resistant chronic spontaneous urticaria (rCSU) during the SARS-CoV- 2 pandemic and uptake of COVID-19 vaccination are scarce. This study evaluated 1) safety of omalizumab initiation and continuation during the pandemic;2) rate of COVID-19 positivity in patients on omalizumab therapy and 3) COVID-19 vaccine uptake among patients on biologic therapy. Method(s) A department-held database identified patients who started omalizumab for rCSU between 1 March 2020 and 31 December 2021, and those who contracted COVID-19 infection and their vaccination status. Result(s) Forty-one patients (median age 42 years, 85% females) with rCSU (baseline UAS7 > 28) were started on omalizumab therapy (300mg subcutaneous once every 28 days, 6 doses/cycle), and 17 (41%) were transferred to home care. A total of 316 doses were used with no anaphylaxis events. Nineteen patients had excellent response (UAS < 6) and remained on treatment (53% patients on 2nd cycle), including two patients now on 4th cycle having required almost continuous biologic therapy. A total of 22 patients had stopped omalizumab, 14 having responded to therapy (12 patients had complete response in cycle 1 and two patients in cycle 2) while 8 patients were non-responders (20% overall non-responders;7 patients within cycle 1 and one in cycle 2). Seven patients (17%) tested positive for SARS-CoV- 2 (PCR) whilst on omalizumab therapy, but none had severe illness or required hospitalisation. 90% of patients had at least 1 dose of COVID-19 vaccine, while 27 patients (66%) had 3 doses (2 primary and 1 booster). All patients deferred omalizumab for a week after COVID-19 vaccination. Ninety-eight vaccine doses were given including 64 doses of BNT162b2 mRNA (Pfizer-BioNTech) vaccine, followed by AstraZeneca at 33 doses and 1 dose of Moderna vaccine. One patient had worsening of severe urticaria after first dose of AZ vaccine, and refused further vaccines, subsequently contracted SARS-CoV- 2 whilst on omalizumab therapy. Yet another patient who was never vaccinated having stopped omalizumab after complete response (2nd cycle), subsequently tested positive for SARS-CoV- 2 but did not report relapse of urticaria. Conclusion(s) Omalizumab therapy was safe and effective in rCSU and none of the patients who contracted SARS-CoV- 2 on the biological therapy developed severe illness. (Table Presented).