Title : Use of tixagevimab/cilgavimab in Omicron outbreak in China: baseline characteristics and interim analysis of the clinical outcomes
Introduction: The prevalence rate of SARS-CoV-2 Omicron variant infection reached approximately 80% in late 2022 in China. Tixagevimab/cilgavimab, a combination of two neutralizing monoclonal antibodies, showed significant efficacy for preventing COVID-19 in previous clinical trials. This study aimed to investigate the utilization and clinical outcomes of tixagevimab/cilgavimab in a real-world setting in China.
Methods: This observational study used real-world data obtained during the Omicron outbreak in China. Subjects who received tixagevimab/cilgavimab from July to December 2022 were included. Data on COVID?19 diagnosis, outcomes, and adverse events were collected up to at least 6 months after administration. COVID-19 diagnosis was confirmed by RT-PCR or rapid antigen test and its severity was classified based on the WHO Clinical Progression Scale and Guideline on Diagnosis and Treatment of Novel Coronavirus Pneumonia (10th Interim Edition). Here we report the baseline subject characteristics and interim analysis results of the clinical outcomes based on the modified full analysis set (mFAS), including subjects who received at least one dose of tixagevimab/cilgavimab (300 mg) for pre-exposure prophylaxis.
Results: A total of 248 subjects received tixagevimab/cilgavimab, only one (0.4%) of whom received two doses of the drug and the remaining 247 (99.6%) had a single dose. In total, 229 subjects were included in the mFAS. As of the cut-off date for interim analysis (March 28, 2023), the median follow-up time was 95 (range, 19-263) days. The mean age of the subjects was 44.4±15.92 years, 11.8% of whom were ≥65 years old and 41.5% were males. The majority (88.2%) of the subjects were never smokers. Fifty-eight (25.3%) subjects had comorbidities, including diabetes (3.1%), obesity (3.9%), hypertension (14.8%), chronic obstructive pulmonary disease (0.4%), asthma (1.3%), and cardiovascular diseases (4.8%). Thirty-seven (16.2%) subjects had key immune compromised conditions, including hematologic malignancies (4.4%), solid organ transplantation (4.8%), autoimmune diseases (2.2%), solid tumors (3.5%), and chronic kidney diseases (1.7%). In total, 195 (78.6%) subjects had previously received one (4.8%), two (15.7%), three (55.5%), more than three (1.7%), or unkown (0.9%) dose(s) of COVID-19 vaccines. Further, 4.0% of the subjects had experienced a previous SARS-CoV-2 infection. In subjects with at least one post-baseline record in the mFAS (n=221), 72 (32.6%) had laboratory-confirmed and/or healthcare-attended SARS-CoV-2 infection up to 3 months after the first administration of tixagevimab/cilgavimab, including 71 (98.6%) mild and 1 (1.4%) moderate cases. Two (0.9%) patients had COVID-related hospitalization; one had prior renal transplantation and the other had hematological malignancy. No COVID-19-related ICU admissions or deaths occurred. In patients with SARS-CoV-2 infection, the most common (>10%) signs or symptoms were fever (62 [86.1%]), cough (48 [66.7%]), muscle aches (17 [23.6%]), sore throat (14 [19.4%]), headache (10 [13.9%]), fatigue (9 [12.5%]), and new loss of taste (8 [11.1%]). Treatment-emergent adverse events were observed in 5 (2.2%) patients, and only one (0.4%) patient experienced a serious adverse event (upper respiratory tract infection) which was moderate in severity.
Conclusions: Prophylactic tixagevimab/cilgavimab administration led to a low risk of COVID-19-related hospitalization, ICU admission, or death. Tixagevimab/cilgavimab needs to be promoted among those with comorbidities and immunocompromised individuals.
Audience Take Away:
- This was the first study investigating the use and clinical outcomes of prophylactic tixagevimab/cilgavimab in a wide range of populations during the Omicron outbreak in a real-world setting in China.
- Tixagevimab/cilgavimab could protect immunocompromised individuals and people with comorbidities from severe/critical COVID-19 or COVID-19-related death.
- Tixagevimab/cilgavimab demonstrated a good safety profile in a real-world setting, with extremely low incidences of treatment-emergent adverse events and serious adverse events.