NCT04625972.

Study name	Phase III double‐blind, placebo‐controlled study of AZD7442 for post‐exposure prophylaxis of COVID‐19 in adults (STORM CHASER)
Methods	Drug name: tixagevimab/cilgavimab (AZD7442) Trial design: randomised, placebo‐controlled, double‐blind, multicentre, single‐dose, phase 3 study NCT number: NCT04625972 (date of trial registration: 12 November 2020) Target sample size: 1121 participants (actual enrolment) Estimated completion date: 19 June 2022
Participants	Setting Outpatient, PEP Recruitment period: November 2020 to April 2021 57 study locations (US, UK) Eligibility criteria Inclusion criteria Aged ≥ 18 years at the time of signing the informed consent Adults with potential exposure, within 8 days, to a specific identified individual with laboratory‐confirmed SARS‐COV‐2 infection, symptomatic or asymptomatic Participants must not have had COVID‐19 symptoms within 10 days of dosing Negative result from point of care SARS‐CoV‐2 serology test at screening Contraception used by women of childbearing potential, condom by men Able to understand and comply with study requirements/procedures based on the assessment of the investigator Exclusion criteria History of laboratory‐confirmed SARS‐CoV‐2 infection or SARS‐CoV‐2 seropositivity at screening History of infection with SARS or MERS Known history of allergy or reaction to any component of the study drug formulation Previous hypersensitivity, infusion‐related reaction, or severe adverse reaction following administration of an mAb Any prior receipt of investigational or licensed vaccine or other mAb/biological indicated for the prevention of SARS‐CoV‐2 or COVID‐19 or expected receipt during the period of study follow‐up Clinically significant bleeding disorder or prior history of significant bleeding or bruising following IM injections or venepuncture Any other significant disease, disorder, or finding that, in the judgement of the investigator, may significantly increase the risk to the participant because of participation in the study, affect the ability of the participant to participate in the study, or impair interpretation of the study data Receipt of any IMP in the preceding 90 days of expected receipt of IMP during the period of study follow‐up, or concurrent participation in another interventional study Currently pregnant or breastfeeding Blood drawn in excess of a total of 450 mL (1 unit) for any reason within 30 days prior to randomisation Employees of the sponsor involved in planning, executing, supervising, or reviewing the tixagevimab/cilgavimab programme, clinical study site staff, or any other individuals involved with the conduct of the study, or immediate family members of such individuals In nations, states, or other jurisdictions that for legal or ethical reasons bar the enrolment of participants who lack capacity to provide their own informed consent, such subjects are excluded
Interventions	Intervention Tixagevimab/cilgavimab (AZD7442) (approximately 750 participants)  Target: RBD region of SARS‐CoV‐2 spike protein Origin: NR Dose: tixagevimab/cilgavimab 300 mg Frequency: single dose (× 2 IM injections) Route of administration: IM injections Other name: combination of 2 mAbs (tixagevimab (AZD8895) and cilgavimab (AZD1061)) Comparator (approximately 375 participants)  Placebo, single dose (× 2 IM injections) of saline placebo
Outcomes	Efficacy outcomes Infection with SARS‐CoV‐2 (confirmed by positive RT‐PCR test) within 30 days: not planned Development of COVID‐19 symptoms within 30 days: planned as incidence of the first case of SARS‐CoV‐2 RT‐PCR‐positive symptomatic illness Mortality at day 28, day 60, longest follow‐up, and time‐to‐event: planned through day 457 Admission to hospital within 30 days: not planned Admission to ICU within 30 days: not planned Quality of life assessed with standardised scales (e.g. WHOQOL‐100) at up to 7 days; up to 30 days, and longest follow‐up available: not planned Safety outcomes Number of participants with AEs: planned Number of participants with SAEs: planned Additional study outcomes Incidence of COVID‐19‐related death occurring after dosing with IMP Incidence of SARS‐CoV‐2 RT‐PCR‐positive severe or critical symptomatic illness occurring after dosing with IMP Incidence of participants who have a post‐treatment response (negative at baseline to positive at any time postbaseline) for SARS‐CoV‐2 nucleocapsid antibodies Efficacy of tixagevimab/cilgavimab: incidence of participants who have a post‐treatment response (negative at baseline to positive at any time postbaseline) for SARS‐CoV‐2 nucleocapsid antibody through day 457 Pharmacokinetics of tixagevimab/cilgavimab: serum concentration and pharmacokinetic parameters Incidence of ADA responses to tixagevimab/cilgavimab
Starting date	2 December 2020
Contact information	Myron Levin, MD; AstraZeneca
Notes	Developer: AstraZeneca Funding: AstraZeneca, Iqvia Pty Ltd Recruitment status: active, not recruiting