ABSTRACT
Background Surrogates of antiviral efficacy are needed for COVID-19. We investigated the relationship between the virological effect of treatment and clinical efficacy as measured by progression to severe disease in unvaccinated outpatients treated for mild to moderate COVID-19. Methods We searched PubMed, Scopus and medRxiv from inception to 27th September 2022, for randomised controlled trials (RCTs) which tested potential treatments for COVID-19 in non-hospitalized patients. We included studies that reported both clinical and virological outcomes. Clinical outcomes were the rate of disease progression (generally hospitalization or death within 28 days of commencing treatment) and virological outcomes were viral load (viral RNA copies in upper respiratory tract swabs) within the first 7 days of treatment. Studies were excluded if they did not report on the outcome of a primary randomised controlled trial, or if results were reported in a more complete form in another publication. Risk of Bias assessment was performed using the RoB 2.0 tool. We used generalised linear models with random effects to assess the association between outcomes and account for study heterogeneity. Findings We identified 1372 unique studies of which 14 (with a total of 9257 participants) met inclusion criteria. Larger virological treatment effects at both day 3 and day 5 were associated with decreased odds of progression to hospitalisation or death in unvaccinated ambulatory subjects. The odds ratio (OR) for each extra two-fold reduction in viral load in treated compared to control subjects was 0.54 on both days 3 and 5 post treatment (day 3 95% CI 0.38 to 0.74, day 5 95%CI 0.41 to 0.72). There was no relationship between the odds of hospitalisation or death and virological treatment effect at day 7 (OR 0.91, 95%CI 0.74 to 1.13). Interpretation Despite the aggregation of studies with differing designs, and evidence of risk of bias in some virological outcomes, this review provides evidence that treatment-induced acceleration of viral clearance within the first 5 days after treatment is a surrogate of clinical efficacy to prevent hospitalisation with COVID-19. This work supports the use of viral clearance as an early phase clinical trial endpoint of therapeutic efficacy. Funding The authors were supported by the Australian Government Department of Health, Medical Research Future Fund, National Health and Medical Research Council and the University of New South Wales.
Subject(s)
COVID-19 , DeathABSTRACT
Multiple monoclonal antibodies have been shown to be effective for both prophylaxis and therapy for SARS-CoV-2 infection. Here we aggregate data from randomized controlled trials assessing the use of monoclonal antibodies in preventing symptomatic SARS-CoV-2 infection. We use data on changes in the in vivo concentration of monoclonal antibodies, and the associated protection from COVID-19, over time to model the dose-response relationship of monoclonal antibodies for prophylaxis. We estimate that 50% protection from COVID-19 is achieved with a monoclonal antibody concentration of 939-fold of the in vitro IC50 (95% CI: 135 - 2073). This relationship provides a quantitative tool allowing prediction of the prophylactic efficacy and duration of protection for new monoclonal antibodies administered at different doses and against different SARS-CoV-2 variants. Finally, we compare the relationship between neutralization titer and protection from COVID-19 after either monoclonal antibody treatment or vaccination. We find no evidence for a difference between the 50% protective titer for monoclonal antibodies and vaccination, although vaccination is predicted to be capable of achieving a higher maximum level of protection.
Subject(s)
COVID-19ABSTRACT
Background: The SARS-CoV-2 pandemic is a public health emergency. Safe and effective therapies are urgently needed. Methods: Therapeutics for Inpatients with COVID-19 (TICO), is a global multi-arm, multi-stage (MAMS) platform master protocol, which facilitates the rapid evaluation of the safety and efficacy of candidate anti-viral therapeutic agents for adults hospitalized with COVID-19. The protocol design allows multiple therapeutic agents to be evaluated in an efficient and scientifically rigorous manner, with efficiencies delivered by the MAMS design, and began by studying neutralizing monoclonal antibodies. TICO employs an agile and robust approach to futility and safety evaluation at 300 patients enrolled (Stage 1), with subsequent expansion to full sample size and an expanded target population (Stage 2) if the agent shows an acceptable safety profile and evidence of efficacy. Two ordinal outcomes applied early (Day 5) determine the efficacy signals of the investigational agents(s) and progression to Stage 2. These ordinal outcomes assess both respiratory and other organ failure events, recognizing the broad range of COVID-19 morbidity. In Stage 2, overall efficacy is assessed using the primary outcome of time to sustained recovery, assessed over 90 days. This approach to early futility assessment using an early intermediate outcome and a primary endpoint out to 90 days allows the study team to make rapid decisions on safety and potential efficacy of novel agents while ultimately focusing on patient-centered, longer-term outcomes. The implementation of TICO across a global network allows for continued enrollment despite variations in geographic epidemiology. Study Status: The TICO master protocol moved from conception to first patient enrolled in approximately 9 weeks, a testament to the expedited regulatory and ethics review, coupled with flexible and responsive study operations. The first agent to be tested using this protocol, LY-CoV-555, enrolled N=326 participants before undergoing Stage 1 futility and safety assessment. Two additional agents will enter the study in November 2020, with other agents planned. Conclusion: The TICO MAMS platform trial has been implemented efficiently across a global network of sites and several trial networks. It will generate results rapidly for multiple novel neutralizing monoclonal antibodies and other therapeutics agents.