ABSTRACT
Background: Whether early antiviral therapy reduces the risk of Long COVID is not known. The combination SARS-CoV-2 monoclonal antibodies amubarvimab+romlusevimab (A+R) were highly effective in reducing 28-day all-cause hospitalization/death among high-risk adults with mild-to-moderate COVID-19 in the randomized, placebo-controlled ACTIV-2/A5401 trial. We assessed the impact of A+R on late outcomes including Long COVID in ACTIV-2. Method(s): A long-term (LT) symptom diary and 2 health-related quality of life questionnaires (EQ-5D-5L and SF-36v2) were completed at week 36. The primary analysis compared the proportion of participants with the composite outcome of self-reported Long COVID (having any COVID-19 symptoms present on a global assessment question in LT diary) at week 36, or hospitalization or death by week 36 between A+R and placebo using regression models with inverse probability weighting to account for incomplete outcome data;supplemental analysis compared the proportion with Long COVID among those alive. Other analyses were restricted to observed data only. Result(s): 807 were randomized and received A+R (n=405) or placebo (n=402) from Jan-July 2021. At entry, median age was 49 years, 51% were female, >99% cis-gender, 17% Black/African American, 50% Hispanic/Latino, and 9% previously received COVID vaccination. 70 (17%) on A+R and 93 (23%) on placebo met the primary outcome;113 (14%) had incomplete data for determining the outcome (Figure 1). Accounting for incomplete data, weighted Risk Ratio [wRR]=0.74;95% CI: 0.56, 0.97;p=0.03. The difference was driven by fewer hospitalizations/deaths in the A+R arm (5%) than placebo arm (15%), particularly by day 28. Excluding 12 participants who died by week 36, frequency of Long COVID was similar in the arms, 16% for A+R and 14% for placebo (wRR=1.09;95%CI: 0.75, 1.58;p=0.64). There were no differences in the proportions reporting return to pre-COVID health (global assessment) or individual symptoms, or in number of symptoms reported or distribution of worst symptom severity. RRs favored the A+R arm on several EQ-5D-5L domains, but none met statistical significance. No differences were observed on SF-36v2 assessments. Conclusion(s): While A+R was highly effective in preventing all-cause hospitalizations and deaths in high-risk outpatients with mild-to-moderate COVID-19, there was no meaningful effect of treatment on measures of Long COVID at 36 weeks. Additional interventions are needed for Long COVID prevention. (Figure Presented).
ABSTRACT
Background: Amubarvimab and romlusevimab are anti-SARS-CoV-2 monoclonal antibodies (mAbs) that significantly reduced the risk of hospitalizations or death in the ACTIV-2/A5401 trial. SARS-CoV-2 variants (e.g., Delta, Epsilon, Lambda) harbor mutations against romlusevimab. We evaluated viral kinetics and resistance emergence in individuals treated with mono versus dual-active mAbs. Method(s): The study population included 789 non-hospitalized participants at high risk of progression to severe COVID-19 enrolled in the ACTIV-2/ A5401 platform trial (NCT04518410) and received either placebo (n=400) or amubarvimab plus romlusevimab (n=389). Anterior nasal (AN) swabs were collected for SARS-CoV-2 RNA testing on days 0-14, and 28. Spike (S) gene nextgeneration sequencing were performed on samples collected at study entry and the last sample with viral load >=2 log10 SARS-CoV-2 RNA copies per ml. We compared viral load kinetics and resistance emergence with single versus dual-active mAbs by categorizing participants as harboring variants sensitive to amubarvimab alone (Delta, Epsilon, Lambda, Mu) versus those sensitive to both mAbs (Alpha, Beta, Gamma, Others). Result(s): Study participants receiving single and dual-active mAbs had similar demographics, baseline AN viral load, baseline symptom score and duration since symptom onset. The most common SARS-CoV-2 variant in the study population was Delta (26%) followed by Gamma (19%), Alpha (12%), and Epsilon (10%). In those with successful sequencing, 37% (N=111) were infected with a variant sensitive to amubarvimab alone and 63% (N=188) were infected with a variant sensitive to both mAbs. Compared to treatment with a singleactive mAb, treatment with dual-active mAbs led to faster viral load decline at study day 3 (p=0.0001) and day 7 (p=0.003). Treatment-emergent resistance mutations were significantly more likely to be detected after amubarvimab plus romlusevimab treatment than placebo (2.6% vs 0%, P=0.0008). mAb resistance was also more frequently detected in the setting of single-active mAb treatment compared to dual-active mAb treatment (7.2% vs 1.1%, p=0.007). Participants with emerging mAb resistance had significantly higher pretreatment SARS-CoV-2 nasal viral RNA levels. Conclusion(s): Compared to single-active mAb therapy, dual-active mAb therapy led to significantly faster viral load decline and lower risk of emerging mAb resistance. Combination mAb therapy should be prioritized for the next generation of mAb therapeutics.
ABSTRACT
Background. BRII-196 and BRII-198 are human monoclonal antibodies (mAb) with an extended half-life targeting distinct epitopes of the spike protein on SARSCoV-2. Mutations in these epitope regions are continuously emerging, potentially conferring resistance to COVID-19 therapeutics in development. Individual phase I studies showed that BRII-196 or BRII-198 alone were safe and well tolerated in healthy subjects. The BRII-196 and BRII-198 cocktail is currently under evaluation in Phase 2/3 studies for the treatment of COVID-19. Methods. Preclinical study: BRII-196 and BRII-198 were evaluated in the microneutralization assay using pseudo-viruses encoding mutations identified in the spike protein of a panel of SARS-CoV-2 variants of concerns, including strains originating in UK, SA, BR, CA, and India. The fold-change in neutralization IC50 titers relative to wild-type virus was calculated. Phase 1 study: healthy adults received sequential IV BRII-196 and BRII-198 (n=9) or placebo (n=3);and were followed for 180 days. Two dose levels (750mg/750mg and 1500mg/1500mg) were evaluated for safety, pharmacokinetics and immunogenicity. Interim analysis results are presented. Results. Preclinical: BRII-196 and BRII-198 exhibited neutralizing activity against pseudo-virus variants that contained spike mutations of a panel of variants including B.1.1.7 (UK), B.1.351(SA), P.1(BR), B.1.427/429 (CA), B.1.526 (NY), and B.1.617 (IN), comparable to that against wild-type virus. Phase I study: BRII-196 plus BRII-198 was well tolerated with no dose-limiting adverse events (AEs), deaths, serious adverse events, or infusion reactions. The majority of AEs were isolated asymptomatic grade 1-2 laboratory abnormalities. (Table 1). Each mAb displayed pharmacokinetic characteristics expected of extended half-life YTE-antibodies. Conclusion. The BRII-196 and BRII-198 cocktail was well-tolerated, and maintains neutralization against currently reported circulating variants of concern. These preclinical and clinical results support further development of BRII-196 and BRII-198 as a therapeutic or prophylactic option for SARS-CoV-2.
ABSTRACT
Background. SARS-CoV-2 continues to spread and the development of safe and effective therapeutics for the prevention of severe disease remains a priority. BRII-196 and BRII-198 are non-competing anti-SARS-CoV-2 mAbs with YTE triple amino acid substitution in Fc to extend half-life and reduce receptor binding, that are being studied for treatment of COVID-19 in the ACTIV-2 Trial, sponsored by NIAID and led by ACTG. Methods. ACTIV-2 evaluates safety/efficacy of investigational agents for treatment of non-hospitalized adults with mild-moderate COVID-19 under a randomized, blinded, controlled adaptive platform. BRII-196/BRII-198 (1000 mg each) as a single dose given as sequential infusions, or placebo to those at high risk of clinical progression (i.e., age ≥ 60 years or presence of other medical conditions) within 10 days of symptom onset and positive test for SARS-CoV-2. The primary endpoint was hospitalization and/or death through day 28. We report Phase 3 BRII-196/BRII-198 trial results per DSMB recommendation following an interim analysis. Results. Between January and July 2021, 837 participants (418 active, 419 placebo) from sites in the US (66%), Brazil, South Africa, Mexico, Argentina and the Philippines were randomized and received study product at time of emerging variants. Median age 49 years (Q1, Q3: 39, 58), 51% female, 17% Black/African-American and 49% Hispanic/Latino, with median 6 days from symptom onset. At interim analysis 71% and 97% had a day 28 and 7 visit, respectively. For all available data at interim review, BRII-196/BRII-198 compared to placebo had fewer hospitalizations (12 vs. 45) and deaths (1 vs. 9). At day 28 of follow-up, there was an estimated 78% reduction in hospitalization and/or death (2.4 vs. 11.1%), relative risk 0.22 (95% CI: 0.05, 0.86), P=0.00001 (nominal one-sided). Grade 3 or higher adverse events (AEs) were observed less frequently among BRII-196/BRII-198 participants than placebo (3.8% vs. 13.4%) with no severe infusion reactions or drug related serious AEs. Conclusion. BRII-196/BRII-198 was safe, well-tolerated, and demonstrated significant reduction compared to placebo in the risk of hospitalization and/or death among adults with mild-moderate COVID-19 at high risk for progression to severe disease.