To evaluate the impact of sex on acute SARS-CoV-2 infection, 668 participants from the ACTIV-2/A5401 study were followed over a 28-day period. A primary analysis was performed on the 469 participants who had quantifiable viral loads at baseline. Male and female participants had comparable nasal SARS-CoV-2 RNA levels at study entry and throughout follow-up. However, sex-specific differences in viral shedding emerged when stratified by duration of symptoms. In the first three days from symptom onset, female participants exhibited higher nasal SARS-CoV-2 RNA levels than males, but lower viral RNA levels thereafter. The higher viral RNA levels in females during the earliest phase of acute COVID-19 was seen even after adjusting for age, race and region of enrollment. Female participants also tended to have higher symptom scores across days since symptom onset but no significant correlation was observed between nasal SARS-CoV-2 RNA levels and symptom score regardless of sex. These findings highlight the impact of sex on both viral shedding and symptom dynamics and underscore the importance of considering time since symptom onset when evaluating respiratory virus antiviral therapies in clinical trials.

Background: To evaluate the impact of sex on acute SARS-CoV-2 infection, 668 participants from the ACTIV-2/A5401 study were followed over a 28-day period. Methods: A primary analysis was performed on 469 participants with quantifiable viral loads at baseline. Results: Male and female participants had comparable nasal SARS-CoV-2 RNA levels at study entry and throughout follow-up. However, sex-specific differences in viral shedding emerged when stratified by symptom duration. In the first 3 days after symptom onset, female participants exhibited higher nasal SARS-CoV-2 RNA levels than males, but lower viral RNA levels thereafter. The higher viral RNA levels in females during the earliest phase of acute COVID-19 were observed even after adjusting for age, race, and region of enrollment. Female participants also tended to have higher symptom scores across days since symptom onset, but no significant correlation was observed between nasal SARS-CoV-2 RNA levels and symptom score regardless of sex. Conclusion: These findings highlight the impact of sex on both viral shedding and symptom dynamics and underscore the importance of considering time since symptom onset when evaluating antiviral therapies for respiratory viruses in clinical trials.

BACKGROUND:Tecovirimat is approved for smallpox treatment under the Food and Drug Administration Animal Rule on the basis of efficacy in nonhuman primate models of mpox (previously known as monkeypox). However, the clinical efficacy of tecovirimat against human clade II mpox is unclear. METHODS:In a phase 3, international, double-blind, randomized, placebo-controlled trial, we evaluated the efficacy of oral tecovirimat in adults with laboratory-confirmed clade II mpox. Participants were randomly assigned in a 2:1 ratio to receive tecovirimat or placebo for 14 days. The primary outcome was clinical resolution, assessed in a time-to-event analysis in participants with active skin or mucosal lesions. Secondary outcomes included reduction in pain, assessed in all participants with laboratory-confirmed mpox and in those with severe pain at baseline (pain score, 7 to 10; scale, 0 [no pain] to 10 [worst pain imaginable]); complete lesion healing (assessed in a time-to-event analysis); viral DNA clearance; and safety. RESULTS:Of 412 participants who underwent randomization (275 to tecovirimat and 137 to placebo), 344 had laboratory-confirmed mpox, and 336 had active skin or mucosal lesions and were included in the primary analysis. By day 29, the estimated cumulative incidence of clinical resolution was 83% with tecovirimat and 84% with placebo; the competing-risks hazard ratio for clinical resolution was 0.98 (95% confidence interval [CI], 0.74 to 1.31; P = 0.89). No substantial between-group differences were seen in pain reduction among participants with severe pain (difference, 0.1 point; 95% CI, -0.8 to 1.0), in complete lesion healing (competing-risks hazard ratio, 0.97; 95% CI, 0.75 to 1.26), or in viral DNA clearance. The incidence of adverse events of grade 3 or higher was similar in the two groups (4% with tecovirimat and 3% with placebo). CONCLUSIONS:This trial showed no evidence that tecovirimat therapy shortened the time to clinical resolution, reduced pain, or increased viral clearance among adults with clade II mpox. (Funded by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health; STOMP/A5418 ClinicalTrials.gov number, NCT05534984.).

BACKGROUND:How anti-SARS-CoV-2 monoclonal antibodies (mAbs) change subsequent vaccine responses remains uncertain. METHODS:We conducted a prospective, phase IV, open-label study of adults who received mRNA-1273 or BNT162b2. Cohort 1 included outpatients with acute COVID-19 previously randomized to mAbs (tixagevimab/cilgavimab or amubarvimab/romlusevimab), camostat, or placebo in ACTIV-2/A5401. Cohort 2 included unvaccinated adults without reported prior COVID-19 and was analyzed as naive or non-naive by baseline neutralizing antibodies (nAbs). We measured binding IgG, nAbs, spike-specific memory B cells, and CD4+/CD8+ T cells at baseline and days 28, 56, and 140. RESULTS:Forty-three participants were analyzed. At day 140, nAb titers were lower among prior mAb recipients and COVID-19-naive participants than among placebo/camostat recipients and those with evidence of prior infection (overall P = .018). RBD-specific, but not spike-specific, memory B cells were reduced after prior mAb therapy at days 56 and 140. Frequency of spike-specific CD4 + and CD8+ T-cell responses did not differ by prior mAb exposure. Adverse events were mostly grade 1-2 and consistent with vaccine trials. CONCLUSIONS:Prior anti-SARS-CoV-2 mAb treatment limits endogenous RBD-focused B-cell responses to later mRNA vaccination without measurably affecting T-cell immunity. Timing of vaccination after mAb therapy may matter and warrants study. CLINICAL TRIALS REGISTRATION:NCT04952402.

ABSTRACT Interferon resistance has been implicated in SARS-CoV-2 escape from innate immunity, but exogenous interferon’s impact on viral evolution and diversity is unknown. SNG001, an inhaled interferon-β1a treatment, was evaluated in the ACTIV-2/A5401 randomized controlled trial of therapeutics for COVID-19. We measured viral kinetics and performed whole-genome sequencing on longitudinal nasal swabs collected from ACTIV-2 participants who received either SNG001 or placebo to assess viral sequence diversity. No difference in nasal viral load decay was detected between study arms when stratifying by SARS-CoV-2 variant or by viral culture conversion. Compared to placebo participants, the SNG001-treated participants displayed significantly lower nonsynonymous amino acid average pairwise distance, indicating lower sequence diversity. Similarly, SNG001-treated individuals also developed numerically fewer nonsynonymous mutations during their infection in ORF1a, ORF1b, Spike, and Nucleocapsid. No specific emerging SARS-CoV-2 nonsynonymous amino acid changes indicating signatures of viral escape were enriched in those receiving SNG001. These in vivo data provide an intriguing signal that exogenous interferon-β1a may restrict SARS-CoV-2 viral diversity and add to growing evidence that interferon levels play a critical role in antiviral responses during COVID-19.IMPORTANCESARS-CoV-2 encodes several genes which can antagonize the interferon signaling cascade, preventing it from activating antiviral responses and thereby facilitating viral establishment and dissemination. It is unknown how the administration of exogenous interferon might affect viral evolution and immune escape. ACTIV-2/A5401 represents a unique opportunity to study the virologic effects of interferon treatment in a rigorous randomized, placebo-controlled clinical trial setting. Our characterization of longitudinal nasal samples shows that interferon-treated individuals had lower viral diversity and no evidence of viral escape mutations.CLINICAL TRIALSThis study is registered with ClinicalTrials.gov as NCT04518410.

Monoclonal antibodies have potential as rapidly developable agents for treatment and prevention of emerging viruses. The ACTIV-2 trial randomized persons with mild-moderate COVID-19 to the monoclonal antibody combination tixagevimab/cilgavimab via intramuscular injection (600 mg IM) or infusion (300 mg IV) versus placebo. We present final safety and laboratory outcomes; primary outcomes were previously reported. The analyzed IM group included 214 participants, and the IV group, 106 participants. Adverse events were not different between treatment and placebo. The half-life of both components was >90 days for IM or 75 days for IV. New anti-drug antibodies were about 3 times more likely in active vs. placebo recipients. SARS-CoV-2 neutralizing antibodies increased 157-fold at 7 days and 127-fold at 1 month (IM-treated) but were less robust in IV participants. These data can inform future development of monoclonal antibodies against SARS-CoV-2 and other viruses, even if this intervention is of low utility for contemporary SARS-CoV-2 variants.

We evaluated intramuscular (IM) versus intravenous (IV) administration of tixagevimab/cilgavimab in early COVID-19. Both routes achieved rapid elimination of culturable virus and minimal emergence of resistance. These results support IM delivery as a viable alternative to IV, with important implications for scalable deployment in future viral pandemics.

Seamless phase 2/3 study designs provide a framework for a more efficient trial. During the COVID-19 pandemic, such study designs were considered particularly appealing as there was an urgent global need to rapidly identify effective therapeutics. However, limited in vivo safety and efficacy data was available early in the pandemic to inform decisions. As part of the ACTIV-2 study, we implemented a phase 2/3 platform trial to evaluate multiple candidate treatments for non-hospitalized adults with COVID-19. In addition to an adequate safety profile, the decision to graduate an agent from phase 2 to phase 3 was based on showing treatment effects on clinical or laboratory markers. Decision criteria evolved over time as more data became available during the global pandemic. A seamless transition and approximately 20 % reduction in total sample size was achieved for one agent, amubarvimab plus romlusevimab. Using both simulation studies and actual results from graduation assessments of five ACTIV-2 candidate therapeutics, we provide a discussion of lessons learned from our implementation and recommendations for future seamless trials of interventions for emergent infections.

Inflammation is the body's response to infection, trauma or injury and is activated in a coordinated fashion to ensure the restoration of tissue homeostasis and healthy physiology. This process requires communication between stromal cells resident to the tissue compartment and infiltrating immune cells which is dysregulated in disease. Clinical innovations in patient diagnosis and stratification include measures of inflammatory activation that support the assessment of patient prognosis and response to therapy. We propose that (i) the recent advances in fast, dynamic monitoring of inflammatory markers (e.g., cytokines) and (ii) data-dependent theoretical and computational modeling of inflammatory marker dynamics will enable the quantification of the inflammatory response, identification of optimal, disease-specific biomarkers and the design of personalized interventions to improve patient outcomes - multidisciplinary efforts in which biomedical engineers may potentially contribute. To illustrate these ideas, we describe the actions of cytokines, acute phase proteins and hormones in the inflammatory response and discuss their role in local wounds, COVID-19, cancer, autoimmune diseases, neurodegenerative diseases and aging, with a central focus on cardiac surgery. We also discuss the challenges and opportunities involved in tracking and modulating inflammation in clinical settings.

The United States Government (USG) public-private partnership “Accelerating COVID-19 Treatment Interventions and Vaccines” (ACTIV) was launched to identify safe, effective therapeutics to treat patients with Coronavirus Disease 2019 (COVID-19) and prevent hospitalization, progression of disease, and death. Eleven original master protocols were developed by ACTIV, and thirty-seven therapeutic agents entered evaluation for treatment benefit. Challenges encountered during trial implementation led to innovations enabling initiation and enrollment of over 26,000 participants in the trials. While only two ACTIV trials continue to enroll, the recommendations here reflect information from all the trials as of May 2023. We review clinical trial implementation challenges and corresponding lessons learned to inform future therapeutic clinical trials implemented in response to a public health emergency and the conduct of complex clinical trials during “peacetime,” as well.

We explored viral and symptom rebound after coronavirus disease 2019 amubarvimab-romlusevimab monoclonal antibody therapy versus placebo in the randomized ACTIV-2/A5401 trial. Participants underwent nasal severe acute respiratory syndrome coronavirus 2 polymerase chain reaction testing at study days 3, 7, 14, and 28. Viral rebound was defined as RNA >= 3 and >= 0.5 log(10) copies/mL increase from day 3 or 7, and symptom rebound as hospitalization or any moderate/severe symptom for >= 2 days after initial symptom improvement. There was no difference in viral rebound (similar to 5%/arm) (analysis population n = 713) or symptom rebound among participants who initially improved (hazard ratio, 0.95 [95% confidence interval, .52- 1.75]; analysis population n = 574); < 1% had both viral/ symptom rebound.

Background It is unknown if early COVID-19 monoclonal antibody (mAb) therapy can reduce risk of Long COVID. The mAbs amubarvimab/romlusevimab were previously demonstrated to reduce risk of hospitalization/death by 79%. This study assessed the impact of amubarvimab/romlusevimab on late outcomes, including Long COVID. Methods Non-hospitalized high-risk adults within 10 days of COVID-19 symptom onset enrolled in a randomized, double-blind, placebo-controlled phase 2/3 trial of amubarvimab/romlusevimab for COVID-19 treatment. Late symptoms, assessed using a participant-completed symptom diary, were a pre-specified fi ed exploratory endpoint. The primary outcome for this analysis was the composite of Long COVID by participant self-report (presence of COVID-19 symptoms as recorded in the diary at week 36) or hospitalization or death by week 36. Inverse probability weighting (IPW) was used to address incomplete outcome ascertainment, giving weighted risk ratios (wRR) comparing amubarvimab/romlusevimab to placebo. Findings Participants received amubarvimab/romlusevimab (n = 390) or placebo (n = 390) between January and July 2021. Median age was 49 years, 52% were female, 18% Black/African American, 49% Hispanic/Latino, and 9% COVID-19-vaccinated at entry. At week 36, 103 (13%) had incomplete outcome ascertainment, and 66 (17%) on amubarvimab/romlusevimab and 92 (24%) on placebo met the primary outcome (wRR = 0.70, 95% confidence fi dence interval (CI) 0.53-0.93). - 0.93). The difference was driven by fewer hospitalizations/deaths with amubarvimab/ romlusevimab (4%) than placebo (13%). Among 652 participants with available diary responses, 53 (16%) on amubarvimab/romlusevimab and 44 (14%) on placebo reported presence of Long COVID. Interpretation Amubarvimab/romlusevimab treatment, while highly effective in preventing hospitalizations/deaths, did not reduce risk of Long COVID. Additional interventions are needed to prevent Long COVID.

Background. We evaluated the fully human polyclonal antibody product SAB-185 in a phase 3 trial for COVID-19. Methods. Nonhospitalized high-risk adults within 7 days of symptom onset were randomized 1:1 to open-label SAB-185 3840 units/kg or casirivimab/imdevimab 1200 mg. Noninferiority comparison was undertaken for pre-Omicron population (casirivimab/imdevimab expected to be fully active) and superiority comparison for the Omicron population (casirivimab/imdevimab not expected to be active). Primary outcomes were the composite of all-cause hospitalizations/deaths and grade >= 3 treatment-emergent adverse events (TEAEs) through day 28. A secondary outcome was time to sustained symptom resolution. Results. Enrollment ended early due to low hospitalization/death rates upon Omicron emergence; 255 adults were in pre-Omicron and 392 in Omicron populations. Hospitalizations/deaths occurred in 6 (5.0%) and 3 (2.2%) of pre-Omicron SAB-185 and casirivimab/imdevimab arms (absolute difference 2.7%; 95% confidence interval [CI], -2.3%-8.6%); and 5 (2.5%) versus 3 (1.5%) (absolute difference 1.0%; 95% CI, -2.3%-4.5%) for Omicron. All risk ratios for grade >= 3 TEAEs were not significant. Time to symptom resolution was significantly shorter for SAB-185 for Omicron only: 18 versus >25 days; P =.006. Conclusions. SAB-185 had an acceptable safety profile with faster symptom resolution in the Omicron population. Clinical Trials Registration. NCT04518410.

Background:Outpatient COVID-19 monoclonal antibody (mAb) treatment via subcutaneous delivery, if effective, overcomes the logistical burdens of intravenous administration. Methods:ACTIV-2/A5401 was a randomized, masked placebo-controlled platform trial where participants with COVID-19 at low risk for progression were randomized 1:1 to subcutaneously administered BMS-986414 (C135-LS) 200 mg, plus BMS-986413 (C144-LS) 200 mg, (BMS mAbs), or placebo. Coprimary outcomes were time to symptom improvement through 28 days; nasopharyngeal SARS-CoV-2 RNA below the lower limit of quantification (LLoQ) on days 3, 7, or 14; and treatment-emergent grade 3 or higher adverse events (TEAEs) through 28 days. Results:A total of 211 participants (105 BMS mAbs and 106 placebo) initiated study product. Time to symptom improvement favored the active therapy but was not significant (median 8 vs 10 days, P=0.19). There was no significant difference in the proportion with SARS-CoV-2 RNA <LLoQ at day 3 (risk ratio [RR] for BMS mAbs versus placebo: 1.03; 95%CI: 0.80, 1.32), at day 7 (RR: 1.04; 95%CI: 0.94, 1.15), or at day 14 (RR: 1.00; 95%CI: 0.90, 1.12). Fewer grade 3 TEAEs were reported for the BMS mAbs arm than placebo (RR: 0.58 [95%CI: 0.25, 1.32]). Through day 28, there were no deaths, and there were 4 hospitalizations in the BMS mAbs arm versus 3 in the placebo arm. Higher early plasma mAb concentrations were associated with more favorable outcomes. Conclusions:While safe, the BMS mAbs delivered subcutaneously were not effective at treating COVID-19 at low risk for progression. The lack of clinically significant activity may relate to the pharmacokinetics of subcutaneous administration of mAbs.

BACKGROUND:Camostat inhibits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in vitro. We studied the safety and efficacy of camostat in ACTIV-2/A5401, a phase 2/3 platform trial of therapeutics for COVID-19 in nonhospitalized adults. METHODS:We conducted a phase 2 study in adults with mild-to-moderate COVID-19 randomized to oral camostat for 7 days or a pooled placebo arm. Primary outcomes were time to improvement in COVID-19 symptoms through day 28, proportion of participants with SARS-CoV-2 RNA below the lower limit of quantification (LLoQ) from nasopharyngeal swabs through day 14, and grade ≥3 treatment-emergent adverse events (TEAEs) through day 28. RESULTS:Of 216 participants (109 randomized to camostat, 107 to placebo) who initiated study intervention, 45% reported ≤5 days of symptoms at study entry and 26% met the protocol definition of higher risk of progression to severe COVID-19. Median age was 37 years. Median time to symptom improvement was 9 days in both arms (P = .99). There were no significant differences in the proportion of participants with SARS-CoV-2 RNA <LLoQ on days 3, 7, and 14. Through day 28, 6 (5.6%) participants in the camostat arm and 5 (4.7%) in the placebo arm were hospitalized; 1 participant in the camostat arm subsequently died. Grade ≥3 TEAEs occurred in 10.1% of camostat versus 6.5% of placebo participants (P = .35). CONCLUSIONS:In a phase 2 study of nonhospitalized adults with mild-to-moderate COVID-19, oral camostat did not accelerate viral clearance or time to symptom improvement, or reduce hospitalizations or deaths. Clinical Trials Registration. ClinicalTrials.gov identifier: NCT04518410.

BACKGROUND:Time to symptom resolution measures were used in outpatient coronavirus disease 2019 (COVID-19) treatment trials without prior validation. METHODS:ACTIV-2/A5401 trial participants completed a COVID-19 diary assessing 13 targeted symptoms and global experience (overall COVID-19 symptoms, return to pre-COVID-19 health) daily for 29 days. We evaluated concordance of time to sustained (2 days) resolution of all targeted symptoms (TSR) with resolution of overall symptoms and return to health in participants receiving placebo. RESULTS:The analysis included 77 high-risk and 81 standard-risk participants with overall median 6 days of symptoms at entry and median age 47 years, 50% female, 82% white, and 31% Hispanic/Latino. Correlation between TSR and resolution of overall symptoms was 0.80 and 0.68, and TSR and return to health, 0.66 and 0.57 for high- and standard-risk groups, respectively. Of the high- and standard-risk participants, 61% and 79%, respectively, achieved targeted symptom resolution, of which 47% and 43%, respectively, reported symptom recurrence. Requiring >2 days to define sustained resolution reduced the frequency of recurrences. CONCLUSIONS:There was good internal consistency between TSR and COVID-19-specific global outcomes, supporting TSR as a trial end point. Requiring >2 days of symptom resolution better addresses natural symptom fluctuations but must be balanced against the potential influence of non-COVID-19 symptoms. CLINICAL TRIALS REGISTRATION:NCT04518410.

BACKGROUND There is little information regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA as a predictor for clinical outcomes in outpatients with mild-to-moderate coronavirus disease 2019 (COVID-19). METHODS Anterior nasal (AN) and plasma SARS-CoV-2 RNA data from 2115 nonhospitalized adults who received monoclonal antibodies (mAbs) or placebo in the ACTIV-2/A5401 trial were analyzed for associations with hospitalization or death. RESULTS One hundred two participants were hospitalized or died through 28 days of follow-up. Higher day 0 (pretreatment) AN RNA was associated with increasing risk of hospitalization/death (risk ratio [RR], 1.24 per log10 copies/mL [95% confidence interval {CI}, 1.04-1.49]) among placebo recipients, ranging from 3% to 16% for <2 to ≥6 log10 copies/mL. Although only 1% had quantifiable levels, there was a similar trend across day 0 plasma RNA categories. Higher day 3 AN RNA was associated with subsequent hospitalization/death among placebo recipients (RR, 1.42 per log10 copies/mL [95% CI, 1.00-2.03]), but not mAb recipients (RR, 1.02 per log10 copies/mL [95% CI, 0.68-1.56]). The proportion of treatment effect (reduction in hospitalizations/deaths after day 3 for mAb vs placebo) explained by day 3 AN RNA was 8%. CONCLUSIONS SARS-CoV-2 RNA levels are predictive of hospitalization/death in the natural history setting, but AN RNA levels may not be a reliable surrogate marker of mAb treatment effect in COVID-19 trials. Clinical Trials Registration. NCT04518410.

Background With the emergence of SARS-CoV-2 variants resistant to monoclonal antibody therapies and limited global access to therapeutics, the evaluation of novel therapeutics to prevent progression to severe COVID-19 remains a critical need. Methods Safety, clinical and antiviral efficacy of inhaled interferon-beta 1a (SNG001) were evaluated in a phase II randomized controlled trial on the ACTIV-2/A5401 platform (ClinicalTrials.gov NCT04518410). Adult outpatients with confirmed SARS-CoV-2 infection within 10 days of symptom onset were randomized and initiated either orally inhaled nebulized SNG001 given once daily for 14 days (n = 110) or blinded pooled placebo (n = 110) between February 10 and August 18, 2021. Findings The proportion of participants reporting premature treatment discontinuation was 9% among SNG001 and 13% among placebo participants. There were no differences between participants who received SNG001 or placebo in the primary outcomes of treatment emergent Grade 3 or higher adverse events (3.6% and 8.2%, respectively), time to symptom improvement (median 13 and 9 days, respectively), or proportion with unquantifiable nasopharyngeal SARS-CoV-2 RNA at days 3 (28% [26/93] vs. 39% [37/94], respectively), 7 (65% [60/93] vs. 66% [62/94]) and 14 (91% [86/95] vs. 91% [83/81]). There were fewer hospitalizations with SNG001 (n = 1; 1%) compared with placebo (n = 7; 6%), representing an 86% relative risk reduction (p = 0.07). There were no deaths in either arm. Interpretation In this trial, SNG001 was safe and associated with a non-statistically significant decrease in hospitalization for COVID-19 pneumonia. Copyright (c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Clinical Trials Registration ClinicalTrials.gov Identifier: NCT04518410.