Publications by authors named "Mark Giganti"

Background: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory illness among young children. Human immunodeficiency virus (HIV)-exposed, uninfected (HEU) children experience a higher burden of RSV disease and have immune abnormalities that may influence their responses to live-attenuated RSV vaccines.

Methods: In a pooled analysis of clinical trials of 7 live-attenuated, intranasal RSV vaccines conducted by the IMPAACT Network among children 6 to <25 months of age with serum RSV-neutralizing titers of <1:40, the infectivity and immunogenicity of these vaccines were compared among HEU and HIV-unexposed, uninfected (HUU) children.

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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).

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Background: Reliable biomarkers of coronavirus disease 2019 (COVID-19) outcomes are critically needed. We evaluated associations of spike antibody (Ab) and plasma nucleocapsid antigen (N Ag) with clinical outcomes in nonhospitalized persons with mild-to-moderate COVID-19.

Methods: Participants were nonhospitalized adults with mild-to-moderate COVID-19 enrolled in ACTIV-2 between January and July 2021 and randomized to placebo.

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Article Synopsis
  • Outpatient treatment of COVID-19 using subcutaneous monoclonal antibodies (mAbs) could simplify logistics compared to intravenous delivery.
  • In a clinical trial with 211 participants, the BMS mAbs did not show significant benefits in symptom improvement or viral load reduction compared to placebo, despite being safe with fewer severe adverse events reported.
  • The results suggest that subcutaneous administration of BMS mAbs may not be effective for low-risk COVID-19 patients, potentially due to how the body absorbs mAbs through this method.
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Article Synopsis
  • Monoclonal antibodies are an important treatment for COVID-19, and a study compared the effects of single vs. dual mAb treatments, specifically amubarvimab and romlusevimab.
  • The study found that dual-active mAbs resulted in a quicker reduction of viral load in patients, though hospitalizations and death rates were similar between the two treatment types.
  • Additionally, dual-active therapy showed a lower incidence of resistance mutations compared to single-active treatment.
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Objective: HIV treatment regimen during pregnancy was associated with preterm delivery (PTD) in the PROMISE 1077 BF trial. Systemic inflammation among pregnant women with HIV could help explain differences in PTD by treatment regimen. We assessed associations between inflammation, treatment regimen, and PTD.

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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-β1a (SNG001) were evaluated in a phase II randomized controlled trial on the ACTIV-2/A5401 platform (ClinicalTrials.govNCT04518410).

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Article Synopsis
  • Clinical trials for COVID-19 therapeutics often measure antiviral activity by assessing changes in nasal SARS-CoV-2 RNA levels, typically using statistical methods like ANCOVA or MMRM.
  • Using single imputation for results below the assay’s lower limits of quantification (LLoQ) can introduce bias in estimating treatment effects.
  • The article underscores best practices for analyzing quantitative viral RNA data, emphasizing the importance of detailing assay specifics, completeness summaries, and considering values below LLoQ as censored measurements.
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Understanding variant-specific differences in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral kinetics may explain differences in transmission efficiency and provide insights on pathogenesis and prevention. We evaluated SARS-CoV-2 kinetics from nasal swabs across multiple variants (Alpha, Delta, Epsilon, Gamma) in placebo recipients of the ACTIV-2/A5401 trial. Delta variant infection led to the highest maximum viral load and shortest time from symptom onset to viral load peak.

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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.

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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.

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Importance: Development of effective, scalable therapeutics for SARS-CoV-2 is a priority.

Objective: To test the efficacy of combined tixagevimab and cilgavimab monoclonal antibodies for early COVID-19 treatment.

Design, Setting, And Participants: Two phase 2 randomized blinded placebo-controlled clinical trials within the Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV)-2/A5401 platform were performed at US ambulatory sites.

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Article Synopsis
  • A phase 2 and 3 clinical trial was conducted to evaluate the safety and effectiveness of two monoclonal antibodies, amubarvimab and romlusevimab, in treating patients with SARS-CoV-2 who are at high risk for severe illness.
  • *The trial involved 807 participants across multiple countries, showing that the antibody combination significantly reduced hospitalizations and deaths by 79% compared to a placebo group, with fewer severe adverse events reported.
  • *However, a limitation of the study is that the majority of participants were unvaccinated against COVID-19, which may impact the generalizability of the results.
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Article Synopsis
  • Many clinical trials for COVID-19 treatments assess antiviral effectiveness by monitoring changes in nasal SARS-CoV-2 RNA levels.
  • Using methods like ANCOVA or MMRM and filling in missing data (imputation) can distort treatment effect estimates.
  • The paper emphasizes best practices for data analysis, recommending the careful treatment of measurements below the lower limits of quantification (LLoQ) and full transparency regarding assay details and participant outcomes.
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Background: SAB-185, a novel fully human IgG polyclonal immunoglobulin product, underwent phase 2 evaluation for nonhospitalized adults with mild-moderate coronavirus disease 2019 (COVID-19).

Methods: Participants received intravenous SAB-185 3840 units/kg (low-dose) or placebo, or 10 240 units/kg (high-dose) or placebo. Primary outcome measures were nasopharyngeal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA < lower limit of quantification (LLOQ) at study days 3, 7, and 14, time to symptomatic improvement, and safety through day 28.

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Acute Coronavirus Disease 2019 symptoms limit daily activities, but little is known about its association with severe acute respiratory syndrome coronavirus 2 viral burden. In this exploratory analysis of placebo recipients in the ACTIV-2/A5401 platform trial, we showed that high anterior nasal RNA levels and detectable plasma RNA were associated with delayed symptom improvement. Clinical Trials Registration.

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Article Synopsis
  • - Anti-SARS-CoV-2 monoclonal antibodies, like bamlanivimab, are important treatments for COVID-19, and their safety and effectiveness were tested in a study called ACTIV-2/A5401.
  • - In this randomized trial, non-hospitalized adults with early COVID-19 symptoms were given either bamlanivimab or a placebo, but the primary results showed no significant differences in undetectable viruses or symptom improvement between the two groups.
  • - Although bamlanivimab didn’t reduce symptom duration, it was linked to lower viral levels in the nose after three days and quicker drops in inflammation and viral levels, suggesting it may help control the virus's spread early on. *
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Objective: We investigated dynamics of inflammatory biomarkers in children with perinatally acquired HIV (PHIV) who started antiretrovirals at age less than 3 years and achieved sustained virologic control (HIV plasma RNA <400 copies/ml).

Design: This was a retrospective analysis of inflammatory biomarkers in children enrolled in a randomized trial of early (<3 years of age) PI-based versus NNRTI-based regimens (P1060), who achieved sustained virologic control and participated in a neurodevelopmental follow-up study (P1104s) between ages 5 and 11 years.

Methods: We measured 20 inflammatory biomarkers using ELISA or chemiluminescence at onset of sustained virologic control (Tc) and at P1104s entry (Te).

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Importance: The antiviral activity and efficacy of anti-SARS-CoV-2 monoclonal antibody (mAb) therapies to accelerate recovery from COVID-19 is important to define.

Objective: To determine safety and efficacy of the mAb bamlanivimab to reduce nasopharyngeal (NP) SARS-CoV-2 RNA levels and symptom duration.

Design: ACTIV-2/A5401 is a randomized, blinded, placebo-controlled platform trial.

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Objective: We examined relationships between plasma biomarkers and neurodevelopment in children from sub-Saharan Africa with perinatal HIV (PHIV) with controlled viremia on antiretroviral therapy (ART).

Design: Longitudinal retrospective cohort study of children with controlled blood HIV replication.

Methods: Children (N = 213; 57% girls) started ART at less than 3 years of age, had neurodevelopmental assessments (cognition, attention/impulsivity, motor proficiency, global executive functions) at 5-11 years, and achieved controlled viremia (HIV-1 RNA <400 copies/ml for ≥9 months before initial assessment).

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Data from electronic health records (EHR) are prone to errors, which are often correlated across multiple variables. The error structure is further complicated when analysis variables are derived as functions of two or more error-prone variables. Such errors can substantially impact estimates, yet we are unaware of methods that simultaneously account for errors in covariates and time-to-event outcomes.

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In observational studies using routinely collected data, a variable with a high level of missingness or misclassification may determine whether an observation is included in the analysis. In settings where inclusion criteria are assessed after imputation, the popular multiple-imputation variance estimator proposed by Rubin ("Rubin's rules" (RR)) is biased due to incompatibility between imputation and analysis models. While alternative approaches exist, most analysts are not familiar with them.

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Background: A growing population of older adults with HIV will increase demands on HIV-related healthcare. Nearly a quarter of people receiving care for HIV in Latin America are currently 50 years or older, yet little is known about the frequency of comorbidities in this population. We estimated the prevalence and incidence of non-communicable diseases (NCDs) among people 50 years of age or older (≥50yo) receiving HIV care during 2000-2015 in six centers affiliated with the Caribbean, Central and South American network for HIV epidemiology (CCASAnet).

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