Publications by authors named "Katleen Callewaert"

We examined candidate biomarkers for efficacy outcomes in hospitalized COVID-19 patients who were treated with sirukumab, an IL-6 neutralizing antibody, in a randomized, double-blind, placebo-controlled, phase 2 trial. Between May 2020 and March 2021, 209 patients were randomized (sirukumab, n = 139; placebo, n = 70); 112 had critical COVID-19. Serum biomarkers were evaluated for the pharmacodynamic effect of sirukumab and for their potential prognostic and predictive effect on time to sustained clinical improvement up to Day 28, clinical improvement at Day 28, and mortality at Day 28.

View Article and Find Full Text PDF

Background: Upregulation of IL-6 has been associated with worse prognosis in COVID-19 patients. Impact on IL-6 signalling has mostly been limited to clinical outcomes in IL-6 receptor antagonist trials.

Methods: We performed a phase 2, randomised, double-blind, placebo-controlled trial (NCT04380961) of US-based hospitalised adults (<85 years) with laboratory-confirmed SARS-CoV-2 infection and severe (low levels of supplemental oxygen) or critical disease (high levels of oxygen supplementation).

View Article and Find Full Text PDF
Article Synopsis
  • * The authors created a method called MASCALE that uses mass spectrometry to accurately quantify antibody levels by calibrating ELISA reference sera.
  • * MASCALE allows for improved comparison of immune responses across different labs and studies, helping to better evaluate vaccine efficacy and immune responses in clinical trials.
View Article and Find Full Text PDF

The functionality of CD8+ T cells against human immunodeficiency virus-1 (HIV-1) antigens is indicative of HIV-progression in both animal models and people living with HIV. It is, therefore, of interest to assess CD8+ T cell responses in a prophylactic vaccination setting, as this may be an important component of the immune system that inhibits HIV-1 replication. T cell responses induced by the adenovirus serotype 26 (Ad26) mosaic vaccine regimen were assessed previously by IFN-γ ELISpot and flow cytometric assays, yet these assays only measure cytokine production but not the capacity of CD8+ T cells to inhibit replication of HIV-1.

View Article and Find Full Text PDF

Background: Developing a cross-clade, globally effective HIV vaccine remains crucial for eliminating HIV.

Methods: This placebo-controlled, double-blind, phase 1/2a study enrolled healthy HIV-uninfected adults at low risk for HIV infection. They were randomized (1:4:1) to receive 4 doses of an adenovirus 26-based HIV-1 vaccine encoding 2 mosaic Gag and Pol, and 2 mosaic Env proteins plus adjuvanted clade C gp140 (referred to here as clade C regimen), bivalent protein regimen (clade C regimen plus mosaic gp140), or placebo.

View Article and Find Full Text PDF

Background: Bioinformatically designed mosaic antigens increase the breadth of HIV vaccine-elicited immunity. This study compared the safety, tolerability, and immunogenicity of a newly developed, tetravalent Ad26 vaccine with the previously tested trivalent formulation.

Methods: This randomised, parallel-group, placebo-controlled, double-blind, phase 1/2a study (TRAVERSE) was done at 11 centres in the USA and one centre in Rwanda.

View Article and Find Full Text PDF

Background: More than 1·8 million new cases of HIV-1 infection were diagnosed worldwide in 2016. No licensed prophylactic HIV-1 vaccine exists. A major limitation to date has been the lack of direct comparability between clinical trials and preclinical studies.

View Article and Find Full Text PDF

Background: Mosaic immunogens are bioinformatically engineered human immunodeficiency virus type 1 (HIV-1) sequences designed to elicit clade-independent coverage against globally circulating HIV-1 strains.

Methods: This phase 1, double-blinded, randomized, placebo-controlled trial enrolled healthy HIV-uninfected adults who received 2 doses of a modified vaccinia Ankara (MVA)-vectored HIV-1 bivalent mosaic immunogen vaccine or placebo on days 0 and 84. Two groups were enrolled: those who were HIV-1 vaccine naive (n = 15) and those who had received an HIV-1 vaccine (Ad26.

View Article and Find Full Text PDF

Background: Interferon-free regimens are needed to treat hepatitis C virus (HCV) infections. We investigated the efficacy of combined simeprevir and sofosbuvir.

Methods: We enrolled patients with chronic HCV genotype 1 infections who had previously not responded to pegylated interferon (peginterferon) and ribavirin or were treatment naive.

View Article and Find Full Text PDF