42 research outputs found

    A multicenter phase II trial of anti-EGFR-immunoliposomes loaded with doxorubicin in patients with advanced triple negative breast cancer

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    Advanced triple negative breast cancer (TNBC) is an aggressive, but initially chemo-sensitive disease. The prognosis is poor and more than three quarters of patients experience progression 12 months after the initiation of conventional first-line chemotherapy. Approximately two thirds of TNBC express epidermal growth factor receptor 1 (EGFR). We have developed an anti-EGFR targeted nanocontainer drug by inserting anti-EGFR antibody fragments into the membrane of pegylated liposomes (anti-EGFR-ILs-dox). The payload consists of doxorubicin, a standard drug for TNBC. In a first-in-human phase I trial in 26 patients with various advanced solid malignancies, anti-EGFR-ILs-dox has shown little toxicity and encouraging efficacy. In this single-arm phase II trial, we assessed the efficacy of anti-EGFR-ILs-dox as first-line therapy in patients with advanced, EGFR + TNBC. The primary endpoint was progression-free survival at 12 months (PFS12m). Secondary endpoints included overall response rate (ORR), duration of response (DOR), time to progression (TTP), overall survival (OS) and adverse events (AEs). 48 patients received anti-EGFR-ILs-dox 50 mg/m2^{2} iv, on day one of a 28 days-cycle until progression. The Kaplan-Meier estimate for PFS12m was 13% (one-sided 90% CI 7%, 95% CI [5%, 25%]), median PFS was 3.5 months (95% CI 1.9, 5.4). The trial has not reached its primary endpoint. There were no new toxicity signals. Based on these results, anti-EGFR-ILs-dox should not be further developed for TNBC. It remains an open question whether anti-EGFR-ILs-dox would offer more opportunities in other EGFR-expressing malignancies, where targeting this receptor has already shown anticancer effects.Trial registration: This trial was registered at clinicaltrials.gov: NCT02833766. Registered 14/07/2016

    Autopsy Prevalence of Tuberculosis and Other Potentially Treatable Infections among Adults with Advanced HIV Enrolled in Out-Patient Care in South Africa: Lesedi Kamoso study data

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    Early mortality among HIV-positive adults starting antiretroviral therapy (ART) remains high in resource-limited settings, with tuberculosis (TB) the leading cause of death. However, current methods to estimate TB-related deaths are inadequate and most autopsy studies do not adequately represent those attending primary health clinics (PHCs). The TB Fast Track study aimed to determine the autopsy prevalence of TB and other infections in adults enrolled at South African PHCs in the context of a pragmatic trial of empiric TB treatment. This dataset contains basic demographic information and lab investigation results of 34 HIV-positive individuals who died after study enrolment. This includes MGIT culture and Xpert MTB/RIF; aerobic and fungal cultures; and histological finding

    Ex vivo drug response profiling detects recurrent sensitivity patterns in drug-resistant acute lymphoblastic leukemia

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    Drug sensitivity and resistance testing on diagnostic leukemia samples should provide important functional information to guide actionable target and biomarker discovery. We provide proof of concept data by profiling 60 drugs on 68 acute lymphoblastic leukemia (ALL) samples mostly from resistant disease in cocultures of bone marrow stromal cells. Patient-derived xenografts retained the original pattern of mutations found in the matched patient material. Stromal coculture did not prevent leukemia cell cycle activity, but a specific sensitivity profile to cell cycle-related drugs identified samples with higher cell proliferation both in vitro and in vivo as leukemia xenografts. In patients with refractory relapses, individual patterns of marked drug resistance and exceptional responses to new agents of immediate clinical relevance were detected. The BCL2inhibitor venetoclax was highly active below 10 nM in B-cell precursor ALL (BCP-ALL) subsets, including MLL-AF4 and TCF3-HLF ALL, and in some T-cell ALLs (T-ALLs), predicting in vivo activity as a single agent and in combination with dexamethasone and vincristine. Unexpected sensitivity to dasatinib with half maximal inhibitory concentration values below 20 nM was detected in 2 independent T-ALL cohorts, which correlated with similar cytotoxic activity of the SRC inhibitor KX2-391 and inhibition of SRC phosphorylation. A patient with refractory T-ALL was treated with dasatinib on the basis of drug profiling information and achieved a 5-month remission. Thus, drug profiling captures disease-relevant features and unexpected sensitivity to relevant drugs, which warrants further exploration of this functional assay in the context of clinical trials to develop drug repurposing strategies for patients with urgent medical needs.Peer reviewe

    Fine Scale Analysis of Crossover and Non-Crossover and Detection of Recombination Sequence Motifs in the Honeybee (Apis mellifera)

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    BACKGROUND: Meiotic exchanges are non-uniformly distributed across the genome of most studied organisms. This uneven distribution suggests that recombination is initiated by specific signals and/or regulations. Some of these signals were recently identified in humans and mice. However, it is unclear whether or not sequence signals are also involved in chromosomal recombination of insects. METHODOLOGY: We analyzed recombination frequencies in the honeybee, in which genome sequencing provided a large amount of SNPs spread over the entire set of chromosomes. As the genome sequences were obtained from a pool of haploid males, which were the progeny of a single queen, an oocyte method (study of recombination on haploid males that develop from unfertilized eggs and hence are the direct reflect of female gametes haplotypes) was developed to detect recombined pairs of SNP sites. Sequences were further compared between recombinant and non-recombinant fragments to detect recombination-specific motifs. CONCLUSIONS: Recombination events between adjacent SNP sites were detected at an average distance of 92 bp and revealed the existence of high rates of recombination events. This study also shows the presence of conversion without crossover (i. e. non-crossover) events, the number of which largely outnumbers that of crossover events. Furthermore the comparison of sequences that have undergone recombination with sequences that have not, led to the discovery of sequence motifs (CGCA, GCCGC, CCGCA), which may correspond to recombination signals

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

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    Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Degeneracy and additional alloreactivity of drug-specific human αβ+ T cell clones

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    It has been well established that T cells can recognize small mol. wt compounds such as drugs. Results from previous studies revealing a high heterogeneity and cross-reactivity of drug-specific T cell clones (TCC) in individual patients prompted us to analyze the degeneracy of drug-reactive TCR in detail. Hence, we analyzed the MHC restriction pattern of a panel of 100 drug-specific TCC isolated from different drug-allergic donors. We found that 28 of the tested clones showed an MHC allele-unrestricted drug recognition. Most of these clones were at the same time highly drug specific, i.e. they could only be stimulated by the original drug and not by any drug derivatives. In contrast, TCC with the ability to interact with different drug derivatives displayed a clearly MHC allele-restricted drug recognition. Therefore, we concluded that the TCR of these clones is mainly interacting with side chains of the appropriate drug molecules and hence able to tolerate alterations in the MHC molecule. Moreover, we tested all clones for additional alloreactivity and found that 27 clones could be stimulated by a self-MHC-peptide-drug complex as well as by a non-self-MHC-peptide complex. This cross-reactivity with allogeneic MHC molecules was substantially higher in drug-specific TCC compared to tetanus toxoid-specific clones from the same donors. This suggests that from the point of view of drug-specific TCR, non-self-MHC-peptide complexes have a higher incidence to mimic the 'soriginal' self-MHC-peptide-drug complex and this may occur for TCR recognizing self-MHC-pathogen-derived peptide complexes. Finally, the biological functions of bispecific TCC were not influenced by the nature of the stimulating ligand. Both drug as well as allogeneic stimulation led to similar reaction patterns in the analyzed TC
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