A high-throughput microfluidic nanoimmunoassay for detecting anti-SARS-CoV-2 antibodies in serum or ultralow-volume blood samples.

Novel technologies are needed to facilitate large-scale detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies in human blood samples. Such technologies are essential to support seroprevalence studies and vaccine clinical trials, and to monitor quality and duration of immunity. We developed a microfluidic nanoimmunoassay (NIA) for the detection of anti-SARS-CoV-2 IgG antibodies in 1,024 samples per device. The method achieved a specificity of 100% and a sensitivity of 98% based on the analysis of 289 human serum samples. To eliminate the need for venipuncture, we developed low-cost, ultralow-volume whole blood sampling methods based on two commercial devices and repurposed a blood glucose test strip. The glucose test strip permits the collection, shipment, and analysis of 0.6 µL of whole blood easily obtainable from a simple finger prick. The NIA platform achieves high throughput, high sensitivity, and specificity based on the analysis of 289 human serum samples, and negligible reagent consumption. We furthermore demonstrate the possibility to combine NIA with decentralized and simple approaches to blood sample collection. We expect this technology to be applicable to current and future SARS-CoV-2 related serological studies and to protein biomarker analysis in general.

Prevalence of Immunoglobulin G (IgG) Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Evaluation of a Rapid MEDsan IgG Test in Children Seeking Medical Care.

In 208 children seeking medical care, the seropositivity rate of anti-SARS-CoV-2 IgG antibodies was 8.7%, suggesting an infection rate similar to that observed in adults but >100-fold the incidence of RT-PCR-confirmed pediatric cases. Compared with the gold-standard combined ELISA + immunofluorescence, the MEDsan IgG rapid diagnostic test performed accurately.

Two Patient Studies of a Companion Diagnostic Immuno-Positron Emission Tomography (PET) Tracer for Measuring Human CA6 Expression in Cancer for Antibody Drug Conjugate (ADC) Therapy.

An antigen binding fragment (BFab) derived from a tumor-associated mucin 1-sialoglycotope antigen (CA6) targeting antibody (huDS6) was engineered. We synthesized a companion diagnostic positron emission tomography (PET) tracer by radiolabeling BFab with [64Cu] to measure CA6 expression on cancer tissues prior to anti-human CA6 (huDS6-DM4 antibody-drug conjugate) therapy for ovarian and breast cancer patients. After chemotherapy, the ovarian patient received PET scan with 18F-2-fluoro-2-deoxyglucose ([18F]FDG: 10 mCi), followed by [64Cu]-DOTA-BFab ([64Cu]BFab; 5.5 mCi) 1 week later for PET scanning of CA6 expression and subsequent surgery. The breast cancer patient was treated with chemotherapy before primary tumor resection and subsequent [18F]FDG-PET scan. 4 weeks later the patient received of [64Cu]BFab (11.7 mCi) for CA6 PET scan. Whole body [18F]FDG-PET of the breast cancer patient indicated FDG-avid tumor metastases to the liver, bilateral hila and thoracic spine, but no uptake was observed for the ovarian patient. Each patient was also imaged by PET/CT with [64Cu]BFab at 1 and 24 hours after tracer administration. The [64Cu]BFab tracer was well tolerated by both patients without adverse effects, and no significant tracer uptake was observed in both patients. Immunohistochemistry (IHC) data indicated CA6 expressions were weak to intermediate and matched with the [64Cu]BFab-PET signals.

Diagnostic accuracy of Augurix COVID-19 IgG serology rapid test.

AIMS: To validate the diagnostic accuracy of the Augurix SARS-CoV-2 IgM/IgG rapid immunoassay diagnostic test (RDT) for COVID-19. METHODS: In this unmatched 1:1 case-control study, blood samples from 46 real-time RT-PCR-confirmed SARS-CoV-2 hospitalized cases and 45 healthy donors (negative controls) were studied. Diagnostic accuracy of the IgG RDT was assessed against both an in-house recombinant spike-expressing immunofluorescence assay (rIFA), as an established reference method (primary endpoint), and the Euroimmun SARS-CoV-2 IgG enzyme-linked immunosorbent assays (ELISA) (secondary endpoint). RESULTS: COVID-19 patients were more likely to be male (61% vs 20%; P = .0001) and older (median 66 vs 47 years old; P < .001) than controls. Whole blood IgG-RDT results showed 86% and 93% overall Kendall concordance with rIFA and IgG ELISA, respectively. IgG RDT performances were similar between plasma and whole blood. Overall, RDT sensitivity was 88% (95% confidence interval [95%CI]: 70-96), specificity 98% (95%CI: 90-100), PPV 97% (95%CI: 80-100) and NPV 94% (95%CI: 84-98). The IgG-RDT carried out from 0 to 6 days, 7 to 14 days and > 14 days after the SARS-CoV-2 RT-PCR test displayed 30%, 73% and 100% positivity rates in the COVID-19 group, respectively. When considering samples taken >14 days after RT-PCR diagnosis, NPV was 100% (95%CI:90-100), and PPV was 100% (95%CI:72-100). CONCLUSIONS: The Augurix IgG-RDT done in whole blood displays a high diagnostic accuracy for SARS-CoV-2 IgG in high COVID-19 prevalence settings, where its use could be considered in the absence of routine diagnostic serology facilities.

Ombrabulin plus cisplatin versus placebo plus cisplatin in patients with advanced soft-tissue sarcomas after failure of anthracycline and ifosfamide chemotherapy: a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Ombrabulin (AVE8062) disrupts the vasculature of established tumours and has shown preclinical synergistic anti-tumour activity when combined with cisplatin. In this phase 3 trial, we aimed to assess the efficacy and safety of ombrabulin plus cisplatin compared with placebo plus cisplatin in patients with advanced soft-tissue sarcomas. METHODS: We did this multinational, randomised, double-blind, placebo-controlled phase 3 study at 44 centres in ten countries. Patients aged 18 years and older with metastatic soft-tissue sarcomas, an Eastern Cooperative Oncology Group performance status of 0-2, and who had previously received treatment with anthracycline and ifosfamide were randomly assigned (1:1) to intravenous infusion of ombrabulin 25 mg/m(2) plus cisplatin 75 mg/m(2) or intravenous infusion of placebo plus cisplatin 75 mg/m(2) every 3 weeks. Patients were allocated to treatment using a permuted blocks randomisation scheme (block size of four) via an interactive voice-response system, and stratified by histological subtype. Patients, medical staff, study investigators, and individuals who handled and analysed the data were masked to treatment assignment. Our primary endpoint was median progression-free survival in the intention-to-treat population. Safety analyses were done on all randomised patients who received at least one dose of study drug. This trial is now closed, and is registered with ClinicalTrials.gov, number NCT00699517. FINDINGS: Between June 13, 2008, and April 26, 2012, we randomly assigned 355 patients to ombrabulin plus cisplatin (n=176) or placebo plus cisplatin (n=179). Median duration of follow-up was 27·9 (IQR 20·9-33·2) in the placebo group and 30·5 months (20·7-37·6) in the ombrabulin group. Progression-free survival was slightly, but significantly, improved in the ombrabulin group compared with the placebo group (median 1·54 months [95% CI 1·45-2·69] vs 1·41 [1·38-1·58] months; hazard ratio 0·76 [95% CI 0·59-0·98]; p=0·0302). Grade 3 or 4 adverse events occurred more frequently in individuals in the ombrabulin group than in those in the placebo group and included neutropenia (34 [19%] in the ombrabulin group vs 14 [8%] in the placebo group) and thrombocytopenia (15 [8%] vs six [3%] for placebo). Adverse events leading to death occurred in 18 patients in the ombrabulin group and 10 patients in the placebo group. INTERPRETATION: The combination of ombrabulin and cisplatin significantly improved progression-free survival; however, it did not show a sufficient clinical benefit in patients with advanced soft-tissue sarcomas to support its use as a therapeutic option. Predictive biomarkers are needed for the rational clinical development of tumour vascular-disrupting drugs for soft-tissue sarcomas. FUNDING: Sanofi.

Impact of Shaking EDTA, Citrate, or MgSO4 Tubes on Platelet Count Results.

Background: In EDTA-induced pseudothrombopenia, citrate or MgSO4 are recommended for platelet counting. Pre-analytical conditions are poorly defined for tubes containing MgSO4 or citrate. In this study, we analyzed the impact of agitation of these tubes on platelet counts. Methods: K2EDTA, citrate, and MgSO4 tubes from 70 patients were gently agitated on a wheel rotating at 20 rpm. Platelets were analyzed on the Sysmex XN analyzer at different times, and the percentage of platelet deviation from T0 was assessed and compared with the desirable bias of the EFLM. Results: at 180 min in fluorescence, the relative variation of platelets after shaking is 1.17% for K2EDTA, -29.76% for citrate, and -33.18% for MgSO4, while for unshaken MgSO4 platelets the variation is -1.3%. The reduction in platelet numbers when citrate or MgSO4 tubes are shaken is linked to the appearance of platelet clusters. Conclusions: agitation of MgSO4 and especially citrate tubes led to a decrease in platelet counts due to the formation of platelet aggregates; on the other hand, platelet counts on EDTA are virtually stable. During transport, we recommend putting sodium citrate and MgSO4 tubes in an upright position and avoiding shaking them to avoid giving an erroneous platelet result.

Joint modeling of tumor dynamics and progression-free survival in advanced breast cancer: Leveraging data from amcenestrant early phase I-II trials.

A joint modeling framework was developed using data from 75 patients of early amcenestrant phase I-II AMEERA-1-2 dose escalation and expansion cohorts. A semi-mechanistic tumor growth inhibition (TGI) model was developed. It accounts for the dynamics of sensitive and resistant tumor cells, an exposure-driven effect on tumor proliferation of sensitive cells, and a delay in the initiation of treatment effect to describe the time course of target lesion tumor size (TS) data. Individual treatment exposure overtime was introduced in the model using concentrations predicted by a population pharmacokinetic model of amcenestrant. This joint modeling framework integrated complex RECISTv1.1 criteria information, linked TS metrics to progression-free survival (PFS), and was externally evaluated using the randomized phase II trial AMEERA-3. We demonstrated that the instantaneous rate of change in TS (TS slope) was an important predictor of PFS and the developed joint model was able to predict well the PFS of amcenestrant phase II monotherapy trial using only early phase I-II data. This provides a good modeling and simulation tool to inform early development decisions.

Randomized Phase III Study of Amcenestrant Plus Palbociclib Versus Letrozole Plus Palbociclib in Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Primary Results From AMEERA-5.

PURPOSE: AMEERA-5 investigated amcenestrant (oral selective estrogen receptor [ER] degrader) plus palbociclib versus letrozole plus palbociclib as first-line treatment for ER-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced/metastatic breast cancer (aBC). MATERIALS AND METHODS: In AMEERA-5 (ClinicalTrials.gov identifier: NCT04478266), a double-blind, double-dummy, international phase III trial, adult pre-/post-menopausal women and men without previous systemic therapy for ER+/HER2- aBC were randomly assigned 1:1 to amcenestrant 200 mg once daily + standard palbociclib dosage (125 mg once daily, 21 days on/7 days off) or letrozole 2.5 mg once daily + standard palbociclib dosage, stratified by de novo metastatic disease, postmenopausal women, and visceral metastasis. The primary end point was progression-free survival (PFS), compared using a stratified log-rank test with one-sided type I error rate of 2.5%. Secondary end points included overall survival (key secondary), pharmacokinetics, and safety. RESULTS: Between October 14, 2020, and December 2, 2021, 1,068 patients were randomly assigned to amcenestrant + palbociclib (N = 534) or letrozole + palbociclib (N = 534). At the interim analysis (median follow-up 8.4 months), the stratified hazard ratio for PFS was 1.209 (95% CI, 0.939 to 1.557; one-sided P value = .9304); therefore, the study was stopped for futility. The 6-month PFS rate was 82.7% (95% CI, 79.0 to 85.8) with amcenestrant + palbociclib versus 86.9% (95% CI, 83.5 to 89.6) with letrozole + palbociclib. In the amcenestrant + palbociclib versus letrozole + palbociclib groups, treatment-emergent adverse events (any grade) occurred in 85.6% versus 85.4% of patients and grade ≥3 events in 46.3% versus 60.8%, respectively. CONCLUSION: The AMEERA-5 study was discontinued on the basis of the recommendation of the data monitoring committee at the interim futility analysis. No new safety signals were identified.

Comparison of platelet count results on the Sysmex XN between citrate or MgSO4 and K2 EDTA anticoagulants.

INTRODUCTION: The aim of this study performed on Sysmex XN is to compare platelet values on citrate and MgSO4 (TBX) in patients with K2EDTA-induced platelet clusters and to identify platelet biases of these matrices compared to K2EDTA. METHODS: Sixty patients with K2EDTA-induced platelet clusters were re-sampled with K2EDTA, citrate and TBX. Platelet results were then compared, and smears were analysed for clumping. Platelet results from 120 patients without K2EDTA-induced platelet clusters were compared between K2 EDTA, citrate, and MgSO4 with impedance and fluorescence modes. Biases from regressions were analysed. RESULTS: Out of the 60 patients with K2EDTA-induced platelet clusters, none showed platelet clusters with MgSO4 whereas 50% still showed clusters with citrate. Among those without platelet clusters on citrate, the mean relative difference between (citrate- MgSO4 )/MgSO4 was -12.7% in impedance and -9.8% in fluorescence. Among the 120 patients without K2EDTA-induced platelet clusters, in fluorescence the mean relative bias with respect to K2EDTA was -2.06% for MgSO4 and -10.3% for Citrate. For the MgSO4 versus K2 EDTA regressions, the maximum absolute values of the 95% CI of the relative biases at 150 × 109 /L (5.45%) and 450 × 109 /L (3.56%) were below the desirable analytical objectives of the EFLM. CONCLUSION: In patients with K2EDTA-induced platelet clusters, MgSO4 is preferable to citrate. MgSO4 provides a bias with XN in fluorescence when compared to EDTA which is within analytical tolerance.

AMEERA-3: Randomized Phase II Study of Amcenestrant (Oral Selective Estrogen Receptor Degrader) Versus Standard Endocrine Monotherapy in Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer.

PURPOSE: Amcenestrant (oral selective estrogen receptor degrader) demonstrated promising safety and efficacy in earlier clinical studies for endocrine-resistant, estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer (aBC). PATIENTS AND METHODS: In AMEERA-3 (ClinicalTrials.gov identifier: NCT04059484), an open-label, worldwide phase II trial, patients with ER+/HER2- aBC who progressed in the (neo)adjuvant or advanced settings after not more than two previous lines of endocrine therapy (ET) were randomly assigned 1:1 to amcenestrant or single-agent endocrine treatment of physician's choice (TPC), stratified by the presence/absence of visceral metastases, previous/no treatment with cyclin-dependent kinase 4/6 inhibitor, and Eastern Cooperative Oncology Group performance status (0/1). The primary end point was progression-free survival (PFS) by independent central review, compared using a stratified log-rank test (one-sided type I error rate of 2.5%). RESULTS: Between October 22, 2019, and February 15, 2021, 290 patients were randomly assigned to amcenestrant (n = 143) or TPC (n = 147). PFS was numerically similar between amcenestrant and TPC (median PFS [mPFS], 3.6 v 3.7 months; stratified hazard ratio [HR], 1.051 [95% CI, 0.789 to 1.4]; one-sided P = .643). Among patients with baseline mutated ESR1; (n = 120 of 280), amcenestrant numerically prolonged PFS versus TPC (mPFS, 3.7 v 2.0 months; stratified HR, 0.9 [95% CI, 0.565 to 1.435]). Overall survival data were immature but numerically similar between groups (HR, 0.913; 95% CI, 0.595 to 1.403). In amcenestrant versus TPC groups, treatment-emergent adverse events (any grade) occurred in 82.5% versus 76.2% of patients and grade ≥3 events occurred in 21.7% versus 15.6%. CONCLUSION: AMEERA-3 did not meet its primary objective of improved PFS with amcenestrant versus TPC although a numerical improvement in PFS was observed in patients with baseline ESR1 mutation. Efficacy and safety with amcenestrant were consistent with the standard of care for second-/third-line ET for ER+/HER2- aBC.