ABSTRACT
Purpose@#Pemigatinib is a fibroblast growth factor receptor-2 (FGFR2) inhibitor approved for use in patients with previously treated cholangiocarcinoma (CCA) and FGFR2 fusions or rearrangements. This ongoing global Expanded Access Program (EAP) allows physicians in regions where pemigatinib is not commercially available to request pemigatinib for patients with locally advanced or metastatic CCA who, in the physician’s opinion, could benefit from pemigatinib treatment. @*Materials and Methods@#Eighty-nine patients from Europe, North America, and Israel were treated from January 2020 through September 2021. @*Results@#Patients had FGFR gene fusions (68.5%), rearrangements (12.4%), translocations (5.6%), amplifications (2.2%), and other alterations (11.2%). Median duration of treatment in the EAP was 4.0 months (range, 0.1 to 13.6 months). The most frequently reported adverse event (AE) was hyperphosphatemia (22.5%); the most common serious AE was cholangitis (3.4%). Treatment discontinuation was associated with reports of AEs for seven patients (7.9%). AEs associated with pemigatinib were consistent with those observed in clinical trials. @*Conclusion@#Efficacy was not assessed in this EAP. However, some patients remained on treatment for up to a year, suggesting that they observed a benefit from treatment. Patients with CCA should undergo molecular testing to identify those who could benefit from targeted treatments such as pemigatinib.
ABSTRACT
The rapid emergence of the Omicron variant and its large number of mutations has led to its classification as a variant of concern (VOC) by the WHO(1). Initial studies on the neutralizing response towards this variant within convalescent and vaccinated individuals have identified substantial reductions(2-8). However many of these sample sets used in these studies were either small, uniform in nature, or were compared only to wild-type (WT) or, at most, a few other VOC. Here, we assessed IgG binding, (Angiotensin-Converting Enzyme 2) ACE2 binding inhibition, and antibody binding dynamics for the omicron variant compared to all other VOC and variants of interest (VOI)(9), in a large cohort of infected, vaccinated, and infected and then vaccinated individuals. While omicron was capable of binding to ACE2 efficiently, antibodies elicited by infection or immunization showed reduced IgG binding and ACE2 binding inhibition compared to WT and all VOC. Among vaccinated samples, antibody binding responses towards omicron were only improved following administration of a third dose. Overall, our results identify that omicron can still bind ACE2 while pre-existing antibodies can bind omicron. The extent of the mutations appear to inhibit the development of a neutralizing response, and as a result, omicron remains capable of evading immune control.
ABSTRACT
As global vaccination campaigns against SARS-CoV-2 proceed, there is particular interest in the longevity of immune protection, especially with regard to increasingly infectious virus variants. Neutralizing antibodies (Nabs) targeting the receptor binding domain (RBD) of SARS-CoV-2 are promising correlates of protective immunity and have been successfully used for prevention and therapy. As SARS-CoV-2 variants of concern (VOCs) are known to affect binding to the ACE2 receptor and by extension neutralizing activity, we developed a bead-based multiplex ACE2-RBD inhibition assay (RBDCoV-ACE2) as a highly scalable, time-, cost-, and material-saving alternative to infectious live-virus neutralization tests. By mimicking the interaction between ACE2 and the RBD, this serological multiplex assay allows the simultaneous analysis of ACE2 binding inhibition to the RBDs of all SARS-CoV-2 VOCs and variants of interest (VOIs) in a single well. Following validation against a classical virus neutralization test and comparison of performance against a commercially available assay, we analyzed 266 serum samples from 168 COVID-19 patients of varying severity. ACE2 binding inhibition was reduced for ten out of eleven variants examined compared to wild-type, especially for those displaying the E484K mutation such as VOCs beta and gamma. ACE2 binding inhibition, while highly individualistic, positively correlated with IgG levels. ACE2 binding inhibition also correlated with disease severity up to WHO grade 7, after which it reduced.
ABSTRACT
The pathophysiology of COVID-19 associated thrombosis seems to be multifactorial, involving interplay between cellular and plasmatic elements of the hemostasis. We hypothesized that COVID-19 is accompanied by platelet apoptosis with subsequent alteration of the coagulation system. We investigated depolarization of mitochondrial inner transmembrane potential ({Delta}{Psi}m), cytosolic calcium (Ca2+) concentration, and phosphatidylserine (PS) externalization by flow cytometry. Platelets from intensive care unit (ICU) COVID-19 patients (n=21) showed higher {Delta}{Psi}m depolarization, cytosolic Ca2+ concentration and PS externalization, compared to healthy controls (n=18) and COVID-19 non-ICU patients (n=4). Moreover significant higher cytosolic Ca2+ concentration and PS was observed compared to septic ICU control group (ICU control). In ICU control group (n=5; ICU non-COVID-19) cytosolic Ca2+ concentration and PS externalization was comparable to healthy control, with an increase {Delta}{Psi}m depolarization. Sera from ICU COVID-19 13 patients induced significant increase in apoptosis markers ({Delta}{Psi}m depolarization, cytosolic Ca2+ concentration and PS externalization). compared to healthy volunteer and septic ICU control. Interestingly, immunoglobulin G (IgG) fractions from COVID-19 patients induced an Fc gamma receptor IIA dependent platelet apoptosis ({Delta}{Psi}m depolarization, cytosolic Ca2+ concentration and PS externalization). Enhanced PS externalization in platelets from ICU COVID-19 patients was associated with increased sequential organ failure assessment (SOFA) score (r=0.5635) and DDimer (r=0.4473). Most importantly, patients with thrombosis had significantly higher PS externalization compared to those without. The strong correlations between apoptosis markers and increased D-Dimer levels as well as the incidence of thrombosis may indicate that antibody-mediated platelet apoptosis potentially contributes to sustained increased thromboembolic risk in ICU COVID-19 patients. Key pointsO_LISevere COVID-19 is associated with increased antibody-mediated platelet apoptosis. C_LIO_LIPlatelet apoptosis in severe COVID-19 is correlated with D-Dimer and higher incidence of thromboembolisms. C_LI
