Bcr-Abl inhibitors paved the way of targeted therapy epoch. Imatinib was the first tyrosine kinase inhibitor to be discovered with high specificity for Bcr-Abl protein resulting from t(9, 22)-derived Philadelphia chromosome. Although the specific targeting of that oncoprotein, several Bcr-Abl-dependent and Bcr-Abl-independent mechanisms of resistance to imatinib arose after becoming first-line therapy in chronic myelogenous leukemia (CML) treatment.Consequently, new specific drugs, namely dasatinib, nilotinib, bosutinib, and ponatinib, were rationally designed and approved for clinic to override resistances. Imatinib fine mechanisms of action had been elucidated to rationally develop those second- and third-generation inhibitors. Crystallographic and structure-activity relationship analysis, jointly to clinical data, were pivotal to shed light on this topic. More recently, preclinical evidence on bafetinib, rebastinib, tozasertib, danusertib, HG-7-85-01, GNF-2, and 1,3,4-thiadiazole derivatives lay promising foundations for better inhibitors to be approved for clinic in the near future.Notably, structural mechanisms of action and drug design exemplified by Bcr-Abl inhibitors have broad relevance to both break through resistances in CML treatment and develop inhibitors against other kinases as targeted chemotherapeutics.
Aspergillus fumigatus (AF) is a ubiquitous mold and is the most common cause of invasive aspergillosis, an important source of morbidity and mortality in immunocompromised hosts. Using cytokine flow cytometry, we assessed the magnitude of functional CD4 ؉ and CD8 ؉ T-cell responses following stimulation with Aspergillus antigens. Relative to those seen with cytomegalovirus (CMV) or superantigen stimulation, responses to Aspergillus antigens were near background levels. Subsequently, we confirmed that gliotoxin, the most abundant mycotoxin produced by AF, was able to suppress functional T-cell responses following CMV or staphylococcal enterotoxin B (SEB) stimulation. Additional studies demonstrated that crude AF filtrates and purified gliotoxin inhibited antigen-presenting cell function and induced the preferential death of monocytes, leading to a marked decrease in the monocyte-lymphocyte ratio. Analysis of caspase-3 activation confirmed that gliotoxin preferentially induced apoptosis of monocytes; similar effects were observed in CD83 ؉ monocyte-derived dendritic cells. Importantly, the physiologic effects of gliotoxin in vitro were observed below concentrations recently observed in the serum of patients with invasive aspergillosis. These studies suggest that the production of gliotoxin by AF may constitute an important immunoevasive mechanism that is mediated by direct effects on antigenpresenting cells and both direct and indirect effects on T cells. IntroductionAspergillus fumigatus (AF) is the most common cause of invasive aspergillosis (IA) and a major source of infection-related mortality in immunocompromised patients, such as allogeneic stem cell transplant (SCT) recipients. 1,2 In these patients prophylactic antifungal therapy has been found to have little effect on disease incidence. 1,[3][4][5] Despite advances in early diagnosis and new antifungal agents, 3,6,7 IA remains a leading cause of death in this patient population, with an attributable mortality rate ranging from 30% to 80%. 8 AF is among the most ubiquitous of those fungi with airborne conidia (spores) and is commonly found in human domiciles. Pulmonary infection by AF, the predominant type of IA, is acquired through the inhalation of Aspergillus conidia, while the invasion stage of the disease is characterized by hyphal destruction of pulmonary tissue. 1 The mediocre efficacy of antifungals in the setting of profound immunosuppression contributes to the poor prognosis of this opportunistic infection. The development of effective strategies to improve AF-specific immune reconstitution should greatly influence the natural history of IA.Historically, there was a biphasic distribution of IA following bone marrow transplantation (BMT); IA was most common in the pre-engraftment period associated with neutropenia, with a second peak in incidence associated with acute and/or chronic graft-versushost disease (GVHD). 5 However, recent reports have indicated late-onset IA predominates after allogeneic SCT, often in concomitance with the occurrence o...
Infections by multidrug-resistant (MDR) bacteria are a worrisome phenomenon in hematological patients. Data on the incidence of MDR colonization and related bloodstream infections (BSIs) in haematological patients are scarce. A multicentric prospective observational study was planned in 18 haematological institutions during a 6-month period. All patients showing MDR rectal colonization as well as occurrence of BSI at admission were recorded. One-hundred forty-four patients with MDR colonization were observed (6.5% of 2226 admissions). Extended spectrum beta-lactamase (ESBL)-producing (ESBL-P) enterobacteria were observed in 64/144 patients, carbapenem-resistant (CR) Gram-negative bacteria in 85/144 and vancomycin-resistant enterococci (VREs) in 9/144. Overall, 37 MDR-colonized patients (25.7%) developed at least one BSI; 23 of them (62.2%, 16% of the whole series) developed BSI by the same pathogen (MDRrel BSI), with a rate of 15.6% (10/64) for ESBL-P enterobacteria, 14.1% (12/85) for CR Gram-negative bacteria and 11.1% (1/9) for VRE. In 20/23 cases, MDRrel BSI occurred during neutropenia. After a median follow-up of 80 days, 18 patients died (12.5%). The 3-month overall survival was significantly lower for patients colonized with CR Gram-negative bacteria (83.6%) and VRE (77.8%) in comparison with those colonized with ESBL-P enterobacteria (96.8%). CR-rel BSI and the presence of a urinary catheter were independent predictors of mortality. MDR rectal colonization occurs in 6.5% of haematological inpatients and predicts a 16% probability of MDRrel BSI, particularly during neutropenia, as well as a higher probability of unfavourable outcomes in CR-rel BSIs. Tailored empiric antibiotic treatment should be decided on the basis of colonization.
We present here a systematic analysis of lymphoma and MM patients recruited into 2 clinical trials or treated with radretumab according to compassionate use, describing the biodistribution, dosimetry, safety, and clinical activity of radretumab. Methods: Uptake in lymphoma lesions, safety, and clinical activity of radretumab radioimmunotherapy (R-RIT) were evaluated in 18 relapsed lymphoma or multiple myeloma patients. Results: In 14 of 18 patients, selective tumor uptake was found; 11 of 15 lymphoma patients, including 9 of 11 with Hodgkin lymphoma (HL), were eligible for R-RIT (a priori criteria-based target-tobone marrow ratio . 10:1 for EudraCT no. 2005-000545 or . 4:1 for EudraCT no. 2007-007241-12 at dosimetric imaging). Two HL and 1 diffuse large B cell lymphoma patient achieved complete response; 1 HL patient had partial response. Both multiple myeloma patients receiving R-RIT experienced stabilization of disease. Therefore, the overall objective response rate was 40%. Uncomplicated grade 3-4 thrombocytopenia or leukocytopenia was observed in 5 R-RIT patients, lasting 4-129 d. Conclusion: R-RIT showed a favorable benefit and risk profile in advanced relapsed lymphoma patients and induced complete response in 2 heavily pretreated, relapsed HL patients and in 1 diffuse large B cell lymphoma patient. These results warrant further exploration of R-RIT in larger phase II clinical trials.
Compelling biological and epidemiological evidences point to a key role of genetic variants of the TERT and TERC genes in cancer development. We analyzed the genetic variability of these two gene regions using samples of 2,267 multiple myeloma (MM) cases and 2,796 healthy controls. We found that a TERT variant, rs2242652, is associated with reduced MM susceptibility (OR = 0.81; 95% CI: 0.72–0.92; p = 0.001). In addition we measured the leukocyte telomere length (LTL) in a subgroup of 140 cases who were chemotherapy‐free at the time of blood donation and 468 controls, and found that MM patients had longer telomeres compared to controls (OR = 1.19; 95% CI: 0.63–2.24; ptrend = 0.01 comparing the quartile with the longest LTL versus the shortest LTL). Our data suggest the hypothesis of decreased disease risk by genetic variants that reduce the efficiency of the telomerase complex. This reduced efficiency leads to shorter telomere ends, which in turn may also be a marker of decreased MM risk.
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