Background and purpose:
Chemotherapy-induced neutropenia and neutrophil-to-lymphocyte ratio (NLR) are potentially useful prognostic markers in patients with metastatic castration-resistant prostate ...cancer (mCRPC). This post hoc analysis investigated whether these markers can be utilized for dose considerations and evaluated the prognostic impact of leukocyte subtypes.
Patients and methods:
PROSELICA assessed the non-inferiority of cabazitaxel 20 mg/m2 (C20; n = 598) versus 25 mg/m2 (C25; n = 602) for overall survival (OS) in patients with mCRPC previously treated with docetaxel. The association of grade ⩾ 3 neutropenia, NLR, baseline neutrophilia and lymphopenia with OS, progression-free survival (PFS), and prostate-specific antigen response rate (PSArr) was investigated by an unplanned uni- and multivariate analyses.
Results:
PROSELICA confirmed the negative prognostic value of increased baseline NLR ⩾3, hazard ratio (HR) 1.40; p < 0.0001, but did not identify a subgroup of patients benefiting more from C20 or C25. In this post hoc analysis, patients who developed grade ⩾3 neutropenia (n = 673) had a significantly improved OS ∆OS = 2.7 months, HR = 0.78 (95% CI 0.68–0.89) with the greatest advantage observed in patients with baseline neutrophilia n = 85; 5.3 months, 0.60 (0.42–0.84). After adjustment for the Halabi criteria, neutropenia grade ⩾ 3 was the only biomarker that remained significantly associated with OS (HR 0.86 (0.75–0.98), PFS HR 0.78 (0.68–0.88), and PSArr odds ratio (OR) 1.82 (1.37–2.41) while neutrophilia showed the strongest association with OS 1.53 (1.29–1.81).
Conclusions:
Grade ⩾ 3 neutropenia was the only leukocyte-based biomarker associated with all key outcome parameters in mCRPC patients receiving cabazitaxel and might be able to overcome the negative prognostic effect of baseline neutrophilia.
NCT number:
NCT01308580
Stimulation of the immune system by targeting the PD-1/PD-L1 pathway can result in activation of anti-tumor immunity. Besides its clinical benefit immune checkpoint therapy leads to significant ...immune-related adverse events (irAEs). Some rare irAEs are not well described yet but are critical in patient management.
Here, we describe a case of autoimmune cerebral vasculitis/encephalitis after PD-1 inhibitor treatment for metastatic adenocarcinoma of the lung. Upon PD-1 blockade, the patient developed cerebral lesions, while having disease stabilization of extracranial metastases. Imaging suggested that the patient had new progressing brain metastases. Despite stereotactic irradiation the lesions progressed further. The largest lesion became symptomatic and had to be surgically resected. On examination, cerebral vasculitis was detected but not evidence of metastatic lung cancer. Analysis of the patient's serum revealed the presence of antinuclear antibodies that were already present before starting PD-1 blockade. In addition, we also found anti-vascular endothelial antibodies in the serum.
This finding suggests that the patient had preformed autoantibodies and the checkpoint inhibitor induced a clinically relevant autoimmune disease. Taken together, encephalitic lesions in patients under PD-1/PD-L1 blockade can mimic metastatic brain lesions and this rare irAE has to be considered as a differential diagnosis in patients treated with immunotherapy.
The Golgi associated retrograde protein complex (GARP) or Vps fifty-three (VFT) complex is part of cellular inter-compartmental transport systems. Here we report the identification of the VFT ...tethering factor complex and its interactions in mammalian cells. Subcellular fractionation shows that human Vps proteins are found in the smooth membrane/Golgi fraction but not in the cytosol. Immunostaining of human Vps proteins displays a vesicular distribution most concentrated at the perinuclear envelope. Co-staining experiments with endosomal markers imply an endosomal origin of these vesicles. Significant accumulation of VFT complex positive endosomes is found in the vicinity of the Trans Golgi Network area. This is in accordance with a putative role in Golgi associated transport processes.
In
Saccharomyces cerevisiae, GARP is the main effector of the small GTPase Ypt6p and interacts with the SNARE Tlg1p to facilitate membrane fusion. Accordingly, the human homologue of Ypt6p, Rab6, specifically binds hVps52.
In human cells, the “orphan” SNARE Syntaxin 10 is the genuine binding partner of GARP mediated by hVps52. This reveals a previously unknown function of human Syntaxin 10 in membrane docking and fusion events at the Golgi. Taken together, GARP shows significant conservation between various species but diversification and specialization result in important differences in human cells.
T-cell interaction with a target cell is a key event in the adaptive immune response and primarily driven by T-cell receptor (TCR) recognition of peptide-MHC (pMHC) complexes. TCR avidity for a given ...pMHC is determined by number of MHC molecules, availability of coreceptors, and TCR affinity for MHC or peptide, respectively, with peptide recognition being the most important factor to confer target specificity. Here we present high-resolution crystal structures of 2 Fab antibodies in complex with the immunodominant NY-ESO-1₁₅₇₋₁₆₅ peptide analogue (SLLMWITQV) presented by HLA-A*0201 and compare them with a TCR recognizing the same pMHC. Binding to the central methionine-tryptophan peptide motif and orientation of binding were almost identical for Fabs and TCR. As the MW "peg" dominates the contacts between Fab and peptide, we estimated the contributions of individual amino acids between the Fab and peptide to provide the rational basis for a peptide-focused second-generation, high-affinity antibody library. The final Fab candidate achieved better peptide binding by 2 light-chain mutations, giving a 20-fold affinity improvement to 2-4 nM, exceeding the affinity of the TCR by 1,000-fold. The high-affinity Fab when grafted as recombinant TCR on T cells conferred specific killing of HLA-A*0201/NY-ESO-1₁₅₇₋₁₆₅ target cells. In summary, we prove that affinity maturation of antibodies mimicking a TCR is possible and provide a strategy for engineering high-affinity antibodies that can be used in targeting specific pMHC complexes for diagnostic and therapeutic purposes.
Carbonic anhydrase 9 (CA9) and carbonic anhydrase 12 (CA12) were proposed as potential targets for cancer therapy more than 20 years ago. However, to date, there are only very few antibodies that ...have been described to specifically target CA9 and CA12 and also block the enzymatic activity of their targets. One of the early stage bottlenecks in identifying CA9- and CA12-inhibiting antibodies has been the lack of a high-throughput screening system that would allow for rapid assessment of inhibition of the targeted carbon dioxide hydratase activity of carbonic anhydrases. In this study, we show that measuring the esterase activity of carbonic anhydrase offers a robust and inexpensive screening method for identifying antibody candidates that block both hydratase and esterase activities of carbonic anhydrase's. To our knowledge, this is the first implementation of a facile surrogate-screening assay to identify potential therapeutic antibodies that block the clinically relevant hydratase activity of carbonic anhydrases.
We report a case of POEMS syndrome which relapsed six years after autologous peripheral blood stem cell transplantation. According to encouraging data published recently, we treated the patient with ...cyclophosphamide, dexamethasone and the VEGF-antibody bevacizumab. After an initial improvement, the subsequent course was complicated by severe adverse events leading to multiorgan failure and death. This dramatic decline highlights the need for further investigation before using bevacizumab in patients with POEMS syndrome.
Abstract Background Cabazitaxel significantly improves overall survival (OS) in men with metastatic castration-resistant prostate cancer (mCRPC) progressing during or after docetaxel, but is ...associated with a higher rate of grade ≥3 neutropenia compared with docetaxel. We thus examined the relationship between cabazitaxel-induced grade ≥3 neutropenia, baseline neutrophil-lymphocyte ratio (NLR) and treatment outcomes. Methods Data from the experimental arm of the TROPIC phase 3 trial which randomly assigned men with mCRPC to cabazitaxel or mitoxantrone every 3 weeks, both combined with daily prednisone, were analysed. The influence on OS (primary end-point) and progression-free survival (PFS) of at least one episode of grade ≥3 neutropenia during cabazitaxel therapy was investigated using Cox regression models, adjusted for pain at baseline. The relationships with prostate-specific antigen (PSA) responses during cabazitaxel therapy and baseline NLR were also analysed. Findings The occurrence of grade ≥3 neutropenia during cabazitaxel therapy was associated with a prolonged OS (median 16.3 versus 14.0 months, hazard ratio (HR) 95% confidence interval = 0.65 0.43–0.97, p = 0.035), a twice longer PFS (median 5.3 versus 2.6 months, HR = 0.56 0.40–0.79, p = 0.001) and a higher confirmed PSA response ≥50% (49.8% versus 24.4%, p = 0.005), as compared with patients who did not develop grade ≥3 neutropenia. Grade ≥3 neutropenia was more common in case of NLR <3 as compared with NLR ≥3 at baseline (88.8% versus 75.3%, p = 0.002). Combining low NLR at baseline and grade ≥3 neutropenia during therapy was associated with the longest OS (median 19.2 months) while high NLR at baseline and no grade ≥3 neutropenia was associated with a poor OS (median 12.9 months, HR 0.46 0.28–0.76, p = 0.002). In the subgroup of neutropenic patients the median OS was 19.7 months in those treated with granulocyte colony-stimulating factor (G-CSF) and 16 months on those without G-CSF support. Interpretation This post-hoc analysis of TROPIC suggests that the occurrence of grade ≥3 neutropenia with cabazitaxel is associated with improved OS and PFS. Patients with a low NLR at baseline were more likely to develop grade ≥3 neutropenia during cabazitaxel therapy and showed the longest OS. High NLR at baseline and no grade ≥3 neutropenia during therapy was associated with poor outcomes which may suggest insufficient drug exposure or a limited impact on the tumour-associated immune response. Primary or secondary prophylactic use of G-CSF had no adverse impact for outcome. If prospectively confirmed, these results would justify maintaining the intended cabazitaxel dose of 25 mg/m2 whenever possible.
We report here the identification of a bacterial protein capable of interacting with mammalian death receptors in vitro and in vivo. The protein is encoded in the genome of Chlamydia trachomatis and ...has homologues in otherChlamydia species. This protein, which we refer to as “Chlamydia protein associating with death domains” (CADD), induces apoptosis in a variety of mammalian cell lines when expressed by transient gene transfection. Apoptosis induction can be blocked by Caspase inhibitors, indicating that CADD triggers cell death by engaging the host apoptotic machinery. CADD interacts with death domains of tumor necrosis factor (TNF) family receptors TNFR1, Fas, DR4, and DR5 but not with the respective downstream adaptors. In infected epithelial cells, CADD is expressed late in the infectious cycle of C. trachomatisand co-localizes with Fas in the proximity of the inclusion body. The results suggest a role for CADD modulating the apoptosis pathways of cells infected, revealing a new mechanism of host-pathogen interaction.
The Chlamydia protein CADD (Chlamydia protein associating with death domains) has been implicated in the modulation of host cell apoptosis via binding to the death domains of tumor necrosis factor ...family receptors. Transfection of CADD into mammalian cells induces apoptosis. Here we present the CADD crystal structure, which reveals a dimer of seven-helix bundles. Each bundle contains a di-iron center adjacent to an internal cavity, forming an active site similar to that of methane mono-oxygenase hydrolase. We further show that CADD mutants lacking critical metal-coordinating residues are substantially less effective in inducing apoptosis but retain their ability to bind to death domains. We conclude that CADD is a novel redox protein toxin unique to Chlamydia species and propose that both its redox activity and death domain binding ability are required for its biological activity.
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