In vivo efficacy and PK/PD analyses of zifanocycline (KBP-7072), an aminomethylcycline antibiotic, against Acinetobacter baumannii in a neutropenic murine thigh infection model.

INTRODUCTION: Zifanocycline (KBP-7072) is a novel aminomethylcycline antibiotic with a broad spectrum of antibacterial activity. This study determined the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of zifanocycline in mice and the optimal PK/PD index for efficacy against Acinetobacter baumannii in a neutropenic murine thigh infection model. METHODS: Zifanocycline PK properties were characterized in plasma after single-dose subcutaneous injection in healthy mice at doses of 1, 4, 16, 64, and 256 mg/kg. PK/PD analyses were performed with zifanocycline against 8 clinical A. baumannii isolates in a neutropenic murine thigh infection model. RESULTS: Plasma total and free drug Cmax, AUC0-inf, and AUC0-24 increased with dose, where Cmax of total drug was 0.12-25.2 mg/L, AUC0-inf was 1.13-234 h*mg/L, AUC0-24 was 1.09-225 h*mg/L, and free drug Cmax was 0.03-5.68 mg/L, AUC0-inf was 0.25-52.6 h*mg/L, and AUC0-24 was 0.25-50.5 h*mg/L. MICs of zifanocycline against A. baumannii ranged from 0.06 to 0.5 mg/L, with significant activity against all 8 strains. Average daily doses of zifanocycline to achieve a static, 1-log10 kill, and 2-log10 kill effect were projected to be 6.92, 9.63, and 13.22 mg/kg, and the mean fAUC/MIC ratios were 6.91, 9.10, and 12.60, respectively. AUC/MIC was the optimal PK/PD index of zifanocycline against A. baumannii. CONCLUSION: The in vivo efficacy results and PK/PD analyses support the design of optimal dosing regimens in clinical studies and assist with determining clinical breakpoints for zifanocycline.

Deferiprone versus deferoxamine for transfusional iron overload in sickle cell disease and other anemias: Pediatric subgroup analysis of the randomized, open-label FIRST study.

BACKGROUND: Children with sickle cell disease (SCD) who are chronically transfused often, require iron chelation therapy. There are limited data that allow for comparison of the efficacy and safety of the iron chelator deferiprone versus deferoxamine in children with SCD. METHODS: This post hoc analysis of the phase 3b/4, randomized, open-label FIRST (Ferriprox in Patients with IRon Overload in Sickle Cell Disease Trial) study (NCT02041299) included patients 17 years and younger with SCD or other anemias receiving deferiprone or deferoxamine. RESULTS: Overall, 142 patients were evaluated; mean ages were 10.5 and 11.7 years in the deferiprone and deferoxamine groups, respectively. At 12 months: mean change from baseline in liver iron concentration was -3.3 mg/g dry weight (dw) with deferiprone and -3.4 mg/g dw with deferoxamine (p = .8216); relative mean change (coefficient of variation %) in log cardiac T2* magnetic resonance imaging was 1.02 (21.8%) with deferiprone and 0.95 (19.5%) with deferoxamine (p = .0717); and the mean (standard error) change in serum ferritin levels was -133.0 (200.3) µg/L with deferiprone and -467.1 (244.1) µg/L with deferoxamine (p = .2924). The most common deferiprone-related adverse events (AEs) were upper abdominal pain (20.2%), vomiting (13.8%), pyrexia (9.6%), decreased neutrophil count (9.6%), increased alanine aminotransferase (ALT; 9.6%), and increased aspartate aminotransferase (AST; 9.6%). All cases of increased ALT, increased AST, and neutropenia resolved, most without intervention. CONCLUSIONS: This post hoc analysis of pediatric patients from FIRST corroborated previous findings in adults that deferiprone is comparable to deferoxamine in reducing iron overload. No new safety concerns were observed. Deferiprone is an oral chelation option that could improve adherence and outcomes in children.

Experience of the use of lock therapy in pediatric patients with central venous catheter. / Experiencia del uso de terapia de sello en pacientes pediátricos con catéter venoso central.

Lock therapy is useful for preserving indwelling catheters. Few lock therapy studies have been published in Latin America. OBJECTIVE: To describe the clinical characteristics of pediatric patients using therapeutic and prophylactic lock therapy for six years in a high-complexity hospital in Colombia. PATIENTS AND METHOD: Cross-sectional descriptive study of patients aged < 18 years who received lock therapy. Collected variables included demographic data, clinical characteristics, blood test results, therapeutic interventions, frequency of admission to the pediatric critical care unit, and mortality. Descriptive analysis was performed. RESULTS: 54 patients were included in the study, most of them males, with 67 episodes of therapeutic lock therapy use. The most frequent diagnosis was hematological neoplasm (61%). Among these patients, 88% presented neutropenia while receiving lock therapy. Catheter preservation was achieved in 75% of the cases. Aminoglycosides were the most commonly used antibiotics (38%). Mortality due to catheter-related bacteremia was 6%. Catheter preservation using ethanol solution 70% was achieved in 62% of the patients with prophylactic lock therapy, all of whom had chronic gastrointestinal pathology. CONCLUSION: Catheter preservation rates were 75% and 62% in patients with therapeutic and prophylactic lock therapy, respectively, with a higher rate achieved among cancer patients with neutropenia (80%). Aminoglycosides and vancomycin were the most commonly used antibiotics.

Efficacy and Safety of Oxaliplatin-based Regimens as First-line Chemotherapy in Elderly Patients With Metastatic Colorectal Cancer.

BACKGROUND/AIM: Metastatic colorectal cancer (mCRC) is mainly a disease of the elderly. The aim of this retrospective study was to investigate the efficacy and safety of oxaliplatin-based regimens as first-line chemotherapy in elderly patients with mCRC. PATIENTS AND METHODS: We recruited mCRC patients aged ≥75 years who were treated with oxaliplatin-based chemotherapy as first-line therapy from October 2011 to November 2020. Primary outcome was median progression-free survival (PFS) and incidence of adverse events, while secondary outcomes included overall survival (OS), relative dose intensity (RDI) and tumor response rate. RESULTS: The study enrolled 41 patients with mCRC aged ≥75 years. Median PFS and OS were 9.3 months and 38.9 months, respectively. Median rate of starting dose per standard dose and median RDI of L-OHP were 94.6% [interquartile range (IQR)=80.0-100] and 52.4% (IQR=30.2-71.1), respectively. The most common adverse events of grade ≥3 were neutropenia (21.4%), high blood pressure (16.7%), and anorexia (14.3%). CONCLUSION: Although the RDI of L-OHP drug was low, the PFS, OS, and incidence of adverse events were similar to previous reports of oxaliplatin-based regimens not limited to the elderly. Oxaliplatin-based regimens as first-line chemotherapy may be safely and effectively adapted to patients aged ≥75 years with mCRC by continuing chemotherapy with implementation of a reduction and discontinuation of anticancer drugs depending on adverse events.

Antithyroid drug-induced leukopenia and G-CSF administration: a long-term cohort study.

Although antithyroid drug (ATD)-induced agranulocytosis is a significant concern, its risks associated with long-term use and re-administration are not fully elucidated. Therefore, we performed this study to determine the incidence of ATD-induced leukopenia and G-CSF administration using administrative claims database. Retrospective cohort study. This study was performed using the DeSC Japanese administrative claims database. A total of 12,491 patients with newly diagnosed Graves' disease (GD) who received methimazole or propylthiouracil between April 2014, and February 2021 among 3.44 million patients in the database were included in the study. We measured the six-year incidence of leukopenia and granulocyte colony-stimulating factor (G-CSF) administration. The incidence of leukopenia and G-CSF administration was 1.34% (168 patients) and 0.30% (38 patients), respectively. Leukopenia had a dose-dependent and biphasic incidence. The incidence of leukopenia and G-CSF administration was 37.2 (0.7%) and 8.0 (0.2%) per 1000 person-years during the first 72 days of ATD initiation, whereas it was 3.1 and 0.7 per 1000 person-years during the subsequent 6 years, respectively. The incidence of both outcomes was comparable between first administration and re-administration of ATD. The incidence of ATD-induced leukopenia and G-CSF administration was high in the first 72 days, with a reduced risk for at least 6 years thereafter. The incidence was similar between first administration and re-administration. ATD, a standard therapy, is often administered for a long period; therefore, our findings can guide the treatment of GD.

Prognostic impact of severe neutropenia in colorectal cancer patients treated with TAS-102 and bevacizumab, addressing immortal-time bias.

BACKGROUND: Several studies have reported an association between severe neutropenia and long-term survival in patients treated with trifluridine-tipiracil (TAS-102). Because some of these studies failed to address immortality time bias, however, their findings should be interpreted with caution. Additionally, the association between severe neutropenia and survival in patients receiving TAS-102 in combination with bevacizumab (Bmab) remains unclear. PATIENTS AND METHODS: We conducted a single-center retrospective cohort study in patients with colorectal cancer who received Bmab + TAS-102. We compared overall survival (OS) between patients who developed grade ≥ 3 neutropenia during the treatment period and those who did not. To account for immortal time bias, we used two approaches, time-varying Cox regression and landmark analysis. RESULTS: Median OS was 15.3 months [95% CI: 14.1-NA] in patients with grade ≥ 3 neutropenia and 10.0 months [95% CI: 8.1-NA] in those without. In time-varying Cox regression, onset grade ≥ 3 neutropenia was significantly related to longer survival after adjustment for age and modified Glasgow Prognostic Score. Additionally, 30-, 60-, 90-, and 120-day landmark analysis showed that grade ≥ 3 neutropenia was associated with longer survival after adjustment for age and modified Glasgow Prognostic Score, with respective HRs of 0.30 [0.10-0.90], 0.65 [0.30-1.42], 0.39 [0.17-0.90], and 0.41 [0.18-0.95]. CONCLUSION: We identified an association between long-term survival and the development of severe neutropenia during the early cycle of Bmab + TAS-102 using an approach that addressed immortality time bias.

Evaluation of the relationship between toxicity of cyclin-dependent kinase 4/6 inhibitors and body surface area.

OBJECTIVE: This study aimed to evaluate the relationship between the toxicity of cyclin-dependent kinase 4/6 inhibitors and body mass index and body surface area. METHODS: A total of 83 patients were included in the study. Patients were divided into 4 groups as 18-24.9, 25-29.9, 30-39.9, and >40 kg/m2 according to body mass index and into two groups as below and above 1.77 according to body surface area. The relationship between body mass index and body surface area and side effects was evaluated. RESULTS: No statistically significant difference was found between body mass index groups and side effects. Grade 3 neutropenia was more common in patients on palbociclib with a body surface area≤1.77. In our study, it was revealed that less hematological side effects can be encountered when body surface area is taken into account.

RC48-ADC treatment for patients with HER2-expressing locally advanced or metastatic solid tumors: a real-world study.

BACKGROUND: RC48-antibody-drug conjugates (ADC) link humanized anti-HER2 immunoglobulin with monomethyl auristatin E (MMAE). Clinical trials suggest promising antitumor activity in HER2-expressing solid tumors. This study probes RC48-ADC's efficacy and safety in patients with HER2-expressing advanced or metastatic solid tumors. METHOD: Data was collected from 23 advanced cancer patients treated with RC48-ADC at our oncology center between July 2021 and December 2022. These patients exhibited at least 1 + expression of HER2 immunohistochemistry, had previously experienced at least one failed systemic chemotherapy, and were treated with RC48-ADC until the occurrence of intolerable adverse reactions or disease progression. The primary endpoint was the disease control rate (DCR), and secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety. RESULTS: 23 of 25 screened patients received RC48 treatment. The ORR was 43.5% (95% CI, 23.2-63.7%) with a median PFS of 6.0 months (95% CI, 4.8-7.4). In the low-to-medium HER2 expression subgroup, ORR was 37.5%, median PFS 5.75 months. In the high HER2 expression subgroup, ORR was 57.1%, median PFS 7 months. For the cohort combining RC48 with PD-1 inhibitors, ORR was 53.8%, median PFS 8 months. In the concurrent local radiation therapy subgroup, ORR was 40.0%, median PFS 6.0 months. Treatment-related adverse events (TRAEs) were anemia (60.8%), leukopenia (56.2%), raised transaminases (52.17%), and neutropenia (43.5%). Five patients (21.7%) experienced Grade 3 symptoms, including anemia (21.7%) and neutropenia (14.0%). No Grade 4 adverse reactions or deaths were reported. CONCLUSION: RC48-ADC shows promising efficacy and manageable safety in HER2-expressing advanced or metastatic solid tumor patients.

Molecular diagnosis, phylogenetic analysis, and antifungal susceptibility profiles of Candida species isolated from neutropenic oncological patients.

BACKGROUND: Neutropenia is the most important cause of life-threatening invasive fungal infections (IFIs). Here, we studied the frequency and antifungal susceptibility profiles of Candida species that colonized or caused infections among neutropenic patients with solid or hematological malignancies. METHODS: A total of 362 clinical samples were collected from 138 patients. After initial isolation using a mix of mycological methods, isolates were screened using chromogenic culture media. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was applied for molecular identification. Positive or suspected cases were confirmed using the reference method of sequencing. Antifungal susceptibility testing for voriconazole and caspofungin was carried out using the microbroth dilution method. An in-silico assay was applied for phylogenetic analysis. RESULTS: Thirty-four Candida strains were isolated. C. albicans (47.06%) and C. glabrata (29.41%) were the most frequent strains. Antifungal treatment reduced the chance of Candida colonization by almost 76% in neutropenic patients (OR: 1.759; 95% CI: 1.349 to 2.390; p value: 0.000). An unusual and non-resistant strain, C. lambica, was reported from the bloodstream of a 56-year-old man with hematologic malignancy (HM). Eight isolates were non-susceptible, and one isolate was resistant to voriconazole. Also, four isolates were non-susceptible to caspofungin. CONCLUSION: We can conclude that there is a cause-and-effect relationship between neutropenia, HM background, and Candida species separated from neutropenic patients, which can lead to possible infections. Further and repetitive studies are recommended using different molecular methods for better prediction and management of fungal infections in neutropenic patients.

Screening for ELANE, HAX1 and GFI1 gene mutations in children with neutropenia and clinical characterization of two novel mutations in ELANE gene.

BACKGROUND: Congenital neutropenia is a rare disease. Recurrent infections since young age are the presentation. The most common mutation causing severe congenital neutropenia (SCN) and cyclic neutropenia (CyN) is the ELANE gene. The objectives of this study were to screen the three common genetic mutations of ELANE, HAX1 and GFI1 in children with chronic neutropenia and to describe the clinical characteristics of children who had the mutations. METHODS: Infants having ANC < 1,000/cu mm or children aged > 1 year having ANC < 1,500/cu mm at least 3 times in 3 months were enrolled in the study. Patients who had acquired neutropenia due to infection, immune deficiency, or drugs were excluded. The ELANE gene was first studied; and if mutations were not identified, the HAX1 and GFI1 genes were further examined. RESULTS: A total of 60 patients were enrolled in the study. The median (range) age, ratio of female to male, ANC, and last follow-up age were 9.2 (0.5-45.2) months, 1:1.2, 248 (0-1,101) /cu mm, and 19.9 (3.5-202.3) months, respectively. Infections were noted in 67.3% of all patients. ELANE gene mutation was found in only four patients (6.7%), and the rest (56 patients) showed no mutations in the HAX1 and GFI1 genes. In patients without mutations, 66.0% had normal ANC during the follow-up, with a median (range) age for normal ANC of 19.8 (4.0-60.0) months. Two novel mutations p. Ala79del (c.234_236del) and p. Val197GlufsTer18 (c.589_590insAGGCCGGC) were identified, and they respectively cause SCN and CyN. Patients with the two novel mutations presented with several episodes of infection, including pneumonia, sepsis, abscess, otitis media, and gum infection. CONCLUSION: The genetic screening for ELANE, HAX1, and GFI1 gene mutations in 60 patients with chronic neutropenia could identify four patients (6.7%) with ELANE gene mutation and two novel mutations, p. Ala79del in exon 3 and p. Val197GlufsTer18 in exon 4 causing SCN; and CyN, respectively.

Neutropenic ulcers in oncology: terminology, diagnosis, and management.

Neutropenic ulcerations are characterized by mucosal ulcerations which occur in the presence of neutropenia, suggesting a direct link between neutropenia and mucosal ulceration. An oral ulcer can be labeled as "neutropenic" only if the patients have primary (typically congenital) or secondary neutropenia, and neutropenia is the sole causative factor. Oral mucosal ulcers observed in patients undergoing oncologic therapy may also be termed as "neutropenic ulcers", but the pathogenesis of these oral ulcers more likely involves mucosal events related to trauma, microbial factors, and direct cytotoxicity. In cancer patients, the early appearance of oral ulcers is often attributed to oral mucositis which is a condition primarily caused by the direct mucosal cytotoxicity of chemotherapeutic agents and radiation therapy. Oral ulcers that develop later during or after active cancer therapy may result from intraoral trauma and typically manifest on non-keratinized areas of the oral mucosa which are more susceptible to mucosal damage. In patients undergoing chemotherapy, factors such as disturbances in mucosal barrier function as well as bone marrow suppression lead to reduced neutrophil count and function, and can contribute to the development of oral ulcers. While the etiology of oral ulcers in cancer therapy receiving patients can vary, it is important to emphasize that the host's response plays a crucial role in the progression and repair process of these lesions. This narrative review presents the etiopathogenesis, clinical presentation, and potential management approaches for oral ulcerations in neutropenic patients, with a particular focus on clarifying the usage of the term "neutropenic ulcer" since this term lacks diagnostic specificity and can be misleading in clinical practice regarding the underlying causes and treatment strategies.

Clozapine-Associated Agranulocytosis: A Systematic Review. Is It Really So Frighteningly Common?

BACKGROUND: Clozapine is a very effective therapeutic option for schizophrenic disorders that have been refractory to most other therapies. This extremely positive aspect clashes easily with an adverse effect of the drug that is deemed to be a very dangerous one: agranulocytosis. We asked whether the mandatory strict hematological follow-up prescribed in the black box warning of clozapine's label is proportioned to the actual incidence of agranulocytosis, considering that is the main reason that such a drug is often used only late in the treatment course. METHODS: We carried out a systematic review of reports examining clozapine administration and agranulocytosis incidence. We specifically selected those where mild and moderate neutropenia was not used as a trigger to stop administration of clozapine, to better estimate the sheer incidence of agranulocytosis when clozapine was continued even with mild hematological effect, where detected. We used PubMed, MEDLINE, EMBASE, Cochrane, and ScienceDirect databases to identify clinical studies conducted between January 1975 and April 2023. RESULTS: We included 14 studies, mostly retrospective ones, that examined the incidence of hematological adverse effects in patients using clozapine. A total of 2354 subjects were included. The mean age of the subjects was 33.5 years. The mean duration of observation of subjects who took clozapine was 800 days, with a mean daily dose of 319.5 mg per day. Of the 2354 subjects examined, we found that 11 of them experienced agranulocytosis (0.47%). CONCLUSIONS: These results suggest the evidence of a lower incidence of agranulocytosis than previously estimated and are in line with more recent meta-analyses. We may therefore think that clinical practice may demand a revision of the approach that both psychiatrists and supervising organizations often take when talking about clozapine.

Case Report: Characterization of known (c.607G>C) and novel (c.416C>G) ELANE mutations in two Mexican families with congenital neutropenia.

The most common causes of congenital neutropenia are mutations in the ELANE (Elastase, Neutrophil Expressed) gene (19p13.3), mostly in exon 5 and the distal portion of exon 4, which result in different clinical phenotypes of neutropenia. Here, we report two pathogenic mutations in ELANE, namely, c.607G>C (p.Gly203Arg) and a novel variant c.416C>G (p.Pro139Arg), found in two Mexican families ascertained via patients with congenital neutropenia who responded positively to the granulocyte colony-stimulating factor (G-CSF) treatment. These findings highlight the usefulness of identifying variants in patients with inborn errors of immunity for early clinical management and the need to rule out mosaicism in noncarrier parents with more than one case in the family.

Efficacy and Safety of RET-Specific Kinase Inhibitors in RET-Altered Cancers: A Systematic Review.

RET proto-oncogene encodes receptor tyrosine kinase. Selpercatinib and pralsetinib are the only RET-specific tyrosine kinase inhibitors approved by FDA in RET-altered tumors. We searched PubMed, Embase, Cochrane, WOS, and Clinicaltrials.gov. Objective-response, complete-response, and partial-response were 60-89%, 0-11%, and 55-89%, respectively, with the use of RET-specific drugs. ≥Grade 3 adverse events were seen in 28-53% of the patients, with hypertension, change in ALT, QT prolongation, neutropenia, and pneumonitis among the common side effects. Hence, selpercatinib and pralsetinib were effective and well tolerated by most of the patients with RET-altered tumors.

[Clinical features and genetic analysis of a child with 3-methylglutenedioic aciduria type VII due to novel variants of CLPB gene].

OBJECTIVE: To explore the clinical features and genetic basis for a child with 3-methylglutaconic aciduria type VII. METHODS: A child who was diagnosed at the Gansu Provincial Maternity and Child Health Care Hospital on August 9, 2019 was selected as the study subject. Clinical data of the child, including urine gas chromatography and mass spectrometry, were collected. The child and her parents were subjected to whole exome sequencing. RESULTS: The child, a female neonate, had presented mainly with intermittent skin cyanosis, convulsions, hypomagnesemia, apnea, neutropenia after birth. Her urine 3-methylpentenedioic acid has increased to 17.53 µmol/L. DNA sequencing revealed that she has harbored compound heterozygous variants of the CLPB gene, namely c.1016delT (p.L339Rfs*5) and c.1087A>G (p.R363G), which were respectively inherited from her mother and father. Both variants were unreported previously. Based on the standards from the American College of Medical Genetics and Genomics (ACMG), the variants were respectively predicted to be pathogenic and likely pathogenic. CONCLUSION: The child was diagnosed with 3-methylglutenedioic aciduria type VII. Discovery of the c.1016delT and c.1087A>G variants has enriched the mutational spectrum of the CLPB gene.

Fosfomycin-induced agranulocytosis: a case report and review of the literature.

BACKGROUND: The intravenous form of fosfomycin, a bactericide antibiotic used to treat multiresistant bacterial infections is little prescribed. The most common reported adverse effects are hypokaliemia and hypernatremia. We describe a case of agranulocytosis, a rarely described side effect that may be fatal. CASE PRESENTATION: A 45 year-old woman was admitted to the intensive care unit for post-surgical meningitis following meningioma resection. Meropenem and vancomycin were first introduced. A DRESS-syndrom with meropenem was suspected. Neutropenia was diagnosed three days after the introduction of parenteral fosfomycin and agranulocytosis four days later. Eosinophilia was also observed. A bone marrow aspiration was performed showing a disappearance of the neutrophil granulocyte line and a significant eosinophilia. Meropenem was discontinued. Fosfomycin was maintained and filgrastim was added. As filgrastim had no effect, the relationship with fosfomycin was suspected, so it was then withheld. An increase of the neutrophil count was observed. Because of the complexity of the case, the unfavorable course of the illness and the urgent need for revision surgery, a rechallenge with fosfomycin was done followed by a decrease of the neutrophil count. CONCLUSION: This is the third paper reporting agranulocytosis induced by fosfomycin, and the first detailed description of a case. Based on chronological and semiological criteria and bibliographic data, the event was qualified as probable with the Naranjo adverse drug probability scale. Literature data is scarce. The summary of product characteristics mentions that only a few cases of transient neutropenia and agranulocytosis have been reported. An analysis of the FDA Adverse Event Reporting System Database highlighted a higher than expected frequency of agranulocytosis in patients treated with fosfomycin. Parenteral fosfomycin is often used in patients receiving other medications, so that it is rarely the only suspect. In our case, the results of the bone marrow aspiration, the sudden drop of the neutrophil count with concomitant eosinophilia and the absence of improvement despite the dose decrease, point towards an immuno-allergic mechanism. However, the overlap between the suspected DRESS induced by meropenem and the agranulocytosis do not allow to conclude with certainty on the causality. Awareness should be raised about this side effect.

Large T-cell extradural lymphoma with concurrent marked cerebrospinal fluid eosinophilia in a dog.

A 3-year-old male pit bull terrier was presented for a 4-day history of progressive tetraparesis and cervical pain. Magnetic resonance imaging confirmed an extradural mass within the left lateral vertebral canal extending from caudal C5 to mid-T2. Lumbar cerebrospinal fluid (CSF) demonstrated marked (90%) eosinophilic inflammation. A C6-7 dorsal laminectomy and C7-T2 left hemilaminectomy were done, with gross disease remaining. Histopathology revealed a large T cell lymphoma with marked eosinophilic infiltration. The dog underwent CHOP-based chemotherapy with resolution of clinical signs, with a similar course of therapy performed at recurrence 37 months after initial presentation. The dog was euthanized 39 months after presentation for multiorgan failure secondary to neutropenic sepsis and aspiration pneumonia. This represents a positive long-term response to multimodal treatment of extradural T-cell lymphoma within the vertebral canal associated with a marked CSF eosinophilia.

Aponermin or placebo in combination with thalidomide and dexamethasone in the treatment of relapsed or refractory multiple myeloma (CPT-MM301): a randomised, double-blinded, placebo-controlled, phase 3 trial.

BACKGROUND: Aponermin, a circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, is a potential death receptor 4/5-targeted antitumour candidate. Previous phase 1/2 studies have demonstrated the efficacy of aponermin in patients with relapsed or refractory multiple myeloma (RRMM). To confirm the superiority of aponermin plus thalidomide and dexamethasone (aponermin group) over placebo plus thalidomide and dexamethasone (placebo group) in RRMM, a randomized, double-blinded, placebo controlled phase 3 trial was performed. METHODS: Four hundred seventeen patients with RRMM who had previously received at least two regimens were randomly assigned (2:1) to receive aponermin, thalidomide, and dexamethasone or placebo, thalidomide, and dexamethasone. The primary endpoint was progression-free survival (PFS). Key secondary endpoints included overall survival (OS) and overall response rate (ORR). RESULTS: A total of 415 patients received at least one dose of trial treatment (276 vs. 139). The median PFS was 5.5 months in the aponermin group and 3.1 months in the placebo group (hazard ratio, 0.62; 95% confidence interval [CI], 0.49-0.78; P < 0.001). The median OS was 22.4 months for the aponermin group and 16.4 months for the placebo group (hazard ratio, 0.70; 95% CI, 0.55-0.89; P = 0.003). Significantly higher rates of ORR (30.4% vs. 13.7%, P < 0.001) and very good partial response or better (14.1% vs. 2.2%, P < 0.0001) were achieved in the aponermin group than in the placebo group. Treatment with aponermin caused hepatotoxicity in some patients, as indicated by the elevated alanine transaminase, aspartate transaminase, or lactate dehydrogenase levels (52.2% vs. 24.5%, 51.1% vs. 19.4% and 44.9% vs. 21.6%, respectively), mostly grade 1/2, transient and reversible. The main grade 3/4 adverse events included neutropenia, pneumonia and hyperglycemia. The incidence of serious adverse events was similar between the two groups (40.6% vs. 37.4%). There was no evidence that aponermin leads to hematological toxicity, nephrotoxicity, cardiotoxicity, or secondary tumors. CONCLUSIONS: Aponermin plus thalidomide and dexamethasone significantly improved PFS, OS and ORR with manageable side effects in RRMM patients who had received at least two prior therapies. These results support the use of aponermin, thalidomide, and dexamethasone as a treatment option for RRMM patients. TRIAL REGISTRATION: The trial was registered at http://www.chictr.org.cn as ChiCTR-IPR-15006024, 17/11/2014.

SBDSR126T rescues survival of sbds -/- zebrafish in a dose-dependent manner independently of Tp53.

Defects in ribosomal biogenesis profoundly affect organismal development and cellular function, and these ribosomopathies produce a variety of phenotypes. One ribosomopathy, Shwachman-Diamond syndrome (SDS) is characterized by neutropenia, pancreatic exocrine insufficiency, and skeletal anomalies. SDS results from biallelic mutations in SBDS, which encodes a ribosome assembly factor. Some individuals express a missense mutation, SBDS R126T , along with the common K62X mutation. We reported that the sbds-null zebrafish phenocopies much of SDS. We further showed activation of Tp53-dependent pathways before the fish died during the larval stage. Here, we expressed SBDS R126T as a transgene in the sbds -/- background. We showed that one copy of the SBDS R126T transgene permitted the establishment of maternal zygotic sbds-null fish which produced defective embryos with cdkn1a up-regulation, a Tp53 target involved in cell cycle arrest. None survived beyond 3 dpf. However, two copies of the transgene resulted in normal development and lifespan. Surprisingly, neutropenia persisted. The surviving fish displayed suppression of female sex differentiation, a stress response in zebrafish. To evaluate the role of Tp53 in the pathogenesis of sbds -/- fish phenotype, we bred the fish with a DNA binding deficient allele, tp53 M214K Expression of the loss-of-function tp53 M214K did not rescue neutropenia or survival in sbds-null zebrafish. Increased expression of cdkn1a was abrogated in the tp53 M214K/M214K ;sbds -/- fish. We conclude that the amount of SBDSR126T protein is important for development, inactivation of Tp53 fails to rescue neutropenia or survival in the sbds-null background, and cdkn1a up-regulation was dependent on WT tp53 We hypothesize that additional pathways are involved in the pathophysiology of SDS.