Pegylated liposomal doxorubicin combined with cyclophosphamide and vincristine in pediatric patients with relapsed/refractory solid tumor: a single-arm, open-label, phase I study.

Background: The combined vincristine, pegylated liposomal doxorubicin (PLD), and cyclophosphamide (VPC) regimen has never been studied in pediatric patients. Methods: This open-label, single-center, single-arm phase I study utilizing a "3 + 3" design enrolled children with relapsed/refractory (R/R) solid tumors. Three dose levels of PLD (Duomeisu®) were studied (30, 40, or 50 mg/m2) in combination with cyclophosphamide (1500 mg/m2), mesna (1500 mg/m2), and vincristine (1.5 mg/m2, maximum 2 mg) once every 3 weeks. The primary endpoints included safety, the maximum tolerated dose (MTD) of PLD (Duomeisu®), and the recommended phase 2 dose (RP2D) of PLD (Duomeisu®) for further phase 2 investigation. The secondary endpoints were objective response rate (ORR) and disease control rate (DCR). This study is registered with ClinicalTrials.gov, NCT04213612. Findings: Between January 7, 2020, and November 18, 2021, 34 patients were eligible and evaluable for toxicity, while 26 patients were evaluable for response. The MTD of PLD (Duomeisu®) was 30 mg/m2. The most common adverse event (AE) was grade 3 or 4 neutropenia (61.8%). The most common grade 1 or 2 non-hematologic AE and cardiotoxicity effects were vomiting (35.3%) and abnormal electrocardiogram T waves (20.6%), respectively. ORR and DCR to VPC regimen after two cycles were 50.0% and 92.3%, respectively. Targeted gene panel sequencing revealed the activation of TP53 mutation may be an adverse prognostic factor. Interpretation: The VPC regimen showed a promising safety profile and had preliminary efficacy in children with R/R solid tumors. The RP2D for PLD (Duomeisu®) combined with cyclophosphamide and vincristine is 30 mg/m2 once every 3 weeks. Funding: CSPC Ouyi Pharmaceutical Co., Ltd., Shijiazhuang, the National Key Research and Development Program of China [No. 2022YFC2705005], the National Natural Science Foundation of China [No. 82203303], and the Basic and Applied Basic Research Foundation of Guangdong Province [No. 2021A1515110234].

Stratified Treatment in Pediatric Anaplastic Large Cell Lymphoma: Result of a Prospective Open-Label Multiple-Institution Study.

Purpose: The risk stratification of pediatric anaplastic large cell lymphoma (ALCL) has not been standardized. In this study, new risk factors were included to establish a new risk stratification system for ALCL, and its feasibility in clinical practice was explored. Materials and Methods: On the basis of the non-Hodgkin's lymphoma Berlin-Frankfurt-Munster 95 (NHL-BFM-95) protocol, patients with minimal disseminated disease (MDD), high-risk tumor site (multiple bone, skin, liver, and lung involvement), and small cell/lymphohistiocytic (SC/LH) pathological subtype were enrolled in risk stratification. Patients were treated with a modified NHL-BFM-95 protocol combined with an anaplastic lymphoma kinase inhibitor or vinblastine (VBL). Results: A total of 136 patients were enrolled in this study. The median age was 8.8 years. The 3-year event-free survival (EFS) and overall survival of the entire cohort were 77.7% [95% Confidence Interval (CI), 69.0%-83.9%] and 92.3% (95% CI,86.1%-95.8%), respectively. The 3-year EFS rates of low-risk group (R1), intermediate-risk group (R2), and high-risk group (R3) patients were 100%, 89.5% (95% CI, 76.5%-95.5%, and 67.9% (95% CI, 55.4%-77.6%), respectively. The prognosis of patients with MDD (+), stage IV cancer, SC/LH lymphoma, and high-risk sites was poor, and the 3-year EFS rates were 45.3% (95% CI, 68.6%-19.0%), 65.7% (95% CI, 47.6%-78.9%), 55.7% (95% CI, 26.2%-77.5%), and 70.7% (95% CI, 48.6%-84.6%), respectively. At the end of follow-up, one of the 5 patients who received maintenance therapy with VBL relapsed, and seven patients receiving ALK inhibitor maintenance therapy did not experience relapse. Conclusion: This study has confirmed the poor prognostic of MDD (+) ，high risk site and SC/LH ,but patients with SC/LH lymphoma and MDD (+) at diagnosis still need to receive better treatment (ClinicalTrials.gov number, NCT03971305).

Searching for Two-Neutrino and Neutrinoless Double Beta Decay of

^{134}Xe is a candidate isotope for neutrinoless double beta decay (0νßß) search. In addition, the two-neutrino case (2νßß) allowed by the standard model of particle physics has not yet been observed. With the 656-kg natural xenon in the fiducial volume of the PandaX-4T detector, which contains 10.4% of ^{134}Xe, and its initial 94.9-day exposure, we have established the most stringent constraints on 2νßß and 0νßß of ^{134}Xe half-lives, with limits of 2.8×10^{22} yr and 3.0×10^{23} yr at 90% confidence level, respectively. The 2νßß (0νßß) limit surpasses the previously reported best result by a factor of 32 (2.7), highlighting the potential of large monolithic natural xenon detectors for double beta decay searches.

MTHFD1 regulates the NADPH redox homeostasis in MYCN-amplified neuroblastoma.

MYCN amplification is an independent poor prognostic factor in patients with high-risk neuroblastoma (NB). Further exploring the molecular regulatory mechanisms in MYCN-amplified NB will help to develop novel therapy targets. In this study, methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) was identified as the differentially expressed gene (DEG) highly expressed in MYCN-amplified NB, and it showed a positive correlation with MYCN and was associated with a poor prognosis of NB patients. Knockdown of MTHFD1 inhibited proliferation and migration, and induced apoptosis of NB cells in vitro. Mouse model experiments validated the tumorigenic effect of MTHFD1 in NB in vivo. In terms of the mechanism, ChIP-qPCR and dual-luciferase reporter assays demonstrated that MTHFD1 was directly activated by MYCN at the transcriptional level. As an important enzyme in the folic acid metabolism pathway, MTHFD1 maintained the NADPH redox homeostasis in MYCN-amplified NB. Knockdown of MTHFD1 reduced cellular NADPH/NADP+ and GSH/GSSG ratios, increased cellular reactive oxygen species (ROS) and triggered the apoptosis of NB cells. Moreover, genetic knockdown of MTHFD1 or application of the anti-folic acid metabolism drug methotrexate (MTX) potentiated the anti-tumor effect of JQ1 both in vitro and in vivo. Taken together, MTHFD1 as an oncogene is a potential therapeutic target for MYCN-amplified NB. The combination of MTX with JQ1 is of important clinical translational significance for the treatment of patients with MYCN-amplified NB.

METTL14-mediated m6A epitranscriptomic modification contributes to chemotherapy-induced neuropathic pain by stabilizing GluN2A expression via IGF2BP2.

Epigenetics is a biological process that modifies and regulates gene expression, affects neuronal function, and contributes to pain. However, the mechanism by which epigenetics facilitates and maintains chronic pain is poorly understood. We aimed to determine whether N6-methyladenosine (m6A) specifically modified by methyltransferase-like 14 (METTL14) alters neuronal activity and governs pain by sensitizing the GluN2A subunit of the N-methyl-d-aspartate receptor (NMDAR) in the dorsal root ganglion (DRG) neurons in a model of chemotherapy-induced neuropathic pain (CINP). Using dot blotting, immunofluorescence, gain/loss-of-function, and behavioral assays, we found that m6A levels were upregulated in L4-L6 DRG neurons in CINP in a DBP/METTL14-dependent manner, which was also confirmed in human DRGs. Blocking METTL14 reduced m6A methylation and attenuated pain hypersensitivity. Mechanistically, METTL14-mediated m6A modification facilitated the synaptic plasticity of DRG neurons by enhancing the GluN2A subunit of NMDAR, and inhibiting METTL14 blocked this effect. In contrast, overexpression of METTL14 upregulated m6A modifications, enhanced presynaptic NMDAR activity in DRG neurons, and facilitated pain sensation. Our findings reveal a previously unrecognized mechanism of METTL14-mediated m6A modification in DRG neurons to maintain neuropathic pain. Targeting these molecules may provide a new strategy for pain treatment.

Treatment Outcome of Response-Based Radiation Therapy in Children and Adolescents With Central Nervous System Nongerminomatous Germ Cell Tumors: Results of a Prospective Study.

PURPOSE: The optimal dose and range of radiation therapy for central nervous system nongerminomatous germ cell tumors (NGGCTs) have not been uniformly established. Therefore, this study aimed to investigate the effect of individualized radiation therapy, based on the response to induction chemotherapy combined with surgery, on the prognosis of patients with NGGCTs. METHODS AND MATERIALS: Based on the imaging examination and tumor markers after induction chemotherapy and pathologic results of second-look surgery, patients with NGGCT received different radiation therapy strategies, including 30.6 Gy whole ventricular irradiation + tumor-bed boost to 54 Gy, 30.6 Gy craniospinal irradiation + tumor-bed boost to 54 Gy, 36 Gy craniospinal irradiation + tumor-bed boost to 54 Gy, and 36 Gy craniospinal irradiation + 54 Gy tumor-bed boost with 45 Gy to metastatic spinal lesions. RESULTS: A total of 51 patients were enrolled between January 2015 and March 2021, with a median age of 10.3 years. The 3-year event-free survival and overall survival (OS) of the entire cohort were 70.2% ± 6.9% and 77.5% ± 6.0%, respectively. The 3-year OS of patients achieving partial response after induction chemotherapy was higher than that of patients with stable disease (P = .03) or progressive disease (P = .002). The 3-year event-free survival and OS of the 18 patients receiving 30.6 Gy whole ventricular irradiation and 54 Gy tumor-bed boost were 88.9% ± 7.4% and 94.4% ± 5.4%, respectively. CONCLUSIONS: The results suggest that an individualized radiation therapy strategy based on response to induction chemotherapy and surgery is a feasible and promising means of achieving reduction in dose and extent of radiation in patients while still providing good response.

PD-L1-expressing natural killer cells predict favorable prognosis and response to PD-1/PD-L1 blockade in neuroblastoma.

T/NK cell-based immunotherapy has achieved remarkable success in adult cancers but has limited efficacy in pediatric malignancies including high-risk neuroblastoma (NB). Immune defects of NB tumor microenvironment are poorly understood compared with adults. Here, we described the unique characteristics of NB immune contexture and determined the phenotype signatures of PD-L1-expressing CD8+ T and NK cells in NB tumors by systemically analyzing the spatial distribution of T and NK cells and the distinct expression of programmed death 1 (PD-1) and its ligand (PD-L1) in patients with NB. We found that PD-L1-expressing CD8+ T and NK cells in NB tumors were highly activated and functionally competent and associated with better clinical outcomes. Intratumoral NK cells were a favorable prognostic biomarker independent of CD8+ T cells, PD-1/PD-L1 expression, tumor stage, MYCN amplification, and risk classification. NK cells combined with anti-PD-1/PD-L1 antibodies showed potent antitumor activity against both MYCN-amplified and non-amplified NBs in vitro and in vivo, and PD-L1-expressing NK cells associated with improved antitumor efficacy. Collectively, we raise novel insights into the role of PD-L1 expression on CD8+ T-cell and NK-cell activation. We highlight the great potential of intratumoral NK cells in better defining risk stratification, and predicting survival and response to anti-PD-1/PD-L1 therapy in NB. These findings explain why single anti-PD-1/PD-L1 therapy may not be successful in NB, suggesting its combination with NK cell-adoptive cellular therapy as a promising strategy for relapsing/refractory NB. This study provides a potential prospect that patients with PD-L1-expressing NK cells may respond to anti-PD-1/PD-L1 therapy.

The dual HDAC and PI3K inhibitor, CUDC­907, inhibits tumor growth and stem­like properties by suppressing PTX3 in neuroblastoma.

Neuroblastoma (NB) is one of the common solid tumors in childhood and poses a threat to the lives of children. Patients with advanced­stage or recurrent NB have a poor prognosis. CUDC­907, as a novel dual­target inhibitor of histone deacetylase (HDAC) and phosphatidylinositol­3­kinase (PI3K), has been proven to play an antitumor role in several types of tumors. However, the exact role of CUDC­907 in NB remains unclear. In the present study, in vivo and in vitro assays were performed to investigate the anti­NB activity of CUDC­907. Pentraxin 3 (PTX3) small interfering RNA (siRNA) and PTX3 overexpression plasmid were transfected into cells to define the underlying mechanisms of CUDC­907. Tumor tissues and clinical information were collected and immunohistochemistry (IHC) was conducted to analyze the association between the expression of HDAC1, HDAC2, HDAC3 and CD44, and the prognosis of patients with NB. The results indicated that CUDC­907 significantly inhibited the proliferation and migration, and induced the apoptosis of NB cells, downregulating the expression level of MYCN, and suppressing the PI3K/AKT and MAPK/ERK pathways. Furthermore, CUDC­907 suppressed the stem­like properties of NB cells by inhibiting PTX3, a ligand and upstream protein of CD44. IHC revealed that the high expression of HDAC1, 2, 3 and CD44 was associated with a poor prognosis of patients with NB. On the whole, these findings indicate that CUDC­907 may be developed into a possible therapeutic approach for patients with NB.

Search for Dark-Matter-Nucleon Interactions with a Dark Mediator in PandaX-4T.

We report results of a search for dark-matter-nucleon interactions via a dark mediator using optimized low-energy data from the PandaX-4T liquid xenon experiment. With the ionization-signal-only data and utilizing the Migdal effect, we set the most stringent limits on the cross section for dark matter masses ranging from 30 MeV/c^{2} to 2 GeV/c^{2}. Under the assumption that the dark mediator is a dark photon that decays into scalar dark matter pairs in the early Universe, we rule out significant parameter space of such thermal relic dark-matter model.

Safety and clinical efficacy of sintilimab (anti-PD-1) in pediatric patients with advanced or recurrent malignancies in a phase I study.

The aim of this phase I study is to evaluate, for the first time, the safety and efficacy of sintilimab in pediatric patients diagnosed with advanced or recurrent malignancies. During the dose escalation phase, patients received a single intravenous infusion of sintilimab at varying doses of 1, 3, and 10 mg/kg. The primary endpoints included the identification of dose-limiting toxicities (DLTs) as well as the evaluation of safety and tolerance. Secondary endpoints focused on assessing objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). A total of 29 patients were enrolled, including 10 individuals diagnosed with Hodgkin lymphoma (HL) and 19 patients with various other tumor categories. Notably, diverse pathological types such as thymoma, choroid plexus carcinoma, and NK/T-cell lymphoma were also included in the study cohort. By the safety data cutoff, most adverse events were grade 1 or 2, with grade 3 or higher treatment-related adverse events (TRAE) occurring in 10% of patients. Among the 27 evaluated subjects, four achieved confirmed complete response (CR) while seven patients exhibited confirmed partial response (PR). Additionally, seven patients maintained disease (SD) during the study period. Notably, sintilimab demonstrated remarkable tolerability without DLTs and exhibited promising anti-tumor effects in pediatric HL. Whole-exome sequencing (WES) was conducted in 15 patients to assess the mutational landscape and copy number variation (CNV) status. The completion of this phase I study establishes the foundation for potential combination regimens involving sintilimab in childhood cancer treatment. The trial is registered on ClinicalTrials.gov with the identifier NCT04400851.

Proteomic characteristics of six snake venoms from the Viperidae and Elapidae families in China and their relation to local tissue necrosis.

Patients envenomed by snakes from the Viperidae and Elapidae families in China often have varying degrees of local tissue necrosis. Due to the relative clinical characteristics of local tissue necrosis and ulceration following envenoming, this study has analyzed the proteome of six snake venoms from the Viperidae and Elapidae family, and the toxin profiles of each snake were compared and correlated with the clinical manifestations that follow cytotoxic envenoming. Deinagkistrodon acutus and Naja atra envenomation induce severe ulceration, which is absent in Bungarus multicinctus envenomation and mild in the other three vipers. It is interesting to note that the proportion of c-type lectins (CTL) (20.63%) in Deinagkistrodon acutus venom was relatively high, which differs from the venom of other vipers. In addition, three-fingered toxin (3FTx) (2.15%) is present in the venom of Deinagkistrodon acutus, but has not been detected in the remaining three vipers. Snake venom metalloprotease (SVMP) (34.4%-44.7%), phospholipase A2 (PLA2) (9.81%-40.83%), and snake venom serine protease (SVSP) (9.44%-16.2%) represent the most abundant families of toxin in Viperidae venom. The Elapidae venom proteome was mainly composed of neurotoxins and cytotoxins, including 3FTx (39.28%-60.08%) and PLA2 (8.24%-58.95%) toxins, however, the proportion of CRISPS (26.36%) in Naja atra venom was relatively higher compared to Bungarus multicinctus venom. Significant differences in SVMP, SVSP, and 3FTx expression levels exist between the Viperidae and the Elapidae family. The main toxins responsible for the development of tissue necrosis and ulcerations following Viperidae envenoming are hematotoxins (SVSMP, SVSP) and myotoxins (PLA2). Deinagkistrodon acutus venom contains high levels of CTL and traces of 3FTx, leading to more severe local necrosis. However, Naja atra venom can also cause severe local necrosis through the effects of myotoxin (3FTx, CRISP, PLA2). Bungarus multicinctus venom does not contain myotoxins, resulting in pure systemic neurological manifestations no obvious necrosis of local tissue in patients.

Programmable nanocomposites of cellulose nanocrystals and zwitterionic hydrogels for soft robotics.

Stimuli-responsive hydrogels have garnered significant attention as a versatile class of soft actuators. Introducing anisotropic properties, and shape-change programmability to responsive hydrogels promises a host of opportunities in the development of soft robots. Herein we report the synthesis of pH-responsive hydrogel nanocomposites with predetermined microstructural anisotropy, shape-transformation, and self-healing. Our hydrogel nanocomposites are largely composed of zwitterionic monomers and asymmetric cellulose nanocrystals. While the zwitterionic nature of the network imparts both self-healing and cytocompatibility to our hydrogel nanocomposites, the shear-induced alignment of cellulose nanocrystals renders their anisotropic swelling and mechanical properties. Thanks to the self-healing properties, we utilized a cut-and-paste approach to program reversible, and complex deformation into our hydrogels. As a proof-of-concept, we demonstrated the transport of light cargo using tethered and untethered soft robots made from our hydrogels. We believe the proposed material system introduce a powerful toolbox for the development of future generations of biomedical soft robots.

Treatment outcomes for response-based radiotherapy in children and adolescents with central nervous system germinoma: a prospective study.

PURPOSE: The optimal dose and range of radiotherapy for central nervous system (CNS) germinoma have not yet been established. This study aimed to investigate the effects of individualized radiotherapy on the prognosis of patients with germinoma. METHODS: Based on imaging examination, tumor markers, and pathologic results, patients with germinoma received different radiotherapy strategies, including R1 (24 Gy whole ventricular irradiation + tumor-bed boost to 40 Gy), R2 (24-30 Gy craniospinal irradiation + tumor-bed boost to 54 Gy), R3 (24 Gy craniospinal irradiation + tumor-bed boost to 40 Gy), and R4 (30 Gy craniospinal irradiation + tumor-bed boost to 54 Gy with 45 Gy to spinal metastasis). RESULTS: A total of 77 patients were enrolled in this study between January 2015 and March 2021. The 3-year event-free survival (EFS) and overall survival (OS) of the whole cohort were 94.7% ± 2.6% and 96.0% ± 2.3%, respectively. The 3-year EFS for patients with localized and metastatic disease were 96.6% ± 2.4% and 89.2% ± 7.2%, respectively. The 3-year EFS of patients receiving R1, R2, R3, and R4 radiotherapy were 100%, 94.1% ± 5.7%, 100%, and 86.2% ± 9.1%, respectively. CONCLUSION: Good prognosis was still achieved after reducing dose and extent of radiation for the patients who achieved complete response (CR) after induction chemotherapy or pathological CR after second-look surgery.

Search for Light Dark Matter from the Atmosphere in PandaX-4T.

We report a search for light dark matter produced through the cascading decay of η mesons, which are created as a result of inelastic collisions between cosmic rays and Earth's atmosphere. We introduce a new and general framework, publicly accessible, designed to address boosted dark matter specifically, with which a full and dedicated simulation including both elastic and quasielastic processes of Earth attenuation effect on the dark matter particles arriving at the detector is performed. In the PandaX-4T commissioning data of 0.63 tonne·year exposure, no significant excess over background is observed. The first constraints on the interaction between light dark matter generated in the atmosphere and nucleus through a light scalar mediator are obtained. The lowest excluded cross section is set at 5.9×10^{-37} cm^{2} for a dark matter mass of 0.1 MeV/c^{2} and mediator mass of 300 MeV/c^{2}. The lowest upper limit of η to the dark matter decay branching ratio is 1.6×10^{-7}.

Inhibitory insula-ACC projections modulate affective but not sensory aspects of neuropathic pain.

The insula and anterior cingulate cortex (ACC) are brain regions that undergo structural and functional reorganization in neuropathic pain states. Here, we aimed to study inhibitory parvalbumin positive (PV+) posterior insula (pIC) to posterior ACC (pACC) projections, and to evaluate the effects of direct optogenetic manipulation of such projections on mechanical nociception and spontaneous ongoing pain in mice with Spared Nerve Injury (SNI). CTB488 tract-tracing in male PVCrexAi9 mice revealed a small proportion of PV+ projections from the pIC to the pACC. Electrophysiological analysis confirmed the existence of synaptic inputs into the pACC by pIC GABAergic cells. Optogenetic stimulation of these pathways did not change mechanical nociception, but induced conditioned place preference behavior responses. Our results suggest the presence of inhibitory projections between the pIC and the pACC which are able to selectively modulate affective aspects of neuropathic pain.

Activation of G-protein-coupled receptor 183 initiates inflammatory pain via macrophage CCL22 secretion.

Chronic pain is a major public health problem with limited effective therapeutic options. G-protein-coupled receptors play a significant role in pain modulation; however, whether and how G-protein-coupled receptor 183 participates in pain regulation remain unclear. In the present study, we found that G-protein-coupled receptor 183 expression was specifically upregulated in the hind paws of mice in various inflammatory pain models. Activation of G-protein-coupled receptor 183 induced acute pain, whereas inhibition or silencing of this receptor alleviated mechanical allodynia and thermal hyperalgesia in complete Freund's adjuvant (CFA) model. Mechanistically, activating G-protein-coupled receptor 183 triggers pain responses via the upregulation of C-C motif chemokine 22(CCL22) in macrophages while blocking the CCL22 receptor C-C motif chemokine receptor 4 (CCR4) attenuates pain hypersensitivity. Taken together, our findings indicate that the G-protein-coupled receptor 183-CCL22 axis has a critical role in the development and maintenance of inflammatory pain.

Efficacy and safety of programmed cell death receptor 1 inhibition-based regimens in patients with pediatric malignancies: the real-world study in China.

Background: Programmed death receptor 1 (PD-1) inhibition has shown durable response and mild adverse events (AEs) in adult malignancies. However, data on the clinical activity of PD-1 inhibition in pediatric patients are lacking. We comprehensively assessed the efficacy and safety of PD-1 inhibitor-based regimens for pediatric malignancies. Methods: We conducted a real-world, multi-institutional, retrospective analysis of pediatric malignancies treated with PD-1 inhibitor-based regimens. The primary endpoints were objective response rate (ORR) and progression-free survival (PFS). The secondary endpoints included disease control rate (DCR), duration of response (DOR), and AEs. The Kaplan-Meier method was used to calculate PFS and DOR. The National Cancer Institute Common Toxicity Criteria for AEs (version 5.0) were used to grade toxicity. Results: A total of 93 and 109 patients were evaluated for efficacy and safety, respectively. For all efficacy-evaluable patients, PD-1 inhibitor monotherapy, combined chemotherapy, combined histone deacetylase inhibitor, and combined vascular endothelial growth factor receptor tyrosine kinase inhibitor cohorts, the ORR and DCR were 53.76%/81.72%, 56.67%/83.33%, 54.00%/80.00%, 100.00%/100.00%, and 12.50%/75.00%, respectively; the median PFS and DOR were 17.6/31.2 months, not achieved/not achieved, 14.9/31.2 months, 17.6/14.9 months, and 3.7/1.8 months, respectively; the incidence rate of AEs were 83.49%, 55.26%, 100.00%, 80.00%, and 100.00%, respectively. One patient in the PD-1 inhibitor-combined chemotherapy cohort discontinued treatment due to diabetic ketoacidosis. Conclusions: This largest retrospective analysis demonstrate that PD-1 inhibitor-based regimens are potentially effective and tolerable in pediatric malignancies. Our findings provide references for future clinical trials and practice of PD-1 inhibitors in pediatric cancer patients.

A multicenter phase II trial of primary prophylactic PEG-rhG-CSF in pediatric patients with solid tumors and non-Hodgkin lymphoma after chemotherapy: An interim analysis.

BACKGROUND: Pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) can be used in pediatric patients. This study assessed the safety and efficacy of PEG-rhG-CSF as a primary prophylactic drug against neutropenia after chemotherapy in pediatric patients with solid tumors or non-Hodgkin lymphoma (NHL). PATIENTS AND METHODS: This phase II study (between October 2020 and March 2022) enrolled pediatric patients with solid tumors or NHL treated with high-intensity chemotherapy and with grade ≥3 myelosuppression for at least 14 days during chemotherapy. Prophylactic PEG-rhG-CSF was given at 100 µg/kg body weight (maximum total dosage of 6 mg) once 24-48 h following chemotherapy for two cycles. The primary endpoint was the incidence of PEG-rhG-CSF-related adverse events (AEs). The key secondary endpoints were the rates of grade 3/4 neutropenia and febrile neutropenia (FN). RESULTS: This study included 160 pediatric patients with a median age of 6.22 (0.29, 18.00) years. Fifty-eight patients (36.25%) were diagnosed with sarcoma. AEs potentially related to PEG-rhG-CSF included bone pain (n = 32), fatigue (n = 21), pain at the injection site (n = 21), and myalgia (n = 20). The rates of grade 3/4 neutropenia and FN during treatment were 57.28% and 29.45%, respectively. CONCLUSION: PEG-rhG-CSF is well tolerated and effective in pediatric patients with solid tumors or NHL. These findings should be substantiated with further trials. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04547829.

Oral vinorelbine and continuous low doses of cyclophosphamide in pediatric rhabdomyosarcoma: a real-world study.

Introduction: Metronomic maintenance therapy (MMT) has significantly improved the survival of patients with high-risk rhabdomyosarcoma in clinical trials. However, there remains a lack of relevant data on its effectiveness in real-world situations. Methods: We retrospectively retrieved data of 459 patients < 18 years of age diagnosed with rhabdomyosarcoma at Sun Yat-sen University Cancer Center from January 2011 to July 2020 from our database. The MMT regimen was oral vinorelbine 25-40 mg/m2 for twelve 4-week cycles on days 1, 8, and 15, and oral cyclophosphamide 25-50 mg/m2 daily for 48 consecutive weeks. Results: A total of 57 patients who underwent MMT were included in the analysis. The median follow-up time was 27.8 (range: 2.9-117.5) months. From MMT to the end of follow-up, the 3-year PFS and OS rates were 40.6% ± 6.8% and 58.3% ± 7.2%, respectively. The 3-year PFS was 43.6% ± 11.3% in patients who were initially diagnosed as low- and intermediate-risk but relapsed after comprehensive treatment (20/57), compared with 27.8% ± 10.4% in high-risk patients (20/57) and 52.8% ± 13.3% in intermediate-risk patients who did not relapse (17/57). The corresponding 3-year OS for these three groups was 65.8% ± 11.4%, 50.1% ± 12.9%, and 55.6% ± 13.6%, respectively. Conclusion: We present a novel study of MMT with oral vinorelbine and continuous low doses of cyclophosphamide in real-world pediatric patients with RMS. Our findings showed that the MMT strategy significantly improved patient outcomes and may be an effective treatment for high-risk and relapsed patients.

Risk factors for totally implantable access ports-associated thrombosis in pediatric oncology patients.

The application of totally implantable access ports (TIAPs) reduces treatment-related discomfort; however, the existence of catheter may cause side effects, with the most common one being the occurrence of TIAPs-associated thrombosis. The risk factors for TIAPs-associated thrombosis in pediatric oncology patients have not been fully described. A total of 587 pediatric oncology patients undergoing TIAPs implantation at a single center over a 5-year period were retrospectively analyzed in the present study. We investigated the risk factors for thrombosis, emphasizing the internal jugular vein distance, by measuring the vertical distance from the highest point of the catheter to the upper border of the left and right extremitas sternalis claviculae on chest X-ray images. Among 587 patients, 143 (24.4%) had thrombosis. Platelet count, C-reactive protein, and the vertical distance from the highest point of the catheter to the upper border of the left and right extremitas sternalis claviculae were demonstrated to be the main risk factors for the development of TIAPs-associated thrombosis. TIAPs-associated thrombosis, especially asymptomatic events, is common in pediatric cancer patients. The vertical distance from the highest point of the catheter to the upper border of the left and right extremitas sternalis claviculae was a risk factor for TIAPs-associated thrombosis, which deserved additional attention.