Phase II trial of imatinib mesylate in patients with PDGFRA/B-negative hypereosinophilic syndrome.

The role of imatinib in PDGFRA/B-negative hypereosinophilic syndromes (HES) is controversial because of the heterogeneity of HES and the scarcity of prospective studies. We conducted a phase II clinical trial to evaluate the efficacy of imatinib in PDGFRA/B-negative HES. Thirty-two patients were treated with imatinib (100-400 mg daily), and the molecular basis of their response was identified using whole-exome sequencing (WES) and whole-transcriptome sequencing (WTS). The haematological response rate was 46.9%, with a complete haematological response (CHR) rate of 18.8%. The median time to response was 1.5 months. Among the six patients who achieved CHR, five maintained it until the 24th cycle of imatinib and one lost response after 20 months. The median progression-free survival was 4.3 months. WES and WTS were conducted for 11 patients. The number of non-silent mutations did not differ between responders and non-responders. Nine differentially expressed genes, including SNORD15A, were downregulated in responders. STAT5B::RARA, PAK2::PIGX, and FIP1L1::CHIC2 fusions were identified in patients with sustained responses, and RNF130::BRAF and WNK1::KDM5A fusions were identified in non-responders. Imatinib, along with an appropriate biomarker, could be a promising option for PDGFRA/B-negative HES.

Direct Oral Anticoagulants in Antiphospholipid Syndrome-Associated Venous Thromboembolism: Real World Evidence.

BACKGROUND: The efficacy and safety of direct oral anticoagulants (DOACs) versus warfarin in patients with antiphospholipid syndrome-associated venous thromboembolism (APS-VTE) remain uncertain. We aimed to evaluate efficacy and safety of DOACs in patients with APS-VTE. METHODS: Using the Korean Health Insurance Review and Assessment Service database, we retrospectively identified all APS-VTE cases. We examined the VTE recurrence, arterial thrombosis, death and bleeding in patients who received DOACs compared with warfarin for therapeutic anticoagulation. RESULTS: Of all the VTE cases (n = 84,916) detected between 2014 and 2018, patients with APS-VTE (n = 410) accounted for 0.48%. Most patients with APS-VTE (73%) were aged < 60 years. The recurrent VTE occurred in 8 of 209 patients (3.8%) who received DOACs and in 7 of 201 (3.5%) who received warfarin (relative risk [RR], 1.099; 95% confidence interval [CI], 0.41-2.98; P = 1.000). The arterial thrombosis (ATE) occurred in 8 of 209 patients (3.8%) who received DOAC and in 20 of 201 (10%) who received warfarin (RR, 0.385; 95% CI, 0.17-0.85; P = 0.024). The composite outcomes of VTE recurrence, ATE, or mortality were significantly lower in patients (9.1%) on DOAC than in those (16.3%) on warfarin (RR, 0.537; 95% CI, 0.32-0.91; P = 0.028). The bleeding outcome occurred in 7 of 209 (3.4%) patients in the DOACs group and 7 of 201 (3.5%) patients in the warfarin group (RR, 0.96; 95% CI, 0.34-2.69; P = 0.840). CONCLUSION: In patients with APS-VTE, DOACs group showed comparable rates of recurrent VTE, bleeding, and deaths, but a significantly lower incidence of ATE and composite outcomes compared with the warfarin group in Korea.

Skeletal-Related Events in Patients With Multiple Myeloma: A Comprehensive Retrospective Cohort Study.

BACKGROUND: Multiple myeloma (MM) patients are at risk of skeletal-related events (SREs) like spinal cord compression, pathologic fractures, bone surgery, and radiation to bone. Real-world data regarding SREs in MM are limited. METHODS: We conducted a large, retrospective, nationwide cohort study using the Korean Health Insurance Review and Assessment Service (HIRA) database from 2007 to 2018. RESULTS: Over a 12-year study period, we identified 6,717 patients who developed symptomatic MM. After a median follow-up of 35.1 months (interquartile range [IQR], 20.8-58.2 months), 43.6% of these patients experienced SREs, and 39.6% had four or more SREs. One in five patients (20.0%) experienced pathologic fractures within the first year of follow-up. The median time to first SRE was 9.6 months (IQR, 1.2-25.8 months), with 3.0 months in the group with prior SREs and 19.8 months in the group without prior SREs. During follow-up, 78.5% of patients received bisphosphonates. Multiple logistic regression analysis revealed several factors associated with an increased risk of SREs, including being female (odds ratio [OR], 1.44), aged 50 or older (OR, 1.87), having cerebrovascular disease (OR, 1.34), undergoing first-line chemotherapy regimens not containing bortezomib or lenalidomide (OR, 1.49), and being in the group with prior SREs and bisphosphonate use (OR, 5.63), compared to the group without prior SREs and without bisphosphonate use. CONCLUSION: This population-based study is the first to report the incidence and risk factors of SREs in Korean MM patients, which can be used to assess their bone health.

Incidence of Venous Thromboembolism: The 3rd Korean Nationwide Study.

BACKGROUND: The incidence of venous thromboembolism (VTE) has gradually increased in the Korean population. This study aimed to evaluate the annual age- and sex-adjusted incidence rates (ASR) of VTE and anticoagulation trends between 2014 and 2018. METHODS: Using the Korean Health Insurance Review and Assessment Service database, we retrospectively identified VTE patients between 2014 and 2018 using both diagnostic and medication anticoagulant codes assigned within 6 months of the initial index event. Anticoagulant patterns were classified as follows: direct oral anticoagulants (DOAC), parenteral anticoagulants, warfarin, and mixed anticoagulation regimens. RESULTS: We identified 95,205 patients with VTE (female, 56.8%). The ASR for VTE per 100,000 person-years increased from 32.8 in 2014 to 53.7 cases in 2018 (relative risk of 1.63; 95% confidence interval, 1.6-1.67). The VTE incidence rates were 25 times higher in the ≥ 80 group than in the 30s group. VTE occurred 1.29 times more often in women than in men. The proportion of DOAC prescriptions increased from 40.5% to 72.8%, whereas warfarin prescriptions decreased from 27% to 5.6% in 2014 and 2018. CONCLUSION: In Korea, the ASRs of VTE continued to increase since 2014, but the rate of increase slowed in 2018. The VTE occurred more often in the elderly and in women. Five years after the introduction of DOACs in 2013, they accounted for 73% of all anticoagulants used to treat VTE.

Evaluation of the need for cytoreduction and its potential carcinogenicity in children and young adults with myeloproliferative neoplasms.

Myeloproliferative neoplasms are rare at a young age, and few reports have described the disease characteristics and outcomes in this group. This study aimed to elucidate the clinical course of essential thrombocythemia (ET) and polycythemia vera (PV) in children and young adults aged <39 years focusing on thromboembolic events (TE) and second primary malignancies (SPMs). A total of 990 patients who were diagnosed from 2008 to 2017 were included by analyzing the Health Insurance Review and Assessment Service database in Korea. The incidence was 2.53 per 1,000,000 for ET (643 patients; 276 male patients; median 31 years) and 1.37 per 1,000,000 for PV (347 patients; 309 male patients; median 32 years). Three ET patients developed secondary acute myelogenous leukemia and three developed secondary myelofibrosis. The 5-year cumulative incidence of TE was 14.2% in ET and 21.3% in PV. Thus, the incidence was higher in PV; in particular, arterial TE (ATE) was evidently higher in PV than in ET. The 5-year cumulative incidence of SPMs was 2.5% in ET and 2.6% in PV. While the use of both aspirin and hydroxyurea reduced the incidence of ATE, hydroxyurea significantly increased the incidence of SPMs. The incidence of ET and PV was very low, and ET was more common than PV in children and young adults. The high incidence of TE in young patients suggests the importance of thrombosis prevention. However, hydroxyurea appears to increase the incidence of SPMs; therefore, the risks and benefits should be considered.

Early-Life Stress Modulates Gut Microbiota and Peripheral and Central Inflammation in a Sex-Dependent Manner.

Recent studies have reported that changes in gut microbiota composition could induce neuropsychiatric problems. In this study, we investigated alterations in gut microbiota induced by early-life stress (ELS) in rats subjected to maternal separation (MS; 6 h a day, postnatal days (PNDs) 1-21), along with changes in inflammatory cytokines and tryptophan-kynurenine (TRP-KYN) metabolism, and assessed the differences between sexes. High-throughput sequencing of the bacterial 16S rRNA gene showed that the relative abundance of the Bacteroides genus was increased and that of the Lachnospiraceae family was decreased in the feces of MS rats of both sexes (PND 56). By comparison, MS increased the relative abundance of the Streptococcus genus and decreased that of the Staphylococcus genus only in males, whereas the abundance of the Sporobacter genus was enhanced and that of the Mucispirillum genus was reduced by MS only in females. In addition, the levels of proinflammatory cytokines were increased in the colons (IFN-γ and IL-6) and sera (IL-1ß) of the male MS rats, together with the elevation of the KYN/TRP ratio in the sera, but not in females. In the hippocampus, MS elevated the level of IL-1ß and the KYN/TRP ratio in both male and female rats. These results indicate that MS induces peripheral and central inflammation and TRP-KYN metabolism in a sex-dependent manner, together with sex-specific changes in gut microbes.

Retinal VEGFA maintains the ultrastructure and function of choriocapillaris by preserving the endothelial PLVAP.

Fenestrations in choriocapillaris act as a window for molecular transports between the retina and choroid, and is crucial for maintaining visual function. Plasmalemma vesicle-associated protein (PLVAP) is essential for the development of endothelial fenestrations. There is little knowledge about how the choriocapillaris maintains the fenestrated endothelium. This study aimed to evaluate the role of vascular endothelial growth factor-A (VEGFA)-PLVAP axis in the maintenance of choroidal fenestrations using oxygen-induced retinopathy (OIR) model. In C57BL/6 J mice, the mice with OIR on postnatal day 12 (P12) presented thicker endothelium and less fenestration compared to the non-OIR mice. However, the OIR on 17 mice showed thinner endothelium with more fenestration compared to OIR on P12. In vivo angiography demonstrated the presence of hyperpermeable choroidal vessels on P17 in OIR mice. These dramatic changes in choriocapillaris were not observed in the BALB/cJ OIR model. The ultrastructural changes in the choriocapillaris were correlated with temporal variations in the expression of VEGFA and PLVAP. VEGFA stimulated expression of PLVAP in the choroidal endothelial cells. Loss of PLVAP disrupts the polarized structure of the choriocapillaris leading to retinal degeneration. These results indicate that the expression of retinal VEGFA is essential for maintaining the structure and function of choriocapillaris by preserving the endothelial PLVAP.

Alpha-Smooth Muscle Actin-Positive Perivascular Cells in Diabetic Retina and Choroid.

Structural alterations of pericytes in microvessels are important features of diabetic retinopathy. Although capillary pericytes had been known not to have α-smooth muscle actin (αSMA), a recent study revealed that a specific fixation method enabled the visualization of αSMA along retinal capillaries. In this study, we applied snap-fixation in wild type and streptozotocin-induced diabetic mice to evaluate the differences in vascular smooth muscle cells of the retina and the choroid. Mice eyeballs were fixed in ice-cold methanol to prevent the depolymerization of filamentous actin. Snap-fixated retina showed αSMA expression in higher-order branches along the capillaries as well as the arterioles and venules, which were not detected by paraformaldehyde fixation. In contrast, most choriocapillaris, except those close to the arterioles, were not covered with αSMA-positive perivascular mural cells. Large choroidal vessels were covered with more αSMA-positive cells in the snap-fixated eyes. Diabetes induced less coverage of αSMA-positive perivascular mural cells overall, but they reached higher-order branches of the retinal capillaries, which was prominent in the aged mice. More αSMA-positive pericytes were observed in the choroid of diabetic mice, but the αSMA-positive expression reduced with aging. This study suggests the potential role of smooth muscle cells in the pathogenesis of age-related diabetic retinopathy and choroidopathy.

Utility of allogeneic hematopoietic stem cell transplantation using international donors in a homogenous ethnic population: question in the era of various alternative donors.

The advent of various alternative donors in allogeneic hematopoietic stem cell transplantation (HSCT) raises the question of using international donors, especially in ethnically homogenous populations. We analyzed the clinical outcome and medical expense of human leukocyte antigen (HLA)-matched HSCT using domestic and international donors. We analyzed the patients who received allogeneic HSCT at five medical centers in Korea in the last 10 years. Using propensity-score matching, we compared overall survival (OS), relapse-free survival (RFS), and transplantation-related complications. Medical expense was analyzed based on National Health Insurance Service (NHIS) data. A total of 269 patients were analyzed after 3:1 (domestic/international) matching. There was no difference in OS (p = 0.395) and RFS (p = 0.604) between the domestic and international donor groups (5-year OS rate 42.9 and 37.8%, 5-year RFS rate 37.6 and 33.5% for domestic and international groups, respectively). No difference in chronic graft-versus-host disease (GVHD) incidence was observed (34.2% in domestic and 35.9% in international group, p = 0.804). Early infection was more frequent in the domestic group (55.0 vs. 35.8%, p = 0.007), whereas infection after 30 days was more frequent in the international group (28.7 vs. 49.3%, p = 0.001). Mean medical expense was far higher in the international group, by US $51,944 in the entire follow-up period (p < 0.001). We would expect similar outcomes for international and domestic donors in terms of survival and treatment-related complications with HLA-matched HSCT in other ethnically homogenous populations. These findings should be considered together with the high cost of using international donors in the era of various alternative donors.

Current Management of Cancer-associated Venous Thromboembolism: Focus on Direct Oral Anticoagulants.

Cancer-associated venous thromboembolism (CAT) is a common complication associated with high morbidity and mortality. In accordance with major clinical trials comparing low-molecular-weight heparin (LMWH) with a vitamin K antagonist (VKA), LMWH is currently the standard treatment for CAT, owing to its efficacy for thrombosis recurrence and improved safety profile compared to VKA. Over the past few years, direct oral anticoagulants (DOACs) have emerged as potential alternative therapies to LMWH due to their convenient route of administration and predictable pharmacokinetics, but evidence for their use in CAT is inconclusive, as only a small fraction of the study populations in these trials had CAT. Recently, two large head-to-head trials comparing DOACs to LMWH in CAT patients reported comparable efficacies of DOACs with increased bleeding risk. Occasionally, CAT treatment can be challenging due to the heterogeneity of underlying malignancies and comorbidities. Renal insufficiency and gastrointestinal defects are the main obstacles in anticoagulant selection. Careful choice of treatment candidates and proper anticoagulant strategies are critical for the treatment of CAT; hence, more studies are required to address these challenges.

Punicalagin suppresses methicillin resistance of Staphylococcus aureus to oxacillin.

Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that is cross-resistant to most ß-lactam antibiotics. We investigated whether oxacillin, which is a ß-lactam antibiotic, alone or in combination with punicalagin can affect the penicillin binding protein 2a (PBP2a)-mediated resistance of MRSA. Susceptibility testing of punicalagin with oxacillin was performed using the microdilution and checkerboard assay and the growth curve assay. Binding affinity of punicalagin for cell wall peptidoglycan (PGN) was confirmed by an increased concentration of PGN in bacterial cultures containing punicalagin. The level of PBP2a was analyzed by western blotting. Punicalagin exhibited antimicrobial activity in the viability assay and increased the susceptibility of MRSA to oxacillin. PGN interfered with the antimicrobial activity of punicalagin and prevented the synergistic activity of punicalagin and oxacillin. Increasing the concentration of punicalagin and maintaining a constant concentration of oxacillin resulted in synergistic suppression of the expression of the mec operon (mecA, mecI, and mecR1). The production of PBP2a was suppressed by the addition of punicalagin to oxacillin. Our findings demonstrate that punicalagin potentiates the effect of oxacillin on MRSA by reducing the transcription of mecA (a gene marker for methicillin resistance), which resulted in a reduced level of PBP2a.

Cryptotanshinone Induces Cell Cycle Arrest and Apoptosis of NSCLC Cells through the PI3K/Akt/GSK-3ß Pathway.

Cryptotanshinone (CTT) is a natural product and a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miltiorrhizabunge. Notably, CTT has a variety of anti-cancer actions, including the activation of apoptosis, anti-proliferation, and reduction in angiogenesis. We further investigated the anti-cancer effects of CTT using MTS, LDH, and Annexin V assay, DAPI staining, cell cycle arrest, and Western blot analysis in NSCLC cell lines. NSCLC cells treated with CTT reduced cell growth through PI3K/Akt/GSK3ß pathway inhibition, G0/G1 cell cycle arrest, and the activation of apoptosis. CTT induced an increase of caspase-3, caspase-9, poly-ADP-ribose polymerase (PARP), and Bax, as well as inhibition of Bcl-2, survivin, and cellular-inhibitor of apoptosis protein 1 and 2 (cIAP-1 and -2). It also induced G0/G1 phase cell cycle arrest by decreasing the expression of the cyclin A, cyclin D, cyclin E, Cdk 2, and Cdk 4. These results highlight anti-proliferation the latent of CTT as natural therapeutic agent for NSCLC. Therefore, we investigated the possibility of CTT as an anti-cancer agent by comparing with GF, which is a representative anti-cancer drug.

Nivolumab in Relapsed or Refractory Primary CNS Lymphoma: Multicenter, Retrospective Study.

Purpose: Given that 40~50% of primary central nervous system lymphoma (PCNSL) tissues exhibit aberrancy on 9p24.1, immune-checkpoint inhibitors (ICI) may work for the disease. Materials and Methods: To define the role of ICIs in PCNSL, we carried out a nationwide retrospect analysis for 22 patients who had been treated with nivolumab monotherapy for relapsed or refractory PCNSL. Results: The median age at diagnosis was 66, and male: female ratio was 1:1. Patients received nivolumab after a median of 3 lines (range, 2 - 6) of therapy and at the median age of 67 (range, 37 - 82). Eleven patients (50%) were refractory to the last treatment prior to nivolumab. With a median follow-up duration of 22.3 months (95% CI, 13.1 - 31.5), nine patients (41%) had an objective response (6 complete responses, 3 partial responses), and the median duration of response was 20.9 months (95% CI, 1.7 - 40.0). The median progression-free survival and overall survival were 2.1 months (95% CI, 0.2 - 4.0) and 18.9 months (95% CI, 5.0 - 32.8), respectively. Nivolumab was generally well-tolerated as no patients required dose reduction and only 2 patients required delay of treatment. Conclusion: Our study suggests that nivolumab can be a reasonable option with the durable response for RR PCNSL.

Microplastic ingestion in aquatic and soil biota: A comprehensive review of laboratory studies on edible size and intake pattern.

Microplastic contamination is ubiquitous and can be transferred through the food chain to humans. However, studies on microplastic size have mainly focused on large animals with a body length >20 mm. To address this gap, we conducted a comprehensive review of 169 laboratory studies to determine the edible size of microplastics for macrofauna and flora in aquatic and soil biota. Our findings indicate that microplastics with a size of <300 µm and 1 µm, respectively, are edible for these organisms, which are positioned at the base of the food chain. We also analyzed intake and depuration patterns and identified factors affecting microplastic ingestion. Our study fills an important knowledge gap by identifying the range of microplastic sizes that can enter the food chain and be transferred to humans. The study findings have strong implications for the ecological risk assessment of microplastics and suggest a starting point for mitigating this threat.

Diagnostic Approaches to Investigate JAK2-Unmutated Erythrocytosis Based on a Single Tertiary Center Experience.

INTRODUCTION: Erythrocytosis is attributed to various clinical and molecular factors. Many cases of JAK2-unmutated erythrocytosis remain undiagnosed. We investigated the characteristics and causes of JAK2-unmutated erythrocytosis. METHODS: We assessed the clinical and laboratory results of patients with erythrocytosis without JAK2 mutations and performed targeted next-generation sequencing (NGS) panels for somatic and germline mutations. RESULTS: In total, 117 patients with JAK2-unmutated erythrocytosis were included. The median hemoglobin and hematocrit levels were 17.9 g/dL and 53.4%, respectively. Erythropoietin levels were not below the reference range. Thrombotic events were reported in 17 patients (14.5%). Among JAK2-unmutated patients, 44 had undergone targeted panel sequencing consisting of myeloid neoplasm-related genes, and 16 had one or more reportable variants in ASXL1 (5/44), TET2, CALR, FLT3, and SH2B3 (2/44). Additional testing for germline causes revealed eight variants in seven genes in eight patients, including NF1, BPGM, EPAS1, PIEZO1, RHAG, SH2B3, and VHL genes. One NF1 pathogenic, one BPGM likely pathogenic, and six variants of undetermined significance were detected. CONCLUSION: Somatic and germline mutations were identified in 36.4% and 33.3 % of the JAK2-unmutated group; most variants had unknown clinical significance. Not all genetic causes have been identified; comprehensive diagnostic approaches are crucial for identifying the cause of erythrocytosis.

A Phase II Study to Evaluate the Efficacy of Bortezomib in Combination with Thalidomide in Treatment-Naïve Waldenstrom Macroglobulinemia Patients.

PURPOSE: Despite the recent success of Bruton's tyrosine kinase (BTK) inhibitors for the treatment of Waldenstrom macroglobulinemia (WM), their indefinite treatment duration ultimately tantamount to substantial financial and emotional burden. On the other hand, fixed duration of proteasome inhibitors (PI) have shown rapid and reasonable response in WM treatment. Despite the well-known synergism between PI and immunomodulatory drugs (IMiD), there is no trials evaluating such combination in WM. MATERIALS AND METHODS: Based on above, we designed this phase II study to investigate the efficacy and safety of 6 cycles of 28-day bortezomib-thalidomide-dexamethasone (VTD) regimen for treatment-naïve WM. RESULTS: A total of 15 patients were enrolled: major response rate was 64.3%, and overall response rate was 78.6%. During the median follow-up of 41 months, median progression-free survival (PFS) was 13 months and overall survival 40 months. For responders, median duration of response was 13 months and median PFS 19 months. The most common adverse event (AE) of any grade was constipation (57.1%). The most common grade ≥ 3 AE was anemia (21.4%). CONCLUSION: All in all, we hereby provide proof-of-concept that PI + IMiD may be an attractive backbone for fixed duration treatment. It should be noted that granting the same level of access to newer drugs globally is virtually impossible. Thus efforts to develop regimens using readily available drugs to yield similar or adequate treatment outcomes should not be disregarded. In this sense, we believe our study holds its place for its novelty and eloquently addresses achieving the daunting societal quest of health equity.

MG4101, an allogeneic natural killer cell, in patients with relapsed or refractory acute myeloid leukemia: a pilot study.

We evaluated the safety and efficacy of allogeneic, ex-vivo expanded, NK cells, MG4101, in patients with refractory or relapsed AML. The relationship between immunological characteristics and clinical responses was analyzed. Between April 2018 and February 2020, 11 patients (male:female = 5:6) were treated with MG4101. Of eight evaluable patients, two (25.0%) showed partial response and two (25.0%) showed stable disease. The median overall survival was 3.4 months (95% confidence interval [95% CI], 2.5-4.3 months), and the allogeneic hematopoietic stem cell transplantation (HSCT) censored duration of response was 2.9 months (95% CI, 1.5-4.4 months). Two patients underwent HSCT after MG4101 treatment. Except for one grade 3 infusion-related reaction, no serious adverse events were observed. The sum of activating KIRs in responders tended to be higher than that in non-responders. Analyses of NKRL and KIR highlighted the importance of immunological mechanisms in treating myeloid neoplasms.

False-positive results of galactomannan assays in patients administered glucose-containing solutions.

Galactomannan (GM) is a polysaccharide cell wall component released by Aspergillus spp., and an immunoenzymatic GM assay is used for the diagnosis of invasive pulmonary aspergillosis. We evaluated the cause of strong positivity for GM in patients with no typical signs of aspergillosis. Repeat assays were performed using different instruments and reagent lots, but there were no differences in results among the assays. Patients with strongly positive GM results were investigated. Medication histories revealed that 14 of 23 patients had been administered total parenteral nutrition solution from one manufacturer and 4 patients had been administered dextrose solution from a different manufacturer before being tested. The results of GM assays conducted on samples of dextrose solution and the glucose fraction of the total parenteral nutrition solution were strongly positive, confirming the causes of the false-positive reactions. We hypothesize that a trace amount of GM was introduced into the glucose-containing solutions because glucoamylase, which is necessary for the saccharification step of glucose synthesis, was derived from Aspergillus niger. To enhance patient care and prevent unnecessary antifungal prescriptions, healthcare providers and manufacturers of healthcare products need to be aware of the possibility of false-positive reactions for GM.

Association of TP53 Mutation Status and Sex with Clinical Outcome in NSCLC Treated with Immune Checkpoint Inhibitors: A Retrospective Cohort Study.

Purpose: Some studies suggest that TP53 mutations are associated with the response to immune checkpoint inhibitors (ICI) in patients with non-small cell lung cancer (NSCLC) and also contribute to sex disparities in several cancers. Thus, we hypothesized that TP53 mutations might serve as sex-dependent genomic biomarkers of ICI treatment response in patients with NSCLC. Materials and Methods: Clinical data of 100 patients with metastatic NSCLC treated with ICI monotherapy at Seoul National University Bundang Hospital (SNUBH) were retrospectively reviewed. Genomic and clinical datasets of TCGA and an ICI-treated lung cancer cohort (cBioPortal) were also analyzed. Results: In SNUBH cohort, no statistically significant difference was observed in disease control rate per the TP53 mutation status (p=0.503); however, female patients with TP53 mutated (MT) had a significantly prolonged median progression-free survival (PFS) compared to wild-type (WT) (6.1 months in TP53 MT vs. 2.6 months in TP53 WT; p=0.021). PD-L1 high (≥50%) expression was significantly enriched in female patients with TP53 MT (p=0.001). The analysis from publicly available dataset also revealed that females with NSCLC with TP53 MT showed significantly longer PFS than those with TP53 WT (p<0.001). In TCGA analysis, expression of immune-related genes, and TMB score in TP53 MT females were higher than in males without TP53 MT. Conclusion: Female patients with NSCLC with TP53 mutations had high PD-L1 expression and showed favorable clinical outcomes following ICI therapy, suggesting a need for further research to explore the role of TP53 mutations for sex disparities in response to ICI therapy.