Citations

Abstract Background These recommendations address the empiric choice of antibiotics in suspected complicated urinary tract infection (cUTI). Issues to balance include the need for appropriate initial empiric antimicrobial therapy, the patient's severity of illness, and antimicrobial stewardship concerns. Methods The panel's recommendations are based upon evidence derived from systematic literature reviews that focused on comparative benefits and harms of classes of antibiotics approved for cUTI, starting with publications from 2008 onwards, and our review of predictors of resistance in uropathogens included references identified since 2000. These recommendations adhere to a standardized methodology for rating the certainty of evidence and strength of recommendation according to the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Results The guidelines panel suggests initially selecting among preferred empiric antibiotic choices rather than alternative options, stratified for the patient's severity of illness and antimicrobial stewardship considerations. When choosing among these antibiotics for a specific patient, the guideline panel suggests a 4-step process to account for changing resistance patterns and individualized patient needs. The steps are: (1) assess the severity of illness (for initial prioritization of antibiotics), (2) consider patient-specific risk factors for resistant uropathogens (for optimization of coverage), (3) evaluate other patient-specific considerations (to reduce the risk of adverse events), and (4) for patients with sepsis, consult a relevant local antibiogram if available (to further improve the likelihood of giving appropriate empiric therapy). Lastly, the guideline panel suggests selecting definitive effective therapy with a targeted spectrum based on the result of the urine culture. Conclusions Many of the classes of antibiotics approved to treat cUTI demonstrate similar efficacy as other classes of antibiotics in randomized controlled trials. Bacterial resistance prevalence is always changing, and new antibiotics will be developed. In this context, the guidelines panel provides recommendations for choosing empiric antibiotic therapy for cUTI that will help clinicians decide among available antibiotic options at the point of care.

Pathways Linking Parental Social Support and Decision-Making Participation to Medication Adherence in Children With Epilepsy: The Moderating Role of Parental Anxiety. Yang C, Huang R, Tao Q, Hao Z, Zhao L, Zhang L. Depress Anxiety . 2025 Sep 16;2025:7159579. doi: 10.1155/da/7159579. PMID: 40995429; PMCID: PMC12457068. Background: Medication adherence among pediatric epilepsy patients is frequently suboptimal, and the complex interplay between parental social support, decision-making participation, treatment satisfaction, and parental anxiety in influencing medication adherence remains underexplored. This study investigates both the direct and indirect pathways linking these factors to medication adherence and examines the mediating role of treatment satisfaction and the moderating role of parental anxiety. Methods: A cross-sectional study was conducted at three medical institutions between January 2020 and June 2024. Data on patient demographics and standardized scales measuring medication adherence, social support, communication and decision-making participation, treatment satisfaction, and parental anxiety were collected. Relationships among these variables were analyzed using structural equation modeling (SEM) and moderation analysis. Results: A total of 1056 patients were included in the study, with a mean age of 8.86 ± 3.99 years; 51.7% were male. Path analysis showed that parental social support (STD = 0.344, p < 0.001), communication and decision-making participation (STD = 0.392, p < 0.001), and treatment satisfaction (STD = 0.090, p < 0.05) had significant positive effects on medication adherence. Parental social support (STD = 0.483, p < 0.001) and communication and decision-making participation (STD = 0.203, p < 0.001) also strongly influenced treatment satisfaction. The indirect effects of social support and decision-making participation on medication adherence, mediated through treatment satisfaction, were statistically significant ( p < 0.05). Parental anxiety, as a moderating factor, weakened the positive effects of social support, decision-making participation, and treatment satisfaction on medication adherence ( p < 0.05). Conclusion: This study systematically develops an integrated model linking parental social support, communication and decision-making participation, treatment satisfaction, and anxiety to medication adherence in pediatric epilepsy. It highlights the mediating role of treatment satisfaction and the moderating role of parental anxiety. Enhancing parental social support and communication, improving treatment satisfaction, and addressing parental anxiety are key strategies to promote medication adherence.

OBJECTIVE Glucagon-like peptide-1 (GLP-1) agonists are established therapeutics for weight loss that are increasingly used for BMI optimization prior to spine surgery. However, emerging evidence has suggested that GLP-1 agonists might reduce bone mineral density (BMD), increasing the risk of postoperative biomechanical complications. CT-based Hounsfield units (HUs) have gained popularity as a method for measuring spinal BMD. The aim of this study was to evaluate the effects of GLP-1 agonist–induced weight loss on spinal BMD as measured by opportunistic CT-based HUs. METHODS Patients who were treated with any GLP-1 agonist (2017–2022) for > 3 months were retrospectively identified. Patient body weight (BW), BMI, and HU measurements in the L1 vertebral body were measured before and after GLP-1 therapy. Patients were grouped according to the percentage of weight loss during GLP-1 therapy. One-way ANOVA was used to compare the mean changes in spinal HUs across the groups. RESULTS Among the 102 included patients, the mean ± standard error of the mean BW reduction was 14.5 ± 2.5 kg over 15.9 ± 1.2 months of GLP-1 agonist therapy. Of these, 7 patients (6.9%) lost > 20% BW (mean decrease of 31.9 ± 7.0 HU, p = 0.011), 14 (13.7%) lost 15%–20% BW (mean decrease of 19.1 ± 8.3 HU, p = 0.038), 14 (13.7%) lost 10%–15% BW (mean decrease of 12.2 ± 5.1 HU, p = 0.036), 24 (23.5%) lost 5%–10% BW (mean decrease of 15.7 ± 3.3 HU, p < 0.0001), 26 (25.5%) lost < 5% BW (mean decrease of 14.7 ± 6.0 HU, p = 0.022), and 17 (16.7%) gained BW during GLP-1 therapy (mean decrease of 6.3 ± 5.0 HU, p = 0.229). One-way ANOVA testing did not show a significant difference in HU reduction across the weight loss groups (F = 1.12, p = 0.355). In addition, there was a significant correlation between the decrease in L1 HUs and the duration of GLP-1 therapy (r = −0.38, p = 0.0001) but not the amount of weight loss (r = −0.18, p = 0.070). In the multivariate analysis, the duration of GLP-1 therapy (p = 0.032) was a significant independent predictor of vertebral HU reduction, but the amount of weight loss (p = 0.664) was not. CONCLUSIONS Despite similar pretreatment BW and HU measurements, all weight loss groups had significant decreases in vertebral HUs following GLP-1 agonist therapy, with a significant correlation observed between HU reduction and treatment duration. This suggests that long-term GLP-1 agonist therapy can significantly diminish spinal BMD regardless of the amount of weight loss achieved.

ABSTRACT Purpose There is limited evidence regarding the optimal timing of urosymphyseal fistula (USF) repair. Our aim was to conduct a comparative analysis evaluating the postoperative complications and surgical outcomes among patients undergoing surgery for USF, comparing those treated in an early versus delayed fashion. Methods Fifty‐eight patients with diagnosis of USF and who underwent fistula decompression, pubic bone resection, and urinary tract reconstruction were included. Patients who underwent USF repair within 100 days of diagnosis were classified as having early repair, while those treated after 100 days were considered to have delayed repair. Results Thirty‐one underwent delayed USF repair (53.4%), while 27 underwent early repair (46.6%). Most patients were male (96.8%). The median age (72 years vs . 69 years, p = 0.13) and mean BMI (28.7 vs . 28.6, p = 0.97) were comparable between groups. The rate of overall 90‐day complications following USF repair was comparable between groups (77.4% vs . 63%, p = 0.228). We did not find a difference between the rates early complications among groups. The rates of long‐term recurrent pain (46.7% vs . 11.1%, p = 0.004), recurrent osteomyelitis (20% vs . 0%, p = 0.014), and fistula (23.3% vs . 3.7%, p = 0.033) were higher in the delayed USF repair group compared to the early USF repair group. The follow up time was similar between groups too (25.43‐months vs . 32.8‐months, p = 0.257). Conclusion While early USF repair might not affect the incidence of early complications within 90 days post‐surgery, it is associated with reduced rates of long‐term recurrent pain, recurrent osteomyelitis, and fistula recurrence compared to delayed USF repair.

BACKGROUND AND OBJECTIVES: Preventive treatment of unruptured intracranial aneurysms (UIAs) requires assessment of treatment risks vs expected benefit. Although established scores exist to estimate rupture and growth risk, currently, no externally validated tools exist to estimate the risks of microsurgical treatment of UIAs. Clinical prediction models based on machine learning enable generation of personalized risk estimates for each individual patient based on their specific patient and aneurysm characteristics. METHODS: Using data from 20 international centers from the prediction of adverse events after microsurgery for intracranial unruptured aneurysms study on patients treated microsurgically for UIAs, we developed and externally validated clinical prediction models for 3 outcomes measured at hospital discharge: poor neurological outcome (modified Rankin Score ≥3), new sensorimotor neurological deficits, and all-cause adverse events (Clavien-Dindo Grade ≥1). RESULTS: A total of 3705 patients were included. Data from 13 centers (2881, 78%) were used for model development. Fully trained models were evaluated on 824 patients (22%) from 7 additional centers. Average age was 56 ± 12 years, and 1049 (28%) were male. At discharge, poor neurological outcome was seen in 514 patients (14%). New sensorimotor deficits were observed in 534 patients (14%), and 894 patients (24%) experienced adverse events until discharge. At external validation, prediction of poor neurological outcome was achieved with good calibration and an area under the curve (AUC) = 0.70 (95% CI: 0.63-0.75). Similarly, new neurological deficits were predicted with good calibration and with an AUC = 0.69 (95% CI: 0.63-0.74). Prediction of all-cause adverse events only achieved an AUC = 0.59 (95% CI: 0.55-0.64) with fair calibration. The prediction model was integrated into a web application accessible at https://neurosurgery.shinyapps.io/PRAEMIUM/. CONCLUSION: The developed models for prediction of poor neurological outcome and new sensorimotor neurological deficits at discharge exhibit good calibration and fair discrimination based on a multinational external validation, indicating that the predicted probabilities correspond well to real-world risks and may thus be clinically useful in more objectively estimating the risk of microsurgical treatment.

Abstract Background Subglottic stenosis (SS) is a type of laryngotracheal stenosis defined by a location of less than 1.5 cm below the glottis or the vocal cords. Approximately 20% of cases are idiopathic. Objective We performed a systematic literature review of idiopathic subglottic stenosis (ISS) complicating pregnancy. Search Strategy PubMed, Scopus, and clinicaltrials.gov databases were queried from inception through August 10, 2023 with the following terms: idiopathic subglottic tracheal stenosis, subglottic stenosis, subglottic stenoses, tracheal stenosis, tracheal stenoses, and pregnancy. This systematic review was conducted according to the methods described in the Preferred Reporting Items for Systematic Reviews and Meta‐analysis (PRISMA) guidelines for reporting systematic reviews. Selection Criteria Studies detailing cases of ISS affecting pregnancy were included and studies reporting SS in pregnancy from a known etiology were excluded. Data Collection and Analysis Our search identified 31 peer‐reviewed published cases of ISS complicating pregnancy that met the inclusion criteria. We also included two additional cases from our institution. Publication bias was checked by the Joanna Briggs Institute critical appraisal tools. Descriptive statistical analyses were performed using Excel. Main Results A majority of patients (26/33, 79%) were diagnosed with ISS during the reported pregnancy. Prior to pregnancy, 20/33 (61%) patients had a working diagnosis or reported symptoms of airway obstruction. Of these patients, 9/20 (45%) carried a diagnosis of asthma, and 6/20 (30%) carried a diagnosis of ISS. Specific symptoms prior to pregnancy were reported in 10/33 (30%) patients. The most common symptoms in these patients were dyspnea (10/10, 100%) and stridor (4/10, 40%). During pregnancy, all patients experienced worsening respiratory symptoms, with dyspnea (31/33, 94%), stridor (18/33, 55%), cough (13/33, 39%), hoarseness (7/33, 21%), and wheeze (5/33, 15%) being the most common symptoms. A total of 22/33 (67%) patients required medical and/or surgical management with dilation and/or excision during pregnancy. Postpartum outcomes were reported in 27/33 (82%) patients, and 1/27 (3.7%) required a tracheostomy immediately postpartum. The majority (18/27, 67%) of these patients required intervention postpartum, while 9/27 (33.3%) were asymptomatic. Conclusion ISS should be considered in pregnant patients with worsening respiratory symptoms despite medical management of asthma. If high clinical suspicion for upper airway obstruction exists, an otolaryngology referral for evaluation with bronchoscopy is recommended.

Abstract Background Several BsAbs with different treatment (Tx) approaches have been approved by the FDA for Tx of lymphoma, including: fixed-duration and less frequently dosed mosunetuzumab (mosun) and glofitamab (glofit) (Option 1 Tx approach); and treat to progression and more frequently dosed epcoritamab (epcor) (Option 2 Tx approach). Differences in Tx approaches have implications for time spent receiving care, known as “time toxicity”. We previously reported that mosun and glofit were associated with about 2 weeks lower time toxicity vs epcor over the first year in R/R FL and DLBCL, based on registrational trial protocols (Torka et al. Blood 2024; Ma et al. Value in Health 2025). In this study, we assessed time toxicity from the perspective of patients (pts) receiving BsAbs for R/R FL or DLBCL. Methods An online survey was conducted aiming for input from 120 pts with R/R FL or DLBCL, who have received BsAb for ≥1 month in the US. Time toxicity was measured by pts recalling time spent on healthcare contacts related to BsAb Tx, cancer management, and any other reasons in the past 30 days. Pts' preferences were assessed through direct elicitation of choice between 2 hypothetical Tx profiles with different Tx approaches and time toxicity, assuming the same efficacy and safety. The survey was pre-tested and refined based on input from 3 BsAb pts with R/R DLBCL to ensure relevance and comprehension. Descriptive analyses were performed on pts characteristics, mean and standard deviation (SD) of time spent per pt per month, and the proportion of pts preferring the convenience of different Tx profiles. Results At this interim analysis, 101 pts receiving BsAbs responded to the survey: 48 pts with R/R FL (mosun n=28; epcor n=20) and 53 pts with R/R DLBCL (glofit n=32; epcor n=21). Most pts with R/R FL lived in urban/suburban areas (87.5% vs 12.5% in rural areas) and had a shorter one-way travel time to receive care vs pts in rural areas (mean±SD: 28.2±13.5 vs 60.3±30.2 minutes). The median age was 58 years for both mosun and epcor. Mean±SD Tx duration was 6.2±1.8 months for mosun vs 4.5±1.3 months for epcor. In the past 30 days, pts on mosun had fewer BsAb Tx visits vs epcor (mean±SD: 1.0±0.2 vs 2.0±1.2), and fewer all-cause healthcare contacts vs epcor (mean±SD: 1.7±0.8 vs 3.5±2.0). The mean±SD time spent per BsAb Tx visit was 5.0±1.4 hours for mosun vs 3.8±1.8 hours for epcor. Less time was spent per pt per month on recovery at home after Tx visit for mosun vs epcor (22.7±16.5 vs 43.2±47.6 hours). Less time was spent per pt per month on Tx and cancer management for mosun vs epcor (mean±SD: 30.5±16.9 vs 56.9±59.3 hours). Most pts with R/R DLBCL lived in urban/suburban areas (88.7% vs 11.5% in rural areas) and had a shorter one-way travel time to receive care vs pts in rural areas (mean±SD: 31.4±14.1 vs 103.3±19.4 minutes). The median age was 67 years for glofit and 66 years for epcor. The mean±SD Tx duration was 6.1±2.0 months for glofit vs 5.9±1.8 months for epcor. In the last 30 days, pts on glofit had fewer BsAb Tx visits vs epcor (mean±SD: 1.1±0.2 vs 1.7±0.5), and fewer all-cause healthcare contacts vs epcor (mean±SD: 2.2±1.3 vs 3.0±1.1). Irrespective of the route of administration, the time spent per BsAb Tx visit was similar (mean±SD: 5.1±1.6 hours for mosun; 5.6±1.2 hours for epcor). Less time was spent per pt per month on recovery at home after Tx visit for glofit vs epcor (mean±SD: 34.3±23.8 vs 69.3±39.4 hours). Less time was spent per pt per month on Tx visits and cancer management for glofit vs epcor (mean±SD: 43.0±25.9 vs 85.0±44.2 hours). Regardless of which BsAb pts received, most pts (93%) preferred the convenience of Option 1 Tx approach with less time required over Option 2 Tx approach with more time required. Conclusions This is the first study to directly measure pt-reported time toxicity from pts with R/R FL and DLBCL receiving BsAbs in a real-world setting. Fixed-duration less frequently dosed mosun and glofit (Option 1 Tx approach) had less pt-reported time toxicity, with less healthcare contact and less time spent per pt per month vs treat to progression more frequently dosed epcor (Option 2 Tx approach). Over 90% of pts preferred the convenience of a fixed-duration, less frequently dosed, and less time required Tx option, suggesting that time toxicity is a significant factor in shared Tx decision-making for pts with R/R FL and DLBCL. Analysis is ongoing to comprehensively measure pt-reported time toxicity.

Abstract Background: Advantages of covalent Bruton Tyrosine Kinase inhibitor (cBTKi) treatment (tx), as compared to BCL2 inhibitor (BCL2i) containing regimens, include ease of initial administration without a requirement for frequent laboratory monitoring, even in patients (pts) with bulky disease. However, limitations of cBTKi monotherapy include acquired resistance, cumulative toxicity and the financial burden associated with continuous administration. CLL pts treated on the E1912 study who discontinued (dc) ibrutinib for reasons other than progression of disease (PD) had a median progression free survival (PFS) of ~2.7 years from ibrutinib dc, suggesting that a time-limited cBTKi strategy may be feasible for some pts(Shanafelt et al. Blood Advances 2025). We hypothesized that acalabrutinib (acala) and obinutuzumab (O) could be administered as a time-limited initial tx for CLL with duration guided by minimal residual disease (MRD). Methods: This is an ongoing phase II, multicenter, investigator-initiated study of acala and O for previously untx pts with CLL/small lymphocytic lymphoma (SLL) requiring tx per iwCLL 2018 criteria (NCT04722172). Pts with TP53 aberrancy are excluded. Pts receive acala 100 mg twice daily and O during 28-day cycles (C) 2-7. Undetectable MRD is defined with a 10-4 sensitivity in the peripheral blood (PB) by ClonoSeq next generation sequencing (uMRD4). Pts undergo MRD testing at C13; if uMRD4 at C13 with a complete response (CR) or partial response (PR), pts dc acala and enter tx free observation (TFO). If detectable MRD4 (dMRD4) at C13, pts continue acala until uMRD4, with repeat MRD testing occurring at C16, 19, 22 and 25. All pts dc acala after a maximum of 26C and enter TFO, even if dMRD4. If pts have PD meeting iwCLL criteria for tx during TFO, re-tx consists of acala + 6 cycles of O. Pts are followed for 13C of re-tx. Primary endpoint is 36-month PFS. Results: 55 pts initiated tx. Baseline characteristics include: median age 67, 64% male, 47% LN ≥ 5 cm, 73% IGHV unmutated. Best overall response rate (ORR) was 95% (CR: 4, PR: 48, SD: 0, PD: 1, unknown: 2). Best uMRD4 rate at any time during the study was 49% (n=27 pts, intention-to-treat, IIT). 5 pts dc tx prior to C13 MRD testing (2 pt decision, 2 AE, 1 due to PD after ~4C). At C13, 22 pts (40% of IIT) were uMRD4; 21 entered TFO after 13C and 1 pt had 19C tx prior to TFO. 28 pts had dMRD4 (51% ITT) at C13. Between C13 and 26, 2 pts became uMRD4 and entered TFO, 1 pt died (COVID-19), and 2 pts stopped acala for tx of other cancers. 21 pts completed 26C acala per protocol prior to entering TFO; 2 additional pts had PD at C25 and EOT. Median tx duration was 19C. In univariate analyses, age, del11q, del13q, IGHV mutational status and baseline LN ≥ 5 cm were not predictive of uMRD4 at C13. At a median follow-up of 38 months, the median PFS for the overall cohort is 42 months (95% confidence interval (CI): 37, not reached), with an estimated 36-month PFS of 69% (95% CI: 57%, 84%). At data cutoff, of 46 pts entering TFO, 29 pts remained in TFO without PD, 7 pts had PD during TFO but had not met iwCLL criteria for re-tx, and 10 pts had PD requiring tx (5 pts re-tx pe protocol, 5 came off study for non-protocol tx approach). The overall median TFO period (measured from acala dc to PD) was 25 months (95% CI: 21 – not reached, n=46 pts). 5 pts have initiated re-tx with acala + O (1 pt best response PR and uMRD4; 4 ongoing tx). Median time to re-tx was 18 months (range 6-34, n=5 pts). Conclusions: This study is proof-of-concept that cBTKi may be administered as a time-limited tx without the addition of a BCL2i. While the initial PFS is shorter than historical studies examining continuous cBTKi, of patients entering TFO after 1-2 years of acala, the median duration of TFO until PD is 25 months, and longer follow-up will provide re-tx outcomes. Potential advantages to MRD-guided, time-limited cBTKi tx include time off tx for pts, limiting acquired resistance, the ability to re-challenge with cBTKi at progression, and reserving BCL2i for third-line or later tx.

Abstract Introduction: Despite advent of multiple tyrosine kinase inhibitors (TKIs) and newer treatment methods for AML and ALL, the outcomes of patients (pts) with chronic myeloid leukemia in blast phase (CML-BP) remain poor. Consensus guidelines on treatment of CML-BP are scarce. A recent study from the European leukemia network blast phase registry on 240 pts reported marked heterogeneity in treatment patterns and lack of an accepted standard. Hence, we undertook this study through the H Jean Khoury Cure CML Consortium (HJKC3) to describe the treatment patterns and outcomes of pts with CML-BP in the US. Methods: This is a multi-institution, retrospective study. IRB approval was obtained at each institution and data sharing agreements were executed. All pts diagnosed with CML-BP based on modified MD Anderson Criteria (≥30% blasts in the blood or bone marrow or extramedullary (EM) disease) from 2010 to 2025 were included. Categorical variables were compared using Chi-square test. Overall survival (OS) was calculated from time of diagnosis of CML BP to death from any cause. Event free survival (EFS) was calculated from date of best response to event (death or relapse). Results: Of the 283 pts with CML-BP, 96 (33.9%) were female and 187 (66.1%) were males. At the time of diagnosis, 183 (64.6%) had CML-CP, 21 (7.4%) pts had CML-AP and 79 (27.9%) pts had de-novo CML-BP. For the 204 pts that were initially diagnosed with CML-CP or CML-AP, the median time to progression to CML-BP was 22.5 months (1-207 months). Median age at diagnosis of CML-BP was 50 years (range 16-86 years). EM disease was present in 78 (27.6%) pts (38 myeloid sarcoma, 30 central nervous system and 10 skin). Blasts were of myeloid phenotype in 168 (59.4%), lymphoid in 103 (36.4%) and mixed in 9 (3.2%) pts. The bcr-abl protein was p210 in 229 (80.9%), p190 in 8 (2.8%) and p230 in 2 (0.7%) pts. ABL kinase domain mutation was seen in 42.1% (80/190) pts, with T315I being the most common (n=32), followed by E255K (n=16). Next generation sequencing was performed in 117 pts. The most common mutations were ASXL1 (n=27), RUNX1 (n=14), BCOR (n=4), DNMT3A (n=4) and BCORL1 (n=3). Of the 283 pts, 269 underwent CML-BP directed therapy. 63 (23.4%) pts were treated with TKI monotherapy, 184 (68.4%) pts were treated with a combination of chemotherapy (chemo) and TKI and 22 (8.2%) pts were treated with chemo alone. Response rate after CML-BP directed therapy was 75.3% (n=213). Best response was return to CML-CP in 49 pts, CHR with PCyR in 18 pts, CCyR in 31 pts, MMR in 31 pts, MR4 in 18 pts, MR4.5 in 19 pts and MR5 in 47 pts. Rate of response with 2G and ponatinib was significantly better than imatinib (85.3% and 77.3% vs 63.6%; p=0.04). 149 (55.4%) pts proceeded to alloSCT. Of the 213 pts that responded, 59 (27.7%) relapsed. At a median follow-up of 47 months, the median OS for all pts was 19.7 months (95% CI: 16.3-40.2 months), with 5-year OS rate of 38% (95% CI: 32-45%). Pts with myeloid phenotype had a significantly lower OS compared to lymphoid and mixed phenotype (Median OS 14.9 vs 45.9 and 31.1 months respectively; p=0.02). OS of pts that were treated with a combination of TKI and chemo was significantly longer compared to pts treated with TKI or chemo alone (52.9 vs 16.1 or 7.5 months; p&lt;0.0001). Dasatinib (n=99; 34.9%) and ponatinib (n=97; 34.3%) were the most used TKIs followed by imatinib (n=23; 8.1%), nilotinib (n=21; 7.4%), bosutinib (n=8; 2.8%) and asciminib (n=3; 1.1%). Pts treated with ponatinib had a numerically longer OS compared to 2G-TKI and imatinib, however this was not statistically significant (40.1 vs 30.6 and 20.3 months; p=0.52). EFS for pts treated with ponatinib was significantly longer compared to 2G-TKI or imatinib (25.9 vs 17.6 and 15.9 months; p=0.03). In a landmark analysis, pts that underwent alloSCT within 6 months of diagnosis had a significantly longer OS compared to those who did not (69.3 vs 16.0 months; p=0.006). Conclusion: CML-BP continues to have poor prognosis. Treatment is heterogenous involving various combinations of TKI and chemo. In our analysis, treatment with 2G-TKI or ponatinib led to better responses. CML-BP with myeloid phenotype had worse OS. Treatment with ponatinib was associated with a numerically longer OS and significantly longer EFS compared to 2G-TKI and imatinib. In addition, treatment with chemo in combination with TKI and alloSCT led to improved OS.

Abstract PAX5 is genetically altered in over 30% of B-ALL cases, with point mutations representing the second most common type of alteration. These point mutations are highly enriched in the DNA binding (paired) domain and have been recognized as founder events in PAX5 P80R and PAX5alt B-ALL subtypes, which account for over 12% of B-ALL. However, the molecular features and underlying mechanisms of these mutations in B-ALL remain largely undefined, limiting the development of targeted therapies and resulting in poor outcomes, especially in adult patients. We systematically investigated the functional roles and oncogenic mechanisms of PAX5 paired domain mutations. Integrated CRISPR screening and genomic profiling revealed that the paired domain is critical for PAX5 function. Disruptions in this region significantly reduced cell viability in B-ALL cell lines, and analysis of 2,955 B-ALL samples showed that recurrent PAX5 missense mutations are highly enriched in this domain, further underscoring its functional importance. Functional analysis of knock-in mice with PAX5 mutations revealed that R38H and R140L severely impair DNA binding and block B-cell differentiation, while P34L and P80R retain binding ability but alter binding specificity and gene regulation. Mice carrying homozygous (P34L, R38H, P80R, R140L) or heterozygous (R38H, P80R) mutations developed spontaneous B-ALL within one year. To model co-occurring mutations observed in patients, Pax5 R38H/P34L and R38H/R140L mice were generated. These compound mutations exhibited greater leukemogenic potential than single mutants. Transcriptomic analysis of leukemia samples showed consistent up-regulation of metabolic pathways and Myc target genes. Notably, biallelic PAX5 alterations and additional genetic lesions in signaling pathways were detected in all PAX5R38H/+ and PAX5P80R/+ leukemias, faithfully recapitulating the genetic alteration features of patient B-ALL driven by PAX5 mutations. Among Pax5-mutant mouse strains, Pax5P80R/+ mice develop B-ALL with short latency and complete penetrance, making them an ideal model to study the mutational evolution and leukemogenesis of B-ALL. To characterize the stepwise leukemogenesis process, we performed serial bone marrow aspirations in the same Pax5P80R/+ mice. In all 17 mice analyzed, we identified early preleukemic clones with only Pax5 WT deletions, followed by the emergence of leukemic clones harboring Jak1/3 mutations. Single-cell RNA/BCR-seq revealed that Pax5 WT allele deletions relieve metabolic constraints, thereby promoting clonal expansion of preleukemic B cells blocked at the pre-B stage. These changes coincide with downregulation of metabolic checkpoint genes and upregulation of glycolytic enzymes, promoting genetic instability and facilitating malignant transformation. Clinically, PAX5 P80R patients have better outcomes than PAX5alt cases. Using our mouse models, we observed that leukemic cells driven by the PAX5 P80R mutation exhibit greater sensitivity to dexamethasone compared to the ones carrying other PAX5 mutations in PAX5alt subtype, potentially due to their heightened dependence on glucose uptake and glycolysis, suggesting that metabolic rewiring driven by PAX5 mutants may influence therapeutic response. Interestingly, we found that an aberrant isoform of MEGF10 (aMEGF10) is highly and specifically expressed in PAX5 P80R B-ALL. This N-terminal truncated isoform encodes a protein that retains the intracellular immunoreceptor tyrosine-based activation motifs (ITAMs). Using CUT&Tag, we showed that PAX5 P80R directly binds to the aMEGF10 promoter. By engineering human CD34⁺ cells, we established a humanized PAX5 P80R leukemia model that recapitulates the gene expression profile of patient samples, including robust activation of aMEGF10. Functionally, aMEGF10 binds to and activates SYK, thereby promoting leukemic cell proliferation. Importantly, this oncogenic effect depends on intact ITAM motifs and SYK signaling, revealing a novel targetable vulnerability in PAX5 P80R leukemias. Overall, the study establishes that PAX5 DNA binding domain mutations contribute to leukemogenesis through stepwise loss of PAX5 WT alleles and acquisition of signaling pathway mutations, involving impaired differentiation, metabolic deregulation, and novel oncogene activation. These findings not only deepen the understanding of PAX5-driven leukemias but also highlight aMEGF10–SYK signaling as a promising therapeutic target.