Citations

Abstract Response Assessment in Pediatric Neuro-Oncology (RAPNO) is an international working group dedicated to developing standardized recommendations for response assessment in children with central nervous system tumors enrolled on clinical trials. This standardization facilitates easier and more reliable comparison of responses across trials. Since the first RAPNO publication in 2013, response guidelines have been issued for medulloblastoma (MB), low-grade glioma (LGG), high-grade glioma (HGG), diffuse intrinsic pontine glioma, ependymoma, and craniopharyngioma. Many of these guidelines have already been incorporated into clinical trials to evaluate their effectiveness and accuracy. RAPNO has always been predicated on the idea that these consensus recommendations will require updates over time as they are applied in practice given technological advancements, evolving treatment approaches, and growing knowledge of disease pathology. A half-day RAPNO symposium sponsored by the Society of Neuro-Oncology was held in San Diego, California, United States, on May 15, 2025. This event coincided with the 8th Biennial Pediatric Society of Neuro-Oncology meeting. The main objectives were to identify ongoing RAPNO challenges, discuss potential updates, and plan future initiatives across 3 specific groups: (1) LGG/Craniopharyngioma, (2) HGG/diffuse midline glioma (DMG)/Ependymoma, and (3) MB and other seeding tumors. This manuscript reviews the symposium proceedings and highlights key topics and challenges discussed, as well as outlining future RAPNO initiatives.

Abstract Clonal hematopoiesis of indeterminate potential (CHIP), an emerging biomarker for personalized risk-directed interventions, is increased in cancer survivors. However, little is known about patient preferences for CHIP testing. We surveyed participants in a prospective cohort study of young women with breast cancer (BC). The emailed survey included an introduction to CHIP and a vignette eliciting participants’ preferences for CHIP testing, considering sequentially: population-based 10-year risk of BC recurrence, hematologic malignancy, and heart disease; increased CHIP-associated risks; current CHIP management; dedicated CHIP clinic; and hypothetical CHIP treatment. Preference changes were evaluated using the McNemar test. The survey response rate was 82.2% (528/642). Median age at time of survey was 46 years and median time from diagnosis was 108 months. Only 5.9% had prior knowledge of CHIP. After vignette presentation, most survivors (87.1%) recommended CHIP testing for the vignette patient. Presented next with CHIP-independent, population-based risks, 11.1% shifted their preference from testing to not testing. After receiving information about CHIP-associated risks, an additional 10.1% shifted their preference to testing. Preference for testing increased if vignette patient was offered a CHIP clinic or hypothetical CHIP treatment, with 7.2% and 14.1% switching preferences toward testing, respectively. Finally, 75.8% of participants desired CHIP testing for themselves. Among participants, 28.2% reported that learning about CHIP caused at least moderate anxiety. Most young survivors favored CHIP testing, with preferences influenced by risk presentation and potential management strategies. Our findings highlight the importance of risk communication and psychosocial support when considering biomarkers for future risk in cancer survivors. This trial has been registered at www.clinicaltrials.gov as #NCT01468246.

Abstract Myeloid neoplasms and acute leukemias derive from the clonal expansion of hematopoietic cells driven by somatic gene mutations. Although assessment of morphology plays a crucial role in the diagnostic evaluation of patients with these malignancies, genomic characterization has become increasingly important for accurate diagnosis, risk assessment, and therapeutic decision making. Conventional cytogenetics, a comprehensive and unbiased method for assessing chromosomal abnormalities, has been the mainstay of genomic testing over the past several decades and remains relevant today. However, more recent advances in sequencing technology have increased our ability to detect somatic mutations through the use of targeted gene panels, whole-exome sequencing, whole-genome sequencing, and whole-transcriptome sequencing or RNA sequencing. In patients with myeloid neoplasms, whole-genome sequencing represents a potential replacement for both conventional cytogenetic and sequencing approaches, providing rapid and accurate comprehensive genomic profiling. DNA sequencing methods are used not only for detecting somatically acquired gene mutations but also for identifying germline gene mutations associated with inherited predisposition to hematologic neoplasms. The 2022 International Consensus Classification of myeloid neoplasms and acute leukemias makes extensive use of genomic data. The aim of this report is to help physicians and laboratorians implement genomic testing for diagnosis, risk stratification, and clinical decision making and illustrates the potential of genomic profiling for enabling personalized medicine in patients with hematologic neoplasms.

Abstract With aging, somatic mutations in hematopoietic stem and progenitor cells (HSPC) can give rise to clonal hematopoiesis of indeterminate potential (CHIP), a premalignant state associated with diverse age-related diseases. Here we report the largest multi-ancestry genome-wide analysis of CHIP to date (N = 1,018,305), including individuals of African (N = 85,978), Admixed American (N = 191,371), East Asian (N = 13,532), European (N = 694,015), and South Asian (N = 13,193) ancestry. Multi-ancestry meta-analyses identified 72 genome-wide significant loci, including 44 novel associations implicating genes such as AFF1 , ATF7IP , ATP8B4 , BCL2 , CEBPA , CYRIA , DNM2 , ELF1 , NKX2-3 , PIK3CB , PRDM16 , RPN1 , TERC , and TRIM4 . Notably, variants at MECOM and PHF20L1 showed opposite allelic effects between DNMT3A - and non- DNMT3A -driven CHIP, highlighting driver-specific germline influences. Implicated loci converge on pathways regulating telomere maintenance, cell-cycle control, hematopoietic transcription, DNA damage response and immune signaling. These findings support a model in which germline variation both expands the HSPC pool and biases clonal selection in a driver-dependent manner, providing a mechanistic basis for inter-individual heterogeneity in CHIP. Phenome-wide association analyses further linked CHIP to hematologic, neoplastic, and circulatory traits, with enrichment across hematopoietic and non-hematopoietic cell types. Together, this work expands the genomic and phenomic landscape of CHIP and reveals germline–somatic interactions that shape clonal evolution during aging.

Abstract The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.

Human genetic studies support an inverse causal relationship between leukocyte telomere length (LTL) and coronary artery disease (CAD), but directionally mixed effects for LTL and diverse malignancies. Clonal hematopoiesis of indeterminate potential (CHIP), characterized by expansion of hematopoietic cells bearing leukemogenic mutations, predisposes both hematologic malignancy and CAD. TERT (which encodes telomerase reverse transcriptase) is the most significantly associated germline locus for CHIP in genome-wide association studies. Here, we investigated the relationship between CHIP, LTL, and CAD in the Trans-Omics for Precision Medicine (TOPMed) program ( n = 63,302) and UK Biobank ( n = 47,080). Bidirectional Mendelian randomization studies were consistent with longer genetically imputed LTL increasing propensity to develop CHIP, but CHIP then, in turn, hastens to shorten measured LTL (mLTL). We also demonstrated evidence of modest mediation between CHIP and CAD by mLTL. Our data promote an understanding of potential causal relationships across CHIP and LTL toward prevention of CAD.

Abstract To repurpose therapeutics for fibrolamellar carcinoma (FLC), we developed and validated patient-derived xenografts (PDX) from surgical resections. Most agents used clinically and inhibitors of oncogenes overexpressed in FLC showed little efficacy on PDX. A high-throughput functional drug screen found primary and metastatic FLC were vulnerable to clinically available inhibitors of TOPO1 and HDAC and to napabucasin. Napabucasin's efficacy was mediated through reactive oxygen species and inhibition of translation initiation, and specific inhibition of eIF4A was effective. The sensitivity of each PDX line inversely correlated with expression of the antiapoptotic protein Bcl-xL, and inhibition of Bcl-xL synergized with other drugs. Screening directly on cells dissociated from patient resections validated these results. This demonstrates that a direct functional screen on patient tumors provides therapeutically informative data within a clinically useful time frame. Identifying these novel therapeutic targets and combination therapies is an urgent need, as effective therapeutics for FLC are currently unavailable. Significance: Therapeutics informed by genomics have not yielded effective therapies for FLC. A functional screen identified TOPO1, HDAC inhibitors, and napabucasin as efficacious and synergistic with inhibition of Bcl-xL. Validation on cells dissociated directly from patient tumors demonstrates the ability for functional precision medicine in a solid tumor. This article is highlighted in the In This Issue feature, p. 2355

e16771 Background: AbGn-107 is an ADC directed against AG-7 antigen, a Lewis A-like glycol-epitope expressed in 24-61% of gastric (G), colorectal (CRC), pancreatic (PDA), and biliary (BIL) cancers. Based on promising antitumor activity of AbGn-107 in both in vitro and in vivo preclinical studies, we performed a Phase Ia trial in patients with the aforementioned GI malignancies. Methods: Standard 3+3 dose escalation was used. Key eligibility included locally advanced or metastatic G, CRC, PDA, or BIL cancer, previously treated, ECOG PS 0-1; positive AG-7 expression was not required. Two dosing intervals were tested: AbGn-107 administered i.v. Q4 weeks (at doses ranging from 0.1-1.2 mg/kg) and Q2 weeks (at doses from 0.8-1.0 mg/kg). Dose limiting toxicities (DLT) were based on grade 3/4 hematologic and non-heme AEs occurring during the initial 4-week rx window. Patients were treated until disease progression or unacceptable toxicity, with tumor assessments Q8 weeks. 1o objectives: safety and MTD; 2o objectives: PK, immunogenicity, and efficacy defined by ORR (RECIST 1.1). Results: 35 patients were enrolled across 6 dose levels (median age 61.5 yo (range 40 – 81); G (0)/CRC (12)/PDA (20)/BIL (3); median # lines of prior rx = 3 (range 1-7). Safety: 5 patients experienced Grade 3 or 4 neutropenia, all at higher dose levels, inc. 1 episode of febrile neutropenia. Other frequent drug-related AEs, mostly grade 1/2, inc. fatigue (29%), nausea (20%), and diarrhea (14%). DLTs included grade 4 CK elevation (n = 1) at 0.8 mg/kg Q4W and grade 3 arthralgias (n = 1) at 1.2 mg/kg Q4W. Based on safety profile and PK data, 1.0 mg/kg Q2W was selected as the dose schedule for cohort expansion phase. Efficacy: Median duration of treatment = 56 days (range, 8 – 225 days). Six pts have demonstrated a minor response by RECIST (range, -1.3 to -21.1%); 4 pts (all PDA) have had durable dz control > 180 days. Conclusions: Overall, AbGn-107 appears well-tolerated with encouraging prelim signs of efficacy in unselected pts with heavily pre-treated advanced GI cancers. Updated safety and efficacy data will be provided at the time of the meeting for the cohort expansion phase of this study (currently open across multiple sites in U.S. and Taiwan), in which subjects with G, CRC, PDA, and BIL cancers are pre-screened for high levels of AG-7 tumor expression. Clinical trial information: NCT02908451 .

713 Background: AbGn-107 is an ADC directed against AG-7 antigen, a Lewis A-like glycol-epitope expressed in 24-61% of gastric (G), colorectal (CRC), pancreatic (PDA), and biliary (BIL) cancers. Based on promising antitumor activity of AbGn-107 in both in vitro and in vivo preclinical studies, we performed a Phase Ia trial in pts with the aforementioned GI malignancies. Methods: Standard 3+3 dose escalation was used. Key eligibility criteria: locally adv or metastatic G, CRC, PDA, or BIL cancer, previously treated, ECOG PS 0-1; positive AG-7 expression was not required. Two dosing intervals were tested: AbGn-107 administered i.v. Q4 weeks (at doses ranging from 0.1-1.2 mg/kg) and Q2 weeks (at doses from 0.8-1.0 mg/kg). DLTs were based on grade 3/4 hematologic and non-heme AEs occurring during the initial 4-week rx window. Pts were treated until dz progression or unacceptable toxicity, with tumor assessments Q8 weeks. 1o objectives: safety and MTD; 2o objectives: PK, immunogenicity, and efficacy defined by ORR (RECIST 1.1). Results: 35 patients were enrolled across 6 dose levels (median age 61.5 yo (range 40 – 81); G (0)/CRC (12)/PDA (20)/BIL (3); median # lines of prior rx = 3 (range 1-7). Safety: 5 pts experienced Grade 3 or 4 neutropenia, all at higher dose levels, with 1 episode of febrile neutropenia. Other frequent drug-related AEs, mostly grade 1/2, inc. fatigue (29%), nausea (20%), and diarrhea (14%). DLTs include grade 4 CK elevation (n = 1) at 0.8 mg/kg Q4W and grade 3 arthralgias (n = 1) at 1.2 mg/kg Q4W. MTD was not reached at either 1.2 mg/kg Q4W or 0.8 mg/kg Q2W; the 1.0 mg/kg Q2W cohort will complete enrollment in Oct 2019. Efficacy: Median duration of treatment = 56 days (range, 8 – 225 days); best response observed to date is stable dz lasting > 6 months at 0.8 mg/kg Q4W and Q2W cohorts (n = 1 each). Conclusions: Overall, AbGn-107 appears well-tolerated with encouraging prelim signs of efficacy (prolonged dz control) in non-biomarker selected pts with advanced GI cancers. Pre-screening for high AG-7 expression is underway for subjects with G, CRC, PDA, and BIL cancers for the cohort expansion phase of this study, which will be open across multiple sites in U.S. and Taiwan. Clinical trial information: NCT02908451.

AbstractFibrolamellar hepatocellular carcinoma (FLHCC) is a rare liver malignancy in adolescents and young adults. Surgery is the mainstay of therapy for primary and metastatic disease. Most patients relapse, with development of both local and distant metastases. Brain metastases from solid tumors are rare in the pediatric and young adult population. Here, we document three patients with brain metastases from FLHCC, confirmed by histology and molecular characterization of the chimeric fusion DNAJB1–PRKACA, each necessitating neurosurgical intervention. These observations highlight the ability of FLHCC to metastasize to the brain and suggest the need for surveillance neuroimaging for patients with advanced‐stage disease.