Lubner, Sam Joseph

The traditional combined hematology and oncology fellowship model is increasingly strained by accelerating subspecialization and therapeutic complexity. This commentary focuses on structural reforms within fellowship training to better align education with contemporary clinical practice and evolving workforce demands. We propose standardized, career-aligned tracks, earlier subspecialty focus within fellowship, and redesigned continuity clinic models that preserve foundational breadth while enabling depth of expertise. We further highlight how emerging assessment reforms and educational tools can support these structural changes. By aligning fellowship training with both real-world clinical demands and established educational science, we can ensure a more sustainable and effective pathway for preparing future hematologists and oncologists.

Abstract Purpose: Mutant IDH1 (mIDH1) defines a therapeutically targetable subtype of intrahepatic cholangiocarcinoma (ICC), with the mIDH1 inhibitor ivosidenib approved for advanced disease. A subset of patients experiences prolonged disease stabilization; however, the molecular basis for eventual progression remains poorly defined. Experimental Design: We performed molecular profiling of matched baseline and postprogression circulating tumor DNA (ctDNA) samples from patients with mIDH1 ICC enrolled in the ClarIDHy phase III trial. Functional studies were conducted to characterize candidate resistance mechanisms. Results: Longitudinal ctDNA analysis of 18 patients treated with ivosidenib for >6 months revealed emergent genomic alterations in multiple cases. Acquired mutations in mitogen-activated protein kinase (MAPK) pathway genes (KRAS, NRAS, MAP2K1, NF1) were identified in five cases, with instances of concurrent alterations and/or high variant allele fractions (VAF). Additional candidate resistance events included a secondary IDH1 mutation and a hotspot IDH2 mutation, detected at low VAF in the same patient. Functional studies showed that these IDH mutations conferred sustained 2-hydroxyglutarate production and ivosidenib resistance, whereas MAPK activation blunted gene expression induced by ivosidenib plus IFNγ, a key therapeutic output of mIDH1 inhibition. In parallel, baseline ctDNA profiling of 81 patients revealed that ARID1A mutations and elevated mIDH1 VAF were associated with reduced clinical benefit. Conclusions: MAPK pathway alterations represent a recurrent mechanism of resistance to mIDH1 inhibition in ICC, whereas emergent IDH1/IDH2 mutations appear infrequent. Functional data suggest that MAPK-mediated resistance may involve impaired IFN signaling. These results support MAPK-directed combination strategies and highlight the utility of ctDNA profiling to identify predictive and resistance biomarkers in mIDH1-driven ICC.

TPS2689 Background: Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, existing FDA approved companion diagnostic biomarkers like PD-L1, dMMR/MSI-H and TMB have low accuracy in predicting response. Ex vivo cytokine profiling of live tumor samples has shown promise as an improved means of predicting response to PD-1 blockade (Voabil, et al. Nat Med. 2021), but this approach has been limited to tumor resections given the need for large amounts of tissue. Here we present three clinical trials that leverage a novel approach using limited tissue from a single core needle biopsy (CNB) (20 gauge or larger). A sequential ex vivo treatment strategy is used, eliminating the need for a separate control arm and addressing challenges with tumor heterogeneity, particularly in CNBs where tissue is limiting. Using a specialized instrument, CNBs are cut into live tumor fragments (LTFs) which are viable in culture and retain the native tumor microenvironment, enabling cytokine profiling in response to ICI treatment ex vivo. Methods: ELEPHAS-01 (NCT05478538), ELEPHAS-02 (NCT05520099) and ELEPHAS-04 (NCT06349642) are observational prospective clinical trials initiated to characterize the accuracy of this approach for predicting ICI response. Over 750 patients that are being considered for standard of care (SOC) ICI therapy in the metastatic/relapse or neoadjuvant setting will be enrolled (Table). Fresh live CNBs are collected prior to treatment start and processed within 24 hrs enabling prediction of results within 72 hrs of receipt. LTFs are treated using a strategy where control (IgG) and SOC ICI treatments are performed sequentially on the same tissue in a single well. Changes in the cytokine secretion rates are then compared between ICI and control to characterize immunotherapy response. Additionally, tissue viability and tumor content measurements are used to assess tissue quality. Clinical response is measured using pathologic response in patients receiving neoadjuvant ICI therapy, while RECIST v1.1 is used in all other patients. The primary objective of these trials is to determine the platform’s ex vivo accuracy (e.g., sensitivity, specificity) for predicting clinical response to ICIs and comparing it to the accuracy of PD-L1, dMMR/MSI-H and TMB. Clinical trial information: NCT06349642 , NCT05478538 , NCT05520099 . ELEPHAS-01 (Lung) ELEPHAS-02 (Hoosier) ELEPHAS-04 (Mayo) Setting Metastatic & recurrent Metastatic & recurrent Metastatic, recurrent & neoadjuvant Tumor type Lung Bladder, kidney, colorectal, head and neck, lung, melanoma, endometrial Metastatic/recurrent: lung, skin, esophageal, cervical, endometrial, colon, liver, kidney, bladder Neoadjuvant: breast–TNBC, lung Enrollment as of 1/27/2025 26 44 20 Est. total enrollment 216 216 324 Clinical endpoints RECIST v1.1 RECIST v1.1 RECIST v1.1 & Pathologic response at surgery

Abstract Background: Ivosidenib (IVO) is a first-in-class oral inhibitor of the IDH1 mutant (mIDH) enzyme. In the ClarIDHy phase 3 study of previously treated patients with mIDH cholangiocarcinoma (CCA), IVO treatment led to improved progression-free survival (PFS) and overall survival (OS) vs placebo (median PFS: 2.7 vs. 1.4 months and OS 10.3 vs. 5.1 months, when adjusted for the 70% crossover rate; HR, 0.49 [95% CI, 0.34-0.70]; 1-sided P<0.001. Here, we studied the dynamics of mutations emerging after 6 months of IVO treatment using ctDNA analyses. Methods: Prior to enrollment, all subjects in ClarIDHy had IDH1 R132 mutations confirmed by a central NGS panel utilizing tumor biopsy tissue. Since post-progression tissue samples were unavailable, discovery of emerging mutations was limited to plasma ctDNA assessments. To explore molecular changes associated with acquired resistance, an analysis was performed on 18 subjects treated with IVO for ≥6 months (4 partial response; 12 stable disease, 2 NA) using matched baseline and end of treatment (EOT) samples (PGDx elioTM plasma complete, 521 gene panel). A subset of the oncogenic alterations identified were selected for confirmation by ddPCR analysis in ctDNA samples collected longitudinally. Longitudinal plasma 2HG levels were also evaluated. Results: This analysis identified several EOT mutations not present at baseline. The most common mutations were in the MAPK pathway, including activating KRAS, NRAS, and MAP2K1 mutations and loss-of-function NF1 mutations (6/18 patients, 33%). In 2/6 patients, multiple MAPK pathway mutations were detected. There was a range of variant allele frequencies (VAFs) of RAS alterations, including some that had comparable levels to the truncal mIDH, suggesting that MAPK activation may have made a major contribution to the burden of resistant disease. ddPCR analyses from longitudinal plasma samples from selected cases confirmed these findings. In addition, 2 patients had mutations affecting transcription/epigenetics (WT1 and KMT2C). Finally, only 1 patient had acquired mutations in IDH genes (IDH2-R172K and IDH1-G131V). The WT1, KMT2C, and IDH variants had a low VAF. Accordingly, EOT plasma 2HG levels were reduced vs pre-treatment levels in the patient with secondary mIDH, indicating a limited role in the overall emergence of resistance. Conclusion: Analyses of paired baseline/EOT samples suggest that multiple acquired mutations could contribute to IVO resistance, with oncogenic MAPK pathway alterations being the most common. Consistent with previous clinical studies conducted in AML, IDH1 second site mutations and isotype switching to IDH2, rarely emerge during IVO treatment. The lack of detectable mutations in the majority of patients could reflect the sensitivity of the NGS assay or a role for non-genetic mechanisms of resistance. Citation Format: Hatice Duygu Saatcioglu, Haley Ellis, Jinkai Wan, Sam Lubner, Milind Javle, Ghassan K. Abou-Alfa, James M. Cleary, Robin Kate Kelley, Mitesh J. Borad, Teresa Macarulla, Do Youn Oh, Camelia Gliser, Susan Pandya, Sung Chloe, Nabeel Bardeesy, Adriana Tron. Circulating tumor DNA analysis demonstrates newly emerging alterations in previously treated IDH1 mutated cholangiocarcinoma patients enrolled in the ClarIDHy study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4648.

4069 Background: CCA is a rare cancer for which there are limited effective therapies. IDH1 mutations occur in ̃20% of intrahepatic CCAs, resulting in production of the oncometabolite D-2-hydroxyglutarate, which promotes oncogenesis. IVO (AG-120) is a first-in-class, oral, small-molecule inhibitor of mutant IDH1 (mIDH1). ClarIDHy aimed to demonstrate the efficacy of IVO vs PBO in pts with unresectable or metastatic m IDH1 CCA. The primary endpoint was met with significant improvement in progression-free survival (PFS) by independent radiology center (IRC) with IVO vs PBO (hazard ratio [HR] = 0.37, p < 0.0001). Objective response rate (ORR) and stable disease for IVO were 2.4% (3 partial responses) and 50.8% (n = 63) vs 0% and 27.9% (n = 17) for PBO. IVO pts experienced significantly less decline in physical and emotional functioning domains of quality of life at cycle 2 day 1 vs PBO pts (nominal p < 0.05). Methods: Pts with m IDH1 CCA were randomized 2:1 to IVO (500 mg PO QD) or matched PBO and stratified by prior systemic therapies (1 or 2). Key eligibility: unresectable or metastatic m IDH1 CCA based on central testing; ECOG PS 0–1; measurable disease (RECIST v1.1). Crossover from PBO to IVO was permitted at radiographic progression. Primary endpoint: PFS by IRC. Secondary endpoints included overall survival (OS; by intent-to-treat), ORR, PFS (by investigator), safety, and quality of life. The planned crossover-adjusted OS was derived using the rank-preserving structural failure time (RPSFT) model. Results: As of 31 May 2020, ̃780 pts were prescreened for an IDH1 mutation and 187 were randomized to IVO (n = 126) or PBO (n = 61); 13 remain on IVO. Median age 62 y; M/F 68/119; 91% intrahepatic CCA; 93% metastatic disease; 47% had 2 prior therapies. 70% of PBO pts crossed over to IVO. OS data were mature, with 79% OS events in IVO arm and 82% in PBO. Median OS (mOS) was 10.3 months for IVO and 7.5 months for PBO (HR = 0.79; 95% CI 0.56–1.12; one-sided p = 0.093). The RPSFT-adjusted mOS was 5.1 months for PBO (HR = 0.49; 95% CI 0.34–0.70; p < 0.0001). Common all-grade treatment emergent adverse events (TEAEs, ≥ 15%) in the IVO arm: nausea 41%, diarrhea 35%, fatigue 31%, cough 25%, abdominal pain 24%, decreased appetite 24%, ascites 23%, vomiting 23%, anemia 18%, and constipation 15%. Grade ≥ 3 TEAEs were reported in 50% of IVO pts vs 37% of PBO pts, with grade ≥ 3 treatment-related AEs in 7% of IVO pts vs 0% in PBO. 7% of IVO pts experienced an AE leading to treatment discontinuation vs 9% of PBO pts. There were no treatment-related deaths. Conclusions: IVO was well tolerated and resulted in a favorable OS trend vs PBO despite a high rate of crossover. These data – coupled with statistical improvement in PFS, supportive quality of life data, and favorable safety profile – demonstrate the clinical benefit of IVO in advanced m IDH1 CCA. Clinical trial information: NCT02989857.

266 Background: CCA is a rare cancer for which there are limited effective therapies. IDH1 mutations occur in ~20% of intrahepatic CCAs, resulting in production of the oncometabolite D-2-hydroxyglutarate, which promotes oncogenesis. IVO (AG-120) is a first-in-class, oral, small-molecule inhibitor of mutant IDH1 (m IDH1). ClarIDHy aimed to demonstrate the efficacy of IVO vs PBO in pts with unresectable or metastatic m IDH1 CCA. The primary endpoint was met with significant improvement in progression-free survival (PFS) by independent radiology center (IRC) with IVO vs PBO (hazard ratio [HR] = 0.37, p < 0.0001). Objective response rate (ORR) and stable disease for IVO were 2.4% (3 partial responses) and 50.8% (n = 63) vs 0% and 27.9% (n = 17) for PBO. IVO pts experienced significantly less decline in physical and emotional functioning domains of quality of life at cycle 2 day 1 vs PBO pts (nominal p < 0.05). Methods: Pts with m IDH1 CCA were randomized 2:1 to IVO (500 mg PO QD) or matched PBO and stratified by prior systemic therapies (1 or 2). Key eligibility: unresectable or metastatic m IDH1 CCA based on central testing; ECOG PS 0–1; measurable disease (RECIST v1.1). Crossover from PBO to IVO was permitted at radiographic progression. Primary endpoint: PFS by IRC. Secondary endpoints included overall survival (OS; by intent-to-treat), ORR, PFS (by investigator), safety, and quality of life. The planned crossover-adjusted OS was derived using the rank-preserving structural failure time (RPSFT) model. Results: As of 31 May 2020, ~780 pts were prescreened for an IDH1 mutation and 187 were randomized to IVO (n = 126) or PBO (n = 61); 13 remain on IVO. Median age 62 y; M/F 68/119; 91% intrahepatic CCA; 93% metastatic disease; 47% had 2 prior therapies. 70% of PBO pts crossed over to IVO. OS data were mature, with 79% OS events in IVO arm and 82% in PBO. Median OS (mOS) was 10.3 months for IVO and 7.5 months for PBO (HR = 0.79; 95% CI 0.56–1.12; one-sided p = 0.093). The RPSFT-adjusted mOS was 5.1 months for PBO (HR = 0.49; 95% CI 0.34–0.70; p < 0.0001). Common all-grade treatment emergent adverse events (TEAEs, ≥ 15%) in the IVO arm: nausea 41%, diarrhea 35%, fatigue 31%, cough 25%, abdominal pain 24%, decreased appetite 24%, ascites 23%, vomiting 23%, anemia 18%, and constipation 15%. Grade ≥ 3 TEAEs were reported in 50% of IVO pts vs 37% of PBO pts, with grade ≥ 3 treatment-related AEs in 7% of IVO pts vs 0% in PBO. 7% of IVO pts experienced an AE leading to treatment discontinuation vs 9% of PBO pts. There were no treatment-related deaths. Conclusions: IVO was well tolerated and resulted in a favorable OS trend vs PBO despite a high rate of crossover. These data – coupled with statistical improvement in PFS, supportive quality of life data, and favorable safety profile – demonstrate the clinical benefit of IVO in advanced m IDH1 CCA. Clinical trial information: NCT02989857.

OBJECTIVE: The aim of this study was to compare the accuracy of CT colonography versus optical colonoscopy for neoplastic involvement at the surgical anastomosis 1 year after curative-intent colorectal cancer resection. DESIGN, SETTING, PATIENTS, AND INTERVENTIONS: Two hundred one patients (mean age, 58.6 years; 117 men, 84 women) underwent same-day contrast-enhanced CT colonography and colonoscopy approximately 1 year (mean, 12.1 months; median, 11.9 months) after colorectal cancer resection as part of a prospective, multicenter trial. All patients enrolled were without clinical evidence of disease and considered low risk for recurrence (stage I–III). MAIN OUTCOME MEASURES: Suspected neoplastic lesions within 5 cm of the colonic anastomosis were recorded at CT colonography, with subsequent colonoscopy performed for the same, with segmental unblinding of colonography findings. Anastomotic region biopsy or polypectomy was performed at the endoscopist’s discretion. RESULTS: None of the 201 patients had intraluminal anastomotic cancer recurrence or advanced neoplasia (or metachronous cancers). CT colonography detected extramural perianastomotic recurrence in 2 patients (1.0%); neither was detected at colonoscopy. Only 2 patients (1.0%; 2/201) were called positive at CT colonography for intraluminal anastomotic nondiminutive lesions (7- to 8-mm polyps), which were confirmed at colonoscopy but nonneoplastic at histopathology. At optical colonoscopy, the anastomosis was deemed abnormal and/or biopsied in 10.0% (20/201), yielding only 1 nondiminutive benign neoplasm (7-mm tubular adenoma). LIMITATIONS: The lack of luminal cancer recurrence in our lower-risk cohort precludes assessment of sensitivity for detection, rendering the study underpowered in this regard. Potential cost savings of combined CT/CT colonography over the standard CT/colonoscopy approach were not assessed. CONCLUSIONS: Relevant intraluminal anastomotic pathology appears to be very uncommon 1 year after colorectal cancer resection in lower-risk cohorts. Unlike colonoscopy, diagnostic contrast-enhanced CT colonography effectively evaluates both the intra- and extraluminal aspects of the anastomosis. See Video Abstract at http://links.lww.com/DCR/A471.

PurposeBiliary cancers overexpress epidermal growth factor receptor (EGFR), and angiogenesis has been correlated with poor outcome. Erlotinib, an EGFR tyrosine kinase inhibitor, and bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor have each been shown to have activity in biliary cancer. The primary objective of this study was to evaluate the response rate by Response Evaluation Criteria in Solid Tumors (RECIST). Secondary end points included overall survival (OS), time to progression (TTP), VEGF levels, and molecular studies of EGFR and k-ras.Patients and MethodsEligible patients had advanced cholangiocarcinoma or gallbladder cancer. Patients were treated with bevacizumab 5 mg/kg intravenously on days 1 and 15 and erlotinib 150 mg by mouth daily on days 1 through 28. Responses were evaluated by RECIST. VEGF levels were collected, and samples were analyzed for EGFR mutation by polymerase chain reaction.ResultsFifty-three eligible patients were enrolled at eight sites. Of 49 evaluable patients, six (12%; 95% CI, 6% to 27%) had a confirmed partial response. Stable disease was documented in another 25 patients (51%). Rash was the most common grade 3 toxicity. Four patients had grade 4 toxicities. Median OS was 9.9 months, and TTP was 4.4 months. Low repeats (< 16) in EGFR intron 1 polymorphism and G>G k-ras Q38 genotype (wild type) were associated with improved outcomes.ConclusionCombination chemotherapy with bevacizumab and erlotinib showed clinical activity with infrequent grade 3 and 4 adverse effects in patients with advanced biliary cancers. On the basis of preliminary molecular analysis, presence of a k-ras mutation may alter erlotinib efficacy. The combination of bevacizumab and erlotinib may be a therapeutic alternative in patients with advanced biliary cancer.