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8644 Background: RET fusions are targetable oncogenic drivers in 1-2% of non-small cell lung cancers (NSCLC). ARROW (NCT03037385) study results (final data lock May 20, 2024) supported the US FDA approval of pralsetinib, a highly potent, oral, selective RET inhibitor for metastatic RET -altered NSCLC. Here, we present final study results. Methods: ARROW was a phase 1/2 open-label study conducted at 84 sites in 13 countries. Phase 2 included patients with RET -fusion-positive NSCLC who received 400 mg pralsetinib once daily (QD). Initially, treatment-naïve patients were not candidates for platinum-based therapy and presented with several unfavorable prognostic factors; this requirement was removed by protocol amendment in July 2019. Primary objectives were overall response rate (ORR, per RECIST v1.1) and safety. Progression-free survival (PFS) and overall survival (OS) are reported in the full efficacy population; the measurable disease population (MDP) was the primary analysis population for ORR and duration of response (DOR). Results: 281 patients with RET -fusion-positive NSCLC received pralsetinib 400 mg QD, with a median duration of treatment of 14.95 months (mos). Median age was 60 years; 46% were male. In the MDP (n=259), ORR was 70.3% (95% confidence intervals [CI]: 64.3, 75.8) and median DOR was 19.1 mos (95% CI: 14.5, 27.9; Table). In the efficacy population (N=281), median OS was 44.3 mos (95% CI: 30.9, 53.1) with median follow up of 47.6 mos (95% CI: 44.8, 49.2), and median PFS was 13.1 mos (95% CI: 11.4, 16.8). ORR (Table) and median PFS were markedly higher in the US (25.9 mos, n=64) vs. Asia (12.6 mos, n=122) or Europe (12.9 mos, n=95). In the safety population, 95% of patients experienced treatment-related adverse events (TRAEs); 66% experienced ≥grade 3. Common TRAEs included increased AST (n=128 [46%]), anemia (n=121 [43%]), increased ALT (n=98 [35%]), and hypertension (n=77 [27%]). 3 patients died due to TRAEs (pneumonia, n=2; interstitial lung disease and rhabdomyolysis, n=1 each). No new safety signals were identified with this update. Conclusions: Pralsetinib produced clinically meaningful and durable responses in patients with RET -fusion-positive NSCLC (regardless of prior therapies) with a manageable safety profile, confirming with this longer follow up previously published results. Clinical trial information: NCT03037385 . All MDP(n=259) Prior Platinum (n=130) Treatment-naive(n=106) ORR, % (95% CI) Overall 70.3(64.3, 75.8) 63.1(54.2, 71.4) 78.3(69.2, 85.7) US (n=58)77.6(64.7, 87.5) (n=31)64.5(45.4, 80.8) (n=19)100(82.4, 100) Europe (n=89)65.2(54.3, 75) (n=36)63.9(46.2, 79.2) (n=43)65.1(49.1, 79) Asia (n=112)70.5(61.2, 78.8) (n=63)61.9(48.8, 73.9) (n=44)81.8(67.3, 91.8) Median DOR, mos (95% CI) a (n=182)19.1(14.5, 27.9) (n=82)31.8(15.1, 40.4) (n=83)13.4(9.4, 21.7) Median DOR follow up, mos (95% CI) 46.8(42.3, 50.2) 50.3(46.9, 56.8) 42.3(37.4, 44.2) a Per FDA censoring rule.

5108 Background: We previously proposed a hybrid framework combining LLMs and rule based algorithm (RBA) for automating risk stratification in locPCa. Herein, we aim to validate the risk stratification agent (RSA) in a prospective cohort, develop & evaluate the treatment recommendation agent (TRA) based on NCCN guidelines, and develop an interactive interface to facilitate clinicians for accurate risk stratification and treatment recommendations at the point of care. Methods: This study included pts with locPCa (2004-2024) presenting at Mayo Clinic with at least 1 positive prostate biopsy and MRI report available. For RSA prospective validation, GPT4 extracted key phenotypic variables (PSA, T stage, prostate volume, number of cores, Gleason patterns, grade group) from unstructured MRI and biopsy reports using a zeroshot prompt. An RBA then classified pts into NCCN risk groups. The agent performance was compared with the treating clinician's documentation and evaluated against gold-standard labels manually annotated by two independent clinicians. For development of TRA, two experiments were performed using GPT4 with and without retrieval-augmented generation (RAG) to generate treatment plans. Generated treatment plans were evaluated using NCCN guideline-informed treatment decision tree based algorithm (DTA). Evaluation metrics, weighted – accuracy (acc) and F1, were computed. A clinician facing interface (lisr.org/risk) was developed to provide accurate risk stratification and treatment plans. Results: A total of 858 pts were included (500 for prospective validation, 358 for treatment recommendations). Prospective validation for RSA demonstrated a higher F1 score of 0.89 compared to the treating clinician (F1: 0.58). Treatment recommendation experiments showed that GPT4 with RAG achieved higher acc (64% full – all correct treatment options and 36% partial – at least 1 correct treatment option) compared to GPT4 alone (35% and 65%, respectively). Sensitivity analysis using DTA-informed GPT4 note generation achieved 94% full acc and 6% partial acc. GPT4 alone generated hallucinated treatment options in 71% of cases, while GPT4 with RAG reduced this to 32%. Conclusions: The multi-agent framework based on LLM and RBA achieves high accuracy in risk stratification and treatment recommendation for locPCa. A multi-agent framework with an interactive interface holds high promise to enable efficient, accurate decision-making, and improve locPCa management at the point of care Performance evaluation. RSA(acc; F1) % TRA(full acc; partial acc) % Clinician RSA* GPT4 RAG+GPT4 DTA+GPT4 Overall 60; 58 89; 89 29; 71 64; 36 94; 6 V. High 94; 33 96; 96 55; 45 69; 31 93; 7 High 46; 52 92; 89 - - - Int. Unf 80; 61 91; 90 5; 95 38; 62 93; 7 Int. Fav 57; 64 84; 87 0; 100 98; 2 100; 0 Low 57; 65 87; 80 100; 0 95; 5 90; 10 V. Low 8; 13 50; 67^ - - - *Statistical significance (p<0.01) except for ^V. Low.

6061 Background: PDS0101 is a T cell stimulating immunotherapy (therapeutic vaccine) targeting HPV16. The combination of PDS0101 + pembrolizumab (5 cycles) has shown durable clinical responses in HPV-positive recurrent/metastatic HNSCC. MC200710 is a window of opportunity study in patients with HPV-associated oropharyngeal squamous cell carcinoma (HPV+ OPSCC). This prospective phase II trial utilized 2 cycles of neoadjuvant PDS0101 aloneor in combination with pembrolizumab prior to surgical resection or chemoradiotherapy (CRT). Herein, we report the initial results, including primary endpoint of ctDNA response. Methods: Between June 2022 and September 2024, 20 patients (10 per Arm) with locally advanced HPV+ OPSCC were enrolled in a sequential alternating design. Arm A received 2 cycles of PDS0101 and Arm B received 2 cycles of PDS0101 and pembrolizumab with all patients undergoing subsequent surgery or CRT. Assessments were done at baseline, post cycle 1, and post cycle 2 (prior to surgery or CRT). The coprimary endpoint of ctDNA response was defined as a ≥50% decline in ctDNA post cycle 2 compared to baseline as quantified using NavDx (TTMV fragments/mL). Radiologic objective response rate (ORR) was assessed as per RECIST 1.1. Toxicity through the neoadjuvant period was assessed using CTCAE criteria and recurrence rates following surgery or CRT are reported. Results: Patients were similar between arms: male 90%, median age 61 years, cT1/T2 70%, cN1 65%, and no smoking history 65%. All patients completed both cycles of therapy with 13 (65%) undergoing primary operative management and 7 CRT (35%). The most common toxicity was injection site reaction 85% grade 1, 15% grade 2, 0% grade 3, consistent with prior studies. One patient experienced grade 2 pneumonitis during the neoadjuvant window (Arm B). There was one grade 3 toxicity (5%) possibly attributable to study intervention with one patient experiencing transient hepatitis requiring hospitalization (Arm A). Zero of 10 patients in Arm A had a ≥50% decline in ctDNA from baseline while 5 of 10 patients (50%) met this primary endpoint in ARM B (p=0.03). After Cycle 2, based on RECIST 1.1, no Arm A patients had a partial response (PR), with 7 having stable disease (SD); Arm B had 2 patients with PR and 8 with SD. With median follow up of 6 months, 2 patients in Arm A recurred and 0 patients in Arm B. Conclusions: The combination of PDS0101 and pembrolizumab met the trial’s primary endpoint of ctDNA response and shows promise for further evaluation. ctDNA can be used to assess early response and future studies could use ctDNA to adapt neoadjuvant therapy. Based on these findings, a neoadjuvant dose optimization study in HPV16+ oropharyngeal carcinoma is warranted and evaluation of PDS0101 and pembrolizumab in comparison to pembrolizumab alone. Clinical trial information: NCT05232851 .

Abstract Inotuzumab ozogamicin (InO) is an antibody-calicheamicin conjugate with high efficacy in lymphoid malignancies. It targets the B-cell surface protein CD22, which is expressed in most B-cell acute lymphoblastic leukemia (B-ALL) cases, albeit with variable intensity. However, factors governing CD22 expression and thus leukemia sensitivity to InO remain incompletely understood. Using multiomic characterization of 196 human B-ALL samples, coupled with ex vivo InO sensitivity profiling, we showed that early leukemia differentiation arrest at the pre–pro-B stage is associated with resistance to InO. Screening of 1639 transcription factor genes identified early B-cell factor 1 (EBF1) as a key regulator of CD22 expression (false discovery rate of 7.1 × 10−4). When comparing the assay for transposase-accessible chromatin with sequencing profiling results of the most InO-sensitive and -resistant cases (50% lethal concentration &lt;10th vs &gt;90th percentile, n = 18), the binding motif for EBF1 was strikingly enriched in regions with differential open chromatin status (P = 8 × 10−174). CRISPR interference targeting EBF1 binding sites at the CD22 locus led to an ∼50-fold reduction in cell surface CD22 expression and, consequently, an ∼22-fold increase in InO resistance in ALL cell lines. Interestingly, within BCR::ABL1 ALL, we observed intrasubtype heterogeneity linked to EBF1 transcriptional downregulation (P = 1.1 × 10−15) and/or somatic alteration (P = .004), which led to reduced CD22 expression (P = 8.3 × 10−11) and ex vivo and in vivo resistance to InO. Collectively, these findings point to the direct impact of EBF1 on CD22 expression during B-cell development, which, in turn, contributes to interpatient variability in InO response, even within the same subtype of B-ALL.

569 Background: Several studies established the prognostic role of both the amount and locations of tumor-infiltrating lymphocytes (TILs) in TNBC. Three distinct immunotypes were described based on the amount and locations of TILs: immune enriched (IN), immune excluded, and immune desert. Using single-cell spatial transcriptomic analysis in the Mayo Clinic TNBC cohort, our previous studies showed the central role of interferon (IFN) signaling in IN phenotype. Herein, we evaluated the association between IFN and outcomes in TNBC in 3 independent datasets. Methods: NanoString IO360 was performed in 114 samples from FinXX (NCT00114816) to generate 22-gene IFNα and 33-gene IFNγ signatures. RNA sequencing was performed in 388 samples from CALGB 40603 (NCT00861705). 3038 TNBC samples were tested by WTS (NovaSeq; Caris Life Sciences, Phoenix, AZ). Median values were used as cut-offs for high vs low IFNγ RNA expression and 18-gene IFNγ signature scores. Caris Life Science CODEai was used to evaluate real-world overall survival (OS) obtained from insurance claims and calculated from tissue collection to last contact using Kaplan-Meier estimates. Chi-square, Mann-Whitney U, ANOVA, and Cox regression were used. Results: A high 22-gene IFNα signature score was associated with significantly improved recurrence-free survival (RFS) in FinXX (hazard ratio [HR] 0.32, 95% confidence interval [CI] 0.14-0.74, p 0.007) and OS (HR 0.28, 95%CI 0.12-0.66, p 0.003). Similar findings were observed with 33-gene IFNγ signature with significant improvement in RFS (HR 0.21, 95%CI 0.09-0.51, p < 0.001) and OS (HR 0.18, 95%CI 0.08-0.44, p < 0.001). Furthermore, in CALGB 40603, both IFNα and IFNγ scores were positively associated with pathologic complete response (pCR: IFNα p 0.019 and IFNγ p 0.007) and residual cancer burden (RCB: IFNα p 0.044 and IFNγ p 0.013). Using the Caris data platform to further validate, we identified 2899 TNBC patients (pts) with genomic and clinical outcome data. High IFNγ expression was associated with significant improvement in OS (25.95 vs 17.43 months; HR 0.65, 95% CI 0.59 – 0.72, p < 0.001). Similarly, pts with high IFNγ signature scores had significant improvement in median OS (25.79 vs 16.22 months; HR 0.66, 95% CI 0.6 – 0.73, p < 0.001). Conclusions: This study underscores the pivotal role of IFN signaling in TNBC. High IFNα and IFNγ signatures were consistently associated with improved RFS, OS, higher pCR rates, and lower RCB across clinical trial cohorts and real-world data. These findings signify IFN signaling as a potential key biomarker and therapeutic target in TNBC. Support: U10CA180821, U10CA180882, U24CA196171; Breast Cancer Research Foundation, Mayo Clinic Breast Cancer SPORE (P50CA116201-17), Bankhead Coley, W81XWH-15-1-0292, P50CA015083, R35CA253187; https://acknowledgments.alliancefound.org . Genentech. Clinical trial information: NCT00114816 and NCT00861705 .

e17064 Background: Analyses of clinical trials data suggest thatBlack men have equal or even improved overall survival (OS) with certain treatments for mCRPC compared with other races. Moreover, retrospective analysis of the PROCEED registry indicated that Black men who received Sip-T, an autologous cellular immunotherapy, had longer survival compared with other men with mCRPC. The Abi Race and PANTHER clinical trials prospectively assessed the effect of ARPIs on clinical outcomes among Black and White patient (pt) cohorts, and included pts who had received Sip-T either prior to or during study. We combined data from Abi Race and PANTHER to investigate associations between OS, Sip-T and race. Methods: Data from the Abi Race (N=100) and PANTHER (N=93) studies were retrospectively pooled for this analysis. Propensity scores for Sip-T treatment were calculated based on Karnofsky performance status, race, Gleason score, and study. Kaplan-Meier estimates for OS, with and without inverse propensity score weighting, were generated and stratified by Sip-T use. This analysis was stratified by race to examine whether the relationship between Sip-T use and OS differed by race. Results: Of the 93 Black pts and 100 White patients included from both studies, 123 patients did not receive Sip-T, while 70 patients did (60 before study, 10 on study). Pts who received Sip-T had a median OS (mOS) of 44 months (95% Confidence Interval (CI) 39, NR) compared to 36 months (95% CI 31, 48) for those who did not. Weighted by propensity scores, Black men who received Sip-T had a mOS of 72 months (95% CI 43, NR), while those who did not had a mOS of 38 months (95% CI 30, NR). Among White men, patients who received Sip-T had a mOS of 39 months (95% CI 30, NR), while those who did not had a mOS of 32 months (95% CI 29, 48) (see Table). Conclusions: Our findings from an investigator-led retrospective analysis independent of sponsors provide independent clinical trial support of prior retrospective findings that suggest Black men with mCRPC who receive Sip-T may have a greater OS than White men. While our analysis controlled for factors that may influence the use of Sip-T, it is limited by potential unmeasured confounders or timing of Sip-T. Further, adequately powered prospective trials specifically evaluating outcomes with Sip-T by race in earlier clinical settings are needed. Drug support and funding for Abi Race and PANTHER were provided by Janssen Scientific Affairs, LLC. Death counts and median overall survival (mOS) in months by race and Sipuleucel-T use. Black Men White Men Sipuleucel-T use Deaths / Total N No 36 / 64 38 / 59 Yes 12 / 29 24 / 41 Unweighted mOS (95% CI) No 36 (29, NR) 32 (29, 48) Yes 72 (43, NR) 39 (31, NR) Weighted mOS (95% CI) No 38 (30, NR) 32 (29, 48) Yes 72 (43, NR) 39 (30, NR) NR = not reached, mOS = median overall survival, CI = confidence interval.

e17035 Background: 177 Lu-PSMA-617 was approved in March 2022 for patients with mCRPC pretreated with an androgen receptor pathway inhibitor (ARPI) and a taxane. There are limited data on the effectiveness of treatments post- 177 Lu-PSMA-617. The aim of this study was to describe prostate-specific antigen (PSA) responses among patients with mCRPC receiving a guideline-recommended therapy as the next therapy after 177 Lu-PSMA-617 treatment. Methods: This retrospective, observational study used real-world data from the PRECISION data platform, a proprietary dataset developed by Novartis, comprised of patient-level electronic health record and claims data that represent the US advanced prostate cancer population in the community, academic, urology, and medical oncology settings. Patients with mCRPC who received any guideline-recommended therapy at least 14 days after treatment with 177 Lu-PSMA-617 between March 23, 2022 and July 31, 2024 were included. Guideline-recommended therapies included abiraterone, enzalutamide, darolutamide, apalutamide, cabazitaxel, docetaxel, pembrolizumab, sipuleucel-T, niraparib, olaparib, talazoparib, rucaparib, and radium-223. Patients’ PSA values while on 177 Lu-PSMA-617 treatment were compared with their PSA values during the subsequent therapy course. Proportions of patients achieving reductions in PSA levels ≥50% (PSA50) and ≥80% (PSA80) were estimated. All analyses were descriptive. Results: A total of 152 patients receiving any subsequent guideline-recommended therapy after 177 Lu-PSMA-617 were identified. Mean age was 72.1 years. Most patients received an ARPI (n=93, 61.2%) – abiraterone (n=38), enzalutamide (n=37), darolutamide (n=10), or apalutamide (n=8) – as their subsequent therapy. Of patients who received a taxane (n=42, 27.6%), 24 received cabazitaxel and 18 received docetaxel. Median time to initiation of subsequent therapy was 206 days (interquartile range [IQR] 101–301 days) from 177 Lu-PSMA-617 initiation and 44 days (IQR 17–119 days) from 177 Lu-PSMA-617 discontinuation. Overall, among patients with sufficient information for PSA evaluation (n=30), 46.7% achieved PSA50 and 40.0% PSA80 post- 177 Lu-PSMA-617. Among patients receiving an ARPI, PSA50 was observed in 11/18 (61.1%) and PSA80 in 10/18 (55.6%). Among patients receiving a taxane, PSA50 and PSA80 were seen in 3/12 (25.0%) and 2/12 (16.7%), respectively. Conclusions: In this real-world analysis, the majority of patients who received guideline-recommended therapies after 177 Lu-PSMA-617 achieved at least a PSA50 response, suggesting that 177 Lu-PSMA-617 treatment does not preclude response to other subsequent therapies.

e17030 Background: The broad therapeutic arsenal for mCRPC, with overlapping indications, makes selecting the optimal treatment sequence challenging in clinical practice. The aim of this study was to evaluate the prostate-specific antigen (PSA) responses and overall survival (OS) among patients with mCRPC receiving 177 Lu-PSMA-617 based on prior ARPI and taxane treatment exposure. Methods: This retrospective, observational study used real-world data from the PRECISION data platform, a harmonized dataset of advanced prostate cancer patients in the US from diverse clinical settings. Patients with mCRPC who had received ≥1 dose of 177 Lu-PSMA-617 between March 23, 2022 and July 31, 2024, after prior treatment with ≥1 ARPI and ≥1 taxane, were included. To assess PSA response, the baseline PSA value obtained within 90 days before starting 177 Lu-PSMA-617 was compared with the on-treatment PSA value obtained ≥28 days after 177 Lu-PSMA-617 initiation. The number of patients achieving PSA reductions ≥50% (PSA50) and ≥80% (PSA80) were estimated, with patients classified into two cohorts based on prior ARPI and taxane exposure: (1) prompt cohort: after only 1 ARPI and 1 taxane, and (2) deferred cohort: >1 ARPI and/or >1 taxane. Patient characteristics and treatment patterns were evaluated descriptively. OS from 177 Lu-PSMA-617 initiation was estimated using Kaplan–Meier methodology. Results: A total of 431 patients were included: 177 patients in the prompt cohort and 254 patients in the deferred cohort. Of patients in the deferred cohort, 185 (72.8%) received ≥1 ARPI and 1 taxane, 32 (12.6%) received 1 ARPI and ≥1 taxane, and 37 (14.6%) received ≥1 ARPI and ≥1 taxane. Median (interquartile range) age was 73 (67–78) years and most demographic characteristics were balanced between groups. Patients in the deferred cohort had higher median PSA levels at baseline (63.1 ng/mL vs 25.2 ng/mL). PSA50 was observed in 18/33 (55%) patients in the prompt cohort vs 28/66 (42%) in the deferred cohort. PSA80 was observed in 13/33 (39%) patients in the prompt cohort vs 21/66 (31%) in the deferred cohort. Across both cohorts, median OS was 18.0 months (95% confidence interval [CI]: 15.1 months–not reached [NR]). Median OS was NR in patients in the prompt cohort vs 15.1 months in patients in the deferred cohort (95% CI: 11.6 months–NR). Conclusions: In this large real-world study, prompt initiation of 177 Lu-PSMA-617 (after only 1 ARPI and 1 taxane) showed superior clinical outcomes versus deferred initiation of 177 Lu-PSMA-617. Patients were more likely to achieve a PSA reduction ≥50% and ≥80% and had longer OS with prompt initiation of 177 Lu-PSMA-617. These results may help to guide treatment sequencing in clinical practice.

6506 Background: NPM1 -m drives leukemogenesis in ~30% of AML. Despite current risk stratification, nearly half will have R/R disease within a year, after which outcomes are poor with <10% complete response following chemotherapy. Ziftomenib – a potent, highly selective, oral, investigational menin inhibitor – has shown clinical activity as monotherapy and in combination for adults with R/R NPM1 -m and KMT2A -r AML, with 600 mg once-daily (QD) as the recommended phase 2 monotherapy dose for NPM1 -m. Here we present the primary analysis for NPM1 -m patients (pts) treated with ziftomenib 600 mg QD in the pivotal KOMET-001 study. Methods: KOMET-001 (NCT04067336) is a multicenter, open-label phase 1/2 study of ziftomenib in adults with R/R AML. In phase 2, pts with NPM1 -m R/R AML received ziftomenib 600 mg QD. Phase 2 primary endpoint: complete remission with full/partial hematologic recovery (CR/CRh); key secondary endpoints: composite complete remission (CRc), durations of CR/CRh and CRc, and safety. The analyses below include NPM1 -m pts pooled from phase 1b/2. Results: The phase 2 primary endpoint was met ( p =0.0058). As of 20 Dec 2024, 112 pts were enrolled (51% US/Canada, 49% Europe/UK) in phase 1b/2 and treated with ziftomenib 600 mg QD, with a median follow-up of 4.2 months. Median age was 69 yrs (range 22–86), 56% female, 83% ECOG PS 0–1, median of 2 prior therapies (range 1–7), including 60% prior venetoclax (VEN) and 23% prior transplant. CR/CRh rate in all phase 1b/2 pts was 25% (28/112; 95% CI 17–34) and overall response rate was 35% (39/112; 95% CI 26–44). In phase 2 pts, 23% (21/92; 95% CI 15–33) achieved CR/CRh (Table), with 67% (10/15) MRD negativity among CR/CRh responders tested (local). Comparable CR/CRh rates were observed in both VEN-naïve and exposed pts (21% vs. 24%). Ziftomenib was well tolerated with 3% (3/112) discontinuing due to treatment-related adverse events (TRAEs). 40% (45/112) of pts had Grade (Gr) ≥3 TRAEs, including 13% differentiation syndrome (all Gr3), ≤5% each anemia, febrile neutropenia and thrombocytopenia, and 2% QTc prolongation (Gr3). Updated clinical activity and safety data will be presented. Conclusions: In the pivotal KOMET-001, the phase 2 primary endpoint was met: Ziftomenib achieved deep and durable responses in R/R NPM1 -m AML, regardless of prior VEN. Ziftomenib was well tolerated with limited myelosuppression and only 3% ziftomenib-related discontinuations. Taken together, these data support the potential use of ziftomenib monotherapy as a new treatment option for R/R NPM1 -m AML. Clinical trial information: NCT04067336 . Response, n (%) Phase 2600 mg QDN=92 Phase 1b/2600 mg QDN=112 CR 13 (14) 20 (18) CR/CRh 21 (23) 28 (25) CRc 24 (26) 32 (29) Median duration, months (95% CI) CR/CRh 3.7 (1.9–NE) 3.7 (1.9–7.7) CRc 4.6 (2.8–11.4) 5.1 (2.8–8.1) Restricted mean duration, months (95% CI) CR/CRh 4.3 (3.1–5.6) 5.2 (3.6–6.7) CRc 5.9 (4.0–7.7) 6.4 (4.6–8.1)

e13893 Background: For individuals with CNS tumors who have experience difficulties with in-person (IP) evaluations due to disease-related neurologic disability or the costs associated with travel, telehealth (TH) offers a convenient and timely alternative for accessing specialized neuro-oncology care. We report our institution’s experience with telehealth utilization in neuro-oncology. Methods: We conducted a retrospective review of patients who had at least one neuro-oncology telehealth visit between August 2021 and May 2024 at Mayo Clinic in Rochester, Minnesota. Reasons for visits, outcomes of appointments, acute care utilization following visits was reviewed. Results: A total of 660 patients who had at least one TH visit between August 2021 and May 2024 were included in the analysis. Median age was 56 (range 20-98), 49% were female, and 92% were white. Most patients resided in the US Midwest (84%), followed by the South (8%), West (5%), Northeast (1%), and US Territories (< 1%). Less than two percent were international patients. The most common primary visit diagnosis was glioblastoma (GBM, 26%), followed by astrocytoma, IDH-mutant (17%), meningioma (17%), oligodendroglioma, IDH-mutant, 1p/19q codeleted (7%). Of 6657 visits reviewed, 2745 (41%) were conducted via TH. Telehealth visits served various purposes, including consultation for newly diagnosed tumors or abnormal MRIs (n = 26), second opinion for an established tumor diagnosis (n = 119), discussion about clinical trial participation (n = 108), tumor-related treatment discussions (n = 719), chemotherapy education (n = 161), new symptom assessment (n = 117), symptom management (n = 366), and tumor surveillance (n = 1694). Outcomes from telehealth visits included enrollment in clinical trials (n = 28), proceeding with tumor-directed surgery (n = 46), initiation of radiation therapy (n = 88), starting or changing systemic therapy (n = 377), continuing existing systemic therapy (n = 932), transition to supportive care (n = 45), tumor diagnostic workup (n = 28), continuation of tumor surveillance (n = 1254). Acute care utilization, defined as an emergency department visit or hospitalization within one month of an appointment, was the same following telehealth visits compared to in-person visits (6.9% for IP vs 5% for TH, p = 0.507). Conclusions: Our findings demonstrate that telehealth can effectively support all aspects of neuro-oncology care, ranging from initial diagnosis discussions to systemic therapy management and transitions to supportive care. Telehealth offers a convenient and accessible method of care delivery option for patients faced with neurologic illness. Additionally, THs do not lead to increased acute care utilization compared to IP evaluations.