Soefje, Scott A.

Abstract Purpose Bevacizumab is an effective treatment for radiation necrosis; dose dependent radiographic and edema response data are lacking. Methods Multicenter, retrospective cohort study of adult patients with primary central nervous system tumors or brain metastases who received bevacizumab for radiation necrosis between June 2021 and July 2024. Patients were grouped by bevacizumab dose (7.5 mg/kg vs 10 mg/kg administered every three weeks). Primary outcome was edema response, assessed by a blinded neuro-oncologist. Secondary outcomes included contrast enhancing disease response, clinical response, adverse events, treatment discontinuation, and re-dosing for recurrent radiation necrosis. Analyses were performed with and without adjustment for tumor type. Results 104 patients were included (7.5 mg/kg, n = 53; 10 mg/kg, n = 51). Edema response differed between dosing groups in unadjusted analyses (p = 0.032), favoring the 7.5 mg/kg cohort; however, this association was attenuated after adjustment for tumor type. Contrast enhancing disease response did not differ between groups in either unadjusted or adjusted analyses (p = 0.43). Clinical response was higher in the 7.5 mg/kg group (65.2% vs 37.8%, p = 0.013). Tumor type differed significantly between cohorts (p < 0.001), with more primary CNS tumors in the 10 mg/kg group. Rates of adverse events, treatment discontinuation, and re-dosing were similar. Conclusions While lower-dose bevacizumab was associated with greater edema reduction in unadjusted analyses, this effect was attenuated after accounting for tumor type. Importantly, 7.5 mg/kg dosing appeared sufficient for achieving edema control and contrast enhancing disease response. These findings support an individualized approach to bevacizumab dosing in radiation necrosis and highlight the need for prospective, tumor-stratified studies.

e13615 Background: Bacillus Calmette-Guérin (BCG) remains the standard intravesical therapy for high-risk non-muscle-invasive bladder cancer (NMIBC), but weekly clinic-based instillations create substantial travel, time, and indirect costs that may threaten adherence. Therefore, we proposed a pilot trial of delivering BCG at Home as a prospective, single-center pilot testing a pharmacy-to-home pathway with digital patient-reported outcome (PRO) monitoring. Methods: BCG at Home is a prospective, single-center pilot evaluating feasibility and safety of home delivery of induction BCG for treatment-naïve, high-grade T1 and/or carcinoma in situ NMIBC. Dose 1 is administered in clinic to confirm tolerability and catheterization feasibility; doses 2-6 are administered at home by Penn Medicine at Home nurses after a 3 month training and proctorship program in intravesical therapy and exposure precautions. To enable transport beyond conventional short post-preparation windows, the pharmacy prepares BCG using a closed system transfer device (CSTD); bench testing demonstrated stability and sterility for 24 hours after connection. A medical courier delivers the prepared medication to the patient’s home, where the nurse receives the delivery and performs the instillation. The primary endpoint is induction adherence (completion of all recommended doses). Secondary endpoints include PROs (EORTC QLQ-C30/QLQ-NMIBC24), satisfaction, and acute care utilization. PROs are captured before and after treatment using a conversational chatbot; domain summaries are assessed at baseline, 6 weeks, and 12 weeks. Results: The pilot began enrollment in June 2025 (planned sample size: 20). To date, eight participants have enrolled and completed induction. Median age was 76 years (range 41-88); 50% were female and 25% were Black/African American. Participants lived a mean of 30 miles from the treating facility. Forty home instillations were delivered, and all participants completed all recommended induction doses (100% adherence). Median nurse time in the home was 40 minutes. Five episodes of hematuria were self-limited; one urinary tract infection resolved with antibiotics. Self-efficacy improved from a median of 3 pre-treatment to 7 post-treatment. The median COST-FACIT score was 30 (scale 1-44). Mean EORTC QLQ-C30 global health status was 71 (0-100). EORTC QLQ-NMIBC24 averages showed urinary symptoms rising during induction (23 at baseline to 30 at 6 weeks) with improvement by 12 weeks (18) and future worries decreasing (33 to 25); intravesical treatment issues remained low (5 to 2). Conclusions: BCG at Home is, to our knowledge, the first prospective trial to administer intravesical BCG in the home setting using a standardized pharmacy-to-home pathway. Early results support feasibility, complete adherence, and an acceptable short-term safety profile. Clinical trial information: 07048496 .

Abstract BACKGROUND Bevacizumab, an anti-vascular endothelial growth factor (VEGF) monoclonal antibody, has emerged as a treatment for radiation necrosis. Doses ranging from 2.5 mg/kg to 15 mg/kg have been utilized however the optimal dosing remains inadequately studied. METHODS Retrospective review of adult patients with central nervous system tumors or brain metastasis treated with bevacizumab from 6/29/2021 to 7/31/2024. Patients were divided into those who received bevacizumab 7.5 mg/kg every 21 days and those who received bevacizumab 10 mg/kg every 21 days. The primary outcome was radiographic response as assessed by a blinded neuro-oncologist. Secondary outcomes included clinical response as documented in clinical notes, major adverse events including hemorrhage and thromboembolic events and re-dosing for recurrence of radiation necrosis beyond the 4 initially planned doses. RESULTS 104 patients were included (median age 59.3 years, 55% male); 53 patients in the 7.5 mg/kg group and 51 patients in the 10 mg/kg group. In the 7.5 mg/kg group, 1 patient had a complete response (CR), 16 patients had a partial response (PR), 32 patients had stable disease (SD), 3 patients had progression of disease, and 1 patient did not have repeat imaging. Of the 51 patients in the 10 mg/kg group, 3 patients had a CR, 10 patients had a PR, 27 patients had SD, 5 patients had progression of disease, and 6 patients did not have repeat imaging. There was no statistically significant difference in radiographic response between the two dosing groups (p = 0.42). Clinical response rates were higher in the 7.5 mg/kg group (65.2% vs 37.8%, p = 0.013). Major adverse events and need for re-dosing for radiation necrosis recurrence were comparable. CONCLUSION Bevacizumab 7.5 mg/kg was equally as efficacious as 10 mg/kg in terms of radiographic response and may offer a better clinical response for patients with radiation necrosis.

Background: Immunotherapy-based regimens have expanded the treatment landscape for unresectable hepatocellular carcinoma (uHCC); however, real-world data are limited. Methods: This retrospective, observational study used data from electronic medical records from Mayo Clinic sites across the United States. Patients with uHCC who initiated a first-line (1L) systemic therapy between June 2020–October 2022 with ≥2 follow-up visits were included. Treatment patterns, overall survival (OS), and post-index gastrointestinal (GI) bleeding were assessed by GI bleeding risk defined by Child–Pugh Class B or C, pre-index GI bleeding, uncontrolled hypertension, or significant varices and band ligation. Results: Of 186 included patients, 68.8% had GI bleeding risk and 31.2% did not. Atezolizumab plus bevacizumab was the most common 1L systemic therapy in patients with or without GI bleeding risk (72.7% and 29.3%, respectively). Median OS (95% confidence interval) with atezolizumab plus bevacizumab was 12.8 (8.0–19.3) months and not reached in patients with and without GI bleeding risk, respectively. OS rates with atezolizumab plus bevacizumab in patients with or without GI bleeding risk, respectively, were 52.3% and 70.6% at 12 months, 41.6% and 57.8% at 18 months, and 34.6% and 51.3% at 24 months. Post-index GI bleeding with atezolizumab plus bevacizumab occurred in 19.4% and 5.9% of patients with and without GI bleeding risk, respectively. Conclusions: During this study period, atezolizumab + bevacizumab was the most common 1L therapy for patients with uHCC, regardless of GI bleeding risk. OS rates with atezolizumab + bevacizumab were lower in patients with versus without GI bleeding risk. Findings highlight the unmet need for guidance on characteristics-driven treatment decisions.

55 Background: Prior authorization (PA) processes are known to create administrative burdens and delays in care, but little is known about how these challenges impact rural oncology patients and practice settings. Methods: To understand the broad impact of prior authorization on rural oncology patients and practices, we conducted this study across three community oncology practices serving majority rural patient populations with distinct geography, healthcare infrastructure, and models of care. Sites included one critical access hospital system located in a highly-rural community (Lakewood Health System; Staples, Minnesota), a community-based hub-and-spoke hospital system-based practice located in a mid-sized community (Mayo Clinic Health System – Northfield; Northfield, Minnesota), and a standalone referral level III trauma center serving a highly rural patient base (Self Regional Healthcare; Greenwood, South Carolina). This retrospective cohort study examined all intravenous and subcutaneous cancer-directed therapy plans (no oral therapy) that required PA submission at these locations over a three-month period from October 1, 2024 to December 31, 2024. Results: 129 PA submissions were required during the study period. 82 were due to cancer-directed therapy agents (of which 14 were immunotherapy agents), and 47 were due to adjunctive therapies (of which 22, 16, and 9 were due to granulocyte stimulation, bone preservation, and anti-emesis agents, respectively). All 129 PA submissions ultimately resulted in approval of the desired medication or formulary-approved biosimilar. Delays from PA submission to approval ranged from 0 to 18 days. A total of 209 patient-days were delayed due to PA during the study period, which did not ultimately result in change of care or denial of care in any instance. Conclusions: At all sites included in this study, all PA submissions were eventually authorized. The PA process was found to introduce inconsistent and potentially avoidable delays for hundreds of patients and their care teams. These findings highlight the inefficiency of current PA processes among rural cancer populations and the practices that care for them, underscoring the need for ongoing efforts directed at state and federal PA reform.

e16167 Background: Guidelines recommend systemic therapy for uHCC ineligible for locoregional therapy. Until the approval of tremelimumab + durvalumab for uHCC, in Oct 2022, 1L systemic therapies in the US included multikinase inhibitors and atezolizumab (A) + bevacizumab (B). It is crucial to understand factors driving real-world treatment decisions and outcomes in uHCC. Methods: Data were collected from electronic medical records from US Mayo Clinic sites. Pts with uHCC who initiated a 1L systemic therapy between Jun 2020–Oct 2022 (A + B was the only approved 1L immunotherapy (IO)-based regimen) with ≥2 follow-up visits, were included. Index was the date of first 1L systemic therapy. Pts were assessed by risk of post-index gastrointestinal (GI) bleeding (Child-Pugh class B or C, pre-index GI bleeding, uncontrolled hypertension [HTN] [≥2 anti-HTN drugs or ≥2 vital entries of SBP > 140 mmHg or DBP > 90 mmHg]), or significant varices and band ligation). Treatment patterns, overall survival (OS), and post-index GI bleeding were assessed. Results: A total of 186 pts met the inclusion criteria. Most common etiologies of liver disease were MASH (42.7%) and hepatitis C virus (40.2%). Pre-index GI bleeding was reported in 29.0% of pts, of which 46.3% occurred within 6 months (mo) pre-index; 62.4% of pts had EGD, of which 72.4% had varices. There were 128 (68.8%) pts with GI bleeding risk and 58 (31.2%) pts without GI bleeding risk. The most common 1L systemic therapies for pts with GI bleeding risk were A + B (72.7%) and A only (9.4%), while for pts without GI bleeding risk, A + B (29.3%), nivolumab + ipilimumab (13.8%), and B + chemotherapy (12.1%) were the most common. Median OS and OS rates at 12, 18, and 24 mo were lower, and post-index GI bleeding rate was higher in pts with vs without GI bleeding risk (Table). For pts treated with A + B, median OS and OS rates at 12, 18, and 24 mo were lower in pts with vs without GI bleeding risk (Table). Conclusions: In this network, prior to the approval of other 1L IO-based regimens for uHCC, many pts received A + B, despite risk of post-index GI bleeding. Median OS with A + B was shorter in pts with vs without GI bleeding risk. Data highlight the complexity of uHCC and the unmet need for guidance on characteristics-driven treatment decisions. © 2025 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and previously presented at the 2025 ASCO Gastrointestinal Cancers Symposium. All rights reserved. Table. Full cohort A + B cohort All ptsN=186 GI bleeding risk N=128 No GI bleeding risk N=58 All pts N=110 GI bleeding risk N=93 No GI bleeding risk N=17 Median follow-up, mo 20.6 20.9 20.4 21.3 21.6 20.3 Median OS, mo 14.4 11.4 40.3 13.9 12.8 Not reached OS rates, % 12 mo 55.2 48.9 68.9 55.2 52.3 70.6 18 mo 45.3 38.1 61.1 44.1 41.6 57.8 24 mo 39.4 31.8 56.8 37.1 34.6 51.3 Post-index GI bleed, % 17.2 23.4 3.4 17.3 19.4 5.9

572 Background: Guidelines recommend systemic therapy for uHCC ineligible for locoregional therapy. Until the approval of tremelimumab + durvalumab for uHCC, in Oct 2022, 1L systemic therapies in the US included multikinase inhibitors and atezolizumab (A) + bevacizumab (B). It is crucial to understand factors driving real-world treatment decisions and outcomes in uHCC. Characteristics, treatment patterns, and outcomes were assessed in US pts with uHCC treated with 1L systemic therapy. Methods: Data were collected from electronic medical records from US Mayo Clinic sites. Pts with uHCC who initiated an NCCN-recommended 1L systemic therapy between Jun 2020–Oct 2022 (A + B was the only approved 1L immunotherapy (IO)-based regimen) with ≥2 follow-up visits, were included. Index was the date of first 1L systemic therapy. Pts were assessed by risk of post-index gastrointestinal (GI) bleeding (pts with Child-Pugh class B or C, pre-index GI bleeding, uncontrolled hypertension [HTN] [≥2 anti-HTN drugs or ≥2 vital entries of SBP >140 mmHg or DBP >90 mmHg]), or significant varices and band ligation). Treatment patterns, overall survival (OS), and post-index GI bleeding were assessed. Results: A total of 186 pts met the inclusion criteria. Most common etiologies of liver disease were metabolic dysfunction-associated steatohepatitis (42.7%) and hepatitis C virus (40.2%). Pre-index GI bleeding was reported in 29.0% of pts, of which 46.3% occurred within 6 months (mo) pre-index; 62.4% of pts had EGD, of which 72.4% had varices. There were 128 (68.8%) pts with GI bleeding risk and 58 (31.2%) pts without GI bleeding risk. The most common 1L systemic therapies for pts with GI bleeding risk were A + B (72.7%) and A only (9.4%), while for pts without GI bleeding risk, A + B (29.3%), nivolumab + ipilimumab (13.8%), and B + chemotherapy (13.8%) were the most common. Median OS and OS rates at 12, 18, and 24 mo were lower, and post-index GI bleeding rate was higher in pts with vs without GI bleeding risk (Table). For pts treated with A + B, median OS and OS rates at 12, 18, and 24 mo were lower in pts with vs without GI bleeding risk (Table). Conclusions: In this network, prior to the approval of other 1L IO-based regimens for uHCC, many pts received A + B, despite risk of post-index GI bleeding. Median OS with A + B was shorter in pts with vs without GI bleeding risk. Data highlight the complexity of uHCC and the unmet need for guidance on characteristics-driven treatment decisions. Full cohort A + B cohort All ptsN=186 GI bleeding risk N=128 No GI bleeding risk N=58 All pts N=110 GI bleeding risk N=93 No GI bleeding risk N=17 Median follow-up, mo 20.6 20.9 20.4 21.3 21.6 20.3 Median OS, mo 14.4 11.4 40.3 13.9 12.8 Not reached OS rates, % 12 mo 55.2 48.9 68.9 55.2 52.3 70.6 18 mo 45.3 38.1 61.1 44.1 41.6 57.8 24 mo 39.4 31.8 56.8 37.1 34.6 51.3 Post-index GI bleed, % 17.2 23.4 3.4 17.3 19.4 5.9

Introduction Taxane medications, paclitaxel, and docetaxel, are chemotherapy agents that have a higher incidence of reported hypersensitivity and infusion reactions. To help classify these reactions, the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) is utilized. Prophylactic medications have been used to decrease the incidence and severity of these events. At our institution, medications that patients can receive prior to the initiation of a taxane infusion are a histamine 1 receptor antagonist (H1RA), histamine 2 receptor antagonist (H2RA), a steroid or a combination of these medications. The purpose of this retrospective review was to compare the rates and severity of infusion reactions based on the timing of prophylactic medication administration in the first and second doses of taxane infusions. Methods Patients who received paclitaxel or docetaxel from January 30 th , 2022, through January 30 th , 2023, were included in the analysis. To assist in the identification of a reaction, taxane administrations were flagged for review if a rescue medication was administered after the start of a paclitaxel or docetaxel infusion. The rates and severity of infusion reactions were analyzed based on the timing of prophylactic medication administration. A sub-group analysis comparing infusion reaction characteristics between taxanes given, was performed. Results Of the 1486 taxane infusions that were completed within the year, 249 infusion reactions were confirmed and graded utilizing the NCI CTCAE. When examining the first and second doses of a taxane (N = 536), we identified 222 infusions reactions. The odds of a patient having an infusion reaction, during the first and second doses, was found to be less likely for patients given a prophylactic medication 30 min prior to receiving a taxane compared to those who did not receive a pre-medication (p = 0.037). Conclusion This multisite retrospective study showed that administration of prophylactic medications 30 to 80 min prior to the first and second infusion of a taxane was the optimal timing to decrease the likelihood of patients having an infusion reaction. No difference in the severity of the reaction was seen. Most patients were able to complete the entire infusion, regardless of what rescue medications were used following the infusion reaction.

PURPOSE Teclistamab is initiated with a step-up dosing (SUD) schedule to mitigate the risk of cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS). Early teclistamab users commonly received SUD in a hospital setting. This study aimed to evaluate safety and health care resource utilization (HRU) in real-world patients with multiple myeloma who initiated teclistamab SUD in an outpatient setting. METHODS This was a retrospective study using Mayo Clinic's electronic medical records from October 26, 2022, to October 31, 2023. Patient characteristics were summarized for all patients treated with teclistamab and separately for patients who started SUD outpatient. SUD pattern, safety, HRU, and post-SUD dosing schedule were described in patients with complete SUD. RESULTS At data cutoff, 65 patients received ≥1 teclistamab dose, including 58 patients who initiated SUD outpatient (median age, 69.2 years; male, 63.8%; White, 89.7%). Among 57 patients who completed SUD in an outpatient setting, all received premedications on the days of teclistamab administrations per label recommendation; 18 (31.6%) developed CRS (13 grade 1, four grade 2, and one grade 4) and two developed ICANS (one each with grade 2 and 4). All CRS and ICANS resolved with supportive care and all patients continued treatment. Eighteen patients were admitted to the hospital for CRS treatment, with a median CRS-related hospital stay of 2 days per admission. Most (60%) doses during SUD required <1 hour clinic time between administration and checkout. Post-SUD, clinic time for treatment doses decreased to <30 minutes for most doses (82%). CONCLUSION Outcomes of this study support outpatient administration as a safe and feasible option for teclistamab SUD to potentially reduce HRU and improve patient experiences.