Citations

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.

e12502 Background: In March 2022, the United States Food and Drug Administration approved olaparib as adjuvant treatment (tx) for patients with germline BRCA1/2 pathogenic or likely pathogenic variants and HER2-negative eBC at high risk of recurrence who have been treated with neo-adjuvant or adjuvant chemotherapy. Approval was based on results from the OlympiA trial which demonstrated a significant increase in invasive-disease free survival [hazard ratio, 0.58; 99.5% CI, 0.41 to 0.82; P<0.001] and overall survival [hazard ratio, 0.68; 99% CI, 0.47-0.97; P=0.009] with olaparib vs placebo. To date, there has been limited real-world data for eBC on olaparib utilization patterns and characteristics of olaparib users. Methods: This retrospective analysis using closed claims from KHM included adult pts with HER2-negative eBC receiving first olaparib prescription (index date) from March 11, 2022 to Nov 30, 2023. Continuous medical and pharmacy enrollment of ≥12 months pre-index and ≥30 days post-index was required. Pt characteristics were summarized descriptively, and Kaplan-Meier (KM) analysis was conducted for time-to-event utilization outcomes. Outcomes were evaluated for pts overall and stratified by hormone receptor (HR) status and race/ethnicity. Non-persistence was defined as minimum of 2 consecutive missed prescription fills. Medication possession ratio (MPR) was calculated as the sum of days of olaparib supply, divided by the total number of days from olaparib initiation to the last claim plus days of olaparib supply in the last claim. Results: We identified 176 pts with HER2-negative eBC who received olaparib. Median age was 44 years, and the majority (66.5%) had commercial insurance. KM-calculated median persistence on olaparib was 11 months (95% CI: 9.2-12.2); overall, adherence measured by MPR ≥80% was 74.2% by month 6 of olaparib use; adherence is higher among Caucasian than non-Caucasian pts (Table). While the majority of HR+/HER2- pts (77.9%, N=53/68) took olaparib concurrently with other (88.7% hormonal) adjuvant tx, most TNBC pts (70.4%, N=76/108) received olaparib alone. Among TNBC pts who took olaparib concurrently with other adjuvant tx (N=32/108), 81.3% received olaparib combined with immunotherapy. Conclusions: Our study provides evidence of favorable persistence and adherence to adjuvant olaparib in a real-world setting and data on utilization of olaparib concurrently with other tx. Recent approvals of other adjuvant tx for HER2- high-risk eBC warrants further research on the efficacy of olaparib used alone, versus olaparib combined or sequenced with other treatments. Olaparib MPR ≥80% by follow-up time points between Caucasians and non-Caucasians. Cohorts 30 days 60 days 180 days 365 days Caucasians (N=70) 92.5% 71.7% 80.6% 90.9% Non-Caucasians(N=55) 88.7% 66.7% 70.0% 50.0%

1530 Background: Regular breast cancer screening reduces mortality. The American College of Radiology (ACR) recommends annual screening mammography for asymptomatic, average risk 1) transgender and gender diverse (TGD) men (individuals assigned female sex at birth but identify as men) age 40+ and with residual breast tissue and 2) TGD women (individuals assigned male sex at birth but identify as women) age 40+ and on gender-affirming hormone therapy for 5+ years. This nationwide study investigated screening mammography in TGD individuals. Methods: Four cohorts were identified with complex algorithms of medical and pharmacy data in the OptumLabs Data Warehouse, a longitudinal, administrative insurance claims database that includes patients with commercial insurance and Medicare Advantage: 1) TGD men, 2) TGD women, 3) individuals with gender dysphoria not meeting other TGD criteria (NMOT), and 4) cisgender women -- all of whom met ACR screening criteria. The primary endpoint was the percentage of individuals with high adherence, defined as completing >75% of recommended screenings; comparisons were made across the cohorts (Chi-square test). Multivariable logistic regression was used to compare adherence between TGD men and cisgender women with adjustment for demographics and with 1:4 matching (on race/ethnicity, age group, year of healthcare plan enrollment, and duration of follow-up). Results: 10,478 TGD individuals (3,778 TGD men; 1,294 TGD women; and 5,406 with gender dysphoria NMOT) and 6,218,369 cisgender women were identified. For TGD men, TGD women, individuals with gender dysphoria NMOT, and cisgender women, high adherence was observed in 41.1% (95% confidence interval (CI): 39.5, 42.6%); 7.4% (95% CI: 6.0, 8.8%); 11.9% (95% CI: 11.0, 12.7%); and 38.3% (95% CI: 38.3, 38.4%), respectively, p < 0.0001. No screening ever in these same populations was observed in 23.6% (95% CI: 22.2, 24.9%); 81.3% (95% CI: 79.2, 83.4%), 72.8% (95% CI: 71.6, 74%), and 35.9% (95% CI: 35.8, 35.9%), respectively, p < 0.0001. When TGD men were matched and compared to 15,112 cisgender women, a differential association was observed between gender and high adherence by age group (p < 0.0001); compared to cisgender women, the likelihood of high adherence in TGD men ages 40-49 (n = 2,472), 50-59 (n = 852), 60-69 (n = 320), and 70+ (n = 134) were as follows: odds ratios (OR‘s): 1.38 (95% CI: 1.28, 1.50), p < 0.0001; 1.57 (95% CI: 1.35, 1.81), p < 0.0001; 0.812 (95% CI: 0.619, 1.065), p = 0.1316; and 1.277 (95% CI 0.835, 1.951), p = 0.2595, respectively. Conclusions: This study found that TGD men manifest relatively high adherence to screening mammography, whereas TGD women and individuals with gender dysphoria NMOT manifest low adherence. Future research should focus on improving breast cancer screening in these underserved populations.

11106 Background: Patients with cancer take different types of medication (e.g., enteral, parenteral), with varying treatment schedules, in various settings. They are also sometimes instructed to stop medication in response to toxicity. To measure medication nonadherence in this heterogenous population, we modified and pilot-tested a self-report measure originally developed to assess nonadherence to daily oral medication, the Domains of Subjective Extent of Nonadherence (DOSE-Nonadherence), in adults with cancer. Methods: Participants were ≥21 years, on active cancer treatment at Memorial Sloan Kettering, and spoke English and/or Spanish. A branching logic was added to allow participants to select the setting where they take cancer medication: 1) only at home, 2) only in clinic, or 3) partly at home/partly in clinic. Based on administration setting, participants reported nonadherence to medications their clinician expected them to take over a given reference period (1 week for home and 1 month for clinic medications). Participants then reported on setting-relevant reasons for nonadherence. Survey instructions/items were refined in an iterative process using feedback from a patient investigator committee and participant cognitive interviews. During interviews, we asked participants about the interpretation of instructions/items, recall period, and comprehensiveness of reasons for nonadherence, regardless of their own adherence. After initial testing in English, a Spanish version was developed through transcreation. Adherence was dichotomized for analysis (complete adherence vs. any nonadherence). For all participants who received clinic medications, concordance between chart abstracted and self-reported adherence was evaluated. Results: Of 55 participants who completed the surveys and interviews (67% in English; 33% in Spanish), 87% were female and 44% identified as Latino. The majority (73%) had breast cancer; 60% had metastatic disease. 12 of 45 who received medication in clinic reported nonadherence as did 8 of 35 who took medication at home. Participants felt able to respond accurately to both recall periods. All reasons for nonadherence were perceived as relevant to themselves or other patients. There was 89% concordance between self-reported and chart abstracted adherence for clinic-administered medication. To improve concordance, changes were made to the formatting and instructions. Of 12 participants who completed the final version of the survey for clinic-administered medication, there was 100% concordance between self-reported and chart abstracted nonadherence. Conclusions: Our results support the reliability and validity of modified DOSE-Nonadherence for cancer patients. This instrument can be used to better identify nonadherence to cancer medications in a population of adult patients with cancer receiving various treatment regimens.

4020 Background: In previously treated patients (pts) with advanced extra-pancreatic NET (epNET) or pancreatic NET (pNET), cabozantinib (cabo) demonstrated improved progression-free survival compared to placebo (pbo) in the CABINET trial (NCT03375320). Here we present HRQOL data from CABINET. Methods: Pts with previously treated unresectable, locally advanced or metastatic epNET or pNET were randomized (2:1) in separate cohorts to receive cabo 60 mg daily vs pbo. HRQOL was an exploratory endpoint measured using the EORTC QLQ-C30, QLQ-GI.NET21, Patient Global Impression of Change (PGIC), and PRO-CTCAE questionnaires. Optional participation was by paper surveys at baseline and every 12 weeks (wks) until disease progression or new anticancer therapy. Mean changes from baseline were compared between treatment arms at wk12 using general linear mixed models. Minimally important within-arm improvements and between-arm differences were defined as 8 points on the C30 Global Health Status (GHS)/QOL Scale. PGIC was dichotomized as improved vs unchanged/worsened and compared using Chi-squared tests. Rates of pt-reported adverse events (AEs) by PRO-CTCAE were baseline-adjusted and compared using Fisher’s exact tests. Results: 172 pts (113 cabo, 59 pbo) with epNET and 81 pts (53 cabo, 28 pbo) with pNET consented for survey participation. Pts completed 524 (82%) of 640 expected surveys across baseline, wk12, and wk24. For epNET, C30 GHS/QOL was significantly improved at wk12 in pts receiving cabo (mean change 9.5, standard error (SE) 2.2, p < 0.001) but not pbo (mean change 0.2, SE 3.1, p = 0.95) resulting in significantly different mean changes from baseline between arms (p = 0.02). For pNET, C30 QHS/QOL was significantly improved at wk12 in pts receiving cabo (mean change 8.0, SE 3.0, p = 0.008) but not pbo (mean change 6.8, SE 4.4, p = 0.12); mean changes from baseline did not statistically differ between arms (p = 0.82). No significant differences in mean changes from baseline at wk12 in C30 Physical, Role, Emotional, Cognitive and Social Function were observed between arms in the epNET or pNET cohorts. In both cohorts at wk12, pts on cabo reported improved overall status as measured by PGIC more often than those on pbo (epNET: 38% vs 19%, p = 0.04; pNET: 57% vs 18%, p = 0.006). Rates of pt-reported AEs were statistically significantly higher in cabo for diarrhea (68% vs 53%), hand-foot syndrome (57% vs 26%), mouth or throat sores (47% vs 27%), and dysgeusia (67% vs 37%) [all p < 0.05]. GI.NET21 data will be presented. Conclusions: Although cabo is associated with pt-reported AEs consistent with its known safety profile, global HRQOL was maintained. A higher proportion of patients receiving cabo reported improved overall status. Results support cabo as a treatment option for pts with previously treated advanced NET that preserves patient HRQOL. Clinical trial information: NCT03375320 .

7023 Background: Axi-cel is an autologous chimeric antigen receptor (CAR) T-cell therapy approved for adults with R/R LBCL after ≥ 1 prior line of therapy (LoT). Adverse events, such as cytokine release syndrome (CRS) and neurologic events (NEs), may deter centers from using axi-cel in an outpatient (OPT) setting, though individual centers have observed comparable safety and effectiveness in OPT and inpatient (IPT) care (Furqan et al. Blood Adv . 2024). Here, we present safety and effectiveness outcomes of axi-cel by intention to treat in OPT and IPT settings in a multicenter real-world dataset. Methods: Pts receiving axi-cel for R/R LBCL in the US from 01/2021-07/2023 with data in the Center for International Blood and Marrow Transplant Research (CIBMTR) registry were eligible for analysis. Pts with prior allogeneic transplant or unknown intended care setting were excluded. Of potential pts, 119 OPT pts were identified from 29 centers where an increasing trend was seen (9.6% of pts in 2021 were OPT, 13.5% in 2022, 22.8% in 2023). Pts were matched to 119 IPT pts by propensity score matching on age, sex, comorbidities, lactate dehydrogenase (LDH), bulky disease, prior LoT, chemosensitivity, and infusion year (see table). Results: OPT pts had median age of 63 y (25% ≥ 70), 66% were male, and 67% had ≥ 1 comorbidity. Half (50%) had elevated LDH and 73% had 1 prior LoT. Bulky disease was reported in 3%, and 60% had chemo-resistant disease. Outcomes were analyzed at median follow-up of 12 mo. Safety and effectiveness outcomes were similar between OPT and IPT pts (see table). In multivariate analyses, no differences were found between intended care setting and CRS (odds ratio [OR] 1.09 [95% CI 0.51-2.35]), CRS Gr ≥ 3 (OR 0.57 [0.12-2.60]), NEs (OR 1.14 [0.65-2.00]), or NEs Gr ≥ 3 (OR 0.98 [0.48-2.00]). Among OPT pts, 24% and 50% did not require hospital admission within 30 d and 3 d, respectively. In pts aged ≥ 70 y, only any Gr NEs were higher in the OPT group. Conclusions: After matching on key factors that may be used to select pts for OPT infusion, outcomes were comparable between intended care settings. These findings corroborate prior results and support the consideration of axi-cel in appropriate OPT care settings. Outcomes between matched pts with R/R LBCL receiving axi-cel intended for OPT or IPT. OPT (n=119) a IPT (n=119) a CRS any Gr / Gr ≥ 3 83 (75−89) / 3 (<1−7) 83 (74−89) / 4 (1−10) NE any Gr / Gr ≥ 3 47 (38−57) / 19 (12−27) 46 (37−56) / 21 (14−30) Overall / complete response rates 78 (69−85) / 68 (59−76) 76 (67−83) / 62 (52-70) Duration of response @ 12 mo 64 (52−74) 69 (58−78) Progression-free survival @ 12 mo 53 (43−62) 53 (43−61) Overall survival @ 12 mo 71 (61−78) 72 (62−79) Non-relapse mortality @ 12 mo 6 (2−11) 4 (1−8) Hospital admission within 30 days of infusion / median duration (range), d 76 (67−83) / 9 (2−53) Not Applicable a Percent (95% CI) unless otherwise specified.

e19025 Background: Recent studies suggest that patients with CLL/SLL (herein, CLL) relapsed/refractory (R/R) to both cBTKi and BCL2i (double R/R [DR]) may have poorer outcomes than the broader group of double-exposed (DE) patients. This study evaluated real-world response (rwR) and time-to-event (TTE) outcomes of a CLL DE cohort and DR subcohort in the US. Methods: This retrospective study used the nationwide Flatiron Health electronic health record-derived deidentified database to include patients with CLL treated with sequential or combination cBTKi and BCL2i in any line of therapy (LOT) on or after January 1, 2011, and a subsequent LOT (ie, index LOT) on or before November 30, 2022 (DE cohort). A subset with DR CLL (DR subcohort) was analyzed separately. Descriptive statistics were generated for demographic and clinical characteristics. Outcomes included clinician-confirmed rwR rate (rwRR) and median TTE outcomes (real-world duration of response [rwDOR], progression-free survival [rwPFS], time to next treatment [rwTTNT], and overall survival [rwOS]; Kaplan Meier, follow-up to May 31, 2023). Results: The DE cohort included 264 patients, 107 of whom were in the DR subcohort. Patients were mostly male (64%), White (75%), aged ≥65 years at first index LOT (72%) after prior cBTKi and BCL2i treatment, and treated in the community setting (71%). Approximately one-third of patients received a subsequent treatment after each index LOT. Most patients were re-treated with a cBTKi and/or BCL2i in the first index LOT (69% DE; 54% DR), and the percentage treated with chemotherapy increased with each subsequent index LOT. Confirmed rwRR was similar between DE and DR for all index LOTs (Table). More relevant are the median TTE outcomes, which were shorter for DR than DE, especially for the first index LOT, and shorter in subsequent index LOTs for both groups. Conclusions: The high percentage of patients re-treated with cBTKi and BCL2i therapies and increasing use of chemotherapy regimens with each subsequent index LOT indicate a lack of standard of care and options. Our results suggest a high unmet need in the DE CLL population, particularly in patients DR to cBTKi and BCL2i therapy, who have worse outcomes. Efficacious and durable therapy options are needed to address this unmet need. Double Exposed Index LOT Double R/R Index LOT 1st 2nd 3rd 1st 2nd 3rd N 264 90 35 107 41 12 rwRR, % (95% CI) 39(33-45) 42(32-53) 40(24-58) 36(27-45) 34(21-51) 42(16-71) Median TTE outcomes, months (95% CI) rwDOR 20.3 (13.5-32.6) 6.0(5.5-NR) 3.1(2.7-NR) 11.5 (7.9-23.5) 6.0(3.6-NR) 2.9(2.7-NR) rwPFS 8.8(7.5-10.6) 5.1(4.0-7.3) 4.3(2.9-6.3) 5.0 (4.0-7.3) 3.6(2.6-5.7) 4.7(2.7-NR) rwTTNT 13.8 (10.3-18.3) 7.9(5.7-11.3) 5.7(4.2-14.6) 8.0 (6.2-11.5) 5.9(4.4-11.4) 5.0(4.2-NR) rwOS 25.2 (22.1-37.1) 15.2(11.4-22.6) 6.6(5.7-NR) 14.7 (12.3-22.6) 11.4(5.9-NR) 6.6(5.0-NR)

4545 Background: The treatment landscape of front-line nccRCC has evolved with recent trials demonstrating the efficacy of combination systemic therapy. However, the efficacy of treatment after combination therapy is unknown. This study evaluates the efficacy of VEGF-based regimens in nccRCC patients (pts) previously treated with combination regimens. Methods: ORACLE is a real-world, multi-center, retrospective database that includes nccRCC patients that received combination systemic therapies (IO+IO, IO+VEGF and VEGF+ mTOR) in any line. Subsequent treatments were categorized as VEGF only regimens (cabozantinib vs other VEGF), IO+ VEGF and VEGF+ mTOR. The primary endpoint was objective response rate (ORR) assessed by investigator review using RECIST 1.1. Secondary endpoints included disease control rate (DCR), defined as the proportion of patients achieving complete or partial responses or stable disease, time to treatment progression (TTP), calculated from the date of VEGF-based initiation to progression or last follow-up using the Kaplan-Meier method. Differences between groups were estimated with the log-rank test, and categorical outcomes were compared with the chi-square test. Results: 105 pts who received VEGF – based regimens after combination therapy were included in the analysis. Baseline characteristics: median age: 59years, 71 % male, 58% white, 25% black, 87% ECOG 0-2. IMDC-risk categories included:21% favorable, 59% intermediate and 20% poor risk. Histology included papillary (40%), unclassified (32%), chromophobe (16%) and other rare subtypes (12%). Prior combination therapies included IO+IO: 62%, IO+ VEGF: 34% and VEGF+ mTORi:4%. 70% pts received combination therapy in the first line setting while the remainder received combination therapy in a second or later line. Outcomes with subsequent treatments are described in Table1. IMDC risk score correlated with TTP. Conclusions: Modest antitumor activity was observed with VEGF- based approaches in combination therapy refractory nccRCC. Optimal management of nccRCC remains an unmet need. Outcomes of nccRCC patients by treatment and histologic type. Outcomes per Treatment n ORR (%) DCR (%) mTTP (mo.) Cabozantinib 56 18 47 3.6 VEGF/mTOR 19 16 42 9.3 IO+VEGF 17 29 47 5.6 Other VEGF 13 15 46 5.5 Outcomes per Histology Papillary 42 19 43 6.5 Unclassified 33 21 42 6.1 Chromophobe 17 29 59 8.9 Other * 13 0 46 NR

TPS2677 Background: Despite the success in hematologic malignancies, CAR T therapies face significant challenges in solid tumors due to the lack of tumor-specific targets that distinguish cancer from normal cells. EGFR plays a critical role in oncogenesis across several cancers and is often upregulated (TCGA 2022). While monoclonal antibodies targeting EGFR have demonstrated efficacy, these approaches are often limited by on-target, off-tumor toxicities, such as skin rash, which constrains dose escalation and efficacy (Macdonald, et al. J Am Acad Dermatol . 2015). A2B395 is an allogeneic, logic-gated, EGFR-targeted Tmod CAR T therapy designed to address these limitations and provide a convenient and consistent off-the-shelf option. This therapy incorporates 2 CARs: an activator targeting EGFR, and a blocker targeting HLA-A*02. The activator recognizes EGFR on both tumor and normal cells, while the blocker inhibits CAR T activity against normal cells with preserved HLA expression and decreases the risk for graft-versus-host disease (Hamburger, et al. Mol Immunol . 2020). To address potential host-vs-graft response, an shRNA expression module targeting B2M is included in the Tmod construct, which significantly reduces major histocompatibility complex class I levels and subsequent host immune response (DiAndreth, et al. Clin Immunol. 2022). Importantly, the Tmod system is modular and adaptable to multiple targets. Initial data on autologous Tmod CAR T therapy suggest reduced off-tumor toxicity and encouraging clinical efficacy (Grierson, et al. SITC 2024. Abstract 588). A2B395 represents a novel approach for EGFR-expressing solid tumors with HLA-A*02 LOH. Methods: DENALI-1 (NCT06682793) is a phase 1/2, open-label, nonrandomized study evaluating the safety and efficacy of A2B395 in adults. Patients are enrolled through BASECAMP-1 (NCT04981119), a master prescreening study that identifies patients with HLA LOH at any time in the course of their disease via next-generation sequencing (Tempus AI, Inc.). Key inclusion criteria include histologically confirmed recurrent unresectable, locally advanced, or metastatic cancers associated with EGFR expression, including colorectal, non-small cell lung, squamous cell head and neck, triple negative breast, and renal cell cancers. Patients must have received ≥1 line of prior therapy, such as a checkpoint inhibitor, molecular targeted therapy, or chemotherapy. The primary objective of phase 1 is to evaluate safety, tolerability, and the recommended phase 2 dose (RP2D) using a Bayesian optimal interval design for dose escalation. The dose-expansion phase will confirm RP2D and collect biomarker data. Phase 2 will assess overall response rate per RECIST v1.1. Clinical trial information: NCT06682793 .