Citations

556 Background: Combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) is a rare and complex liver cancer with features of both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), making its management challenging. This study aims to analyze the clinical characteristics, genomic profiles, and treatment outcomes of cHCC-CCA patients in a real-world setting. Methods: We conducted a retrospective analysis of cHCC-CCA patients across three first-line treatment groups: chemotherapy alone(Gemcitabine/Cisplatin, FOLFOX), HCC-directed therapies (atezolizumab/bevacizumab, lenvatinib, nivolumab, durvalumab, sorafenib), and chemoimmunotherapy (Gemcitabine/Cisplatin combined with immunotherapy). This international study, involving Mayo Clinic and the National Cancer Center East (Japan), assessed overall survival (OS) using Kaplan-Meier and Cox regression models. Results: A total of 68 patients were included, with a mean age of 66 years; 74% were male and 66% were White Non-Hispanics. Cirrhosis was present in 74% of patients at diagnosis, and Hepatitis B and C were common etiologies in 57%. Prior primary resection and regional therapies (Transarterial chemoembolization (TACE), Transarterial radioembolization (TARE)) were recorded in 39% and 50% of patients, respectively. Advanced/metastatic disease was present in 52% of the cohort. The distribution of first-line treatments was as follows: 47% received chemotherapy alone, 39% received HCC-directed therapy, and 14% received chemoimmunotherapy. Genomic alterations were detected in 44% patients, with TP53 (28%), ARID1A (25%), and TERT (22%) being the most frequent. The HCC-directed therapy group demonstrated the best overall response rate (52%) and had a median OS of 15.8 months (mo), compared to 11.8 mo for chemotherapy and 4.7 mo for chemoimmunotherapy (p=0.8). Patients who received regional treatments had a longer median OS of 15.8 mo compared to those who did not (10.2 mo) (p=0.4). Conclusions: HCC-directed therapy showed a trend towards better survival outcomes compared to other treatments, though not statistically significant. A considerable proportion of patients had genomic alterations, which may have influenced survival outcomes. Ongoing research with larger cohorts is underway to further elucidate the impact of genomic variations on treatment efficacy and refine therapeutic strategies for this challenging malignancy. Baseline characteristics of patients with combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA). Total(N=68) Mean age at diagnosis, years (SD) 66(6.4) Gender, n (%) Male 50 (74%) Ethnicity, n (%) White, Non-Hispanic 45 (66%) Cirrhosis at diagnosis, n (%) 50 (74%) Etiology of Liver disease, n (%) Viral (Hepatitis B and C) 39 (57%) History of Primary resection, n (%) 27 (39%) Regional treatment, n (%) 34 (50%) Afp, n (%) < 200 23 (64%) ca19_9, n (%) < 50 27 (82%)

277 Background: While HER2-targeted therapies benefit patients (pts) with advanced HER2-positive mCRC, the development of resistance remains inevitable. This study aims to explore the landscape and frequency of genetic alterations putatively associated with acquired resistance to anti-HER2 therapy in HER2-positive mCRC. Methods: In this retrospective-multicenter international study involving Mayo Clinic, Duke Cancer Center and National Cancer Center Hospital East (Japan), we descriptively compared comprehensive genomic analyses from tissue or blood samples of pts with HER2-positive CRC pre-treatment and post-treatment with HER2-targeting agents. Results: A total of 36 pts were included in this study. 29 (80%) had HER2-positive mCRC as confirmed by immunohistochemistry (IHC) and fluorescent in situ hybridization (ISH), the remaining pts had HER2 amplification detected on blood or tissue . 34/36 (94%) pts were administered their first anti-HER2 agent after progressing on ≥2 prior lines of treatment. The most common anti-HER2 regimen administered was trastuzumab/pertuzumab (50%, 18/36), followed by trastuzumab-tyrosine kinase inhibitors (TKIs) (tucatinib or neratinib) (30%, 11/36) and trastuzumab deruxtecan (14%, 5/36). Putative genomic mechanisms of acquired resistance were detected in 72% (26/36), while the remaining pts lacked new genomic alterations that might explain resistance to anti-HER2 therapy, suggesting alternative escape mechanisms. Acquired alterations in downstream or alternate bypass pathways were identified in 72% (26/36) of pts; most commonly in the RAS/RAF pathway and in EGFR (34.6%, 9/26 each), followed by 27% (7/26) of pts with MET point mutations (mts) and amplification; activating muts in PI3K/AKT and in 27% (7/26), most commonly CDK12 (60%, 4/7) . HER2 receptor alterations were detected in 3 pts (8.3%), all of whom received trastuzumab-tucatinib and included HER2 L755S, HER2 V777L, HER2 D769Y, HER2 G727A and HER2 S310F, which are known to cause resistance to , however, information about tucatinib resistance is not yet available. Other altered pathways included AR, RB, NOTCH and HRD. Two pts lost HER2 expression on blood and tissue NGS post anti-HER2 therapy. Conclusions: The emergence of resistance might be in part related to acquired alterations that constitutively activate signaling pathways parallel or downstream of HER2, bypassing HER2 inhibition. Additional histologic studies, deep mutational scanning, larger populations and correlative analysis are needed to validate these findings.

536 Background: The prognosis of advanced BTC remains poor. Although targeted agents have expanded late-line options, many patients (pts) become ineligible for these therapies after progressing on first-line treatment. Herein, we examined the real-world impact of targeted therapy on survival in advanced BTC. Methods: In this international collaborative study between the Mayo Clinic (US) and the National Cancer Center East (Japan), we included pts with advanced BTC with comprehensive tumor molecular profiling who had received at least 30 days of systemic therapy. Pts were categorized into 3 groups: 1) non-actionable, 2) pts with alterations who received matched targeted therapy at any point during their treatment (matched group), and 3) those with mutations who did not receive matched therapy (unmatched group). OS was calculated from the start date of first-line therapy until death and compared among three subgroups using Cox regression models. Results: Of 932 pts, 366 (39.3%) had an actionable alteration, and 135 of these received matched therapy. 566 (61.7%) did not have an actionable alteration (Table). The most common alterations were somatic BRCA1/2 (N=106, 11.4%), HER2 amplification (N=65, 7%), FGFR2 fusion (N=61, 6.5%), KRAS G12C/D (N=46, 4.9%), and IDH1 (N=38, 4.1%). 78.7% of FGFR2 fusions were found in Caucasian pts, whereas BRCA1/2 (97.5%), HER2 (78.5%), and KRAS G12C/D (67.4%) alterations were more prevalent in Asian pts. The median OS was significantly longer in the matched group (21.4 months; 95% CI 18.4-27.9) compared to the unmatched group (14.6 months; 95% CI 12.8-17.6) and the non-actionable group (17.2 months; 95% CI 15.5-19.0). The 36-month OS rate was 33% in the matched group vs. 7% in the unmatched group (p < 0.0001). After adjusting for age, gender, prior surgical resection, primary tumor location, and country of origin, matched targeted therapy remained a strong independent predictor for improved OS (HR 0.61; 95% CI 0.48-0.79). Conclusions: These real-world findings suggest that matched targeted therapies significantly improve survival in advanced BTC, underscoring the need to incorporate them earlier in the treatment course and address barriers to treatment access. The regional prevalence of actionable alterations should also be considered when developing new targeted therapies. Patient baseline characteristics stratified by actionable alterations and targeted therapy. Non-actionable(N=566) Unmatched group(N=231) Matched group(N=135) Site, n (%) Japan 409 (72%) 166 (72%) 50 (37%) US 157 (28%) 65 (28%) 85 (63%) Age at Dx > 65, n (%) 324 (57%) 122 (53%) 54 (40%) Female, n (%) 235 (42%) 92 (40%) 77 (57%) Primary tumor location (category), n (%) Intrahepatic 217 (43%) 115 (55%) 99 (76%) Extrahepatic 150 (30%) 39 (19%) 17 (13%) Gallbladder 142 (28%) 54 (26%) 14 (11%) Prior surgical resection, n (%) 220 (42%) 74 (34%) 48 (37%)

727 Background: PARP inhibition (PARPi) is a standard maintenance therapy for patients (pts) with germline BRCA1/2 mutations in pancreatic cancer. Combination of PARPi therapy and immunotherapy has potential to increase efficacy and may offer benefit beyond germline BRCA1/2 . Methods: We performed a multisite single-arm phase 2 study using the highly potent PARPi niraparib with anti-PD1 drug dostarlimab in pts with germline or somatic HRD mutations in BRCA1/2, PALB2, RAD51C/D, or BARD1 . Pts were required to have metastasis, progressed on ≥1 regimen, and prior platinum-exposure unless refused/intolerant. Pts were treated with niraparib 200 mg orally once daily continuously. Dostarlimab 500 mg was administered IV every 3 weeks for 4 cycles, then 1000 mg IV every 6 weeks. The primary endpoint was disease control rate (DCR) at 12 weeks (DCR12) using iRECIST criteria. At least 8 pts with DCR12 in the first 19 eligible pts (41%) would be considered promising for further trials. Results: 22 pts were enrolled from Dec 2020 to Oct 2023. Two pts withdrew prior to receiving therapy, and 2 were later found to be ineligible, leaving 18 eligible pts for final analyses. Median age was 63.0 yrs, 39% male, 94% non-Hispanic white, 1 black (6%). 17 pts were platinum exposed, 7 were platinum-refractory, and 5 had previously progressed on PARPi maintenance. Mutation distribution was: BRCA2 13/18 (72%), BRCA1 4/18 (22%), BARD1 2/18 (11%). One pt had both BRCA1 (somatic) and BRCA2 (germline) mutations. Germline mutations were identified in 14/18 (78%). DCR12 was achieved in 5/18 (27.8%), so the primary endpoint (>41%) was not met. Pts received a median 2 cycles (range 1-8) of niraparib + dostarlimab. No clinical factors were significantly associated with improved DCR12 (all p > 0.05) in subgroup analyses, but we did observe the following statistically nonsignificant associations. Pts who were platinum-refractory had a lower DCR12 compared to those not (14.3% vs. 36.4%). Counterintuitively, PARPi exposed/refractory pts had a higher DCR12 than non-exposed/non-refractory (50 vs 17% exposed/nonexposed and 40% vs 23% refractory/nonrefractory). Pts with germline mutations had a higher DCR12 compared to those without (38.5% vs. 0%). Non- BRCA2 mutations had a higher DCR12 than those with BRCA2 mutations (50% vs.17%), with highest DCR12 rates among BRCA1 patients (67%). Tolerability was in line with similar combinations, with 60% non-hematologic Gr3 or higher, including fatigue (15%), AST increase (10%), nausea/vomiting (10%), sepsis (10%). Two grade 5 events were not attributed to treatment. Conclusions: PARPi plus anti-PD1 checkpoint inhibition was not sufficiently active as later line therapy in metastatic pancreatic cancer for the majority of patients with HRD mutations. Additional molecular analyses to elucidate predictive markers of sensitivity/resistance are ongoing. Clinical trial information: NCT04493060 .

TPS309 Background: Patients with oligometastatic colorectal cancer (CRC) often experience long-term progression-free survival and overall survival (OS) following aggressive local treatment of isolated metastases, especially in the liver. However, the effectiveness of local ablative therapies, such as microwave ablation (MWA) and stereotactic body radiation therapy (SBRT), in patients with inoperable limited metastatic CRC or those with additional metastases outside the liver or lungs, remains uncertain. Despite the historical use of local therapy for oligometastatic CRC, often influenced by provider bias rather than strong evidence, questions persist about the potential benefits of applying this approach to patients with more extensive disease. This trial aims to address this clinical challenge by evaluating the safety and efficacy of adding total ablative therapy (TAT) of all disease sites to standard systemic treatment in patients with limited metastatic CRC. Methods: A022101/NRG-GI009 is a randomized phase III study within the National Clinical Trials Network, set to enroll 364 patients with newly diagnosed metastatic CRC (BRAF wild-type, microsatellite stable). Patients with liver-only metastatic disease are excluded. Pre-registration during first-line systemic therapy induction is encouraged. Eligible lesions must be treatable with surgical resection, MWA, and/or SBRT. Patients without significant radiographic progression after 12-39 weeks of first-line systemic therapy, with 4 or fewer disease sites post-induction chemotherapy, will be randomized 1:1. Randomization will be stratified by the number of metastatic organ sites (1-2 vs. 3-4), timing of metastatic disease diagnosis (de novo vs. secondary), and the presence of metastatic disease outside the liver/lungs in at least one site. Patients in Arm 1 will receive TAT, targeting all metastatic sites with a combination of surgical resection, MWA, and/or SBRT, followed by standard systemic therapy. Patients in Arm 2 will continue with standard systemic therapy alone. The choice of systemic therapy is at the discretion of the medical oncologist and may include continued therapy, maintenance chemotherapy, or observation. The primary endpoint is OS, with secondary endpoints including event-free survival, treatment-related toxicities, and local recurrence. Exploratory biomarker analyses will also be conducted. The study requires 346 evaluable patients across the two arms to demonstrate an OS improvement with a hazard ratio of 0.7, providing 80% power with a one-sided alpha of 5%. The trial employs a group sequential design with two interim analyses (at 25% and 50% of events) to assess futility. The trial began in January 2023, and patient recruitment is ongoing. Clinical trial information: NCT05673148 .

732 Background: Ampullary carcinoma (AC) is a rare malignancy arising from the ampulla of Vater which has a more favorable prognosis compared to other pancreatic malignancies. Current guidelines favor surgical resection followed by adjuvant therapy for average risk patients (pts), however the type of regimen as well as other perioperative treatment modalities are still being explored. The objective of this retrospective study aims to provide insight into the management of locoregional disease. Methods: Pathology records from Mayo Clinic (AZ, FL, MN) denoting AC between 2010 to 2024 were searched using Mayo Data Explorer and selected for retrospective review. Pt demographics, treatment courses, and next generation sequencing (NGS) data were collected. Statistical analysis was conducted using SAS version 9.04. Results: A total of 137 pts (62% male, n = 85) were identified with median age 66 years old. Histologic subtypes were 54% pancreatobiliary (44/81), 40% intestinal (32/81), 6% mixed (5/81), with 56 pts unknown. Stages at diagnosis were 81% resectable (111/137), 11% locally advanced (15/137), and 8% metastatic (11/137). Nearly all (93%, n = 103/111) pts with localized disease had resection with a 97% R0 resection rate (100/103). Majority (68%, n = 75/111) of resectable pts had perioperative chemotherapy with 5-FU or gemcitabine-based regimens (24%, n = 18/75 neoadjuvant vs. 76%, n = 57/75 adjuvant). Perioperative chemoradiation was given in 17% (19/111) of pts. At median follow up of 30.5 months, recurrence rates were 40% (41/103), primarily to the liver (18/41). Median recurrence free survival (RFS) was 29.3 months (95% CI 24.7 – NE). Median overall survival (OS) has not been reached. The 5-year RFS and OS rates were 0.37 (95% CI 0.25 - 0.55) and 0.69 (95% CI 0.58 - 0.82), respectively. Univariate analysis showed no difference in OS with the addition of neoadjuvant or adjuvant chemotherapy or chemoradiation. Somatic NGS testing showed pathogenic mutations in 90% of pts (63/70): 57% KRAS (36/63; 44% G12D, 19% G12V, 8% G12C, 8% G12D, 19% others); 13% homologous recombination (HR) (8/63); 6% ERRB2 /Her2 amplification (4/63), and 5% mismatch repair (MMR) (3/63). Conclusions: AC has a favorable prognosis in resectable pts. However, high recurrence rates indicate the need for better systemic therapies and improved selection of pts who would benefit from these treatments. Future research should focus on refining perioperative strategies to enhance outcomes and reduce recurrence.

Silver foam dressings have been extensively used in the management of burn injuries; however, its application in children requires elucidation. A literature search was conducted from database inception to October 2023. Eligible studies reported paediatrics patients under 21 years of age receiving silver dressings for burns or scalds. This review was registered prospectively with PROSPERO (CRD42023470239). 18 studies met the inclusion criteria with a total of 701 patients. The pooled mean time to re-epithelisation (TTRE) was 12.9 days (95% CI: 11.2, 14.6, I2 = 94%). The pooled mean duration of hospitalisation was 9.8 days (95% CI: 3.9, 15.7; I2 = 100%). Mean number of total dressing changes per patient was 3.6 (95% CI: 2.2, 4.9; I2 = 99%). There were a total of 98 complications, including 30 (30.6%) infections, 29 (29.6%) surgical requirements, 14 (14.3%) hypertrophic scarring, 17 (17.3%) escalations of care, 5 (5.1%) burn depth progression, and 3 (3.1%) others. Silver foam dressings appear as a safe and effective approach in terms of healing rate and dressing change frequency for selected paediatric patients with burn injuries. Despite the promising results, further comparative studies are required to evaluate the selection criteria and long-term effect of silver foam dressing.

ImportanceUnderstanding the interplay between diabetes risk factors and diabetes development is important to develop individual, practice, and population-level prevention strategies.ObjectiveTo evaluate the progression from normal and impaired fasting glucose levels to diabetes among adults.Design, Setting, and ParticipantsThis retrospective community-based cohort study used data from the Rochester Epidemiology Project, in Olmsted County, Minnesota, on 44 992 individuals with at least 2 fasting plasma glucose (FPG) measurements from January 1, 2005, to December 31, 2017. People who met criteria for diabetes on or before their first FPG measurement were excluded. Data were electronically retrieved in December 2019 with analyses finalized in November 2024.ExposuresThe exposure was baseline FPG level, with covariates including the following measures that are consistently recorded in the electronic health record: body mass index (BMI), age, and sex.Main Outcomes and MeasuresThe cumulative probability of freedom from diabetes was estimated and presented graphically using a Kaplan-Meier curve. Multivariable Cox proportional hazards regression modeling was used to estimate the partial hazard ratios (HRs) for variables of interest. Diabetes was defined as an FPG level greater than 125 mg/dL.ResultsA total of 44 992 individuals (mean [SD] age at baseline, 43.7 [11.8] years; 26 025 women [57.8%]) were included. The baseline mean (SD) BMI was 28.9 (6.6). Over a median follow-up of 6.8 years (IQR, 3.6-9.7 years), 3879 individuals (8.6%) developed diabetes. The Kaplan-Meier 10-year cumulative risk of incident diabetes was 12.8% (95% CI, 12.4%-13.2%). All initial FPG levels outside a range of 80 to 94 mg/dL were associated with increased risk for diabetes (ie, FPG &amp;lt;70 mg/dL: HR, 3.49 [95% CI, 2.19-5.57]; FPG 120-125 mg/dL: HR, 12.47 [10.84-14.34]). Other independent risk factors were male sex (HR, 1.31 [95% CI, 1.22-1.40]), older age (≥60 years: HR, 1.97 [95% CI, 1.71-2.28]), and any abnormal category of BMI, including underweight (BMI &amp;lt;18.5: HR, 2.42 [95% CI, 1.77-3.29]; BMI ≥40: HR, 4.03 [95% CI, 3.56-4.56]). There was a significant additive association of variables, particularly FPG level and BMI. For instance, a woman aged 55 to 59 years with a BMI of 18.5 to 24.9 and an FPG level of 95 to 99 mg/dL had an estimated 10-year diabetes risk of 7.0%. However, an almost doubling of risk to 13.0% was observed if the BMI was 30.0 to 34.9, and risk more than doubled again to 28.0% if FPG level also increased to 105 to 109 mg/dL. A nomogram was generated to facilitate individual classification into one of four 10-year risk categories.Conclusions and RelevanceThis retrospective cohort study of 44 992 individuals suggests that FPG level, age, BMI, and male sex were all associated with development of diabetes, with significant interaction between these variables. These data contribute to understanding the clinical course of diabetes and highlight the substantial individual variation in diabetes risk according to commonly measured clinical variables. The findings facilitate lifestyle and pharmacologic interventions to treat those at highest risk of diabetes to reduce future morbidity and mortality. Further work is needed to validate this risk categorization tool for different populations.

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the ASCO Guidelines Methodology Manual . ASCO Guidelines follow the ASCO Conflict of Interest Policy for Clinical Practice Guidelines . Clinical Practice Guidelines and other guidance (“Guidance”) provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by clinicians and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and 2 (online only) for more . PURPOSE To provide updated guidance regarding neoadjuvant chemotherapy (NACT) and primary cytoreductive surgery (PCS) among patients with stage III-IV epithelial ovarian, fallopian tube, or primary peritoneal cancer (epithelial ovarian cancer [EOC]). METHODS A multidisciplinary Expert Panel convened and updated the systematic review. RESULTS Sixty-one studies form the evidence base. RECOMMENDATIONS Patients with suspected stage III-IV EOC should be evaluated by a gynecologic oncologist, with cancer antigen 125, computed tomography of the abdomen and pelvis, and chest imaging included. All patients with EOC should be offered germline genetic and somatic testing at diagnosis. For patients with newly diagnosed advanced EOC who are fit for surgery and have a high likelihood of achieving complete cytoreduction, PCS is recommended. For patients fit for PCS but deemed unlikely to have complete cytoreduction, NACT is recommended. Patients with newly diagnosed advanced EOC and a high perioperative risk profile should receive NACT. Before NACT, patients should have histologic confirmation of invasive ovarian cancer. For NACT, a platinum-taxane doublet is recommended. Interval cytoreductive surgery (ICS) should be performed after ≤four cycles of NACT for patients with a response to chemotherapy or stable disease. For patients with stage III disease, good performance status, and adequate renal function treated with NACT, hyperthermic intraperitoneal chemotherapy may be offered during ICS. After ICS, chemotherapy should continue to complete a six-cycle treatment plan with the optional addition of bevacizumab. Patients with EOC should be offered US Food and Drug Administration–approved maintenance treatments. Patients with progressive disease on NACT should have diagnosis reconfirmed via tissue biopsy. Patients without previous comprehensive genetic or molecular profiling should be offered testing. Treatment options include alternative chemotherapy regimens, clinical trials, and/or initiation of end-of-life care. Additional information is available at www.asco.org/gynecologic-cancer-guidelines . This guideline has been endorsed by the Society of Gynecologic Oncology.

Abstract Background Tumor necrosis factor-like ligand 1A (TL1A) is upregulated in inflammatory bowel disease and believed to promote inflammation and intestinal fibrosis. RO7790121, an anti-TL1A antibody, showed promising results in the phase IIa TUSCANY trial.1 Here we report post-hoc analyses of patient-reported outcomes from the TUSCANY-2 trial. Methods This phase IIb, multicenter, randomized, double-blind, treat-through, dose-ranging study evaluated RO7790121 in patients (pts) aged 18–75 years with moderately to severely active ulcerative colitis (UC) (total Mayo score [MS] ≥6, endoscopic subscore ≥2). Pts were randomized to receive subcutaneous (SC) RO7790121 50mg, 150mg, 450mg or matched placebo (PBO) monthly during the 12-week induction period, and SC RO7790121 50mg, 150mg or 450mg monthly during the 40-week treat-through maintenance period. To assess efficacy of RO7790121 in supporting pts achieving early symptomatic improvement, rectal bleeding (RB), stool frequency (SF) and partial modified MS (RB+SF) were evaluated at baseline and Weeks 2, 4, 8, 12 and 14. The exploratory endpoint of symptomatic remission, defined as a RB subscore of 0 and a SF subscore of 0 or 1, was assessed throughout induction. Safety was assessed throughout the study. Results Overall, 245 pts received ≥1 dose of RO7790121 or PBO. At Week 2, pts receiving RO7790121 were more likely to report a RB subscore of 0 (34% RO7790121; 20% PBO) and less likely to report a RB subscore of 2 or 3 (25% RO7790121; 40% PBO) (Figure). Improvements in SF increased from Week 2 and throughout induction, with ~60% of pts receiving RO7790121 reporting a SF subscore of 0 or 1 at Weeks 12 and 14, vs ~40% for PBO. Greater rates of symptomatic remission were observed in pts receiving RO7790121 vs PBO throughout induction and from Week 2 (17.5% RO7790121; 8.9% PBO) (Table). Treatment-emergent adverse events (TEAEs) were reported during induction in 117/245 pts, the most common (reported in ≥5% of pts in any treatment group) were nausea, urinary tract infection and UC (highest in the 50mg arm), anemia (highest in the placebo arm) and fatigue, headache and pyrexia (highest in the 450mg arm). Serious TEAEs were reported in ten pts during induction (PBO=4; 50mg=3; 450mg=3); two were treatment related (PBO=1; 450mg=1). There were six treatment discontinuations due to TEAEs and a generally similar safety profile was observed during the maintenance period. Conclusion Greater and earlier improvements in RB and SF were observed in pts receiving RO7790121 vs PBO. These results indicate early symptom relief and a favorable safety profile for pts treated with RO7790121, supporting its further clinical development. RO7790121 is currently being evaluated in phase III studies (NCT06589986 and NCT06588855). References 1.Danese S, Klopocka M, Scherl EJ, et al. Anti-TL1A antibody PF-06480605 safety and efficacy for ulcerative colitis: A phase 2a single-arm study. Clin GastroenterolHepatol. 2021;19(11):2324-2332.e6. http://doi.org/10.1016/j.cgh.2021.06.011