Azad, Nilofer S.

Abstract Purpose: The addition of MEK inhibition (MEKi) to programmed cell death ligand 1 (PD-L1) blockade improves progression-free survival (PFS) in patients with advanced biliary tract cancer. Although MEK inhibitors may increase tumor cell immunogenicity, they can impair T-cell priming/effector function, limiting combination efficacy. We hypothesized that the addition of a CD27 agonist could restore T-cell function and enhance antitumor immunity in this combination. Patients and Methods: We conducted a randomized, phase II trial evaluating atezolizumab (840 mg, intravenously, days 1 and 15) in combination with the CD27 costimulatory monoclonal antibody [CDX-1127/varlilumab (3 mg/kg, intravenously, days 1 and 15)], with/without the addition of an MEK inhibitor [cobimetinib (60 mg, orally, daily, days 1–21, off days 22–28)] in unresectable biliary tract cancer following at least one metastatic therapy. Overall response rate (ORR) and PFS were coprimary endpoints. Treatment-related changes in CD8+ tumor-infiltrating lymphocytes (TIL) were the primary correlative outcomes. Results: The trial was closed early following interim preplanned ORR analysis. At closure, 57 patients had been enrolled [n = 29 in the cobimetinib + atezolizumab + varlilumab (CAV) arm; n = 28 in the atezolizumab + varlilumab (AV) arm]. A majority (67%) had intrahepatic cholangiocarcinoma, and 32% were immunotherapy experienced. Both regimens were well tolerated without new safety signals. Objective responses were rare [0% (CAV); 3.8% (AV)]. The median PFS (mPFS) was 2.40 (CAV) and 1.84 (AV) months [hazard ratio (HR), 0.67; 95% confidence interval (CI), 0.38–1.18]. Among immunotherapy-experienced patients, the mPFS was 3.62 (CAV) and 1.84 (AV) months (HR, 0.54; 95% CI, 0.18–1.62). Treatment with CAV increased intratumoral CD8+ T-cell density compared with treatment with AV. Conclusions: The combinations of atezolizumab and varlilumab with/without cobimetinib were safe, but neither meaningfully improved outcomes in biliary tract cancer treated in the later lines. Correlative tissue studies validated preclinical work that MEKi increases CD8+ TILs.

Abstract Background TOPAZ-1 demonstrated durvalumab + gemcitabine and cisplatin (GemCis) superiority over GemCis in first-line treatment of advanced biliary tract cancers. Real-world data from US patients and patients excluded from TOPAZ-1 (patients with autoimmune conditions [AICs] who did not receive immunotherapy) are lacking. We report real-world data for patients with cholangiocarcinoma treated with durvalumab + GemCis. Methods This retrospective, observational study enrolled adult patients diagnosed with cholangiocarcinoma in the US from the International Cholangiocarcinoma Patient Registry (ICPR) treated with first-line durvalumab + GemCis between 2021–2023. De-identified medical records from ICPR were obtained directly from consenting patients/caregivers. Patient demographics and tumor characteristics (primary objective; assessed at initial diagnosis), comorbidities, second-line treatment modalities, median real-world overall survival (mrwOS), and median real-world time to next treatment (mrwTTNT; initiation of first-line treatment and last activity in the database or death) are reported. Results Seventy patients received first-line durvalumab + GemCis: 13 (18.6%) had AIC(s) and 57 (81.4%) did not. Patient demographics, clinical characteristics, and comorbidities are shown (Table). Median (quartile 1–3) time from diagnosis to start of first-line treatment was 1.0 (0.7–1.7) months; median follow-up from first dose of first-line treatment was 7.0 (3.7–12.1) months. The mrwOS (95% CI) was 15.5 (15.1–not evaluable [NE]) months. mrwTTNT (95% CI) was 10.8 (10.4–15.7) months overall and was 20.8 (10.4–NE) months in patients who died without receiving subsequent treatment (censored at date of last activity). Among patients with AIC(s), <5 received second-line therapy (all received chemotherapy alone). Among patients with no AICs, 15 received second-line treatment; 11 (73.3%) received targeted therapy alone and <5 received chemotherapy alone. Conclusions This dataset demonstrates patients with AIC(s) are treated with durvalumab + GemCis in clinical practice. The mrwOS for durvalumab + GemCis in this patient population is consistent with TOPAZ-1 and global real-world studies.

Abstract Background & Objectives Based on the TOPAZ-I study, durvalumab combined with gemcitabine and cisplatin (GemCis) is now supported as a standard of care treatment for cholangiocarcinoma. Patients with extrahepatic cholangiocarcinoma (eCCA) often have underlying autoimmune conditions (AICs) which could restrict immunotherapy use. Treatment patterns in patients with eCCA with AICs and non-autoimmune conditions (NAICs) are reported. Method This retrospective observational analysis of adult patients diagnosed with eCCA in the United States enrolled in the International Cholangiocarcinoma Patient Registry between 2019 and 2023, focused on those treated with durvalumab. The registry contains de-identified data from medical records obtained directly from consenting patients and caregivers. Patients were followed from index date (date of eCCA diagnosis) until the last activity in the database or death. Demographics, clinical characteristics, biomarkers, treatment patterns, and adverse events (AEs) are reported. Results Overall, 135 patients with eCCA were enrolled: 24 (17.8%) had 2:1 AICs and 111 (82.2%) had NAICs. Baseline demographics were comparable between groups: the median (quartile [Q]l-Q3) age at diagnosis was 63.0 (55.0-70.0) years, the mean number of comorbidities in the overall population was 10.1, and 50.4% of patients were female. PD-Ll positivity was noted in 12.6% of patients and HER2 positivity in 10.4%. Of 91 patients with eCCA who received first-line therapy, 34 (37.4%) received GemCis alone, 27 (29.7%) chemotherapy alone (non-GemCis +/- nab-paclitaxel), 9 (9.9%) GemCis plus nab-paclitaxel, 7 (7.7%) durvalumab plus GemCis, 7 (7.7%) durvalumab monotherapy or in combination, and 7 (7.7%) other regimens. Treatment patterns by autoimmune comorbidity status are also reported (Table). Overall, 129 patients (95.6%) had ≥1 AE; fatigue was the most common (71.1%). Conclusion More patients with eCCA received a first-line durvalumab-based regimen post-March 2022 vs the full study period. The use of durvalumab as first-line treatment in this subgroup may suggest that AICs do not restrict its use.

Abstract Background Eligibility criteria for clinical trials are crucial for maintaining safety and study integrity. However, overly restrictive criteria can result in unrepresentative trial populations, leading to gaps in understanding real‐world treatment efficacy. Addressing potentially modifiable exclusions (PMEs) could enhance trial accessibility and participation without compromising safety. Methods The authors retrospectively analyzed screen‐failed patients with biliary tract cancer or pancreatic cancer between August 2019 and November 2024 at The University of Texas MD Anderson Cancer Center. Screen‐failed patients were those who provided informed consent but did not participate for any reason. Clinical data were obtained from screening logs and electronic health records. PMEs were identified and validated by two independent medical oncologists. Results Of 585 screen‐failed patients from 18 trials, 509 were analyzed (367 with pancreatic cancer and 142 with biliary tract cancer) after excluding 76 because of incomplete data. Leading causes of screen failure were declined participation (19%), comorbidities (12%), suboptimal organ function (11%), absence of a biomarker (10%), and insufficient biospecimens (7%). Reasons for declining included preference for standard care (23%), travel (22%), and competing trials (5%). The authors identified 69 patients (13.6%) who had PMEs (primarily borderline laboratory abnormalities), including liver function (23%), kidney function (20%), platelet count (12%), hemoglobin (7%), and white blood cell count (6%) abnormalities. Other PMEs included previous or concurrent malignancies (9%) and viral hepatitis (4%). PMEs were evenly distributed across trials. Conclusions Rigid eligibility criteria exclude stable patients who might benefit from investigational treatments. Easing criteria related to incidental or asymptomatic laboratory abnormalities could broaden trial accessibility and improve enrollment in populations that are more representative of real‐world use.

Abstract Purpose: Isocitrate dehydrogenase (IDH) 1/2–isoform inhibitors have clinical efficacy in IDH1/IDH2-mutated neoplasms. However, primary resistance and secondary resistance limit their therapeutic potential. LY3410738, an oral, brain-penetrant, dual IDH1/IDH2-mutated isoform-selective inhibitor, was designed to overcome resistance. Patients and Methods: This global, multicenter, open-label, phase I study of patients with IDH-mutant solid tumors evaluated LY3410738 as monotherapy (dose escalation) for advanced solid tumors in combination with cisplatin–gemcitabine (CISGEM) for newly diagnosed cholangiocarcinoma or with durvalumab for relapsed/refractory cholangiocarcinoma (dose expansion; NCT04521686). Primary objectives were the maximum tolerated dose, recommended phase II dose, and preliminary antitumor activity. Safety, pharmacokinetics, inhibition of D-2-hydroxyglutarate, and ctDNA were assessed. Results: Overall, 119 patients received LY3410738 alone (N = 94) or in combination with CISGEM (N = 19) or durvalumab (N = 6). No dose-limiting toxicities were observed; the maximum tolerated dose was not determined. Common adverse events included nausea, vomiting, and decreased appetite. Overall response rates of 5.2% and 11.1% and disease control rates of 56.9% and 63.0% were observed for patients with relapsed/refractory IDH1- or IDH2-mutant cholangiocarcinoma or IDH1-mutant glioma, respectively. D-2-hydroxyglutarate normalization was rapid and durable. In dose-expansion cohorts, combination treatments were tolerable, with one dose-limiting toxicity in the durvalumab cohort. LY3410738 plus CISGEM demonstrated a response rate of 42.1%, a median duration of response of 8.1 months, and a median progression-free survival of 10.2 months for patients with newly diagnosed IDH-mutant cholangiocarcinoma. Conclusions: LY3410738 demonstrated largely cytostatic antitumor activity in IDH1- or IDH2-mutated cholangiocarcinoma and IDH1-mutated gliomas. LY3410738 plus CISGEM exhibited favorable antitumor activity in patients with treatment-naïve IDH-mutated cholangiocarcinoma, warranting further exploration as a treatment strategy.

e23011 Background: Eligibility criteria for clinical trials are crucial for maintaining safety and study integrity. However, they often exclude patients due to medical conditions that are not relevant, leading to gaps in understanding the real-world effectiveness of treatments. Addressing potentially modifiable exclusions (PMEs) could enhance accessibility and participation in trials without compromising safety, particularly given the low rates of enrollment. Methods: We retrospectively analyzed ‘screen-failed’ patients (those who were excluded after providing consent because they did not meet the eligibility criteria or other protocol requirements) with biliary tract (BTC) or pancreatic cancer (PDAC) between August 2019 and November 2024. Screening logs and electronic health records provided clinical data. PMEs were identified and validated by two independent medical oncologists. Results: Of 585 screen-failed patients from 18 trials, 76 were excluded due to incomplete data. Among the 509 patients analyzed (367-PDAC, 142-BTC), the leading causes of screen failure were declined participation (99, 19%), comorbidities (59, 12%), suboptimal organ function (56, 11%), absence of biomarker (49, 10%), and insufficient biospecimens (36, 7%). Among patients declining participation, reasons included preference for standard care (23%), travel (22%), competing trials (5%), adverse event concerns (4%), financial issues (3%), and unknown reasons (43%). Of the 509 patients deemed ineligible for study entry at screening, we identified 69 patients (13.6%) with PMEs, primarily related to borderline laboratory abnormalities: liver function (16, 23%), kidney function (14, 20%), platelet count (8, 12%), hemoglobin (5, 7%), and white blood cell count (4, 6%). Other PMEs included previous or concurrent malignancies (6, 9%) and viral hepatitis (3, 4%). PMEs were evenly distributed across trials. Notably, all screen-failed patients proceeded to receive standard therapy. Conclusions: This analysis underscores the potential for rigid eligibility criteria to exclude stable patients who might benefit from investigational treatments. Easing specific criteria, particularly those related to laboratory abnormalities, could broaden trial accessibility. Furthermore, examining the reasons for declined participation and addressing PMEs could help develop strategies to enhance trial enrollment.

4017 Background: Combined MEK inhibition (MEKi) and PD-L1 blockade significantly improved progression-free survival (PFS) versus PD-L1 monotherapy in patients with advanced biliary tract cancer (BTC) following first-line chemotherapy (NCT03201458). Further study has shown MEKi enhances tumor immunogenicity but impairs host T cell activation/priming. The addition of immune agonists, e.g. a CD27 agonist, can rescue T cell function in the setting of systemic MEKi in vivo and may be an effective strategy to optimize MEKi’s immunomodulatory potential when used in combination with checkpoint blockade. Methods: We conducted a randomized ph 2 trial (NCT04941287) evaluating Atezolizumab in combination with the CD27 immune agonist (CDX-1127 [Varlilumab]) with or without the addition of a MEKi (Cobimetinib) in patients with unresectable, previously treated, BTC. Adults with pathologically-confirmed BTC, s/p at least 1 prior line (no more than 2) of systemic therapy, measurable disease, and ECOG PS ≤1 were enrolled. Patients who had received previous PD-[L]1 were eligible. The study was planned for 64 evaluable subjects randomized in a 1:1 ratio, stratified by BTC site, to either AV (Atezolizumab [840mg IV days 1,15])+ Varlilumab [3mg/kg IV days 1, 15]) or CAV (Cobimetinib [60mg oral daily days 1-21, off 22-28] + Atezolizumab + Varlilumab). Overall response rate (ORR) and PFS were co-primary endpoints. The primary correlative outcome was treatment-related changes in CD8+ infiltrating T cells. Results: A preplanned interim analysis based on objective response rates did not meet the threshold for continuance in either treatment arm, so the trial was closed early for futility. In total, 57 patients were enrolled (n = 29 [CAV], n = 28 [AV], 67% had intrahepatic cholangiocarcinoma, and 33% had received previous PD-[L]1. Both CAV and AV regimens were well-tolerated without new safety signals. Adding CDX-1127 did not appear to meaningful increase immunotoxicity beyond established PD-L1 toxicity profiles. ORR was 0% (CAV) and 4% (AV). With a median follow up time of 6.2 months, median PFS was 2.2 (CAV) and 1.8 (AV) months (HR 0.71 [0.40,1.25]). In PD[L]1-experienced patients, median PFS was 3.6 (CAV) and 1.7 (AV) months (HR 0.44 [0.14,1.33]). Median OS was 10.2 (CAV) and 6.1 (AV) months (HR 0.76 [0.37,1.55]). In PD[L]1-experienced patients, median OS was 6.4 (CAV) and 4.4 (AV) months for CAV and AV (HR 0.68 [0.19,2.42]). Primary correlative endpoint and updated survival will be reported at time of meeting. Conclusions: The combination of Atezolizumab and Varlilumab with or without Cobimetinib was safe but did not improve clinical outcomes in advanced stage BTC patients treated in later lines. Though not statistically significant, treatment with CAV demonstrated numerically favorable PFS/OS compared AV among immunotherapy-experienced patients. Clinical trial information: NCT03201458 .

TPS3160 Background: Patients (pts) with recurrent or metastatic solid tumors, including non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), colorectal cancer (CRC), gastric adenocarcinoma (GC), and pancreatic ductal adenocarcinoma (PDAC), have limited treatment options with short PFS and OS despite recent advances (1-3). Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) is highly expressed across multiple solid tumors, such as CRC, GC, PDAC, and NSCLC. Restricted normal tissue expression and efficient lysosomal trafficking of CEACAM5 highlight its potential as an anticancer target. SGN-CEACAM5C is a novel investigational antibody-drug conjugate (ADC) directed to CEACAM5 composed of the humanized immunoglobulin G (IgG1) anti-CEACAM5 monoclonal antibody tusamitamab chemically conjugated to 8 molecules of the topoisomerase 1 inhibitor 7-aminomethyl-10,11-methylenedioxycamptothecin (AMDCPT). SGN-CEACAM5C selectively binds to CEACAM5 present on the cell surface and is internalized via the endo-lysosomal pathway, with subsequent release of the payload through enzymatic cleavage. Release of the cytotoxic payload induces DNA damage, cell cycle arrest in S phase, and apoptosis in tumor cells. In vitro bystander activity was observed against tumor cells without CEACAM5 surface expression. SGN-CEACAM5C is highly active in multiple patient-derived xenograft models, including CRC, GC, and NSCLC, across various levels of CEACAM5 expression (4,5). These preclinical findings justify evaluation of SGN-CEACAM5C in a clinical trial setting. Methods: SGNCEA5C-001 (NCT06131840) is a phase 1, open-label, multicenter study designed to characterize the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary antitumor activity of SGN-CEACAM5C in adults with select advanced solid tumors. This study consists of dose escalation (Part A), dose and schedule optimization (Part B), and dose expansion (Part C). Eligible pts are adults ≥18 years of age with confirmed metastatic or unresectable solid tumor malignancy, measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, an ECOG PS of 0-1, and 1 of the following tumor types: CRC, GC/gastroesophageal junction adenocarcinoma (GEJ), PDAC, NSCLC (squamous/non-squamous), or SCLC. Primary endpoints include incidence of AEs, laboratory abnormalities, dose modifications due to AEs, dose-limiting toxicities, and cumulative safety. Secondary endpoints include estimates of PK parameters, incidence of antidrug antibodies, objective response rate and best response per RECIST v1.1 by investigator, duration of response, PFS, and OS. Safety and antitumor activity endpoints will be summarized using descriptive statistics. Recruitment is ongoing for Part A in North America. 1. Bordry 2021. 2. Chakrabarti 2022. 3. Merle 2022. 4. Baudat 2023. 5. Baudat 2024. Clinical trial information: NCT06131840 .