Citations

PURPOSE Patients with advanced biliary tract cancers (BTCs) have a dismal prognosis. This multisite, single-institution study analyzed the efficacy and safety of immune checkpoint inhibitors (ICIs) in patients with advanced BTC. MATERIALS AND METHODS The prospectively maintained institutional database was searched for patients with advanced BTC. Electronic medical records of the patients with advanced BTC treated with an ICI that included programmed death-1 or programmed death-ligand 1 blockers were retrospectively reviewed to obtain data on patient characteristics, tumor characteristics including molecular biomarkers, detailed treatment, response characteristics, survival, and toxicities. The analysis included overall response rate, survival, and correlation between survival and molecular biomarkers. RESULTS The institutional database query identified 47 patients with advanced BTC who received at least one dose of an ICI; 11 (24%) patients in the first-line setting and the rest of the patients had refractory disease. The median age of the cohort was 62 years, and 51% were female. The overall response rate was 10.6%, with a disease control rate of 53.2%. The median progression-free survival (PFS) and overall survival were 3.6 months and 6.9 months, respectively. Biomarker analysis revealed improved PFS in patients with tumor mutational burden > 5 mutations per megabase (median PFS: 6.4 v 2.2 months; P = .0027). No unexpected adverse events were observed. CONCLUSION ICIs are well tolerated and have modest antitumor activity in patients with advanced BTC. The study result supports the exploration of tumor mutational burden as a potential predictive biomarker for response to ICIs in patients with advanced BTC.

Abstract Background: Sarcopenia is one of the early pathological features of cancer cachexia, yet the effect of sarcopenia on clinical outcomes in patients with advanced HCC is unclear. Our objective was to determine the effect of Sarcopenia on response to systemic therapy with advanced HCC. Methods: Patients with unresectable and advanced liver cancer were retrospectively evaluated between 2010 to 2019. Skeletal muscle area (SMA) was computed with a previously validated computed tomography (CT) body composition AI algorithm. The skeletal muscle index (SMI) was derived from the skeletal muscle area (SMA) (cm2) divided by patient height (m2) calculated from images at the level of L3 on pretreatment CT. Sarcopenia cutoffs for females was less than 39 cm2/m2 SMI or less than 50 cm2/m2 SMI for males. Patients’ demographics, systemic treatment response, toxicity, progression-free survival (PFS) and overall survival (OS) were compared between first-line therapy groups. Kaplan-Meier and Cox proportional hazards regression were used for survival analysis comparisons. Results: A total of 146 patients with advanced HCC were assessed from Mayo Clinic Arizona and Emory University. Seventy-six patients received immunotherapy as first-line treatment and seventy patients received TKI as first-line therapy. Sarcopenia at baseline was assessed in a total of 91 patients at first-line systemic treatment: n=48 with immunotherapy (IO) and n=43 with tyrosine kinase inhibitor (TKI). Sarcopenia was more prevalent in male patients (p=0.009), and in patients with low BMI (p=0.02). When comparing those with sarcopenia at baseline, higher response rate was observed in patients treated with IO without sarcopenia (47% versus 15%, p=0.019), this was not observed in TKI group. Interestingly, median PFS and OS was not significantly changed in patients with or without sarcopenia treated with IO or TKI on first-line therapy. Conclusions: Sarcopenia was associated with reduced response rate (RR) in patients treated with IO, but not in TKI groups. Both didn’t translate into deleterious effect in PFS and or OS. Further research with sufficient adjustments for confounding factors is warranted to better elucidate the prognostic value of sarcopenia in these patients. Citation Format: Gehan Botrus, Pedro Luiz Serrano Uson Junior, Heidi Kosiorek, Mehmet Akce, Isabela Chang, Zhubene Mesbah, Eric Yancey, Daniel Blezek, Jason Klug, Lana Khalil, Puneet Raman, Mohamad Sonbol, Mitesh Borad, Daniel Ahn, Tanios Bekaii-Saab. Prognostic impact of Sarcopenia on clinical outcomes in advanced hepatocellular carcinoma (HCC) treated with systemic therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6274.

Abstract Background: Cholangiocarcinoma is an aggressive malignancy with limited systemic therapeutics. We have recently identified LCK, a non-receptor tyrosine kinase, as a potential therapeutic target in select subtypes of cholangiocarcinoma. Proteomic profiling in other cancer types has proven beneficial in predicting response to systemic therapies. Herein, we present proteomic profiling of cholangiocarcinoma can predict sensitivity to a novel LCK inhibitor in patient derived xenograft models. Methods: Proteins from 28 unique cholangiocarcinoma patient derived xenograft models (PDX) were isolated, labeled with tandem mass tags (TMT) and then analyzed by liquid chromatography and mass spectroscopy (LC/MS). Phosphopeptides were separately evaluated both by Immobilized Metal Affinity Chromatography and pY-enrichment techniques. Following normalization, the global proteome, serine/threonine phosphoproteome, and tyrosine phosphoproteome were analyzed and a proteomic signature was created for each tumor. These signatures were compared to PDX models with known response profiles to NTRC0652-0, an LCK inhibitor (1 resistant and 1 sensitive). The top 200 differentially abundant proteins (log2FC 2.6) were then utilized to develop a sensitive and a resistant signature. Correlation indices were then calculated across the 28 PDX model library. An additional predicted resistant and predicted sensitive model was expanded. Tumor bearing mice were randomized based on tumor volume to either treatment with NTRC (30mg/kg PO daily), n=5, or vehicle, n=4, (10% Kolliphor, 10% DMSO, 80% Water, 2 mol equivalents HCl). Tumors were measured weekly with calipers and then weighed at the end of the study. Results: In the top 200 differentially abundant proteins that represented the proteomic signature there was over representation of proteins with decreased abundance. There were only 12 proteins with higher abundance in the sensitive model as compared to the resistant. Utilizing the signature developed from the global proteomics data, nine tumors were predicted to be sensitive while 17 were predicted to be resistant to NTRC. PDX115 is a an intrahepatic CCA PDX known to contain an IDH1 mutation and was predicted to be resistant by modeling. The model was resistant to single agent NTRC with no demonstrable effect on tumor growth in vivo. PDX175 is a distal CCA PDX and was predicted to be sensitive by modeling. In vivo growth was inhibited by NTRC as compared to vehicle treated mice following two weeks of treatment (983% vs 435%, p=0.03). Additionally, final tumor weight was significantly lower in NTRC treated mice (0.651 g vs 0.317 g, p=0.04). Conclusion: Cholangiocarcinoma proteomic signatures can be used to predict therapeutic response to a novel LCK inhibitor in preclinical models. Whether or not this could be applied to other treatment modalities in cholangiocarcinoma remains to be determined. Citation Format: Ryan Watkins, Roberto Alva-Ruiz, Caitlin Conboy, Dong-Gi Mun, Erik Jessen, Diep Vu, Jos de Man, Rogier Buijsman, Akhilesh Pandey, Mitesh Borad, Gregory Gores, Rory Smoot. Proteomic profiling of cholangiocarcinoma predicts response to a novel small molecule inhibitor in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3094.

Abstract Gallbladder cancer (GBC) is one of the deadliest cancers, with a 5-year-survival-rate of less than 5 percent for late-stage disease. The response rate to chemotherapy among GBC patients is generally poor. Recent research has attempted to identify diagnostic, prognostic, and predictive biomarkers, however, currently, no biomarkers can accurately diagnose GBC and predict patients’ prognosis. Integrative analysis of molecular and clinical characterization has not been fully established, and minimal improvement has been made to the survival of these patients, in part due to the heterogeneity of GBC. Machine learning techniques have been proven to empower analysis of big data in oncology, allowing for improvement in the generation of biomarkers to predict patient outcomes. Using machine learning, we can utilize high-throughput RNA sequencing with clinicopathologic data to develop a predictive tool for GBC prognosis. Current predictive models for GBC outcomes often utilize clinical data only, with the highest C-statistic reported being 0.71. C-statistic values over 0.7 generally indicate good models, however 0.8 is the threshold for strong predictive models. We aim to build a superior algorithm to predict overall survival in GBC patients with advanced disease, using machine learning approaches to prioritize biomarkers for GBC prognosis. We have identified over 80 fresh frozen GBC tissue samples from Mayo Clinic Rochester, Dongsan Medical Center in Daegu, Korea, University of the Witwatersrand, in Johannesburg, South Africa, Lithuanian University of Health Science in Vilnius, Lithuania, and University of Calgary in Calgary, Canada, from patients enrolled between 2012 and 2021. We will perform next-generation RNA sequencing on these tissue samples. The patients’ clinical, pathologic and survival data will be abstracted from the medical record uniformly across sites. Feature engineering and dimensionality reduction will be performed. Then random forests, support vector machines, and gradient boosting machines will be applied to train the data. Variable importance will prioritize multi-omic markers. Standard 5-fold cross validation will be used to assess performance of each ML algorithm. If overall survival can be better predicted with the addition patients’ transcriptional sequencing data compared to using clinical profiles alone, we can gain a greater understanding of key biomarkers driving the tumor phenotype. Citation Format: Linsey Jackson, Loretta Allotey, Valles Kenneth, Gavin Oliver, Asha Nair, Daniel O'Brien, Rondell Graham, Mitesh Borad, Arjun Athreya, Lewis Roberts. Prognostic biomarkers for gallbladder cancer: A machine learning approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1944.

e16168 Background: Several fibroblast growth factor receptor (FGFR) inhibitors have been recently approved or are in development for the treatment of cholangiocarcinoma (CCA) with FGFR2 fusions/rearrangements (f/r), such as the ATP-competitive inhibitors pemigatinib and infigratinib (FDA-approved in 2020/2021) and the covalent inhibitor futibatinib, which has shown efficacy in a pivotal phase 2 trial. To inform future evaluations of the impact of these agents in clinical practice, and understand other existing gaps in care, we investigated the characteristics and clinical management of patients with CCA and FGFR2 f/r prior to 2021. Methods: This real-world, retrospective cohort study used de-identified, patient-level electronic health records data from Cancer Treatment Centers of America (CTCA) to identify adults with a diagnosis of advanced intrahepatic CCA (iCCA) who received genomic testing between 2013-2021. Clinical/demographic characteristics, time to genomic testing, treatment patterns, and outcomes of patients with and without FGFR2 f/r were described. Results: 23 patients with FGFR2 f/r and 88 with FGFR wild-type (wt) iCCA were identified. Compared to FGFR wt, FGFR2 f/r had a higher proportion of female (65.2 vs 45.5%) and Black (39.1 vs 18.2%) patients (Table). Mean age at diagnosis was ̃60 y and >60% were diagnosed with stage 4 disease in both cohorts; 91.3% of f/r and 78.4% of wt patients had an ECOG PS 0/1. Median time from diagnosis to genomic testing was ̃5 mo; upon entry to CTCA, median time to testing was <2 mo. 17/23 patients in the f/r cohort had FGFR2 fusions (4 BICC1, 13 other). Three FGFR2 f/r patients received an FGFR inhibitor (pemigatinib) as next treatment after testing in 2020. A trend towards longer median overall survival in the f/r vs wt group (24.5 vs 17.8 mo), and a correlation of survival with ECOG PS were observed. Conclusions: This analysis provides insight into the real-world characteristics, clinical management and outcomes among patients with iCCA and FGFR2 f/r, predominantly prior to the introduction of FGFR inhibitors, providing a baseline for further study as the treatment landscape evolves. Of note, the time lag between diagnosis and genomic testing before entry to CTCA underlines the need for earlier testing to guide optimal therapy in clinical practice. [Table: see text]

4079 Background: HER2 mutations are infrequent genomic events in biliary tract cancers (BTCs) and are associated with poor overall survival (OS) in patients with metastatic disease. HER2 overexpression is associated with an increased risk of disease recurrence in patients with resected BTC. There is limited data on targeting HER2 in BTC harboring activating somatic HER2 mutations. Neratinib, an irreversible, pan-HER, oral tyrosine kinase inhibitor, interferes with constitutive receptor kinase activation and has demonstrated activity in several HER2-mutant solid tumors. Methods: SUMMIT is an open-label, single-arm, multi-cohort, phase 2, ‘basket’ trial of neratinib in patients with solid tumors harboring oncogenic HER2 somatic mutations. The primary objective of the BTC cohort was to estimate objective response rate (ORR). Secondary objectives were clinical benefit rate (CBR), progression-free survival (PFS), OS, response duration, safety, and tolerability. Retrospective central confirmation of locally reported HER2 mutation (next-generation sequencing on archival or fresh tumor tissue using MSK-IMPACT or in cfDNA extracted from plasma by MSK-ACCESS) and association with outcome was an exploratory endpoint. This trial is registered with ClinicalTrials.gov (NCT01953926). Results: 25 treatment-refractory patients with metastatic BTC were enrolled (11 cholangiocarcinoma, 10 gallbladder, 4 ampullary cancers). ORR was 16% (95% CI 4.5–36.1%) and CBR was 28% (95% CI 12.1–49.4%). Median PFS and OS were 2.8 (95% CI 1.1–3.7) and 5.4 (95% CI 3.7–11.7) months, respectively. Median PFS for the gallbladder, cholangiocarcinoma and ampulla cohorts was 3.7 (95% CI 0.8–6.4), 1.4 (95% CI 0.5–9.1), and 1.1 (95% CI 1.1–3.8) months, respectively. Corresponding median OS values in these cohorts were 9.8 (95% CI 2.4–NE), 5.4 (95% CI 0.8–16.2), and 5.0 (95% CI 3.7–10.2) months, respectively. Central mutation confirmation was feasible for 23 of 25 patients; 22 were concordant with enrolment assays. The most common HER2 mutations were S310F (n = 11; 48%) and V777L (n = 4; 17%). Exploratory analyses suggested worse outcomes for HER2-mutant tumors with co-occurring oncogenic TP53 and CDKN2A alterations. Loss of amplified HER2 S310F and acquisition of multiple previously undetected oncogenic co-mutations were identified at progression in one of four responders. Diarrhea (56% any grade) was the most common toxicity. Conclusions: Neratinib is tolerable with modest antitumor activity in patients with BTC harboring HER2 mutations. Although the primary endpoint was met, future studies should evaluate rational combinations to augment and/or prolong responses. Clinical trial information: NCT01953926.

TPS2676 Background: Solid tumors comprise > 90% of cancers. Metastatic colorectal cancer, non-small cell lung cancer, and pancreatic cancer are among the leading causes of cancer-related mortality (5-year overall survival: 14%, 6%, and 3%, respectively) (ACS. 2021). Chimeric antigen receptor (CAR) T-cell therapy has demonstrated clinical efficacy in hematologic malignancies (Neelapu S. et al. N Engl J Med. 2017). Translating engineered T-cell therapies to solid tumors has proven to be challenging due to a lack of tumor-specific targets that can discriminate cancer cells from normal cells. Previous studies using carcinoembryonic antigen (CEA) T-cell receptors and mesothelin (MSLN) CARs resulted in dose-limiting on-target, off-tumor toxicities (Parkhurst M, et al. Mol Ther. 2011; Tanyi J. Cellicon Valley '21). To create a therapeutic safety window, Tmod CAR T-cell therapy utilizes dual-signaling receptors to create a robust NOT logic gate capable of killing tumor cells, while leaving healthy cells intact (Hamburger A, et al. Mol Immunol. 2020). The 2 receptors in Tmod CAR T-cell therapy comprise an activator that recognizes an antigen on the surface of tumor cells that may also be present on normal cells, such as CEA and MSLN, and a blocker that recognizes a second surface antigen from an allele lost only in tumor cells. The frequency of HLA LOH among advanced GI solid tumor cancers in the Tempus real-world dataset is 16.3% with a range of 15.6%-20.8% between colorectal, pancreatic, and gastroesophageal tumors (Hecht R. et al. ASCO-GI 2022. Abstract #190). As such, HLA LOH offers a definitive tumor versus normal discriminator target for CAR T-cell therapy. Different activator/blocker combinations can be engineered with the Tmod platform technology and may be applied to T cells and natural killer cells in autologous and allogeneic settings. BASECAMP-1 is a currently enrolling observational study with key objectives of 1) To identify patients with somatic HLA LOH eligible for Tmod CAR T-cell therapy, and 2) To obtain leukapheresis and feasibility for the future EVEREST Tmod CAR T-cell trial. Methods: BASECAMP-1 (NCT04981119) patient eligibility has 2 parts: 1) Patients will be initially screened to identify germline HLA-A*02 heterozygosity by central NGS. If HLA-A*02 heterozygosity is confirmed, primary archival tumor tissue will be analyzed for somatic mutations by xT-Onco NGS testing. 2) If the tumor demonstrates HLA-A*02 LOH and the patient is eligible after screening, the patient will undergo leukapheresis. Banked T cells will be available for the autologous EVEREST Tmod CAR T-cell therapy interventional study to reduce waiting time at relapse. Clinical trial information: NCT04981119.

TPS2670 Background: Tumor necrosis factor receptor-2 (TNFR2) is expressed on effector CD8+ T cells, CD4+ T cells, T regulatory cells, natural killer cells, and myeloid cells. Targeting TNFR2 is anticipated to yield effective anti-tumor immunity by stimulating T-cell and NK-cell activation and proliferation in the tumor microenvironment. HFB200301 is a first-in-class anti-TNFR2 agonistic monoclonal antibody that triggers both innate and adaptive immune stimulation by binding to a specific epitope on TNFR2. HFB200301 has demonstrated dose-dependent anti-tumor activity in human TNFR2 knock-in mice bearing MC38 and Hepa1-6 syngeneic tumors. Methods: HFB200301 is being evaluated in a first-in-human, open-label, multi-center, dose escalation and expansion study in adult patients with advanced solid tumors. A single-cell immune profiling platform, DIS, was deployed to identify unique tumor-infiltrating T cell signatures that could help optimize patient selection for HFB200301 treatment. It is hypothesized that the presence of an effector T cell subpopulation that express both TNFR2 and CD8A in solid tumors may represent a tumor microenvironment favorable to TNFR2 agonism. The following cancer indications have been identified based on the prevalence of a TNFR2 high/CD8 high signature: Epstein-Barr Virus positive (EBV+) gastric cancer, clear cell renal cell carcinoma (ccRCC), cutaneous melanoma, testicular germ cell tumor (TGCT), soft tissue sarcoma (STS), and PD-L1+ cancers: cervical cancer, pleural mesothelioma, lung adenocarcinoma, and head and neck squamous cell carcinoma (HNSCC). The escalation portion of the study explores increasing doses in cohorts of up to six patients, utilizing mTPI-2 design to determine recommended dose(s) for expansion (RDE(s)). Based on pharmacokinetic modeling to maximize HFB200301 activity, 60-minute intravenous infusions of HFB200301 are administered every 4 weeks. Once RDE(s) is determined, expansion into three indication-specific cohorts is planned to determine the recommended phase 2 dose (RP2D). Key eligibility criteria include histologically documented advanced or metastatic solid tumors in the above listed indications. Patient enrollment opened in February 2022 in the USA, with plans for additional clinical sites in Spain and China. The primary objective is to identify the RDE, characterize safety and tolerability of HFB200301, and determine RP2D. Secondary objectives include pharmacokinetic parameters, preliminary evidence of anti-tumor efficacy (e.g., ORR, DCR, DOR) and pharmacodynamic evaluation (e.g., T cell subsets) in the blood and in the tumor. Furthermore, a potential predictive biomarker signature derived based on the DIS single-cell immune profiling approach will be investigated retrospectively. Clinical trial information: NCT05238883.

PURPOSE This investigation sought to evaluate the prognostic value of pretreatment of circulating tumor DNA (ctDNA) in metastatic biliary tract cancers (BTCs) treated with platinum-based first-line chemotherapy treatment. MATERIALS AND METHODS We performed a retrospective analysis of 67 patients who underwent ctDNA testing before platinum-based chemotherapy for first-line treatment for metastatic BTC. For analysis, we considered the detected gene with highest variant allele frequency as the dominant clone allele frequency (DCAF). Results of ctDNA analysis were correlated with patients' demographics, progression-free survival (PFS), and overall survival (OS). RESULTS The median age of patients was 67 (27-90) years. Fifty-four (80.6%) of 67 patients evaluated had intrahepatic cholangiocarcinoma; seven had extrahepatic cholangiocarcinoma, and six gallbladder cancers. Forty-six (68.6%) of the patients were treated with cisplatin plus gemcitabine, and 16.4% of patients received gemcitabine and other platinum (carboplatin or oxaliplatin) combinations, whereas 15% of patients were treated on a clinical trial with gemcitabine and cisplatin plus additional agents (CX4945, PEGPH20, or nab-paclitaxel). TP53, KRAS, FGFR2, ARID1A, STK11, and IDH1 were the genes with highest frequency as DCAF. The median DCAF was 3% (0%-97%). DCAF > 3% was associated with worse OS (median OS: 10.8 v 18.8 months, P = .032). Stratifying DCAF in quartiles, DCAF > 10% was significantly related to worse PFS (median PFS: 3 months, P = .014) and worse OS (median OS: 7.0 months, P = .001). Each 1% increase in ctDNA was associated with a hazard ratio of 13.1 in OS when adjusting for subtypes, metastatic sites, size of largest tumor, age, sex, and CA19-9. CONCLUSION DCAF at diagnosis of advanced BTC can stratify patients who have worse outcomes when treated with upfront platinum-based chemotherapy. Each increase in %ctDNA decreases survival probabilities.

Abstract HER2 mutations are infrequent genomic events in biliary tract cancers (BTCs). Neratinib, an irreversible, pan-HER, oral tyrosine kinase inhibitor, interferes with constitutive receptor kinase activation and has activity in HER2-mutant tumours. SUMMIT is an open-label, single-arm, multi-cohort, phase 2, ‘basket’ trial of neratinib in patients with solid tumours harbouring oncogenic HER2 somatic mutations (NCT01953926). The primary objective of the BTC cohort was objective response rate (ORR). Among 25 treatment-refractory patients (11 cholangiocarcinoma, 10 gallbladder, 4 ampullary cancers), the ORR was 16%. The most common HER2 mutations were S310F (n = 11; 48%) and V777L (n = 4; 17%). Outcomes appeared worse for ampullary tumours or those with co-occurring oncogenic TP53 and CDKN2A alterations. Loss of amplified HER2 S310F and acquisition of multiple previously undetected oncogenic co-mutations were identified at progression in one responder. Neratinib demonstrated anti-tumour activity in patients with refractory BTC harbouring HER2 mutations. Future studies of rational combinations are warranted.