Gemcitabine-based Chemotherapy Research Articles

Preliminary response to Tislelizumab plus chemotherapy drugs in patient with periampullary carcinoma: a report of one case and a literature review

Periampullary carcinoma is a malignant gastrointestinal tumor originating from the head of the pancreas, distal bile duct, duodenum, or the ampulla of Vater. Currently, surgery remains the primary treatment option, yet the postoperative recurrence rate remains high. Chemotherapy is the main approach for controlling postoperative recurrence. Histologically, periampullary carcinoma is categorized into two types: intestinal (IN) and pancreaticobiliary (PB) subtype. Each subtype requires different therapeutic approaches, with the PB type primarily treated with gemcitabine and the IN type with 5-FU. Despite these options, patient outcomes are still unsatisfactory. In recent years, the feasibility of immunotherapy in tumor treatment has been increasingly evidenced, although research on its efficacy in periampullary carcinoma treatment is still limited. In this report, we present a case of a periampullary carcinoma patient who experienced recurrence and metastasis after undergoing radical pancreatoduodenectomy and receiving gemcitabine-based chemotherapy post-surgery. Through next-generation sequencing (NGS), we identified high expression levels of programmed cell death-ligand 1 (PD-L1) with a combined positive score (CPS) of 35, high tumor mutation burden (TMB-H), and high microsatellite instability (MSI-H) in this patient. Therefore, we implemented a combination therapy using Tislelizumab and chemotherapy. According to the latest follow-up, the tumors are effectively controlled. Our utilization of immunotherapy combined with chemotherapy holds significant implication for the treatment of periampullary carcinoma.

Preliminary response to Tislelizumab plus chemotherapy drugs in patient with periampullary carcinoma: a report of one case and a literature review

Periampullary carcinoma is a malignant gastrointestinal tumor originating from the head of the pancreas, distal bile duct, duodenum, or the ampulla of Vater. Currently, surgery remains the primary treatment option, yet the postoperative recurrence rate remains high. Chemotherapy is the main approach for controlling postoperative recurrence. Histologically, periampullary carcinoma is categorized into two types: intestinal (IN) and pancreaticobiliary (PB) subtype. Each subtype requires different therapeutic approaches, with the PB type primarily treated with gemcitabine and the IN type with 5-FU. Despite these options, patient outcomes are still unsatisfactory. In recent years, the feasibility of immunotherapy in tumor treatment has been increasingly evidenced, although research on its efficacy in periampullary carcinoma treatment is still limited. In this report, we present a case of a periampullary carcinoma patient who experienced recurrence and metastasis after undergoing radical pancreatoduodenectomy and receiving gemcitabine-based chemotherapy post-surgery. Through next-generation sequencing (NGS), we identified high expression levels of programmed cell death-ligand 1 (PD-L1) with a combined positive score (CPS) of 35, high tumor mutation burden (TMB-H), and high microsatellite instability (MSI-H) in this patient. Therefore, we implemented a combination therapy using Tislelizumab and chemotherapy. According to the latest follow-up, the tumors are effectively controlled. Our utilization of immunotherapy combined with chemotherapy holds significant implication for the treatment of periampullary carcinoma.

Experience of seven Spanish centres with echoendoscopically implanted 32P microparticles associated with chemotherapy in locally advanced pancreatic adenocarcinoma.

e16358 Background: 32P brachytherapy delivered by echoendoscopy (EUS) represents an innovative therapy in locally advanced pancreatic cancer (LAPC). The device to implant it is approved in unresectable LAPC in combination with gemcitabine-based chemotherapy. Our aim is to present the preliminary efficacy and safety results of a series that brings together the experience of seven centres in Spain. Methods: After being assessed by a multidisciplinary committee and meeting eligibility criteria (Table 1), patients signed consent to receive intratumoural 32P by EUS within the international observational registry OSPREY (March 2022-February 2024). Complications associated with intratumoural 32P injection via EUS, associated adverse events (AEs) and preliminary efficacy results (progression-free survival [PFS], distant and locoregional, and overall survival [OS]) were analysed. Results: Thirteen patients (7 females; age 65 years [range 48, 79]; 10 ECOG 1) with unresectable LAPC (7 in head, 3 in uncinate and 3 in body; tumour size 36.8 mm [range 25, 60]) were included. The median time from tumour diagnosis to procedure was 5 months [1.4, 28.9]. Only 4 patients (30 %) had received a previous line of treatment. Eleven patients (85%) received gemcitabine-based chemotherapy concomitant with intratumoural 32P (8 gemcitabine plus nabpaclitaxel; 3 gemcitabine monotherapy). There were no complications or AEs related to 32P injection or EUS. A total of 7 patients (54%) had chemotherapy-related AEs, with 2 cases of G3 neutropenia; 6 had G1-2 toxicities: neutropenia (1), thrombopenia (2), anaemia (1), nausea (1), asthenia (1), diarrhoea (1) and constipation (1). Two patients underwent surgery after intratumoural treatment. With a median follow-up of 17.3 months after injection, 8 patients (61.5 %) have progressed, all of them distantly, and three also locoregionally. The median PFS since 32P injection is 8.4 months (95% CI 2.7, NR). Six patients are alive at the end of follow-up (46.2 %) with a median OS since 32P injection of 13.8 months 95% CI [10, NR]. At data cut-off, five patients remain on-treatment. Conclusions: Our initial experience suggests that intratumoural 32P associated with gemcitabine-based chemotherapy is safe. Patients after 32P injection achieve long overall survival. Our ongoing prospective registry will allow evaluation of the oncological outcomes of this therapy at longer follow-up times. [Table: see text]

TOURMALINE: A phase 3b study of durvalumab with gemcitabine-based chemotherapy regimens in advanced biliary tract cancer.

TPS4188 Background: In the Phase 3 TOPAZ-1 study (NCT03875235), durvalumab plus gemcitabine + cisplatin (GC) significantly improved overall survival (OS) versus placebo + GC in participants with advanced biliary tract cancer (aBTC) with a manageable safety profile. To expand on TOPAZ-1, there is a need to further assess the safety and efficacy of durvalumab in combination with other gemcitabine (G)-based chemotherapy regimens used in aBTC, and in a more diverse population to reflect real-world clinical practice. Methods: TOURMALINE (NCT05771480) is a Phase 3b, single-arm, multicenter, international study. Approximately 140 adults with aBTC (intra- or extra-hepatic cholangiocarcinoma, gallbladder or ampulla of Vater carcinoma) will be enrolled. Key inclusion criteria include unresectable disease (advanced, metastatic), WHO/ECOG PS of 0–2, and no prior systemic therapy. Key exclusion criteria include any prior immune-mediated therapy and history of another primary malignancy. Participants will receive durvalumab 1500 mg IV plus an investigator-selected, G-based background chemotherapy; durvalumab will be administered Q3W when combined with a G-based chemotherapy Q3W (8 cycles of durvalumab) except for when combined with GC + S-1 Q2W, in which case durvalumab will be administered Q4W (4 cycles of durvalumab/8 cycles of chemotherapy). G-based chemotherapy will consist of G monotherapy, GC (for WHO/ECOG PS 2 participants only), G + oxaliplatin, G + carboplatin, GC + S-1, G + S-1, and GC + albumin-bound paclitaxel. Following the treatment period, durvalumab Q4W +/- chemotherapy (except for paclitaxel) may continue, at the investigator’s discretion, until discontinuation criteria are met. The primary endpoint is the incidence of Grade 3 or 4 adverse events, assessed by the investigator to be possibly related to any study treatment within 6 months after initiation of durvalumab. Secondary endpoints include OS, objective response rate, progression-free survival, and duration of response. Enrollment is ongoing and planned in France, Germany, United States, Spain, Italy, Japan, South Korea, and Singapore. Clinical trial information: NCT05771480 .

6:2 Cl-PFESA, a proposed safe alternative for PFOS, diminishes the gemcitabine effectiveness in the treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC)/pancreatic cancer, is a highly aggressive malignancy with poor prognosis. Gemcitabine-based chemotherapy remains the cornerstone of PDAC treatment. Nonetheless, the development of resistance to gemcitabine among patients is a major factor contributing to unfavorable prognostic outcomes. The resistance exhibited by tumors is modulated by a constellation of factors such as genetic mutations, tumor microenvironment transforms, environmental contaminants exposure. Currently, comprehension of the relationship between environmental pollutants and tumor drug resistance remains inadequate. Our study found that PFOS/6:2 Cl-PFESA exposure increases resistance to gemcitabine in PDAC. Subsequent in vivo trials confirmed that exposure to PFOS/6:2 Cl-PFESA reduces gemcitabine’s efficacy in suppressing PDAC, with the inhibition rate decreasing from 79.5 % to 56.7 %/38.7 %, respectively. Integrative multi-omics sequencing and molecular biology analyses have identified the upregulation of ribonucleotide reductase catalytic subunit M1 (RRM1) as a critical factor in gemcitabine resistance. Subsequent research has demonstrated that exposure to PFOS and 6:2 Cl-PFESA results in the upregulation of the RRM1 pathway, consequently enhancing chemotherapy resistance. Remarkably, the influence exerted by 6:2 Cl-PFESA exceeds that of PFOS. Despite 6:2 Cl-PFESA being regarded as a safer substitute for PFOS, its pronounced effect on chemotherapeutic resistance in PDAC necessitates a thorough evaluation of its potential risks related to gastrointestinal toxicity.

A phase II study of liposomal irinotecan-based chemotherapy with or without PD-1 inhibitor in patients with unresectable locally advanced or metastatic biliary tract cancer.

e15077 Background: Clinical outcomes for advanced biliary tract cancer (BTC) patients (pt) progressed on first-line therapy remain dismal. Liposomal irinotecan (LI) (HE072) is a formulation encapsulating I in a lipid bilayer vesicle and was approved in China in September 2022. It was used with 5-fluorouracil (5-FU) and leucovorin (LV) for patients with metastatic pancreatic cancer progressing on gemcitabine treatment. We conducted an phase II study to investigate HE072 in combination with 5-FU and LV with or without a novel PD-1 inhibitor SG001 in patients with advanced BTC progressed on prior gemcitabine-based chemotherapy. Methods: This is a multi-center, non-randomized, open label phase II study in pts with unresectable locally advanced or metastatic BTC. Key inclusion factors were ECOG PS 0-1, prior gemcitabine-based chemotherapy, evidence of disease progression with at least one measurable lesion and adequate haematological/organ function. Key exclusion factor was brain metastases. Pts were treated with liposomal irinotecan (70 mg/m2) plus LV (400 mg/m2f) and 5-FU (2400 mg/m2) with or without SG001 (240mg) IV every 2 weeks for up to 2 years in absence of disease progression or unacceptable toxicity. Tumor assessments based on RECIST 1.1 were performed every 6 weeks by investigators. Primary endpoint was objective response rate (ORR). Secondary endpoints include progression free survival (PFS), overall survival (OS), disease control rate (DCR) and safety. Results: As of April 25, 2023, 17 BTC pts were enrolled into liposomal irinotecan-based chemotherapy arm (n = 7) and liposomal irinotecan-based chemotherapy plus SG001 arm (n = 10). ORR and DCR were 14.3% and 71.4% for chemotherapy arm, 20% and 40% for chemotherapy+ SG001 arm. Median OS and PFS for chemotherapy arm was 11.5(95% CI, 3.9-NE) and 4.2(95% CI, 1.4-NE) months, and for chemotherapy+PD-1 arm was 15.3 (95% CI, 3.6-17.0) and 3.8(95% CI, 1.4-6.9) months. All pts experienced treatment-related adverse events (TRAEs). The incidence of grade≥3 TRAEs was 58.8%(10/17), which occurred in 57% (4/7) of pts treated in chemotherapy arm vs 60% (6/10) in chemotherapy+SG001 arm. Among all patients, the most frequent grade ≥3 TRAEs were fatigue (29.4%), neutropenia (23.5%) and leukopenia (23.5%). One grade 4 TRAE leading to dose reduction in liposomal irinotecan was febrile neutropenia in chemotherapy arm. There were no treatment-related deaths. Conclusions: These preliminary results suggested that liposomal irinotecan plus 5-FU and LV was well-tolerated and showed promising and durable clinical activity in advanced BTC pts progressed on first-line treatment. Combined use of SG001 further improved clinical outcome in these pts without increased toxicity. Combination of liposomal irinotecan, 5-FU, LV and PD-1 inhibitor is a treatment strategy which is worthy of further exploration.

Inside stent placement is suitable for preoperative biliary drainage in patients with perihilar cholangiocarcinoma

Background/PurposeEndoscopic biliary stenting (EBS) is commonly used for preoperative drainage of localized perihilar cholangiocarcinoma (LPHC). This study retrospectively compared the utility of inside stent (IS) and conventional stent (CS) for preoperative EBS in patients with LPHC.MethodsEBS was performed in 56 patients with LPHC. EBS involved the placement of a CS (n = 32) or IS (n = 24). Treatment outcomes were compared between these two groups.ResultsPreoperative recurrent biliary obstruction (RBO) occurred in 23 patients (71.9%) in the CS group and 7 (29.2%) in the IS group, with a significant difference (p = 0.002). The time to RBO (TRBO) was significantly longer in IS than in CS (log-rank: p < 0.001). The number of stent replacements was significantly lower in IS than CS [0.38 (0–3) vs. 1.88 (0–8), respectively; p < 0.001]. Gemcitabine-based neoadjuvant chemotherapy (NAC) was administered to 26 patients (46.4%). Among patients who received NAC, TRBO was longer in IS than in CS group (log-rank: p < 0.001). The IS group had a significantly shorter preoperative and postoperative hospital stay than the CS group (20.0 vs. 37.0 days; p = 0.024, and 33.5 vs. 41.5 days; p = 0.016). Both the preoperative and the postoperative costs were significantly lower in the IS group than in the CS group (p = 0.049 and p = 0.0034, respectively).ConclusionCompared with CS, IS for preoperative EBS in LPHC patients resulted in fewer complications and lower re-intervention rates. The fact that the IS group had shorter preoperative and postoperative hospital stays and lower costs both preoperatively and postoperatively compared to the CS group may suggest that the use of IS has the potential to benefit not only the patient but also the healthcare system.

Pharmacogenomic study of gemcitabine efficacy in patients with metastatic pancreatic cancer: A multicenter, prospective, observational cohort study (GENESECT study).

Genetic polymorphisms of molecules are known to cause individual differences in the therapeutic efficacy of anticancer drugs. However, to date, germline mutations (but not somatic mutations) for anticancer drugs have not been adequately studied. The objective of this study was to investigate the association between germline polymorphisms of gemcitabine metabolic and transporter genes with carbohydrate antigen 19-9 (CA 19-9) response (decrease ≥50% from the pretreatment level at 8 weeks) and overall survival (OS) in patients with metastatic pancreatic cancer who receive gemcitabine-based chemotherapy. This multicenter, prospective, observational study enrolled patients with metastatic pancreatic cancer patients who were receiving gemcitabine monotherapy or gemcitabine plus nanoparticle albumin-bound paclitaxel combination chemotherapy. Thirteen polymorphisms that may be involved in gemcitabine responsiveness were genotyped, and univariate and multivariate logistic regression analyses were used to determine the association of these genotypes with CA 19-9 response and OS. The significance level was set at 5%. In total, 180 patients from 11 hospitals in Japan were registered, and 159 patients whose CA 19-9 response could be assessed were included in the final analysis. Patients who had a CA 19-9 response had significantly longer OS (372 vs. 241 days; p=.007). RRM1 2464A>G and RRM2 175T>G polymorphisms suggested a weak association with CA 19-9 response and OS, but it was not statistically significant. COX-2 -765G>C polymorphism did not significantly correlate with CA 19-9 response but was significantly associated with OS (hazard ratio, 2.031; p=.019). Genetic polymorphisms from the pharmacokinetics of gemcitabine did not indicate a significant association with efficacy, but COX-2 polymorphisms involved in tumor cell proliferation might affect OS.

Keratin 17 is a prognostic and predictive biomarker in pancreatic ductal adenocarcinoma.

To determine the role of keratin 17 (K17) as a predictive biomarker for response to chemotherapy by defining thresholds of K17 expression based on immunohistochemical tests that could be used to optimize therapeutic intervention for patients with pancreatic ductal adenocarcinoma (PDAC). We profiled K17 expression, a hallmark of the basal molecular subtype of PDAC, by immunohistochemistry in 2 cohorts of formalin-fixed, paraffin-embedded PDACs (n = 305). We determined a K17 threshold of expression to optimize prognostic stratification according to the lowest Akaike information criterion and explored the potential relationship between K17 and chemoresistance by multivariate predictive analyses. Patients with advanced-stage, low K17 PDACs treated using 5-fluorouracil (5-FU)-based chemotherapeutic regimens had 3-fold longer survival than corresponding cases treated with gemcitabine-based chemotherapy. By contrast, PDACs with high K17 did not respond to either regimen. The predictive value of K17 was independent of tumor mutation status and other clinicopathologic variables. The detection of K17 in 10% or greater of PDAC cells identified patients with shortest survival. Among patients with low K17 PDACs, 5-FU-based treatment was more likely than gemcitabine-based therapies to extend survival.

Abstract 7202: Strategy of targeting PKCβΙ protein to overcoming the acquired gemcitabine resistant pancreatic cancer cells

Abstract Pancreatic cancer (PC) is one of the most malignant cancers with limitation of treatment options such as resection surgery, radiation therapy and gemcitabine-based chemotherapy. To treating PC patients, gemcitabine-based chemotherapy is common and effective for PC, acquired gemcitabine resistance is one of the major reasons for treatment failure. Therefore, there is a need to suggest effective strategies and novel therapeutic approach for gemcitabine-resistant PC. Protein Kinase C β1 (PKC β1) is known as involved in multiple signal transduction related to oncogenic functions in cancer. We suggested that PKC β as one of the novel biomarker of drug resistance and further investigated the molecular mechanism. Among the natural products as small molecule inhibitor, we found that evodiamine has potent antitumor activity and various biological activities. Based on various biological activities of evodiamine, the scaffold was synthesized and investigated for antiproliferative and antitumor activities against gemcitabine resistant PANC-1 (PANC-GR) cells. Also, target validation experiment was employed to elucidate the molecular mechanism and verifying the target to overcoming gemcitabine resistance. Mechanistically, evodiamine derivatives have shown that inhibition of PKC β1 can modulate the proliferation of PANC-GR cells and exhibited tumor growth inhibitory activity in xenograft mouse model. Keywords: Pancreatic cancer cell, Gemcitabine resistance, Protein Kinase C β1 (PKC β1), Molecular mechanism Acknowledgements: This research was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (RS-2023-00273240). Citation Format: EunSeo Bae, Yijae Lim, Junhwa Hong, Woong Sub Byun, Simin Chun, Suckchang Hong, Sang Kook Lee. Strategy of targeting PKCβΙ protein to overcoming the acquired gemcitabine resistant pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7202.

Abstract 1605: Oncolytic hsv-1(vc2) gm-csf regulates the proinflammatory profile suggestive of an immunomodulatory effect in PDAC cells

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease that is projected to be the second leading cause of cancer-associated deaths by 2030. Owing to its intrinsic immune evasive tumor microenvironment (TME), PDAC is regarded as an immunologically “cold” tumor with a significant therapeutic challenge. Although 5-fluorouracil or gemcitabine-based chemotherapy is considered as standard of care, harnessing immunological pathways may potentially convert PDAC to a “hot” tumor, thereby providing survival advantage to patients. Lately, the use of oncolytic virus has proven to be an alternative strategy to activate the innate immune response within the TME coupled with its cytotoxic effect against the cancer cells. The FDA approval of T-VEC for the treatment of stage IIIB/IV melanoma validates the preceding argument. In this study, we have investigated the effect of herpes simplex virus type-1 (HSV-1) (VC2) overexpressing granulocyte-macrophage colony-stimulating factor (GMCSF), HSV-1VC2GM-CSF in the murine KRAS, p53, and Cre (KPC), and human MIA PaCa-2 pancreatic carcinoma cells. Following a 24h infection of the KPC and MIA PaCa-2 cells with the HSV-1VC2GM-CSF, the observed cytopathic effects (CPE) included cell rounding, detachment, and aggregation as compared to the wild-type HSV-1VC2 treated or the uninfected control cells. The CPE effect of HSV-1VC2GM-CSF was proven to be a more direct and dynamic response against these cells. In the next steps, the viral titers were determined to be 9.6E7 pfu/ml, 1.26E7 pfu/ml for HSV-1VC2 and VC2GM-CSF respectively. The infection of VC2GM-CSF 0.1, 1.0 and 10 MOI in KPC cells resulted in a significant increase in the expression of proinflammatory markers including interleukin 10 (IL-10), cyclooxygenase -2 (COX-2) and iNOS at the gene level in contrast to the uninfected controls. This was coupled with an increase in the expression of Fas ligand (FasL) in the treated cells. Intriguingly, the treated cells showed a significant upregulation of programmed death ligand (PD-L1). Interestingly, in a 3D-coculture of KPC and RAW264.7 cells the expression of PD-L1 was significantly upregulated. Based on the evidence presented here, it is speculated that VC2GM-CSF-induced proinflammatory profile in KPC and Mia PaCa-2 cells converts to an immunomodulatory one characterized by the regulation of FasL and PD-L1. The effect of VC2GM-CSF in a PDAC organoid model to understand the interplay between the tumor and the stromal cells in response to the virus is currently underway. Citation Format: Naveen Chintala Ramulu, Shilpa Thota, Brent Stanfield, Konstantin Kousoulas, Joseph Francis. Oncolytic hsv-1(vc2) gm-csf regulates the proinflammatory profile suggestive of an immunomodulatory effect in PDAC cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1605.

Deciphering the role of Enterococcus faecium cytidine deaminase in gemcitabine resistance of gallbladder cancer

Gemcitabine-based chemotherapy is a cornerstone of standard care for gallbladder cancer (GBC) treatment. Still, drug resistance remains a significant challenge, influenced by factors such as tumor-associated microbiota impacting drug concentrations within tumors. Enterococcus faecium, a member of tumor-associated microbiota, was notably enriched in the GBC patient cluster. In this study, we investigated the biochemical characteristics, catalytic activity, and kinetics of the cytidine deaminase of E. faecium (EfCDA). EfCDA showed the ability to convert gemcitabine to its metabolite 2',2'-difluorodeoxyuridine. Both EfCDA and E. faecium can induce gemcitabine resistance in GBC cells. Moreover, we determined the crystal structure of EfCDA, in its apo form and in complex with 2', 2'-difluorodeoxyuridine at high resolution. Mutation of key residues abolished the catalytic activity of EfCDA and reduced the gemcitabine resistance in GBC cells. Our findings provide structural insights into the molecular basis for recognizing gemcitabine metabolite by a bacteria CDA protein and may provide potential strategies to combat cancer drug resistance and improve the efficacy of gemcitabine-based chemotherapy in GBC treatment.

Abstract A024: Ploidy as a predictive biomarker for gemcitabine sensitivity in triple-negative breast cancers

Abstract The polyploid giant cancer cell (PGCC) state is a common response of cancer cells to various stressors including chemotherapy, irradiation, hypoxia and viral infection. Upon stress, PGCCs adopt an endoreplication in which the genome replicates, mitosis is omitted, and cells grow in size, causing drug resistance. How accessible endoreplication is to a cell, therefore, directly translates to its resistance to therapy. In this study, we hypothesized that endoreplication and PGCC state are more accessible to cancer cells that already have a higher ploidy content prior to therapy. To test this hypothesis, we developed a comprehensive three-tier framework consisting of i) computational, ii) in-vitro and iii) in silico components. First, we designed a set of ordinary differential equations (ODEs) to mathematically model how cells enter and exit the PGCC state in response to a given stressor. We engineered how this in silico approach interacts with in vitro experiments into a broadly applicable software solution called CLONEID. The software uses computer vision to monitor phenotypic changes in cell and nuclear size from standard bright-field microscopy and classify cells into PGCC and non-PGCC states. We used CLONEID to test various therapeutic agents for their ability to select for a stable near-tetraploid (4N) population in a set of near-diploid (2N) cell lines. Through spontaneous cell fusions, we also obtained tetraploid breast cancer cells matched with their parental lines. Altogether, this framework enabled us to i) monitor the PGCC state experimentally in ii) two sets of matched isogenic cell lines with 2N and 4N DNA content to iii) model the successful entry and exit rates to and from the endoreplication state, respectively. As the first application of this framework, we tested the ability of our 2N and 4N TNBC lines (SUM159 and MDA-MB-231) to access the PGCC state upon treatment with 18 chemotherapy agents. Among those drugs, we observed that only gemcitabine caused continued cell growth without cell division in both tetraploid SUM159 and MDA-MB-231 cells whereas near-diploid parental lines were hypersensitive to the treatment. Consequently, tetraploid cancer cells continued to safely grow in the presence of gemcitabine. Furthermore, these PGCCs re-entered the proliferative cell cycle and grew in cell number when treatment is terminated. Gemcitabine-based chemotherapy is a standard treatment for patients with TNBC although its efficacy is limited mainly due to drug resistance. We expect our findings and three-component framework strategy to help stratify the TNBC patient population by their response to gemcitabine. In addition, our mathematical modelling approach has the promising potential to inform personalized dose optimization and to effectively decrease administered gemcitabine dose for a subset of patients, which would alleviate severe therapy-associated side effects and co-morbidities. Citation Format: Vural Tagal, Jackson Cole, Daria Miroshnychenko, Andriy Marusyk, Noemi Andor. Ploidy as a predictive biomarker for gemcitabine sensitivity in triple-negative breast cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr A024.

Efficacies of anlotinib monotherapy versus gemcitabine-based chemotherapy for patients with advanced soft tissue sarcoma after the failure of anthracycline-based chemotherapy

ObjectiveThe purpose of this study was to compare the antitumor efficacy of anlotinib with gemcitabine-based chemotherapy as subsequent treatment regimens in patients with advanced non-specific soft tissue sarcoma (STS) after the failure of anthracycline-based chemotherapy.MethodsPatients diagnosed with advanced STS who were treated with either anlotinib or gemcitabine-based chemotherapy between May 2009 and May 2023 in our center were eligible. All patients experienced disease progression or recurrence after the anthracycline-based chemotherapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints were disease control rate (DCR), overall survival (OS) and safety.ResultsWe included 49 patients receiving anlotinib and 45 patients receiving gemcitabine-based chemotherapy. The median follow-up time was 76.9 weeks (range 2.9–678.9 weeks). The DCR (65.3% vs. 57.8%; p = 0.610), PFS (24.0 weeks vs. 18.6 weeks; p = 0.669) and OS (79.4 weeks vs. 87.0 weeks; p = 0.471) of anlotinib and gemcitabine-based chemotherapy indicated similar clinical efficacy. Moreover, exploratory subgroup analyses showed that patients with STS originating from limbs and trunk were inclined to benefit from anlotinib treatment (median PFS: 31.3 weeks vs. 12.4 weeks; p = 0.045). ECOG PS was an independent predictor of the PFS [Hazard Ratio (HR) 0.31; 95% confidence interval (CI) 0.11–0.85; p = 0.023] and OS (HR 0.26, 95%CI 0.10–0.70; p = 0.008) in the anlotinib group. While neutrophil-to-lymphocyte ratio (NLR) was an independent prognostic factor of the PFS (HR 0.33, 95%CI 0.11–0.98; p = 0.045) in the gemcitabine-based chemotherapy group. The incidence of grade 3 or higher related AEs in anlotinib and gemcitabine-based chemotherapy was 20.4% (n = 10) and 20.0% (n = 9), respectively.ConclusionOur research suggested that anlotinib and gemcitabine-based chemotherapy showed similar clinical efficacy and safety in the subsequent treatment of advanced STS after the failure of anthracycline-based chemotherapy.

A decade of chemotherapy management in hepatocellular carcinoma: A single-center study in Latin America.

524 Background: Hepatocellular carcinoma (HC) is the most common primary tumor of the liver and is a significant health problem worldwide with check-point inhibitors and oral multikinase inhibitors (TKI) as the first-line therapy for advanced diseases. While chemotherapy treatment may not be standardized in current clinical management guidelines, it remains the only available treatment option in numerous Latin American countries. Methods: A retrospective review was carried out, in patients older than 18 years, between January 2011 and December 2020. 127 patients were analyzed and identified, they had received at least one course of chemotherapy at the Instituto Nacional de Enfermedades Neoplásicas in Lima, Perú. Results: The median age was 40 years, 40 female patients (31.5%) and 87 male patients (68.5%). Among the participants, 77 patients (60.62%) were diagnosed with hepatitis B, 2 patients (1.57%) had hepatitis C virus infections, and 48 patients didn´t have viral hepatitis. 72 patients (91.13%) underwent antiretroviral treatment. Non-cirrhotic patients were 118 (92.91%) and 111 (87.4%) had a Child A score. Chemotherapy was administered as first-line treatment to 118 patients (92.91%), with 47.61% receiving 5-FU-based chemotherapy, 11.11% Adriamycin, and 8.7% Gemcitabine-based chemotherapy. A smaller subset, consisting of 8 individuals (6.29%), received sorafenib as their first-line treatment. The overall survival (OS) rates at 12, 36, and 60 months were 74.14%, 20.69%, and 1.72%, respectively. Regarding disease-free survival (DFS) rates at 12, 24, and 48 months were 28.89%, 6.67%, and 2.22%, respectively. Conclusions: In this updated data for advanced hepatocellular carcinoma, we observed a subset of patients with advanced HC achieved favorable outcomes, with a median OS of 20.37 months and a median DFS of 6.6 months. Additional research is necessary to enhance our understanding of the molecular characteristics and resistance pathways of hepatocellular carcinoma in Peru and their correlation with the favorable survival rates observed in response to chemotherapy treatment.

A phase 1b/2 trial of pepinemab and avelumab as second line therapy for patients with metastatic pancreatic adenocarcinoma.

TPS712 Background: Pancreatic adenocarcinoma (PDAC) is a leading cause of cancer-related mortality with poor prognosis despite maximal therapy and is unresponsive to immune checkpoint blockade (ICB). This failure of response is hypothesized to be driven in part by the characteristic immunosuppressive tumor microenvironment. In PDAC, Semaphorin 4D (SEMA4D) expression is prognostic in patients who have undergone surgical resection and correlates with tumor infiltration of activated CD8+ T-cells. Additionally, preclinical models suggest that antibody-mediated SEMA4D blockade promotes tumoral infiltration and activation of CD8+ T-cells and sensitizes PDAC to ICB, with improved overall survival with standard of care chemotherapy and ICB in combination with pepinemab (humanized anti-SEMA4D). Thus, we hypothesized that pepinemab may improve clinical outcomes in PDAC by sensitizing tumors to ICB. Methods: We designed a phase Ib/II single-arm clinical trial to evaluate the safety, tolerability, and efficacy of humanized anti-SEMA4D (pepinemab) with anti-PD-L1 (avelumab) in patients with chemotherapy-refractory PDAC. Patients must have failed first-line 5-fluorouracil or gemcitabine-based combination chemotherapy. The study follows a dose de-escalation schema starting at a dose combination of 20mg/kg pepinemab and 800mg avelumab every two weeks. Patient accrual for phase 1b utilizes the Bayesian Optimal Interval Design (BOIN) targeting a dose-limiting toxicity rate of 30% or less. After 16 subjects receive a given combination dose, a Simon’s two stage assessment of futility will be undertaken with expansion to phase 2 if 2 or more subjects demonstrate response. The trial is designed to evaluate a total cohort of 40 subjects and powered to detect a response rate of 23% or greater, with alpha set at 0.1% and 80% power. Treatment response is assessed via RECIST 1.1 criteria with surveillance CT prior to enrollment and after completion of two cycles (8 weeks). Baseline and on-treatment tumor biopsies (after completion of one cycle, 4 weeks) are performed to analyze changes in immune, stromal, and genomic profiles to elucidate mechanisms of treatment response and failure. Patient reported outcomes are incorporated (FACT-Hep and FAACT subdomains) to assess disease-specific symptoms. To date, 7 patients have been enrolled (Clinical Trial NCT05102721). Clinical trial information: NCT05102721 .

Advanced pancreatic cancer outcomes and the impact of COVID-19 pandemic: The experience of an academic cancer center.

626 Background: The COVID-19 pandemic increased all-cause mortality and disrupted healthcare delivery in the United States. Interruptions in cancer screening and surveillance because of the pandemic resulted in delayed diagnosis, diagnosis at later stages, and worse cancer-related outcomes. However, the effect of COVID-19 on pancreatic cancer outcomes has not been reported. This study aimed to investigate this question. Methods: We studied consecutive patients with unresectable and metastatic pancreatic cancer treated at the University of Cincinnati Cancer Center. Patients were divided into 2 cohorts: from January 2018 to December 2019 (pre-COVID) and from January of 2020 to December of 2021 (during-COVID). Descriptive data on patient characteristics, ECOG performance status (PS), laboratory values, therapies, and mortality were obtained by pre- and during-COVID. The categorical variables were compared using the Pearson Chi-square test for contingency tables (or Fisher’s exact test when the expected frequency within any cell was less than 5 in the contingency table), and the t-test or ANOVA was used for continuous variables. For overall survival time, the Kaplan-Meier curves were compared between pre- and during-COVID using log rank test. We fitted univariable Cox proportional-hazards model for each interest variable, and the multivariable Cox models, which includes only significant variables. Results: There were 81 and 64 patients in the pre- and during-COVID cohorts, respectively. Patients diagnosed during COVID were more likely to be female, have better PS, have higher proportion of alcohol use, and were more likely to receive 5-FU-based (compared with gemcitabine-based) chemotherapy upfront. There was no overall survival difference between the two cohorts. A Cox proportional hazards model showed that PS at diagnosis, history of chronic pancreatitis, any chemotherapy compared to no chemotherapy, serum albumin prior to initial chemotherapy, and body mass index at time of diagnosis were associated with survival. Conclusions: We observed no difference in overall survival in patients diagnosed with advanced stage pancreatic cancer during the first two years of the COVID-19 pandemic compared with the two prior years. While some differences were observed between patient groups and treatment selection before and during the pandemic, a concerted effort to maintain cancer care appears to have minimized the impact of the pandemic. Further analyses on patients undergoing treatment are being conducted.

Treatment patterns of gemcitabine-based chemotherapy in patients with de novo and recurrent advanced biliary tract cancer.

454 Background: Biliary tract cancers (BTC) are often diagnosed at advanced stages (aBTC) when prognosis is poor. In the Phase 3 TOPAZ-1 study (NCT03875235), durvalumab plus gemcitabine and cisplatin (GemCis) significantly improved overall survival versus placebo plus GemCis. To better understand the context of the TOPAZ-1 trial results in the US, we looked at first-line (1L) treatment patterns in participants with aBTC treated with GemCis and other gemcitabine (Gem)-based chemotherapy (CT) regimens. Methods: This retrospective observational cohort study used linked electronic health records and medical and pharmacy claims data from the Optum Market Clarity Database. Adults diagnosed with de novo or recurrent aBTC, who initiated 1L Gem-based CT between January 2016 and March 2022, were identified and followed from the index date (defined as the first administration of Gem-based CT on or after initial BTC diagnosis date) until death, end of continuous enrollment, or end of study period, whichever occurred first. Variables including patient demographics, clinical characteristics, and treatment patterns were described. Results: A total of 580 patients were included in the analysis with either de novo aBTC (n=481, 82.9%) or recurrent aBTC (n=99, 17.1%) with median follow-up time of 10.4 (interquartile range: 6.4, 17.5) and 12.0 (interquartile range: 6.3, 21.9) months, respectively. Mean (SD) age was 64.6 (11.2) and 66.8 (10.4) years, with 45.7% and 54.5% male in the de novo and recurrent aBTC groups, respectively. Most patients were white (77.6%). The most frequent site of primary tumor diagnosis was single-site intrahepatic (overall 62.8%, de novo 66.7%, recurrent 43.4%). In the 12 months prior to index date, 38.5% of patients had biliary obstruction, 30.2% had biliary stents, 29.3% had jaundice, and 17.1% had nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. Common comorbidities included cardiovascular disease (50.9%), obesity (46.8%), and diabetes (35.2%). The most common 1L CT was GemCis followed by Gem for both the de novo (n=355, 73.8% and n=36, 7.5%) and recurrent groups (n=58, 58.6% and n=26, 26.3%), respectively. Approximately half of participants (50.9%) switched to a new line of treatment, 33.3% discontinued 1L CT, and 15.9% remained on 1L CT at last follow-up. Most frequent 2L treatments included fluorouracil/oxaliplatin (36.9%) and capecitabine (14.2%). Further analysis will characterize outcomes and regimen duration. Conclusions: Findings from this retrospective study showed that the most common 1L therapies were GemCis and Gem among both de novo and recurrent patients with aBTC. These results provide insight into aBTC treatment practices and may help inform treatment decisions.

Abstract C063: Keratin 17 as a predictor of chemotherapy response in pancreatic ductal adenocarcinoma

Abstract Background: Two chemotherapies based on either gemcitabine- or 5-fluorouracil (5-FU) remain standard-of-care for pancreatic ductal adenocarcinomas (PDACs). Patients, however, differ in response and thus many clinical trials for experimental drugs have failed. Therefore, there is an urgent need to establish clinically deployable and rapid biomarkers to decide the best chemotherapeutic regimen for subgroups of patients and prevent toxic side effects. We previously reported that keratin 17 (K17) expression, detected at either the level of messenger RNA or protein by immunohistochemistry (IHC), is as accurate as molecular subtyping to identify subgroups of PDAC patients with shortest survival. In this work, we determined the predictive value of K17 testing for both chemotherapeutic approaches to treat PDAC. Methods: We profiled keratin 17 (K17) expression, a hallmark biomarker of the basal molecular subtype of PDAC, using immunohistochemistry in two cohorts of formalin-fixed paraffin-embedded PDACs (total n=305). These cases were collected through the Know Your Tumor® initiative and three high-volume treating institutions in the U.S. We performed multivariate predictive analyses and determined the threshold to define positive vs negative test. Results: Patients with advance stage disease, low K17, and treated with 5-FU- chemotherapy had three-times longer survival rates compared to counterparts treated with gemcitabine-based chemotherapy. These results contrast to those found in cases with high K17, where no differences were seen with either regimen. Based on RECIST, 72% of low K17 cases responded to treatment compared to 24% of high K17 cases. Predictive value of K17 was independent of mutation status and clinical variables. Conclusions: Our findings indicate that 5-FU-, rather than gemcitabine- based therapies are more likely to extend survival for patient's tumors expressing low rather than high K17. A K17 IHC test rapid test in PDACs has been patented (US11,092,603) and it is currently being tested in prospective phase II clinical trials (NCT04469556, NCT02047474 and NCT03991962). Results from these trials will test the presented findings. Citation Format: Lyanne Oblein, Lucia Roa, Sruthi Babu, Michael Horowitz, Emanuel Petricoin, Lynn M. Matrisian, Edik Blais, Natalia Marchenko, Felicia Allard, Ali Alkalin, Wei Jiang, Brent Larson, Andrew Hendifar, Vincent Picozzi, Minsig Choi, Luisa Escobar-Hoyos, Kenneth Shroyer. Keratin 17 as a predictor of chemotherapy response in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C063.

Different Tumour Marker Kinetics as Prognosticators in Patients with Adenocarcinoma of Gall Bladder Undergoing Chemotherapy: A Cohort Study

Introduction: Gallbladder Cancer (GBC) is the most common malignancy of the biliary tract worldwide. Patients do not have specific symptoms, and therefore, GBC is usually diagnosed at an advanced stage. Carbohydrate Antigen (CA)-242, CA 19-9, and Cancer Antigen 125 (CA-125) have been found to be effective in the diagnosis and prognosis of GBC. Aim: To determine the significance of tumour markers as prognosticators in adenocarcinoma of GBC with chemotherapy. Materials and Methods: The present cohort study was conducted in the Department of Biochemistry, Murshidabad Medical College and Hospital, Baharampur, West Bengal, India, between December 2021 and November 2022. Thirty patients with pathologically confirmed adenocarcinoma of the gallbladder who were treated with gemcitabine-based chemotherapy were included in the study. Differences in serum CA-125 and CA 19-9 levels before and after chemotherapy (KINETICS) were measured along with haemoglobin, serum urea, creatinine, total bilirubin and Neutrophil-Lymphocyte Ratio (NLR). Receiver Operating Characteristic (ROC) curve analysis and Kaplan-Meier analyses of CA-125, CA 19-9, and combined changes were performed to assess survival rates and their statistical relevance as prognosticators in correlation with disease progression. Results: The mean±Standard Deviation (SD) age was 52.4±5.275 years. A total of 25 (83.3%) patients were females. The associations of CA 19-9 change with other baseline variables were analysed, and there were significant associations with baseline Carbohydrate Antigen (CA19-9) levels (p-value=0.003) and metastatic changes (p-value &lt;0.001). Patients with decreased tumour markers had significantly better Progression- Free Survival (PFS) than patients with increased tumour markers. The pre- and post-chemotherapy CA 19-9 ratio had the highest area-under-the-curve values (AUC 0.910) for predicting 6-month PFS, whereas for predicting metastatic changes, the combined pre- and post-chemotherapy marker ratio had the highest AUC 0.842. In the multivariate analysis, CA 19-9 ≥100 U/mL at diagnosis (p-value &lt;0.001) and NLRchange ≥1.0 (p-value=0.003) were independent prognosticators of PFS, with hazard ratios of 1.007 (p-value &lt;0.001) and 15.4 (p-value=0.003), respectively. Conclusion: CA 19-9 kinetics proved to be a reliable prognosticator of metastatic changes in patients with adenocarcinoma of the gallbladder undergoing chemotherapy. The significant decline in tumour markers that were seen throughout the follow-up phase emphasises how important it is to use these markers as primary indicators of treatment response. To validate the present study findings, larger-scale studies involving a longer follow-up period and a greater number of patients are needed.