Intensive Combination Chemotherapy Research Articles

Epithelioid trophoblastic tumor with lung metastasis: A case report and literature review.

Epithelioid trophoblastic tumor (ETT) is an extremely rare variant of gestational trophoblastic neoplasms (GTNs). The biological behavior and therapeutic schedule of ETT remains to be defined which frequently poses diagnostic and therapeutic challenges. Although ETT is a relatively indolent malignancy tumor, the therapeutic efficacy and survival rate decrease significantly when presented with metastases. The lung is the most common site of ETT metastasis. A 39-year-old female patient presented with irregular vaginal bleeding and slight distention pain in lower abdomen. The patient was diagnosed ETT with lung metastasis after surgery and immunohistochemical staining. A total abdominal hysterectomy plus bilateral salpingectomy and histopathology were performed. The patient received 3 cycles of etoposide, methotrexate, actinomycin-D/etoposide, cisplatin (EMA/EP) regimen chemotherapy after surgery. Due to the presence of lung metastasis, she received pulmonary lesion resection and another cycle of postoperative chemotherapy. The patients showed a good response to treatment initially. However, the patient did not complete the full initial treatment for family reasons and had signs of recurrence after 2.5 months. The serum β-hCG level gradually elevated and the lung imaging showed that the lesion area gradually expanded. After 15 months of follow-up, the patient declined further treatment due to a lack of presenting symptoms. The diagnosis of ETT should be taken into consideration in patients with abnormal vaginal bleeding and low levels of β-hCG. Patients with metastatic disease should be treated with complete surgical resection and intensive combination chemotherapy to maximize the opportunity for cure. Targeted biological agents might be potential therapeutic strategies for chemotherapy-resistant or recurrent patients.

Efficacy of Venetoclax and Azacitidine in Acute Myeloid Leukemia Compared to Azacitidine Monotherapy: Real-World Experience.

The combination of venetoclax (VEN) and azacitidine (AZA) (VEN+AZA) leads to higher complete remission rates and longer overall survival (OS) in patients with untreated acute myeloid leukemia (AML) who are ineligible for intensive combination chemotherapy. In practice, the doses of VEN and AZA are reduced at the attending physician's discretion to avoid adverse events; however, the impact of dose and duration reductions has not been fully clarified. We analyzed whether the efficacy was maintained with reduced VEN+AZA compared to AZA monotherapy in the real world. A total of 33 patients were included; 17 (10 newly diagnosed, 7 primary refractory or relapsed) received VEN+AZA, and 16 (7 newly diagnosed, 9 primary refractory or relapsed) received AZA. We analyzed complete remission (CR) and CR with incomplete hematologic recovery (CRi) rates, OS, and the incidence of adverse events. CR/CRi were achieved in 7/17 (41.2%) and 11/17 (64.7%) patients in the VEN+AZA group and 0/15 (0%) and 2/15 (6.7%) patients in the AZA group, respectively. The CR/CRi rate was higher in the VEN+AZA group than in the AZA group (p=0.001). OS was longer in the VEN+AZA group than in the AZA group (p=0.03), with a median of 506 days [95% confidence interval (CI)=234-585 days] and 208 days (95% CI=52-343 days), respectively. The doses of the VEN+AZA combination were reduced at the attending physician's discretion, resulting in a higher CR/CRi rate and longer OS than AZA monotherapy and is considered useful for AML in the real world.

Improving long-term outcomes with intensive induction chemotherapy for patients with AML.

Intensive chemotherapy in combination with allogeneic hematopoietic cell transplantation and supportive care can induce long-term remissions in around 50% of acute myeloid leukemia patients eligible for intensive treatment. Several treatment optimization trials helped to refine schedule and dosing of the historic "7 + 3" combination. Together with the addition of novel agents, increased efficacy and tolerability led to improved long-term outcomes. Unsatisfactory outcomes in fit elderly patients and unfavorable genetic subgroups have raised the question of whether less-intensive venetoclax-based approaches may be beneficial as an alternative. Although tempting and worth exploring, this issue will remain controversial until the results of randomized comparisons appear. To date, intensive chemotherapy remains the only evident curative treatment option for long-term disease eradication in a fixed treatment time. With the advent of more novel agents and advances in minimal residual disease (MRD) detection and maintenance approaches, the face of intensive treatment could change in many ways. Several are being explored in clinical trials, such as (1) combinations of more than 1 novel agent with the intensive backbone, (2) head-to-head comparisons of novel agents, (3) replacement or dose reduction of cytotoxic components such as anthracyclines, and (4) MRD-guided escalation and de-escalation strategies. The combination of intensive treatment with individualized tailored innovative strategies will most certainly reduce treatment-related toxicities and increase the chances for long-term remission in the future.

Concurrent Versus Sequential or No Triazole Anti-Fungal Therapy in Patients Undergoing 7+3 Plus Midostaurin Induction for FLT-3 Acute Myelogenous Leukemia

Background Midostaurin is a multikinase inhibitor approved for the treatment of adult patients with newly diagnosed FMS-like tyrosine kinase 3 (FLT3) mutated acute myeloid leukemia (AML) (Stone RM et al. NEJM 2017). Azole antifungal medications are commonly used in AML and are known to interact with anti-cancer drugs such as Midostaurin through the CYP3A pathway. This could result in an increase in midostaurin concentrations and toxicities, and lead to potential dose interruptions or modifications. However, the literature is scarce on outcomes in patients who are receiving an azole antifungal with intensive induction chemotherapy in combination with midostaurin (Sechaud R et al. Cancer Chemother Pharmacol 2022). In addition to the scarcity of literature, there are no midostaurin related dose modifications that are recommended with strong CYP3A inhibitors. The primary objective of this retrospective study was to compare induction efficacy and safety outcomes in patients receiving concurrent azole antifungal to patients receiving sequential or no azole antifungal therapy. Methods: From January 1, 2017, to January 30, 2023, we retrospectively reviewed all adult patients (18 or older) with newly diagnosed AML who received midostaurin in combination with cytarabine and an anthracycline (7+3). Concurrent azole therapy was defined as patients receiving an azole antifungal therapy with midostaurin for more than 70% of the midostaurin doses. Sequential azole therapy was defined as patients receiving azole antifungal therapy with midostaurin for less than 70% of the doses or no azole antifungal therapy with midostaurin therapy. Response outcome CR and CR without hematological recovery (CRi) were defined per standard International Working Group (IWG) AML response criteria. Minimal residual disease (MRD) assessment was done on post-induction bone marrow aspirate using multiparametric flow cytometric assessment. Adverse events were graded using NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. We compared efficacy and safety outcomes in patients who received azole antifungals concurrently to those who did not receive an azole or received it sequentially to midostaurin for treatment of FLT3 AML. Mann-Whitney U test method was used to compare continuous variables between these two groups. Pearson Chi-square test or Fisher Exact test was used to compare categorical variables (count, rate or proportion) between these two groups. The choice of concurrent azole or sequential azole antifungal was determined by physician choice. Results: There were 40 patients treated with 7+3+midostaurin, 18 of whom received concurrent azole therapy, while 22 received sequential or no azole therapy. There were no significant differences in baseline characteristics (Table 1) except for more patients receiving isavuconazole (moderate CYP 3A4 inhibitor) in the concurrent group (50% vs 0%; p<0.01) and more micafungin in the sequential or no azole group (0% vs 72%; p<0.01). Overall CR/CRi rate with concurrent versus sequential or no azole was 72% (13/18) vs 77% (17/22), with no significant difference in median days to ANC recovery (27 vs 29; p=0.98), platelet recovery (28 vs 32 days; p=0.67), and non-hematologic grade 3 toxicities (22% and 45%; p=0.13), respectively. There were higher, but not significant, rates of midostaurin dose reductions (6% vs 0%; p=0.26) and holds (17% vs 14%; p=0.79) in the concurrent azole group. Conclusion: In conclusion, the addition of azole antifungal was found to be equally safe and effective in the treatment of newly diagnosed FTL3 AML. Dose modifications in midostaurin appeared not to be necessary with concurrent azole antifungal therapy. Further analysis based on a larger cohort is needed to confirm the outcomes and safety endpoints reported in the current study. Given the importance of azole anti-fungal therapy in the treatment of AML and specifically in induction therapy for AML (Cornely et al, NEJM 2007), dose modifications for this drug interaction should be studied in the future to help guide clinicians on how to appropriately dose these drugs.

Prephase Cyclophosphamide: An Advantageous Bridge to Definitive Therapy

Background Classic Hodgkin lymphoma (cHL) and aggressive non-Hodgkin lymphoma (NHL) account for an estimated 0.5% and 4.1% of all new cancer diagnosis in the US in 2023, respectively. At time of diagnosis, approximately 43% of cHL and 53% of NHL are staged as advanced disease (stage III-IV). While these diseases are considered curable, standard treatments involve intensive combination chemotherapy that may preclude certain patients from receiving optimal therapy. One option to minimize risks is to use prephase cyclophosphamide (pCy) as an initial treatment in aggressive lymphomas. There is however limited data on the utility, adverse effects, and outcomes of this approach. Here we present data on our institutional experience of employing pCy for patients ineligible for intensive chemotherapy. Methods We performed a single institution, retrospective chart review of patients with history of cHL and NHL that received cyclophosphamide (Cy) as an initial chemotherapy during hospitalization. Lymphoma subtype, medical history, baseline bloodwork at time of treatment initiation, outcomes including transplant, relapse data and overall survival were collected. Fifty patients received pCy at 200 mg/m2 with the remaining four receiving 100 mg/m2, 150 mg/m2, or 300 mg/m2 based on provider preference. Corticosteroids, including prednisone, dexamethasone or methylprednisolone, were administered simultaneously with varying duration and dosage. We analyzed hepatic and kidney injury at the time of diagnosis, after initiation of pCy and time to recovery. Acute kidney injury (AKI) was defined as an increase in creatine more than 30% from baseline and hepatic injury was defined based on Common Terminology Criteria for Adverse Events (CTCEA) version 5. Charlson scores for all patients were collected. Results Fifty-four patients received pCy as a bridge to possible definitive therapy. The most common diagnosis was diffuse large B-cell lymphoma (DLBCL) and cHL, with 29 (53.7%) and seven (13%) patients, respectively (Figure 1). The median age was 56 years (18-84) with 21 (39%) patients >65 years. Advanced stage was observed in 49 (90.7%) patients. Four patients required treatment for tumor lysis syndrome (TLS) prior to initiation of pCy. Nineteen (35%) patients had AKI and 15 (28%) patients had hepatic injury at the time of initial presentation. Five patients experienced AKI from pCy with an average time to recovery of 11.2 days. Six patients, with only two having concurrent AKI, had hepatic injury from pCy with an average time to recovery of 8.5 days. PCy allowed 42 (78%) patients to undergo definitive treatment in respect to their lymphoma subtype. Eight (14.8%) patients went on to receive a consolidative autologous transplantation (HSCT) after reaching a remission from definitive therapy. At the time of our analysis, 30 (55%) patients are deceased which includes four patients that underwent HSCT. Of the 30 deceased, 10 patients were transitioned to comfort care during the admission after receiving pCy. Median overall survival is 370.5 days. Conclusion Based on our institutional experience, pCy is a reliable method to salvage patients with aggressive lymphomas that are not candidates for intensive chemotherapy. In our analysis, pCy allowed 78% of patients to receive definitive therapy for their respective lymphoma. In general, patients receiving pCy required hospitalization related to disease burden and pCy represents an effective and cost-efficient bridging strategy to outpatient treatment. Cyclophosphamide has a broad indication across hematologic malignancies and is a well-tolerated chemotherapy with a limited side effect profile. The modest dosing in combination with corticosteroids allows initial disease control and provides the ability to start definitive therapy in a timely manner. Additionally, we feel that pCy should be considered when designing clinical trials in an effort to promote enrollment of the “real-world” patient.

Phase I Trial Combining Venetoclax with G-CSF, Cladribine, Cytarabine, and Mitoxantrone (CLAG-M) for Patients with High-Grade Myeloid Neoplasms

Background: Venetoclax in combination with hypomethylating agents or low dose cytarabine is a safe and effective treatment for newly diagnosed older, unfit patients with acute myeloid anemia (AML). Combining venetoclax with high intensity combination chemotherapy may increase response rates and eventual chance for cure. Previous studies have combined venetoclax with fludarabine, cytarabine, idarubicin, and G-CSF (FLAG-ida) with 89% of patients achieving a composite complete remission (CR), of which 93% were MRD negative (DiNardo et. al, AJH, 2022). We report the preliminary results of a phase 1 study examining the addition of venetoclax to a high intensity induction regimen, CLAG-M (cladribine, cytarabine, mitoxantrone, G-CSF), for fit patients with newly diagnosed adverse risk or relapsed/refractory high-grade myeloid neoplasms. Methods: Subjects with AML or other high-grade myeloid neoplasm (≥10% myeloid blasts in peripheral blood or marrow) were eligible if they had (1) new diagnosis with adverse risk disease by European LeukemiaNet 2017 criteria or (2) relapsed/refractory (R/R) disease. Venetoclax was administered on day 1-14 with a 4-day ramp-up. All patients received standard neutropenic prophylaxis and venetoclax was dose-adjusted for concomitant use of CYP3A4 inhibitors. Dose level (DL) is defined in Table 1. Dose limiting toxicity (DLT) was defined as grade >4 non-heme toxicity, prolonged aplasia > 49 days, or grade >3 non-heme toxicity lasting >48h and resulting in a treatment delay beyond day 56. Two subjects were started at DL 2 and a Bayesian optimal interval (BOIN) design was used for subsequent doses, with a true targeted DLT rate of 30%. Re-induction was allowed for persistent disease after the first cycle; subjects with CR were eligible to receive up to three cycles of venetoclax plus cladribine and cytarabine (CLAG) at the same dose level as induction. Target accrual is 20 subjects. Events were defined as death, relapse, or failure to achieve CR/CRi on post induction evaluation. The study was approved by the local IRB, and subjects were consented in accordance with the Declaration of Helsinki. Results: At time of data cutoff (7/6/23), 15 subjects (5 with newly diagnosed and 10 with R/R AML) were enrolled. Median age was 65 (range: 30-74) years. Five were newly diagnosed and 10 were R/R. Two subjects were enrolled at DL 1, 6 at DL 2, 5 at DL 3, and 2 at DL 4 as per the BOIN design. Two DLTs occurred: grade 4 respiratory failure at DL 2 and grade 5 sepsis at DL 3. Treatment related grade 3 adverse events (AE) included febrile neutropenia (5 subjects), dyspnea (2), mucositis (1), hypoxia (1), delirium (1), syncope (1), tumor lysis syndrome (1), and sepsis (1). Non-treatment related grade 3 AEs included hypokalemia (1 patient) and pericarditis (1). 28-day mortality was 7%. Twelve subjects received 1 cycle and 3 subjects received 2. Overall response rate (CR + CRi) was 73%. Two subjects achieved CR without MRD, 1 CR with MRD, 3 CRi without MRD, 5 CRi with MRD, 1 MLFS without MRD, 2 had persistent disease, and 1 died before evaluation. Median overall survival from treatment start was 7.4 months (95% CI 4.2 months - not reached [NR]). Median follow up of survivors was 6 months. Median event free survival was 3.3 months (95% CI 1.2 months - NR). Four subjects (1 newly diagnosed, 3 R/R) went on to receive allogeneic hematopoietic cell transplant (HCT). The administration of venetoclax presented challenges for inpatient and outpatient dosing, as medication diaries showed subjects underdosing venetoclax when taking concomitant posaconazole due to the complexity of the dosing regimen. Discussion: Preliminary results show that venetoclax can be safely added to a high intensity regimen for fit, high-risk patients without adversely affecting standard therapies including subsequent allogeneic HCT. Grade 3 and higher toxicity was common. In this preliminary analysis, the overall response rate was 73%, which is comparable to that observed with other chemotherapy regimens with the addition of venetoclax. A protocol amendment is in process to simplify venetoclax dosing with concomitant CYP3A4 inhibitors. This study will ultimately determine the MTD for subsequent phase II study to evaluate the therapeutic efficacy of venetoclax and CLAG-M.

XPO1 Inhibitor Triggers Autophagy of TP53-Mutated Burkitt's Lymphoma Cells

INTRODUCTION Burkitt lymphoma, a highly aggressive B-cell non-Hodgkin's lymphoma (NHL), has distinct pathological and clinical characteristics. Intensive combination chemotherapy has been widely used in the treatment of Burkitt lymphoma and survival has improved for Burkitt lymphoma patients. TP53 mutation frequency is not age related, and TP53 mutations are significantly associated with higher incidence of relapse. XPO1 inhibitors, novel targeted drugs, reversibly inhibit the nuclear export of tumor-associated proteins and mRNAs by blocking nuclear export protein 1 (XPO1). Preclinical and clinical studies of XPO1 inhibitors have been successfully used in treatment of AML, MM and NHL. METHODS We used CCK8 assays to detect growth inhibition in 4 lymphoma cell lines (Raji, Jeko-1, Daudi, and CA46) under the treatment of different concentrations of KPT330 (XPO1 inhibitor). The 4D-Label-free quantitative proteomics technology was used to determine the changes of protein distribution in the nucleoplasm and cytoplasm of CA46 cells before and after KPT330 treatment (50nM, 48h). The proteomic results were validated by QPCR, westernblotting assay and fluorescent marker analysis. RESULTS The lymphoma cell lines we choosed, Raji, Jeko-1, Daudi, and CA46, all have MYC rearrangement and TP53 mutations. CCK8 assay showed Jeko-1, Daudi and CA46 were relatively sensitive to KPT330 (IC50=86.87nM, 48.34nM and 87.85nM, respectively). The results of the quantitative proteomics suggested proteins with increased nucleo-cytoplasmic ratio after KPT330 treatment were mainly focused on autophagy regulation and p53 signal pathways, including TFEB, USP10, DAP, NRBF2, SQSTM1, etc ( Fig1, a). To confirm the effect of KPT330-triggered autophagy, first, we assessed the apoptosis rates of CA46 after exposure to KPT330 for 24 hours, all of which were below 10%, ruling out apoptosis-induced autophagy ( Fig1, b). Then, westernblotting results showed that the cytoplasm load of autophagy flux related proteins, LC3B-1 and LC3B-II, both increased after KPT330 treatment ( Fig1, c). To confirm whether KPT330 effects the generation or degradation of LC3B-II, we used the late autophagy inhibitor chloroquine (CQ) to cells and observed the p62 protein level reduced and LC3B-II protein level increased with additional use of CQ compared with only KPT330 treatment ( Fig1, d). Furthermore, the ratio of LC3B-II-CQ-presence to LC3B-II-CQ-absence in the KPT330-treated group was higher than that in the control group ( Fig1, d), suggesting that KPT330 may enhance the generation of LC3B-II. We further utilized the pLenti-CMV-mCherry-GFP-LC3B plasmid to establish an LC3B stable-overexpressing CA46 cell line. Flow cytometry analysis showed that the median fluorescence intensity of both GFP and mCherry signals increased after KPT330 treatment( Fig1, e), further confirming the overall elevation of LC3B levels. To investigate the mechanism behind the increased autophagy flux, we utilized westernblotting analysis to validate the results from quantitative proteomics. TFEB protein level showed an increase in nuclear-cytoplasmic ratio upon KPT330 treatment ( Fig2, a). TFEB is known as a transcriptional activation protein, and its nuclear translocation is associated with the upregulated expression of genes involved in autophagosome formation, autolysosome fusion and lysosome biogenesis. QPCR analysis validated that genes associated with the aforementioned processes, such as LC3B, VPS11, CTSD, and CLCN7, exhibited increasing expression levels from 6 to 24 hours after KPT330 treatment ( Fig2, b). More interestingly, USP10, a component of a regulatory loop that controls autophagy and p53/TP53 levels, significantly increased in cell nucleus after drug action ( Fig2, c), which suggested that KPT330 may stabilize p53 function. Finally, we also attempted to discover the potential synergistic therapeutic effect of KPT330 with commonly used chemotherapy drugs in clinical lymphoma treatment. However, none synergistic effect was observed according to KPT330 combined with Cytarabine, Doxorubicin, Azacitidine, Decitabine, Rapamycin, Bortezomib, Duvelisib or Venetoclax, respectively ( Fig2, d). CONCLUSION XPO1 Inhibitor, KPT330 can restrict nuclear export of autophagy-related proteins thus regulate autophagy and stabilize p53 function in TP53-mutated Burkitt's lymphoma cells, which revealed a promising treatment.

CAR T-Cells for the Treatment of B-Cell Acute Lymphoblastic Leukemia

B-cell acute lymphoblastic leukemia (B-ALL) is the most common subtype of acute leukemia in the pediatric population. The prognosis and treatment of B-ALL have dramatically improved over the past decade with the adoption of intensive and prolonged combination chemotherapy regimens. The advent of novel immunologic agents such as blinatumomab and inotuzumab has changed the treatment landscape of B-ALL. However, patients have continued to relapse, raising the need for novel therapies. Chimeric antigen receptor (CAR) T-cells have achieved a milestone in the treatment of B-ALL. Two CD19-targeting CAR T-cells were approved by the Food and Drug Administration and the European Medicines Agency for the treatment of relapsed and/or refractory B-ALL. In this review, we review the available data regarding CD19-targeting CAR T-cells with their safety profile as well as the mechanism of resistance to these agents and the way to overcome this resistance.

Profiling cGAS-STING pathway in T-Acute Lymphoblastic Leukemia

Abstract Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy, accounting for over one-quarter of all childhood malignancies. Approximately 15% of ALL derive from the T-cell lineage (T-ALL). Patients with newly diagnosed T-ALL undergo intensive multidrug combination chemotherapy resulting in many side effects. Despite chemotherapy regimens including steroids, and allogeneic transplantation, relapse remains the main challenge in children with T-ALL. Moreover, genetic alterations have been extensively examined in recent years; however, there are still currently few prognostic markers for therapy response. Therefore, alternative treatments are needed to treat this disease and improve overall survival. The cyclic GMP-AMP synthase - Stimulator of Interferon Genes (cGAS-STING) pathway has emerged as a possible target in treatment of cancers, aiming to increase anti-tumor immunity. Most clinical trials to-date have focused on STING agonists used for solid tumors. Interestingly, the high activation of this pathway in normal T cells can lead to ER stress and cell death via the activation of the BH3-family. The status of cGAS-STING pathway in T-ALL is largely unknown. We hypothesize that the cGAS-STING pathway is defective in T-ALL, thus protecting these malignant cells from apoptosis, and that increasing cGAS-STING activity may be a way of enhancing the treatment of this disease. Our preliminary data shows that some T-ALL cell lines do not produce IFN-β after stimulation to STING agonist. Also, some of these cell lines have a decreased cGAS expression, and have a decreased rate of apoptosis compared to healthy T-cells. Our project will hopefully lay the foundation for future targeted immunotherapies for treating T-ALL. Center for Pediatric Immunotherapy at Rainbow

Abstract 1565: Targeting of KIF11 and AURKA to improve outcomes in Ewing sarcoma

Abstract Ewing Sarcoma (EWS) is a rare and aggressive pediatric malignancy of the bone and soft tissues. Despite intensive systemic combination chemotherapy and surgery/radiotherapy for local control, patients with metastatic disease have dismal prognosis (<30% overall survival rate). To identify better therapies for patients with refractory, recurrent and metastatic disease, we previously conducted in silico and drug re-purposing screens (PMID: 27863422; 31025088) that identified proteins essential for mitotic spindle formation and cell cycle progression such as Aurora Kinase A (AURKA), Kinesin Family Member 11 (KIF11), Kinesin Family Member 15 (KIF15) and its binding partner; targeting protein for Xklp2 (TPX2) that are upregulated by EWS-FLI1, the primary oncogenic driver of EWS, indicating their potential as therapeutic targets. KIF11 and KIF15 are mitotic motor kinesins essential for bipolar spindle formation, whereas AURKA is a mitotic kinase essential for centrosome maturation and mitotic spindle assembly. Though KIF11 and AURKA inhibitors have been extensively used in clinical trials before but have not been tested together in combination for any type of cancer. We hypothesized that targeting these two key proteins essential for mitotic progression provides a therapeutic vulnerability for Ewing Sarcoma by inducing G2/M arrest and mitotic catastrophe. Specific KIF11 (SB-743921) and AURKA (VIC-1911, VITRAC Therapeutics) inhibitors were used for targeting these proteins. We evaluated the in vitro activity of VIC-1911 and SB-743921 and synergy was measured by percentage inhibition of growth via SynergyFinder, that employs reference models (Bliss) to score synergy (scores >10 is synergistic). EWS showed strong synergistic interaction at physiologically relevant doses compared to control cell lines (e.g., mesenchymal stem cells and non-EWS tumor cells). This drug combination was effective in refractory EWS cells established post-chemotherapy (synergy score >24) and at much lower doses in cells established from pre-treatment tumor tissue (synergy score >27) indicating effectiveness at various clinical stages of EWS disease. Importantly, this therapy appeared preferential to EWS cells with an EWS-ETS fusion as compared to non-EWS cells. We observed zero colony formation in vitro with the combination treatment and increased percentage accumulation of cells in G2/M phase upon cell-cycle analysis indicating mitotic arrest. In vivo studies in EWS xenograft mouse models showed sustained tumor regression (NED at 30 days after ending therapy). The combination arm showed significant survival versus control (p≤ 0.001, HR=0.42, 95% CI=0.14-1.25), VIC-1911 (p≤ 0.001, HR=0.48, 95% CI=0.16-1.42) or SB-743921 (p ≤ 0.01, p≤ HR=0.71, 95% CI=0.21-2.34) alone. Efforts are underway to translate these preclinical studies into an early phase clinical trial of patients with histologically proven EWS who have failed standard of care therapy. Citation Format: Soumya M. Turaga, Vikalp Vishwakarma, Stacey Hembruff, Rajni Puri, Priya Sabu, Glenson Samuel, Andrew K. Godwin. Targeting of KIF11 and AURKA to improve outcomes in Ewing sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1565.

Burkitt’s Lymphoma of the Thyroid: A Case Report

Burkitt’s Lymphoma arises from mature B cells and is a highly aggressive neoplasm but potentially responds to intensive combination chemotherapy. Primary thyroid lymphomas are rare and Burkitt lymphoma of thyroid is still rarer. We present the case of middle-aged lady with rapidly enlarging neck mass diagnosed as Burkitt’s Lymphoma post hemithyroidectomy. She received systemic combination chemotherapy and is in remission at a follow up of 1 year.

Moving towards biologically informed treatment strategies for T-cell lymphomas.

The rarity and biological heterogeneity of the peripheral T-cell lymphomas has made subtype- and biomarker-driven approaches challenging to realize and even more challenging to evaluate in clinical practice. Out of necessity, treatment of T-cell lymphomas has historically been derivative of other aggressive lymphomas, utilizing intensive combination chemotherapy programs in the upfront setting and non-overlapping cytotoxic regimens upon relapse. However, due to tremendous work in understanding the oncogenic basis of these varied diseases, an increasing exploration of rational, targeted therapies is underway. Still, clinical successes have at times lagged behind pathobiological realizations, and there is an evolving need for biologically based, subtype-specific strategies in the clinic. Herein we propose a framework for future success that relies upon optimizing standard therapy in populations known to benefit from combination chemotherapy, building upon CHOP (or CHOP-like) induction with the CHOP + X model, exploring the use of targeted platforms in the relapsed and refractory setting, and designing biomarker-informed clinical trials that target-specific subhistologies and unique molecular subsets.

Lymphocyte Exhaustion in AML Patients and Impacts of HMA/Venetoclax or Intensive Chemotherapy on Their Biology.

Simple SummaryPatients with acute myeloid leukemia (AML) are routinely treated with either intensive chemotherapy or DNA hypomethylating agents (HMA) in combination with the Bcl-2 inhibitor, venetoclax. While both treatment regimens are highly cytotoxic to the aggressive AML tumor cells, they are also toxic to immune cells. Therefore, we sought to establish the detrimental impacts of these therapies on lymphocytes and their recovery over time in AML patients. Even prior to treatment initiation, the patients were found to have exhausted lymphocytes in peripheral blood, and additional signs of exhaustion were noted after treatment with HMA/venetoclax. In fact, the lymphocytes were still suppressed for two to three months after the initiation of induction therapy. Furthermore, T cells in a subset of patients subsequently found to be resistant to venetoclax therapy exhibited a higher expression of perforin and CD39 and more pronounced IFN-γ production.Acute myeloid leukemia (AML) is an aggressive malignancy that requires rapid treatment with chemotherapies to reduce tumor burden. However, these chemotherapies can compromise lymphocyte function, thereby hindering normal anti-tumor immune responses and likely limiting the efficacy of subsequent immunotherapy. To better understand these negative impacts, we assessed the immunological effects of standard-of-care AML therapies on lymphocyte phenotype and function over time. When compared to healthy donors, untreated AML patients showed evidence of lymphocyte activation and exhaustion and had more prevalent CD57+NKG2C+ adaptive NK cells, which was independent of human cytomegalovirus (HCMV) status. HMA/venetoclax treatment resulted in a greater fraction of T cells with effector memory phenotype, inhibited IFN-γ secretion by CD8+ T cells, upregulated perforin expression in NK cells, downregulated PD-1 and 2B4 expression on CD4+ T cells, and stimulated Treg proliferation and CTLA-4 expression. Additionally, we showed increased expression of perforin and CD39 and enhanced IFN-γ production by T cells from pre-treatment blood samples of venetoclax-resistant AML patients. Our results provide insight into the lymphocyte status in previously untreated AML patients and the effects of standard-of-care treatments on their biology and functions. We also found novel pre-treatment characteristics of T cells that could potentially predict venetoclax resistance.

Multidisciplinary treatment of advanced or recurrent solid pseudopapillary neoplasm of the pancreas: three case reports

BackgroundSolid pseudopapillary neoplasm (SPN) is a rare pancreatic tumor that predominantly affects young females. Prognosis is excellent; however, 10–15% of patients show metastasis at the time of surgery or develop tumor recurrence after pancreatectomy.Case presentationWe reviewed the clinical course of three patients with advanced or recurrent SPN and subsequently underwent multidisciplinary treatment at our institution between 2002 and 2019. The primary tumor was resected in all three patients, and metastases were also resected if indicated. Intensive combined therapy, including re-resection, chemotherapy, ablation, arterial chemoembolization, and radiation therapy, allowed all patients to survive for a long time. The literature review showed that resection seems to be more effective than other treatments for metastatic SPN.ConclusionsMultidisciplinary treatment, including resection, may improve the prognosis of patients with SPN with recurrence or metastasis.

PCT3, a Combination of Active Steroidal Saponins from the Paris Forrestii (Takht.) H. Li, Displays Potent Activity Against Acute Myeloid Leukemia By Suppressing the PBX1/RNF6/AKT/mTOR Signaling Pathway

Acute myelogenous leukemia (AML) is a class of malignancy derived from the myeloid line of aberrant progenitor/stem cells from bone marrow. AML is incurable and the five year rate of the event free survival (EFS) remains less than 20% even with the intensive chemotherapy in combination with autologous hematopoietic stem cell transplantation. Therefore, it is urgent to find novel drugs to improve the outcome of AML patients. Paris forrestii (Takht.) H. Li is a traditional herb medicine specifically produced in the Yu'nan and Tibet regions of China and it is widely used for the inflammation and coagulation among local people. In the study to identify natural products for cancer treatment, we isolated and evaluated the active ingredients from Paris forrestii (Takht.) H. Li and found that PCT3, a combination of steroidal saponins, displayed potent anti-AML activity. The high performance liquid chromatography/mass spectrometry (HPLC/MS) assay isolated and identified 10 steroidal saponins (SPs). In the preliminary study, each individual SP displayed limited cytotoxicity to AML cell lines K562 and HL-60. However, when a random combinations of the SPs were tested, it turned out that PCT3 (mainly composed of Polyphyllin I and III) was the most potent one in inhibiting AML cell prolipferation. The IC50 of PCT3 on K562 was 2.935 ± 0.772 μg/ml within 24 hrs. Moreover, PCT3 induces potent AML cell apoptosis in a concentration-dependent manner. At the ranges of 0 to 8μg/ml, PCT3 induces apoptosis of selected AML cell lines, including K562, HL-60, HT-93 and KG-1 as evidenced of the cleavage and activation of Caspase-3 and PARP. Consistent with this finding, PCT3 downregulated oncoproteins such as Bcl-2 and Mcl-1 but upregulated pro-apoptotic signaling proteins including Bax. The anti-AML activity of PCT3 was further evaluated in AML xenografts in nude mice derived from K562 cells. Oral administration of PCT3 at 100 mg/kg for a continuous 14 days markedly delayed AML tumor growth but had no effects on mice body weight. These results thus suggested that PCT3 displayed potent anti-AML activity in both molecular, cellular and nude mice levels. To understand the underlying molecular mechanisms PCT3 kills AML cells, we first evaluated the AKT/mTOR signaling pathway, a central node of AML cell proliferation and AML cell survival. To our expectation, PCT3 suppressed the activation of the AKT/mTOR signals. PCT3 inhibited the phosphorylation of AKT and mTOR, but had no effects on their total protein expression levels. Consistently, 4E-BP1 and p70S6K, two typical downstream proteins of the AKT/mTOR pathway, were also inhibited by PCT3 in a concentration-dependent manner. Moreover, we found that PCT3 inhibited the expression of the PBX1, a key transcription factor in AML (Xu X et al, J Biol Chem, 2016). PBX1 promotes leukemia cell proliferation by promoting the transcription of RNF6, a ring finger protein. Interestingly, the PBX1/RNF6 axle upregulated the activation of the AKT/mTOR signaling pathway. Therefore, we found that PCT3 displayed potent anti-AML activity by suppression the PBX1/RNF6/AKT/mTOR signaling pathway. Given its tolerable toxicity and anti-AML activity, PCT3 could be developed for AML treatment. DisclosuresNo relevant conflicts of interest to declare.

Comparison of Induction Chemotherapy in NSG and NOD- Rag1 null IL2rg null Mouse Models of FLT3 Mutant AML

Background and objectives: Induction chemotherapy that combines Ara-C (cytarabine, 7 days) with an anthracycline such as daunorubicin or doxorubicin (Adriamycin, 3 days) (DA) is a standard induction therapy in AML. Immunodeficient NSG or NSGS mice are extremely useful for preclinical drug testing and are promiscuous recipients of primary AML engraftment. However, these models have limitations for use of genotoxic chemotherapy that often induces toxicity and mortality to the recipient mice, particularly in AML patient-derived xenograft (PDX) models when irradiation is required. The sensitivity of NSG or NSGS mice to genotoxic drugs and irradiation are due to SCID mutation in the mice. In this study we have compared tolerability and efficacy of DA chemotherapy in NSG and NRG (NOD- Rag1 null IL2rg null) AML-bearing mice. We used a FLT3 mutant AML Molm13 cell line to generate AML xenograft in NRG and NSG mice and then tested the response to chemotherapy using combined Ara-C and doxorubicin chemotherapy with or without sub-lethal irradiation. Testing of chemotherapy regimen in human AML PDX models is ongoing and will be presented.Methods and results: The AML mouse models were established by i.v. injection of GFP and firefly luciferase transduced Molm13 cells (0.6 x 106 cells per mouse) into NSG and NRG mice (n=5 per group, F, 8 weeks old). In experiments testing sub-lethal radiation, NSG mice were irradiated with 200 cGy and NRG mice with 400 cGy before cell injection. AML cell engraftment and growth in vivo was monitored by bioluminescent imaging (BLI). Engraftment was confirmed on day-3 (Fig. 1A-B) and chemotherapy started on day-4 using combined Ara-C (50 mg/kg, i.v. 5 days) and doxorubicin (1.5 mg/kg, i.v., 3 days) (DA 5+3) or PBS. NSG and NRG mice (n=3 each) that served as naïve controls without bearing Molm13 cells also received the chemotherapy. Mouse health conditions and body weights were monitored daily, and mice were followed for survival.As shown by BLI in Figure 1 A-B, DA 5+3 significantly reduced leukemic burden in both NRG and NSG mice compared to PBS treated mice (p<0.001 on day 13 or 14). The chemotherapy also induced transient toxicity in all treated mice with significant body weight loss in the sub-lethal irradiated AML NSG mice (Figure 1C, 30% loss on day 10, p=0.016 vs PBS treated mice), resulting in lethality earlier than PBS treated mice (Figure 1D, p=0.0019). Complete blood cell counts showed pancytopenia with anemia of the moribund treated Molm13 NSG mice. Overall, chemotherapy induced more body weight loss in NSG than that in NRG mice (a transient 25% body weight loss in naive NSG and AML NSG mice compared to 10% loss in NRG mice on day 10), indicating that NSG mice are more susceptible to chemotherapy-induced toxicity. All AML NRG mice and NSG mice without prior sub-lethal irradiation survived the chemotherapy and had significantly prolonged survival.We further challenged the NRG mice with a more intensive chemotherapy regimen by administrating Ara-C for 7 days (DA 7+3) mimicking the one used in AML patients. BLI confirmed more effective leukemia control by this regimen compared to DA 5+3 and significantly extended survival.Conclusion: The results demonstrate that Molm13 bearing NSG and NRG mice have identical latency, leukemia growth kinetics, and survival, suggesting that like NSG mice, NRG mice are suitable recipients for AML xenograft studies. Both Molm13 NSG mice and NRG mice showed strong efficacy in response to chemotherapy using Ara-C (cytarabine, 50 mg/kg) and doxorubicin (1.5 mg/kg) with the regimen of DA 5+3. However, this regimen was not tolerable when mice required prior sublethal irradiation, with excessive bodyweight loss and mortality in NSG but not in NRG mice. In contrast, Molm13 NRG mice can tolerate a more intensive combination chemotherapy regimen of AraC administered for 7 days (DA 7+3). In summary, NRG mouse model showed better tolerance to chemotherapy and irradiation than the NSG model, thus representing a superior in vivo AML model for pre-clinical studies with genotoxic agents. [Display omitted] DisclosuresCarter:Daiichi Sankyo: Research Funding; novartis: Research Funding.

MicroRNA-155-5p promotes tumor progression and contributes to paclitaxel resistance via TP53INP1 in human breast cancer

MicroRNAs (miRNAs/miRs) are small, non-coding RNAs that are reported to serve numerous important regulatory functions; however, the role of miRNAs in regulating breast cancer cell biology remains poorly understood. Accumulating evidence has demonstrated that miRNAs orchestrate multiple cellular functions and serve crucial roles in cell differentiation and cancer development, either by acting as tumor suppressors or oncogenes. In particular, miR-155-5p expression levels have been found to be upregulated and serve as a prognostic marker in numerous types of solid cancer, including human breast cancer. More than half of patients with breast cancer benefit from treatment with adjuvant paclitaxel chemotherapy following the early postoperative period. Despite the initial response to intensive combination chemotherapy, the majority of most patients will eventually acquire resistance to the drug and succumb to their disease. Therefore, further investigations into the association between miRNAs and the mechanism of paclitaxel resistance are required. The results of the present study revealed a strong positive association between miR-155-5p expression levels and the paclitaxel resistance, as the expression levels of miR-155-5p were upregulated in resistant cells. MiR‐155-5p was further validated to regulate paclitaxel resistance using gain- and loss‐of‐function experiments. TP53INP1 was identified as a direct target gene of miR-155-5p by combining the results from the prediction algorithm based on free energy minimization and reverse transcription-quantitative PCR (qRT-PCR) analysis. Also, miR-155-5p was suggested to be a key regulator of paclitaxel resistance in tumor cells, as it increased cell viability and motility, and promoted resistance to paclitaxel‐induced apoptosis. The transfection with miR-155-5p inhibitors re-sensitized the paclitaxel-resistant breast cancer cells, while the overexpression of miR-155-5p led to an increase in the resistance to paclitaxel. Furthermore, the overexpression of the target gene, TP53INP1, contributed to the re-sensitivity of drug-resistant cells to paclitaxel. The subsequent combination of the knockdown of miR-155-5p and the overexpression of TP53INP1 conferred paclitaxel sensitivity in resistant cells. These results may enhance the understanding of the molecular mechanisms underlying breast cancer progression and resistance to chemotherapy, and suggested that miR-155-5p or TP53INP1 may serve as novel therapeutic approaches to combat resistance to therapy, as well as the proliferation and evasion of apoptosis in breast cancer.

Advances and unanswered questions in management of acute myeloid leukemia in older adults: A glimpse into the future

Advances in molecular diagnostics and drug development have ushered an era of precision oncology in acute myeloid leukemia (AML). The availability of effective molecularly targeted and other novel drugs allows use of low intensive combination chemotherapy in older adults, and even single-agent oral drugs for some patients. These changes are shifting treatment away from intensive chemotherapy requiring prolonged inpatient hospitalization to outpatient treatment closer to home for some patients. While we celebrate our recent successes, we face several challenges and opportunities to further improve quality of life and longer-term survival of older adults with AML.

Therapeutic Targeting of Mesothelin in Acute Myeloid Leukemia with Chimeric Antigen Receptor T Cell Therapy

Background: Acute myeloid leukemia (AML) is one of the most highly refractory hematologic malignancies despite intensive combination chemotherapy and bone marrow stem cell transplantation. Lack of curative treatments is in large part due to our poor understanding of the disease biology and paucity of therapeutic targets. In an effort to identify actionable targets, we recently completed the largest genome, epigenome and transcriptome profiling of AML in nearly 3000 children and young adults. This discovery effort has led to the identification of a library of novel AML-restricted targets (high expression in AML, minimal-to-no expression in normal hematopoiesis) for therapeutic development. One such target was MSLN which encodes for mesothelin, a cell surface adhesion molecule that is highly expressed in 30-50% of AML cases in pediatric (Children Oncology Group) and adult (MD Anderson) cohorts and is entirely absent in normal bone marrow and peripheral blood CD34+ cells. MSLN expression in normal tissues is confined to mesothelial cells lining the pleura, pericardium, and peritoneum. Previous studies targeting MSLN in solid tumors have demonstrated clinical efficacy with minimal toxicities. Given that T cells genetically modified to express chimeric antigen receptors (CARs) are extremely effective at eradicating relapsed and refractory malignancy, we developed MSLN-directed CAR T cells for pre-clinical evaluation in AML. Methods: From primary patient samples, we verified MSLN expression by RT-PCR and confirmed mesothelin surface protein expression on leukemic blasts by flow-cytometry as well as detected soluble mesothelin in the plasma by ELISA. The VH and VL sequences from Amatuximab were used to create the scFv domain of the standard CAR (41-BB and CD3Zeta). For in vivo CAR T study, Nomo-1 cells, which express endogenous level of MSLN, and Kasumi-1 cells engineered to express MSLN with a lentivirus construct (Kasumi-1 MSLN+) were transplanted into NSG mice. Mock transduced MSLN-directed CAR T cells were infused 1 week (Nomo-1) and 2 weeks (Kasumi-1 MSLN+) following leukemic cell injection. Leukemic burden was measured by bioluminescence IVIS imaging weekly. For in vitro study, Nomo-1 cells were treated with GM6001 (50uM), a metalloprotease inhibitor, or DMSO control for 48 hr prior to evaluation of surface mesothelin by flow cytometry and soluble mesothelin in the culture supernatant by ELISA. Results: In vivo cytotoxicity of CAR T cells against Nomo-1 and Kasumi-1MSLN+ AML models demonstrated potent, target-dependent tumor killing. After 1- and 2-weeks post CAR T infusion, leukemic cells were eradicated in both Nomo-1 (p&amp;lt;0.0005, week 2, Figure 1A) and Kasumi-1 MSLN+ xenografts (p&amp;lt;0.005 at week 2, Figure 1B). Mesothelin undergoes shedding at the cell membrane as a result of ADAM17-mediated cleavage. Blocking ADAM17 activity with GM6001 in Nomo-1 cells led to increased cell surface mesothelin (Figure 1C) with a corresponding reduction in the shed form (Figure 1D), suggesting that GM6001 treatment stabilizes mesothelin on the cell surface. Furthermore, GM6001 treatment during co-culture of Nomo-1 and CAR T cells enhanced cytolytic activity of CAR T cells (Figure 1E). GM6001 treatment did not significantly impact cell viability of Nomo-1 cells in the absence of CAR T cells (data not shown). Conclusion: In this study, we demonstrate that mesothelin is a viable therapeutic target and a potential diagnostic biomarker in AML. We show that MSLN CAR T cells were highly effective in eliminating MSLN-positive AML cells in vitro and in vivo. Shedding contributes to the loss of mesothelin antigen and provides a source of soluble mesothelin that may interfere with antibody-based therapies, including CAR T cells. Modulating MSLN shedding by inhibiting ADAM17-mediated cleavage resulted in stabilized mesothelin and improved CAR T cell functionality. This work warrants further evaluation of MSLN CAR T cells to be tested in clinical trials for AML and demonstrates that inhibiting MSLN shedding is a promising approach to improve CAR T efficacy. Disclosures No relevant conflicts of interest to declare.

P-111 Prognostic value of inflammation-based scores for patients treated with FOLFIRINOX or gemcitabine plus nab-paclitaxel

Inflammation-based scores such as the modified Glasgow prognostic score (mGPS) or Neutrophil-Lymphocyte ratio (NLR) is associated with the clinical outcome of patients with various solid tumors. However, the clinical impact of these prognostic scores for patients with advanced pancreatic cancer who received intensive combination chemotherapy remains unclear in the real-world setting.