Current Standard Chemotherapy Research Articles

Role of High-Dose Adjuvant Chemotherapy Followed by Autologous Stem Cell Transplantation in Locally Advanced Triple-Negative Breast Cancer: A Retrospective Chart Review.

Purpose Women with locally advanced/high-risk triple-negative breast cancer treated with the current standard chemotherapy continue to have a poor prognosis. High-dose chemotherapy with autologous stem cell transplant as treatment for locally advanced/high-risk breast cancer remains controversial due to a lack of survival benefit seen in previous phase III trials. However, these trials evaluated a heterogeneous group of patients with different receptor subtypes. A marginal benefit was observed in certain subgroups. We report long-term outcomes of women with stage IIB or III triple-negative breast cancer treated with high-dose chemotherapy followed by autologous stem cell transplant at our institution between 1995 and 2001. Methods This is a retrospective analysis of stage IIB or stage III triple-negative breast cancer treated with high-dose chemotherapy followed by autologous stem cell transplant. We excluded women with hormone-positive, HER2/neu-positive/unknown, and/or metastatic disease prior to transplant as per updated AJCC 7th edition guidelines. Patients underwent surgery and either neoadjuvant or adjuvant anthracycline and taxane-based chemotherapy and then proceeded to high-dose chemotherapy and autologous stem cell transplant using carmustine 600 mg/sqm, cyclophosphamide 5.6gm/sqm, and cisplatin 165 mg/sqm (STAMP 1 regimen) for consolidation. This was followed by locoregional breast and lymph node radiation per standard of care. Results Twenty-nine women (2 stage IIB and 27 stage III) were evaluated. The median age at diagnosis was 43 years (IQR: 40, 51). Eleven patients had 4–9 regional lymph nodes (LN) involved and 16 had 10+ involved LNs. Four patients had T4 or inflammatory breast cancer and two had ipsilateral supraclavicular LNs involved. The median follow-up time is 16 years (95% CI: 12, 19, range <1–19 y) posttransplant. The median overall survival was 15 years (95% CI: 3, 19); the median DFS was 14 years (95% CI: 1, 19). Conclusions This study of locally advanced/high-risk triple-negative breast cancer treated with adjuvant high-dose chemotherapy and autologous stem cell transplant reveals high overall survival rate. With the current improvement in treatment-related mortality, re-evaluating this approach in this subset of high-risk breast cancer in prospective randomized studies may be worthwhile.

Establishment and Genetic Profiling of Platinum/Taxane Doublet-Resistant Cells Generated by Hybridizing Single Resistant Cells

Background: Current standard chemotherapy for gynecologic malignancies consists of platinum agent and taxane though, many patients experience the relapse of disease with drug resistance making the following therapy unsuccessful. It’s a compelling question whether the mechanisms of doubly resistance is a simple combination of single agent resistance or whether the core novel mechanism common to platinum and taxane resistance stands out as a result of combination therapy. The purpose of this study is to establish the doublet drug resistant cell line and to find its genetic characteristics. Methods: Platinum/taxane doublet resistant cell lines (F3 and F4) were generated by hybridizing two independent, platinum or taxane resistant subline (C13 or PX24) stemmed from grand parental ME180 cells. The resistant cells were selected through repeated exposure to cisplatin and paclitaxel. For the assessment of drug sensitivity, colony forming assay was used. For the gene expression analysis, genome-wide expression profiling was done using the Human Genome U133A Array. Protein-protein interaction network (PPI) scaffold networks were retrieved from the Search Tool for the Retrieval of Interacting Genes database and, for the enrichment of pathway analysis, WebGestalt was used. Results: Colony forming assay showed C13 was 5.8-fold cisplatin resistant while PX24 was 5.3-fold paclitaxel resistant compared with parental ME180 cells. F3 and F4 acquired resistance to cisplatin and paclitaxel by 8.3/4.9- and 3.7/3.3-fold (F3/4) respectively. Microarray analysis demonstrated, out of 22284 genes, 103 genes were &gt;4-fold up-regulated in F3/4 and 33 (32%) were identified as simultaneously upregulated genes (SUG) in C13, PX24 and F3/4. The Protein-protein interaction analysis of 33 SUG displayed a scaffold network pivoting aldo-keto reductase 1C1 (AKR1C1), aldo-keto reductase1C2 (AKR1C2) and aldo-keto reductase1C3 (AKR1C3). The enrichment pathway analysis demonstrated AKR1C gene family anchored to molecular function of oxidoreductase and aldo-keto reductase activity and biological process of daunorubicin and doxorubicin metabolism. Conclusions: We report here the establishment of doubly drug-resistant hybridoma to platinum and taxane. Analysis of SUG indicated the AKR1C gene family plays a key role for doubly resistant mechanism that would be possible targets for therapeutic strategies.

SY06-3 Current status and prospects for the development of immune checkpoint inhibitors in Japan

In biliary tract cancers, the efficacy of immune checkpoint inhibitor (ICI) monotherapy is limited except for patients with microsatellite instability high (MSI-H), which account for 1-2% of all biliary tract cancers. Since ICIs are not highly effective as single agents, combination therapies are being developed. Three international phase III trials (NCT04003636, NCT0375235, NCT04066491) are planned to evaluate the efficacy of ICI in addition to the current standard chemotherapy, gemcitabine/cisplatin (GEM/CDDP), and several Japanese institutions are participating these trials.

INTEGRATE IIb: A randomized phase III open label study of regorafenib + nivolumab versus standard chemotherapy in refractory advanced gastroesophageal cancer (AGOC).

TPS366 Background: Advanced Gastro-oesophageal Carcinoma (AGOC) has a poor prognosis, and there is no established standard treatment following failure of first- and second-line chemotherapy. Regorafenib (BAY 73-4506) is an investigational oral multi-targeted tyrosine kinase inhibitor (TKI) which targets angiogenic (VEGF, TIE-2), stromal (PDGF-β), and oncogenic (RAF, RET and KIT) receptor tyrosine kinases, and has shown activity in this setting. Single agent regorafenib prolonged progression free survival (PFS) versus placebo across all regions/subgroups in the INTEGRATE randomised phase 2 trial. Current options in refractory AOGC involves sequencing through chemotherapy with the latest active agent approved being trifluridine/tipiracil, TAS-102. Promising activity in refractory AOGC has been seen with the combination of regorafenib &amp; nivolumab. INTEGRATE IIb–will compare the effectiveness of the combination of regorafenib &amp; nivolumab in pre-treated patients with AGOC to current standard chemotherapy. Methods: Randomised phase III, open label study with 2:1 randomisation (RegoNivo : standard chemotherapy) and stratification by: Geographic region (Asia vs. Rest of World); Prior VEGF inhibitors (Yes vs No); Prior immunotherapy (Yes vs No). RegoNivo arm will receive 90mg (3x30mg) of regorafenib days 1-21 of each 28-day treatment cycle with intravenous nivolumab 240 mg day 1 of each 14 day cycle until disease progression or prohibitive adverse events as per protocol. The control arm will receive the investigator’s choice of the following chemotherapy; a taxane (paclitaxel or docetaxel), irinotecan or oral trifluridine/tipiracil (TAS102). Primary endpoint: OS. Secondary endpoints: PFS, response rate, quality of life, toxicity, exploratory correlative biomarkers. Clinical trial information: NCT04879368.

GPER Agonist G-1 Disrupts Tubulin Dynamics and Potentiates Temozolomide to Impair Glioblastoma Cell Proliferation.

Glioblastoma (GBM) is the most common brain tumor in adults, which is very aggressive, with a very poor prognosis that affects men twice as much as women, suggesting that female hormones (estrogen) play a protective role. With an in silico approach, we highlighted that the expression of the membrane G-protein-coupled estrogen receptor (GPER) had an impact on GBM female patient survival. In this context, we explored for the first time the role of the GPER agonist G-1 on GBM cell proliferation. Our results suggested that G-1 exposure had a cytostatic effect, leading to reversible G2/M arrest, due to tubulin polymerization blockade during mitosis. However, the observed effect was independent of GPER. Interestingly, G-1 potentiated the efficacy of temozolomide, the current standard chemotherapy treatment, since the combination of both treatments led to prolonged mitotic arrest, even in a temozolomide less-sensitive cell line. In conclusion, our results suggested that G-1, in combination with standard chemotherapy, might be a promising way to limit the progression and aggressiveness of GBM.

1438TiP INTEGRATE IIb: A randomised phase III open label study of regorafenib + nivolumab vs standard chemotherapy in refractory advanced gastro-oesophageal cancer (AGOC)

Advanced Gastro-oesophageal Carcinoma (AGOC) has a poor prognosis, and there is no established standard treatment following failure of first- and second-line chemotherapy. Regorafenib (BAY 73-4506) is an investigational oral multi-targeted tyrosine kinase inhibitor (TKI) which targets angiogenic (VEGF, TIE-2), stromal (PDGF-β), and oncogenic (RAF, RET and KIT) receptor tyrosine kinases, and has shown activity in this setting. Single agent regorafenib prolonged progression free survival (PFS) versus placebo across all regions/subgroups in the INTEGRATE randomised phase II trial. Current options in refractory AOGC involves sequencing through chemotherapy with the latest active agent approved being trifluridine/tipiracil, TAS-102. Promising activity in refractory AOGC has been seen with the combination of regorafenib & nivolumab. INTEGRATE IIb – will compare the effectiveness of the combination of regorafenib & nivolumab in pre-treated patients with AGOC to current standard chemotherapy. Randomised phase III, open label study with 2:1 randomisation (RegoNivo: standard chemotherapy) and stratification by: 1. Geographic region (Asia vs. Rest of World) 2. Prior VEGF inhibitors (Yes vs No) 3. Prior immunotherapy (Yes vs No) RegoNivo arm will receive 90mg (3x30mg) of regorafenib days 1-21 of each 28-day treatment cycle with intravenous nivolumab 240 mg day 1 of each 14 day cycle until disease progression or prohibitive adverse events as per protocol. The control arm will receive the investigator’s choice of the following chemotherapy; a taxane (paclitaxel or docetaxel), irinotecan or oral trifluridine/tipiracil (TAS102). Primary endpoint: OS. Secondary endpoints: PFS, response rate, quality of life, toxicity, exploratory correlative biomarkers. NCT04879368. Australasian Gastro-Intestinal Trials Group.

The impact of the SARS-COV2 pandemic on the delivery of chemotherapy for gynecologic cancer at a tertiary care institution in the United States epicenter

Objectives:In New York City, the SARS-CoV2 pandemic epicenter of the United States, the surge of cases predated much of the country by several weeks, leading to changes in practice patterns that have informed decisions made by other medical institutions. As the SARS-CoV2 pandemic unfolded, many professional subspecialty organizations released practice guidelines in order to minimize transmission of COVID-19 and protect vulnerable populations. The impact of modifications to traditional gynecologic cancer treatment is not known. Here, we describe the impact of the SARS-COV2 pandemic on chemotherapy practices for gynecologic cancer during the pandemic surge.Methods:We identified patients age 18 or older at Montefiore Medical Center who had a confirmed or suspected diagnosis of gynecologic cancer and received care between March 16, 2020 and June 7, 2020; these dates reflect a series of executive orders issued by the Governor of New York allowing the State Commissioner of Health to cancel elective procedures at hospitals and ambulatory surgery centers. Clinical data were abstracted from patients’ charts. Patients with incomplete treatment records were excluded.Results:A total of 146 women who were included to whom 169 cycles of cytotoxic chemotherapy were delivered during the study period and 68 women (46.6%) received at least one cycle of chemotherapy. Nine patients screened positive for symptoms of COVID or active infection during the study period. Among patients receiving chemotherapy, 52.9% (n=36) had modifications to traditional cancer treatment as a result of state and institutional regulations. Dose reduction was the leading pandemic-related treatment modification and occurred in 69.4% of patients (n=25). Other treatment modifications included prophylactic use of pegfilgrastim (n=1), and treatment deferral or delay (n=7). Women receiving a platinum-based doublet (n=36) during the study period were more likely to sustain dose reduction in chemotherapy (25%) compared to patients undergoing other regimens (0%). A total of 111 women received at least one dose of disease-modifying therapy during the cohort period including chemotherapy, immunotherapy, anti-angiogenesis agents, hormonal therapy, PARP inhibitors, or investigational agents. Treatments were most often discontinued due to completion of adjuvant therapy (n=5), progression of disease (n=4), or toxicity (n=5). Notably 5 patients chose to defer therapy in the setting of the pandemic surge. Only one patient was identified as receiving neoadjuvant chemotherapy specifically due to COVID pandemic-related restrictions.Conclusions:The SARS-COV2 pandemic has led to modification of current standard chemotherapy delivery for gynecologic malignancies with the shared goal of protecting the most vulnerable populations from COVID infection. The impact of these modifications on cancer specific outcomes is not yet known. Future investigation will focus on identifying whether treatment modification to circumvent iatrogenic immunosuppression compromises oncologic outcomes.

MiR-200c-based metabolic modulation in glioblastoma cells as a strategy to overcome tumor chemoresistance.

Glioblastoma (GB) is the most aggressive and common form of primary brain tumor characterized by fast proliferation, high invasion and resistance to current standard treatment. The average survival rate post-diagnosis is 14.6months, despite the aggressive standard post-surgery radiotherapy concomitant with chemotherapy with temozolomide (TMZ). Currently, efforts are being endowed to develop new and more efficient therapeutic approaches capable to overcome chemoresistance, inhibit tumor progression and improve overall patient survival rate. Abnormal microRNA (miRNA) expression has been correlated with chemoresistance, proliferation and resistance to apoptosis, which result from their master regulatory role of gene expression. Altered cell metabolism, favoring glycolysis, was identified as an emerging cancer hallmark and has been described in GB, thus offering a new target for innovative GB therapies. In this work, we hypothesized that a gene therapy-based strategy consisting of the overexpression of a miRNA downregulated in GB and predicted to target crucial metabolic enzymes might promote a shift of GB cell metabolism, decreasing the glycolytic dependence of tumor cells and contributing to their sensitization to chemotherapy with TMZ. The increase of miR-200c levels in DBTRG cells resulted in downregulation of messenger RNA of enzymes involved in bioenergetics pathways and impaired cell metabolism and mobility. In addition, miR-200c overexpression prior to DBTRG cell exposure to TMZ resulted in cell cycle arrest. Overall, our results show that miR-200c overexpression could offer a way to overcome chemoresistance developed by GB cells in response to current standard chemotherapy, providing an improvement to current GB standard treatment, with benefit for patient outcome.

Overexpression of CD200 is a stem cell-specific mechanism of immune evasion in AML

BackgroundAcute myeloid leukemia (AML) stem cells (LSCs) are capable of surviving current standard chemotherapy and are the likely source of deadly, relapsed disease. While stem cell transplant serves as proof-of-principle...

Pre-operative/Neoadjuvant Therapy and Vascular Debranching Followed by Resection for Locally Advanced Pancreatic Cancer (PREVADER): Clinical Feasibility Trial.

Introduction: Pancreatic cancer continues to have a poor outcome. Many patients are diagnosed with advanced disease, and in a considerable proportion, abutment or invasion of visceral arteries is present. Moreover, some patients have anatomical variations or stenosis of major visceral arteries requiring arterial reconstruction upon pancreatic cancer resection to avoid organ ischemia. Simultaneous arterial reconstruction during resection is associated with relevant morbidity and mortality. This trial evaluates the approach of visceral debranching, that is, arterial reconstruction, prior to neoadjuvant chemotherapy and tumor resection in patients with locally advanced, unresectable pancreatic cancer.Methods and Analysis: The trial includes patients with locally advanced, non-metastatic pancreatic cancer with arterial abutment or invasion (deemed primarily unresectable), variations in vascular anatomy, or stenosis of visceral arteries. The participants undergo visceral debranching, followed by current standard neoadjuvant chemotherapy (mFOLFIRINOX, gemcitabine–nab-paclitaxel, or other) and potential subsequent tumor resection. The primary outcome is feasibility, measured as the proportion of patients who start neoadjuvant therapy within 6 weeks of visceral debranching. The trial has an exact single-stage design. The proportion below which the treatment is considered ineffective is set at 0.7 (H0). The proportion above which the treatment warrants further exploration in a phase III trial is set at 0.9 (H1). With a power (1-beta) of 0.8 and a type 1 mistake (alpha) of 0.05, the required sample size is 28 patients. Feasibility of the approach will be assumed if 24 of the enrolled 28 patients proceed to neoadjuvant chemotherapy within 6 weeks from visceral debranching.Discussion: This trial evaluates a new treatment sequence, that is, visceral debranching followed by chemotherapy and resection, for pancreatic cancer with invasion or abutment of visceral arteries. The primary objective of the trial is to evaluate feasibility. Trial results will allow for estimating treatment effects and calculating the sample size of a randomized controlled trial, in which the approach will be tested if the feasibility endpoint is met.Clinical Trial Registration: clinicaltrials.gov, identifier: NCT04136769.

Development of a Novel 3D Model to Investigate the Role of Heterogeneity in Ovarian Cancer Chemoresistance

More than 70% of all patients diagnosed with epithelial ovarian cancer (EOC) succumb to their disease making EOC the most lethal gynecological cancer. The astonishingly high mortality rate of EOC can be explained largely by the fact that 75% of all cases are diagnosed at advanced or metastatic stages thus highlighting the urgency to better understand what cues in the primary tumor microenvironment (TME) promote metastasis. Up to 80% of these patients experience disease reoccurrence demonstrating that in addition to early events in EOC progression, how EOC populations acquire resistance to our current gold standard of treatment is poorly understood. While two-dimensional (2D) in vitro studies of ovarian cancer have provided fundamental insight, three-dimensional (3D) culture systems that more accurately mimic the in vivoTME in terms of biomechanical and biochemical stimuli, are critical research tools in studying ovarian cancer progression. To address this problem, we have developed a 3D culture model that allows for spatial and temporal control of cancer cell interactions with their TME. Our model has the capability to support 3D EOC growth in a mechanically relevant environment over at least a 4-week period while a physically separated fibroblast-rich matrix evolves under the influence of EOC secreted factors. This model maintains the spatial heterogeneity present in both the EOC growth, as well as the developing microenvironment. Using this model, we chose to address two critical gaps in knowledge in the progression of EOC, namely how heterogenous EOC populations acquire resistance and how EOC progression alters surrounding stromal cell populations to promote invasion and metastasis. Our work reveals that altering the dose and administration schedule of paclitaxel can produce heterogenous EOC populations that differ in the acquisition of single or multidrug resistance. By comparing these populations, we found that paclitaxel treatment induced nonuniform metabolic reprogramming across EOC populations which was crucial for the establishment of single and multidrug resistance. Our results provide insight into how current gold standard chemotherapies contribute to the development of chemoresistant EOC subpopulations and describe potential vulnerabilities in these cells that can be exploited for more effective treatment.

Personalized patient care with aggressive hematological malignancies in non-responders to first-line treatment

ABSTRACT Introduction Whereas most patients with aggressive hematological malignancies can achieve disease remission after receiving current standard first-line chemotherapies, the prognosis of those with primary refractory disease remains poor. Conventional salvage chemotherapies are usually unsuccessful, but significant advances have been achieved in precision medicine for these patients in recent years. Areas covered This article presents a comprehensive review of current personalized care for patients with primary refractory aggressive hematological malignancies, focusing on acute leukemias and aggressive non-Hodgkin lymphomas. Expert opinions Salvage treatment for refractory acute myeloid leukemia (AML) should be personalized by the FMS-like tyrosine kinase 3 (FLT3) mutation status. Additionally, treatment for isocitrate dehydrogenase 1 or 2 (IDH1/2)-mutated refractory AML can be specified. Inotuzumab ozogamicin and blinatumomab are essential drugs for refractory B-cell acute lymphoblastic leukemia. These antibodies can be selected based on the disease status, such as measurable residual disease. For refractory diffuse large B-cell lymphoma, treatment options are different according to the cell-of-origin. Finally, accurate pathological phenotyping is an essential first step to optimize refractory peripheral T-cell lymphoma treatment. Although novel personalized approaches have improved the clinical outcomes of these patients, consolidation with hematopoietic stem cell transplantation has a vital role in most cases.

Cold Atmospheric Plasma Increases Temozolomide Sensitivity of Three-Dimensional Glioblastoma Spheroids via Oxidative Stress-Mediated DNA Damage.

Simple SummaryCold atmospheric plasma (CAP) is gaining increasing interest for cancer treatment, for a wide range of cancer types. The studies performed with CAP as a standalone treatment modality serve as evidence that it can also be a suitable candidate for combination therapy. Temozolomide (TMZ) is used as the gold standard drug for glioblastoma treatment, one of the most aggressive malignant brain tumors in adults that remains incurable despite treatment advances. In this study, we explore whether CAP, a cocktail of reactive oxygen and nitrogen species, can amplify the cytotoxic effect on both TMZ-sensitive and TMZ-resistant glioblastoma multiforme (GBM) in three-dimensional tumor-like tissues through inhibiting the glutathione (GSH)/ glutathione peroxidase 4 (GPX4) antioxidant machinery, which can further lead to DNA damage.Glioblastoma multiforme (GBM) is the most frequent and aggressive primary malignant brain tumor in adults. Current standard radiotherapy and adjuvant chemotherapy with the alkylating agent temozolomide (TMZ) yield poor clinical outcome. This is due to the stem-like properties of tumor cells and genetic abnormalities in GBM, which contribute to resistance to TMZ and progression. In this study, we used cold atmospheric plasma (CAP) to enhance the sensitivity to TMZ through inhibition of antioxidant signaling (linked to TMZ resistance). We demonstrate that CAP indeed enhances the cytotoxicity of TMZ by targeting the antioxidant specific glutathione (GSH)/glutathione peroxidase 4 (GPX4) signaling. We optimized the threshold concentration of TMZ on five different GBM cell lines (U251, LN18, LN229, U87-MG and T98G). We combined TMZ with CAP and tested it on both TMZ-sensitive (U251, LN18 and LN229) and TMZ-resistant (U87-MG and T98G) cell lines using two-dimensional cell cultures. Subsequently, we used a three-dimensional spheroid model for the U251 (TMZ-sensitive) and U87-MG and T98G (TMZ-resistant) cells. The sensitivity of TMZ was enhanced, i.e., higher cytotoxicity and spheroid shrinkage was obtained when TMZ and CAP were administered together. We attribute the anticancer properties to the release of intracellular reactive oxygen species, through inhibiting the GSH/GPX4 antioxidant machinery, which can lead to DNA damage. Overall, our findings suggest that the combination of CAP with TMZ is a promising combination therapy to enhance the efficacy of TMZ towards the treatment of GBM spheroids.

UGT1A1 Polymorphism for Irinotecan Dose Escalation in Patients with BRAF-Mutated Metastatic Colorectal Cancer Treated with First-Line Bevacizumab and FOLFIRI.

Background Patients with metastatic colorectal cancer (mCRC) and BRAF V600E mutation have a poor prognosis, with a median progression-free survival (PFS) of only 5–7 months after initial therapy. The current standard first-line chemotherapy for these patients includes FOLFOX or FOLFIRI plus bevacizumab. In this study, we explored the effects and oncological outcomes of UGT1A1 polymorphism for irinotecan escalation in patients with BRAF-mutated mCRC. Patients and Methods. This retrospective study included 17 patients with BRAF-mutated mCRC between April 2016 and December 2019. UGT1A1 genotyping was performed on all patients prior to initiating bevacizumab plus FOLFIRI chemotherapy. The primary endpoint was PFS, and the secondary endpoints were toxicity, response rate, disease control rate, and overall survival (OS). Results Fifteen and two patients had UGT1A1 1∗/1∗ and 1∗/28∗, respectively. Eight underwent irinotecan dose escalation with tolerable adverse effects (AEs), and nine maintained an irinotecan dose of 180 mg/m2 or required deescalation to 150 mg/m2 due to intolerable AEs. After a median follow-up period of 15.7 (range, 3–54) months, the median PFS and OS were 9.4 and 15.7 months, respectively. Grade 3/4 AEs were observed in three (6%) patients. The disease control and partial response rates were 64.7% and 11.8%, respectively, indicating that most patients (14, 82.3%) could maintain this as a first-line line therapy with stable disease or proceed to second-line therapy if disease progression occurred, thereby maintaining acceptable performance status. Conclusions The oncological outcomes of patients with BRAF-mutated mCRC treated using FOLFIRI plus bevacizumab with irinotecan dose escalation as a first-line therapy are acceptable with tolerable AEs; this may be a feasible treatment option in such patients. Pretherapeutic UGT1A1 genotyping-guided dose adjustment can achieve favorable outcomes.

Efficacy and Safety of Rovalpituzumab Tesirine Compared With Topotecan as Second-Line Therapy in DLL3-High SCLC: Results From the Phase 3 TAHOE Study

IntroductionDLL3, an atypical Notch ligand, is expressed in SCLC tumors but is not detectable in normal adult tissues. Rovalpituzumab tesirine (Rova-T) is an antibody-drug conjugate containing a DLL3-targeting antibody tethered to a cytotoxic agent pyrrolobenzodiazepine by means of a protease-cleavable linker. The efficacy and safety of Rova-T compared with topotecan as second-line therapy in patients with SCLC expressing high levels of DLL3 (DLL3-high) was evaluated. MethodsThe TAHOE study was an open-label, two-to-one randomized, phase 3 study comparing Rova-T with topotecan as second-line therapy in DLL3-high advanced or metastatic SCLC. Rova-T (0.3 mg/kg) was administered intravenously on day 1 of a 42-day cycle for two cycles, with two additional cycles available to patients who met protocol-defined criteria for continued dosing. Topotecan (1.5 mg/m2) was administered intravenously on days 1 to 5 of a 21-day cycle. The primary end point was overall survival (OS). ResultsPatients randomized to Rova-T (n = 296) and topotecan (n = 148) were included in the efficacy analyses. The median age was 64 years, and 77% had the extensive disease at initial diagnosis. The median OS (95% confidence interval) was 6.3 months (5.6–7.3) in the Rova-T arm and 8.6 months (7.7–10.1) in the topotecan arm (hazard ratio, 1.46 [95% confidence interval: 1.17–1.82]). An independent data monitoring committee recommended that enrollment be discontinued because of the shorter OS observed with Rova-T compared with topotecan. Safety profiles for both drugs were consistent with previous reports. ConclusionsCompared with topotecan, which is the current standard second-line chemotherapy, Rova-T exhibited an inferior OS and higher rates of serosal effusions, photosensitivity reaction, and peripheral edema in patients with SCLC. A considerable unmet therapeutic need remains in this population.

Investigating real-world treatment sequencing outcomes in advanced pancreatic cancer: A purple translational registry analysis.

386 Background: Current standard combination first line palliative chemotherapy regimens in advanced pancreatic ductal adenocarcinoma (PDAC) have not been compared in head-to-head trials. Data on optimum treatment sequencing is also lacking. Methods: To assess whether first line (1L) treatment with gemcitabine/nab-paclitaxel (Gem/Nab-P)(SEQ1) or FOLFIRINOX (SEQ2) in the palliative treatment setting impacts survival outcomes, data for patients receiving palliative intent combination chemotherapy between 2016 and May 2020 was extracted from PURPLE, a prospective pancreatic cancer registry enrolling consecutive patients across multiple institutions. Results: Of 637 patients, 180 (28%) who received 1L single agent therapy and/or palliative radiotherapy were excluded. Of the remaining 449 patients, 132 (29%) had locally advanced disease (LA PDAC), 67 had local recurrence (15%), and 250 (56%) had de novo metastatic disease (mPDAC). Patients receiving 1L Gem/Nab-P (n=376, 84%) were older (median 67 vs 59 years, P&lt;0.001), had a higher Charlson Comorbidity Index (CCI) (CCI ≥2: 18% vs 3%, Odds Ratio [OR] 8.0, P=0.002), and poorer performance status (ECOG≥2: 10% vs 1%, OR 8.4, P=0.01) compared to the 1L FOLFIRINOX group (n=73, 16%). 140 (37%) patients receiving 1L Gem/Nab-P (SEQ1) and 32 (44%) patients receiving 1L FOLFIRINOX (SEQ2) received second line (2L) chemotherapy. SEQ1 2L regimens included FOLFIRINOX (n=14), FOLFIRI (n=49), FOLFOX (n=35) and 5FU alone (n=3). SEQ2 2L regimens included Gem/Nab-P (n=19), Gem/5FU (n=4), Gem/Cisplatin (n=1) and gemcitabine alone (n=5). Median progression free survival (mPFS) did not differ between patients receiving 1L Gem/Nab-P vs 1L FOLFIRINOX (5.7 vs 5.1 months, P=0.54); nor did median overall survival (mOS; 11.3 vs 12.3 months, P=0.37). In the subset of patients who went on to receive 2L chemotherapy, mPFS in 2L was shorter for SEQ1 compared to SEQ2 (2.9 vs 5.2 months, Hazard Ratio [HR] 1.3, P=0.03) but mOS did not differ (15.9 vs 17.3 months P=0.91). In the subset with LA PDAC, mPFS in 2L was comparable (2.9 vs 3.3 months, P=0.55) but mOS was significantly longer with SEQ1 (22.5 vs 13.8 months, HR 0.50, P=0.01). In mPDAC, mPFS in 2L was shorter with SEQ1 (2.3 vs 5.6 months, HR 1.64, P=0.03), but mOS did not differ by sequence (13 vs 17 months, P=0.23). Conclusions: There were no significant differences in survival outcomes between 1L choices of chemotherapy, despite patients offered 1L FOLFIRINOX (SEQ2) being younger and fitter. Survival differences observed for LA PDAC versus mPDAC will be further explored. Given the multiple potential confounders, randomised clinical trials are needed to make firmer conclusions regarding the optimal initial treatment for each patient subset.

Neurokinin-1 Receptor (NK-1R) Antagonists: Potential Targets in the Treatment of Glioblastoma Multiforme.

The current standard of care in glioblastoma multiforme (GBM), as the most morbid brain tumor, is not adequate, despite substantial progress in cancer therapy. Among patients receiving current standard treatments, including surgery, irradiation, and chemotherapy, the overall survival (OS) period with GBM is less than one year. The high mortality frequency of GBM is due to its aggressive nature, including accelerated growth, deregulated apoptosis, and invasion into surrounding tissues. The understanding of the molecular pathogenesis of GBM is, therefore, crucial for identifying, designing, and repurposing potential agents in future therapeutic approaches. In recent decades, it has been apparent that several neurotransmitters, specifically substance P (SP), an undecapeptide in the family of neuropeptides tachykinins, are found in astrocytes. After binding to the neurokinin-1 receptor (NK-1R), the SP controls cancer cell growth, exerts antiapoptotic impacts, stimulates cell invasion/metastasis, and activates vascularization. Since SP/NK-1R signaling pathway is a growth driver in many cancers, this potential mechanism is proposed as an additional target for treating GBM. Following an evaluation of the function of both SP and its NK-1R inhibitors in neoplastic cells, we recommend a unique and promising approach for the treatment of patients with GBM.

Overexpression of CD200 Is a Stem Cell-Specific Mechanism of Immune Escape in AML

Background: Acute myeloid leukemia (AML) stem cells (LSC), the likely source of relapsed disease, are capable of surviving current standard chemotherapy. Therefore, novel therapeutic approaches specifically engineered to eradicate LSCs are critical for curing AML. We previously introduced a novel bioinformatics approach that harnessed publically available AML gene expression datasets and identified CD200 as significantly over-expressed in LSCs when compared to paired blast cells, as well as when compared to their normal hematopoietic stem cell (HSC) counterparts (Fig 1A; Herbrich et al Blood. 2018; 130:3962). CD200 can identify AML cells with LSC activity in vivo (Ho et al Blood. 2016; 128:1705). Functionally, CD200 has been shown to have an immunosuppressive effect on macrophages (Hoek et al Science. 2000; 290:1768) and NK cells (Coles et al Leukemia. 2012; 26:2148), and correlates with a high prevalence of FOXP3+ regulatory T cells (Coles et al Leukemia. 2012; 26:2146). Additionally, CD200 has been implicated as a poor prognostic marker in AML (Damiani et al Oncotarget. 2015; 6:30212). To date, we have screened 40 primary AML patient samples by flow cytometry, 95% of which are positive for CD200. Methods: To study the functional role of CD200 in AML, we generated a CD200 overexpression model in the human OCI-AML3 cell line (with no basal expression) and characterized changes in proliferation, survival, and gene expression. To examine the immune function of CD200 in AML in vitro, we performed a series of mixed lymphocyte reactions with isolated effector immune cells and target isogenic AML cell lines to assess immune cell-mediated apoptosis, proliferation, and cytokine secretion. To understand the contribution of CD200 immune protection in a physiological setting, we developed a peripheral blood mononuclear cell (PBMC)-humanized mouse in which we tracked the engraftment and overall survival of the CD200+/- OCI-AML3 cells. Lastly, the utility of CD200-blockade using a fully humanized anti-CD200 monoclonal antibody (CD200-IgG1) was evaluated both in vitro and in vivo. Results: In vitro, CD200+ AML significantly inhibited the secretion of inflammatory cytokines and cytotoxic enzymes from healthy PBMCs; a phenomenon that could be largely reversed by blocking the CD200/CD200R interaction with the CD200 antibody (Fig 1B). In vivo, OCI-AML3 CD200+/- cells showed no difference in engraftment, progression, and overall survival in immunodeficient NSG mice (Fig 1C). However, when mice were humanized using healthy PBMCs, CD200+ leukemia progressed rapidly, escaping T cell-mediated elimination, compared to CD200- control leukemic cells (Fig 1D). Cytokine production in PBMC-humanized mice was significantly compromised in those with CD200-expressing leukemia. Transcriptome analysis revealed that T cells from humanized mice exposed to CD200 expressing disease were metabolically quiescent. In humanized mice, CD200-IgG1 therapy eliminated CD200+ AML disease (Fig 1E). The novel CD200-IgG1 antibody also induced potent, specific NK cell-mediated antibody dependent cellular cytotoxicity (ADCC) and macrophage-mediated antibody dependent cellular phagocytosis (ADCP; Fig 1F). Conclusion: We have identified CD200 as a putative stem cell-specific immunomodulatory target that aids in establishing an immunosuppressive microenvironment by significantly suppressing cytokine secretion in response to AML. In a PBMC-humanized mouse model, the presence of cell-surface CD200 was sufficient to protect AML cells from immune-mediated clearance and could be reversed using a blocking anti-CD200 mAb. These findings indicate a utility of CD200 as a novel immune checkpoint target for the development of therapeutic strategies in AML. Disclosures Konopleva: Calithera: Research Funding; Kisoji: Consultancy; AbbVie: Consultancy, Research Funding; Reata Pharmaceutical Inc.;: Patents &amp; Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; Ablynx: Research Funding; Genentech: Consultancy, Research Funding; F. Hoffmann La-Roche: Consultancy, Research Funding; Eli Lilly: Research Funding; Cellectis: Research Funding; Amgen: Consultancy; Stemline Therapeutics: Consultancy, Research Funding; AstraZeneca: Research Funding; Sanofi: Research Funding; Agios: Research Funding; Forty-Seven: Consultancy, Research Funding; Rafael Pharmaceutical: Research Funding; Ascentage: Research Funding.

Intratumor Heterogeneity of MYO18A and FBXW7 Variants Impact the Clinical Outcome of Stage III Colorectal Cancer.

Many studies failed to demonstrate benefit from the addition of targeted agents to current standard adjuvant FOLFOX chemotherapy in stage III colorectal cancer (CRC) patients. Intratumor heterogeneity may foster the resistant subclones and leads to cancer recurrence. Here, we built a cancer evolution model and applied machine learning analysis to identify potential therapeutic targets. Among 78 CRC cases, whole-genome (WGS) and deep targeted sequencing data generated from paired blood and primary tumor were used for phylogenetic tree reconstruction. Genetic alterations in the PI3K/AKT, and RTK oncogenic signaling pathways were commonly detected in founding clones. The dominant subclones frequently exhibited dysregulations in the TP53, FBXW7/NOTCH1 tumor suppression, and DNA repair pathways. Fourteen genetic mutations were simultaneously selected by random forest and LASSO methods. The logistic regression model had better accuracy (79%), precision (70%), and recall (65%) and area under the curve (AUC) (82%) for cancer recurrence prediction. Three genes, including MYO18A in the founding clone, FBXW7, and ATM in the dominant subclone, affected the prognosis were selected simultaneously by different feature sets. The in vitro studies, HCT-116 cells transfected with MYO18A siRNA demonstrated a significant reduction in cell migration activity by 20–40%. These results indicate that MYO18A plays a crucial role in the migration of human CRC cells. The cancer evolution model revealed the critical mutations in the founding and dominant subclones. They can be used to predict clinical outcomes and the development of novel therapeutic targets for stage III CRC.

Response to trametinib treatment in progressive pediatric low-grade glioma patients

IntroductionA hallmark of pediatric low-grade glioma (pLGG) is aberrant signaling of the mitogen activated protein kinase (MAPK) pathway. Hence, inhibition of MAPK signaling using small molecule inhibitors such as MEK inhibitors (MEKi) may be a promising strategy.MethodsIn this multi-center retrospective centrally reviewed study, we analyzed 18 patients treated with the MEKi trametinib for progressive pLGG as an individual treatment decision between 2015 and 2019. We have investigated radiological response as per central radiology review, molecular classification and investigator observed toxicity.ResultsWe observed 6 partial responses (PR), 2 minor responses (MR), and 10 stable diseases (SD) as best overall responses. Disease control rate (DCR) was 100% under therapy. Responses were observed in KIAA1549:BRAF- as well as neurofibromatosis type 1 (NF1)-driven tumors. Median treatment time was 12.5 months (range: 2 to 27 months). Progressive disease was observed in three patients after cessation of trametinib treatment within a median time of 3 (2–4) months. Therapy related adverse events occurred in 16/18 patients (89%). Eight of 18 patients (44%) experienced severe adverse events (CTCAE III and/or IV; most commonly skin rash and paronychia) requiring dose reduction in 6/18 patients (33%), and discontinuation of treatment in 2/18 patients (11%).ConclusionsTrametinib was an active and feasible treatment for progressive pLGG leading to disease control in all patients. However, treatment related toxicity interfered with treatment in individual patients, and disease control after MEKi withdrawal was not sustained in a fraction of patients. Our data support in-class efficacy of MEKi in pLGGs and necessity for upfront randomized testing of trametinib against current standard chemotherapy regimens.