Standard Cytotoxic Chemotherapy Research Articles

The perplexing role of immuno-oncology drugs in osteosarcoma

Osteosarcoma is a rare, primary tumour of bone. Curative treatment consists of multi-agent chemotherapy and complete surgical resection. Despite the use of multi-agent chemotherapy, the risk of recurrence is high. Survival outcomes for patients with osteosarcoma have not changed since the 1980′s. Based on biologic rationale, there has been interest in adding immunotherapies to upfront curative intent chemotherapy, including mifamurtide (a macrophage activator) and interferon. However, results to date have been disappointing. In the metastatic setting, checkpoint inhibitors alone have not proven effective. Ongoing translational work is needed to further understand which patients may benefit from immune-oncology approaches with standard cytotoxic chemotherapy.

Periostin Exon-21 Antibody Neutralization of Triple-Negative Breast Cancer Cell-Derived Periostin Regulates Tumor-Associated Macrophage Polarization and Angiogenesis.

Simple SummaryDespite remarkable advances in breast cancer treatment, few strategies other than standard cytotoxic chemotherapy are available for patients with triple-negative breast cancer (TNBC) due to the lack of therapeutic target molecules. TNBC is still the most aggressive subtype, with a high risk of recurrence and metastasis within 2 years after initial treatment. Thus, there is an unmet medical need to develop new treatments for metastatic and recurrent TNBC patients. In this study we tested a new antibody, targeting extracellular periostin protein alternative splicing variants, which are induced by conventional chemotherapy or during the process of endothelial mesenchymal transition. This antibody reduced periostin-secreting TNBC in a mouse xenograft model, accompanied by a decrease in the number of M2 tumor-associated macrophages and tumor vessels. Periostin alternative splicing variants might be a specific and safe therapeutic target in patients with TNBC.Periostin (Pn) is involved in multiple processes of cancer progression. Previously, we reported that Pn expression is correlated with mesenchymal tumor markers and poor prognosis in triple-negative breast cancer (TNBC). In the TNBC xenograft model, chemotherapy increased expression of a Pn alternative splicing variant (ASV) with exon 21, and administration of the neutralizing antibody against Pn with exon 21 (Pn-21 Ab) overcame chemoresistance with a reduction in the mesenchymal cancer cell fraction. In the present study, the role of Pn ASV with exon 21 in TNBC progression has been addressed. We first established a stable cell line carrying a fluorescence-based splicing reporter. Pn-positive TNBC has higher expression of genes related to tumor-associated macrophage (TAM) recruitment and ECM-receptor interaction than Pn-negative cells. In a xenograft model, only Pn-positive cells initiated tumor formation, and the Pn-21 Ab suppressed tumor cell growth, accompanied by decreased M2 TAM polarization and the number of tumor vessels. These data suggest that cancer cell-derived Pn ASV educates TAMs and regulates angiogenesis, which in turn establishes a microenvironmental niche that is supportive of TNBC.

Targeted Liposomal Chemotherapies to Treat Triple-Negative Breast Cancer.

Simple SummaryTriple-negative breast cancers (TNBCs) are mainly treated with standard chemotherapies. Combined therapies have been demonstrated as a promising treatment strategy in clinics. The aim of this study was to develop a new formulation of combined chemotherapies facilitated with a targeted delivery vehicle. We found that the mertansine and gemcitabine with different anti-cancer mechanisms resulted in high cytotoxicity in TNBC cells. The in vivo evaluations using two TNBC xenograft models confirmed the anti-tumor efficacy, i.e., significantly reduced tumor growth rate. Furthermore, the antibody-tagged liposomes effectively delivered the therapeutic drugs to TNBC tumor, which could reduce the side effects. This study is highly translational and the targeted liposomal drug formulation can be further investigated in future clinical trials for TNBC treatment.Triple-negative breast cancers (TNBCs) are highly aggressive and recurrent. Standard cytotoxic chemotherapies are currently the main treatment options, but their clinical efficacies are limited and patients usually suffer from severe side effects. The goal of this study was to develop and evaluate targeted liposomes-delivered combined chemotherapies to treat TNBCs. Specifically, the IC50 values of the microtubule polymerization inhibitor mertansine (DM1), mitotic spindle assembly defecting taxane (paclitaxel, PTX), DNA synthesis inhibitor gemcitabine (GC), and DNA damage inducer doxorubicin (AC) were tested in both TNBC MDA-MB-231 and MDA-MB-468 cells. Then we constructed the anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) tagged liposomes and confirmed its TNBC cell surface binding using flow cytometry, internalization with confocal laser scanning microscopy, and TNBC xenograft targeting in NSG female mice using In Vivo Imaging System. The safe dosage of anti-EGFR liposomal chemotherapies, i.e., <20% body weight change, was identified. Finally, the in vivo anti-tumor efficacy studies in TNBC cell line-derived xenograft and patient-derived xenograft models revealed that the targeted delivery of chemotherapies (mertansine and gemcitabine) can effectively inhibit tumor growth. This study demonstrated that the targeted liposomes enable the new formulations of combined therapies that improve anti-TNBC efficacy.

Development of the PARP inhibitor talazoparib for the treatment of advanced BRCA1 and BRCA2 mutated breast cancer

ABSTRACT Introduction BRCA1 and BRCA2 (BRCA1/2) mutation breast cancers constitute an uncommon, but unique group of breast cancers that present at a younger age, and are underscored by genomic instability and accumulation of DNA damage. Talazoparib is a potent poly(ADP-ribose) polymerase (PARP) inhibitor that exploits impaired DNA damage response mechanisms in this population of patients and results in significant efficacy. Based on the results of the EMBRACA trial, talazoparib was approved for the treatment of patients with advanced germline BRCA1/2 mutant breast cancer. Areas covered In this review, the authors highlight the relevant clinical trials of talazoparib, as well as, safety, tolerability, and quality of life considerations. They also examine putative response and resistance mechanisms, and rational combinatorial therapeutic strategies under development. Expert opinion Talazoparib has been a major advance in the treatment of germline BRCA1/2 mutation breast cancer with both clinical efficacy and improvement in quality of life compared to standard cytotoxic chemotherapy. To date, the optimal sequencing of talazoparib administration in the metastatic setting has not yet been established. A deeper understanding of response and resistance mechanisms, and more broadly, the DNA repair pathway, will lead to additional opportunities in targeting this pathway and open up therapeutic indications to a broader patient population.

Abstract CT012: TRX-E-002-1 in treatment-refractory ovarian cancer: Final phase 1 study results from the dose-escalation and dose-expansion cohorts

Abstract Introduction: For women with advanced ovarian cancer survival outcomes with standard cytotoxic chemotherapy are poor and are thought to reflect the existence of drug-resistant ovarian cancer stem cells. TRX-E-002-1 (Cantrixil), a novel third generation benzopyran molecule has been shown to be effective in a mouse model of recurrent chemotherapy-resistant ovarian cancer. We present the final results of a phase I progressive design trial (Part A dose escalation, Part B dose expansion) of Cantrixil (NCT02903771). The objectives were to establish maximum tolerated dose (MTD) when given in combination with chemotherapy, and to evaluate safety, tolerability and anti-tumour activity of intraperitoneal (IP)-administered Cantrixil. Methods: Women who had completed ≥2 prior regimens and whose disease was platinum-refractory, platinum-resistant or who had documented intolerance to platinum therapy, were eligible. Treatment comprised up to eight 3-week cycles. In the first 2 cycles, patients were dosed weekly with Cantrixil as monotherapy after which investigators were allowed to initiate pre-defined standard intravenous chemotherapy regimens (cycles 3-8). All patients were followed up for 3 months after the end of treatment. Results: Of 32 patients enrolled, 25 received ≥1 Cantrixil dose; 6 patients (24%) completed all 8 treatment cycles. Patients (92% Caucasian, mean age 62.5 years) had a median of 2 prior lines of platinum therapy and a median of 3 prior lines of anticancer therapies (including anti-VEGF; n=13, 52% and PARPi; n=6, 24%). Platinum sensitivity: refractory (n=3,12%), resistant (n=17, 68%), sensitive (n=5, 20%). In Part A (n=11), an MTD of 5mg/kg was established on the dose-limiting toxicity of ileus (n=2) and safety signals of bowel obstruction (n=3) and abdominal pain (n=2). The pharmacokinetic profile was multi-exponential, with rapid increases in systemic concentration and distribution and a slower elimination phase. Drug accumulation was minimal and was not influenced by co-administration of chemotherapy. Analysis of weight and dose-normalized (to 1 mg/kg) data found no notable trends. Across Parts A and B, 16 patients received ≥1 Cantrixil dose and had a post-baseline efficacy measurement available. The overall response rate was 18%, including one complete response (platinum-resistant; who remains in remission 37.05 months since starting treatment) and two partial responses (one platinum-resistant, one platinum refractory). The median progression free survival was 3.06 months (95% CI:1.28,∞). Conclusion: IP-administered Cantrixil, a first-in-class, dual acting, anti-cancer therapy has encouraging activity in a cohort of difficult to treat patients with persistent epithelial ovarian, fallopian tube or primary peritoneal cancer who have demonstrated resistance to a range of prior treatments. Disease response compares favorably to a figure of 10% for historical controls. Citation Format: Jermaine Coward, Ganessan Kichenadasse, Paul Harnett, Kathleen Moore, Minal Barve, James Garner, Mary Lopresti, Don S. Dizon. TRX-E-002-1 in treatment-refractory ovarian cancer: Final phase 1 study results from the dose-escalation and dose-expansion cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT012.

Chimeric Antigen Receptor Induced Cytopenia Differs from Chemotherapy Induced Myelosuppression

▪Background: Cytopenias are a potential complication of chimeric antigen receptor (CAR) therapy. The specific degree, duration, or implication of these cytopenias is not well established, and is further confounded by baseline cytopenias in heavily pre-treated patients with active leukemia. Preclinical models suggest that these cytopenias may be due to a cytokine rich milieu which may contribute to nonspecific suppression of marrow progenitors-independent of the CAR target (Sauter, ASH 2016, abstract 3357); which differs from standard cytotoxic chemotherapy based myelosuppression. We systematically analyzed CAR-related cytopenias on our phase I dose-escalation study of CD22 CAR.Design: Children and young adults with relapsed/refractory CD22+ acute lymphoblastic leukemia (ALL) treated on our phase I dose escalation anti-CD22 CAR therapy protocol (NCT02315612) were evaluated for time to neutrophil and platelet recovery (defined by absolute neutrophil count (ANC) of > 500 k/mcL x 3 days and achievement of transfusion independent platelet count > 20 k/mcL, respectively). All patients had bone marrow evaluations by morphology and flow cytometry at baseline, prior to lymphodepleting chemotherapy (Fludarabine 25 mg/m2 x 3 days and Cyclophosphamide 900 mg/m2 x 1 day) and again at day 28 (+/- 4 days) post-CAR. Infections were closely monitored for. All patients were on anti-fungal prophylaxis and were empirically treated for fever during periods of neutropenia.Results: From December 2014 to July 2017, 30 patients with ALL were treated on study at 3 dose levels. All patients had active bone marrow involvement at baseline with the majority (n=21) having an M2 marrow (>5% blasts) or higher. Twenty-six patients had prior transplants, and 21 patients had prior CD19-directed CAR therapy. Cytokine release syndrome (CRS) was seen in 24/30 (80%), with most patients having grade 1-2 CRS. 18/30 patients (60%) attained a complete remission following CD22 CAR therapy. Baseline hematologic parameters for responders prior to lymphodepletion included grade 2-4 neutropenia and grade 2 and 3 thrombocytopenia, with five patients requiring platelet transfusions (Table 1). Amongst complete responders, the bone marrow at day 28 demonstrated a median cellularity of 28% with trilineage hematopoiesis noted in 16/18 patients. The median CAR T cell % in bone marrow at 1 month was 30%. The median time to ANC nadir was 15 days post CAR infusion (range:10-23 days).17/18 patients had ANC recovery >500 k/mcL, at a median of 22 days post-infusion (range: 15-44 days). One patient had ANC recovery to 260 k/mcL but subsequently developed disease relapse. Eight patients received intermittent GCSF, with clinically relevant responses seen in seven of these patients with a median increase in ANC of 2,180 k/mcL (range: 850-4,100 k/mcL) with limited dosing. The median number of days of GCSF administration to time of ANC recovery was 4, with 3 patients requiring only 1 injection to achieve robust ANC response. Interestingly, only 1/18 patient (6%) had a new onset of infection (clostridium difficile colitis) during the period of CAR associated neutropenia, which was confounded by administration of intravenous antibiotic therapy for fevers that was initiated 24 hours prior to onset of diarrhea. There was no new development of fungal infections or worsening of any pre-existing infections. Platelet recovery to > 20 k/mcL was at a median of 36 days (range: 21-55) post-CAR and was seen in 16 of 18 responders. Two patients who remained platelet transfusion dependent post-CAR included one patient who was later found to have donor-cell monosomy 7 MDS and another patient whose disease relapsed prior to recovery.Conclusion: In contrast to chemotherapy associated myelosuppression, CAR-therapy associated peripheral blood cytopenias existed despite evidence for trilineage hematopoiesis on the bone marrow. Although the period of CAR associated neutropenia is substantial, with prophylactic antifungals and intermittent growth factor support, this heavily pre-treated population was not at an increased risk of developing serious bacterial or fungal infections over baseline. The rapid response to G-CSF is suggestive of an alternative modality of bone marrow inhibition distinct from chemotherapy induced cytotoxicity. Further evaluation in the context of multiple CAR targets and constructs are needed to further explore this complication. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A narrative review of chemotherapy in advanced triple negative breast cancer

: Triple-negative breast cancers (TNBCs) are a heterogeneous group of aggressive tumors with high relapse rates and propensity to develop visceral or brain metastasis, representing 15% of the breast carcinomas. Their overall survival (OS) has remained static over the past 20 years. Cytotoxic chemotherapy (CT) was the only treatment option for all stages of TNBC until the first targeted therapy Olaparib was approved in patients with germline BRCA-mutation. This unsystematic narrative review is aimed at presenting an overview of the use of CT in advanced/metastatic triple-negative breast cancer (mTNBC) in these times when the personalized medicine era is slowly reaching TNBC with new therapeutic options. The information used to write it was collected from the published literature, treatment guidelines and hand searches of retrieved literature references. Standard anthracycline-based CT is the treatment of choice as first-line for metastatic breast cancer patients not previously treated with anthracyclines. First-line single-agent taxane is offered to patients who have received prior adjuvant anthracyclines or presented anthracycline failure, or as the second line in patients who have received prior anthracyclines in the metastatic setting. TNBC tumors that carry the germline BRCA1/2 mutations can benefit from the targeted use of platinum. Other drugs as eribulin, capecitabine, platinum, and gemcitabine, that have proven efficacy as single-agents or in combination as further lines, but the sequencing is not established. Combination chemotherapy can be considered when the patient presents a severe organ dysfunction aiming to achieve disease stabilization. CT remains the cornerstone treatment for mTNBC which not express targetable receptors or defective molecular pathways, and as a counterpart for targeted or immune therapies; given the limited access to these last in most countries, CT will continue in the landscape for much longer.

TMB or not TMB as a biomarker: That is the question.

Immune checkpoint inhibitors (ICIs) have revolutionized the landscape of therapeutic options for many cancers. These treatments have demonstrated improved efficacy and often a more favourable toxicity profile compared to standard cytotoxic chemotherapy. There are considerable differences among responders, with some patients experiencing durable long-term disease control and even remission. Given this variability, determining a proper biomarker to select patients for ICI therapy has become increasingly important. The only biomarker proven to be predictive of overall survival benefit with ICI therapy is PD-L1 expression level measured by immunohistochemistry. Several attempts have been made to identify different predictive biomarkers. One of the most intriguing and divisive is tumor mutational burden (TMB). TMB represents the number of mutations per megabase (Mut/Mb) of DNA that were sequenced in a specific cancer. With a higher number of mutations detected, and consequentially an increase in the number neo-epitopes, then it is more likely that one or more of those neo-antigens could be immunogenic and trigger a T cell response. Initially, TMB was identified as a biomarker for ICIs in melanoma and subsequent studies suggested a possible clinical role for TMB in non-small cell lung cancer. The initial data were not confirmed in a prospective study assessing OS as the primary endpoint. Recently, the FDA has approved pembrolizumab in all cancers with a TMB > 10Mut/Mb[12] based on findings from the phase 2 KEYNOTE-158. Much criticism has emerged about this pan-cancer approval, in particular about the use of TMB as biomarker to select patients. Here we review the data about the importance and role of TMB as possible pan-cancer one-size-fits-all biomarker. We highlight the strengths and intrinsic limitations of such a complex biomarker and its adoption in the daily practice.

Impact on second-line treatment after failure of immune checkpoint inhibitor (ICI) combination chemotherapy in extensive-disease small cell lung cancer: Experience of the Okayama Lung Cancer Study Group.

e20590 Background: For patients with extensive-disease small cell lung cancer (ED-SCLC), amrubicin monotherapy is an important therapy in the treatment of recurrence, but there has been no adequate evaluation of how effective it actually is after failure of first-line chemotherapy including immune checkpoint inhibitor (ICI). Therefore, the purposes of this study are to determine the proportion of patients who received amrubicin monotherapy in the treatment of relapse after first-line treatment with ICI (arm A) and to investigate the efficacy of amrubicin therapy after arm A compared with after chemotherapy without ICI (arm B). Methods: Consecutive 40 pts with ED-SCLC NSCLC were retrospectively assessed who underwent ICI-containing chemotherapy (n = 19) or standard cytotoxic chemotherapy (n = 21) in the 1st-line setting between 2017 and 2020. Results: In arm A, 3 of 19 patients (16%) were still on first-line ICI maintenance therapy, 2 (2/19; 11%) had ICI treatment adverse events (interstitial pneumonia, cardiopulmonary arrest), and 1 patient could not receive second-line therapy due to a decrease in performance status (PS) to 3. In arm B, 11 of 21 patients (52%) did not receive amrubicin as second-line therapy, including 1 patient with worsening PS, 1 patient with adverse events (hematologic toxicity), 1 patient refusal, and 6 patients with combination of ICI and chemotherapy. 23 patients (arm A; 13 (57%), arm B; 10 (43%)) were able to receive amrubicin monotherapy, including 7 patients (6 cases vs 1 case) were sensitive relapses, and 16 (7 vs 9 cases) were refractory relapses. There was no significant difference in either PFS or survival after first-line treatment in 16 patients with refractory relapse who received amrubicin as second-line treatment (PFS: 4.8 vs 5.2 months, p = 0.51), (median survival after first-line treatment: 9.6 vs 12.8, p = 0.75). Conclusions: Patients who received ICI in the first-line treatment were fully eligible to receive amrubicin in the second-line treatment. The recurrence pattern tended to be sensitive relapse and we found that the efficacy of amrubicin in refractory relapse was not affected by the administration of ICI in the first-line treatment.

Successful salvage therapy with cetuximab-based modalities in the non-sensitive EGFR-mutant lung cancer patients with leptomeningeal metastasis who have heavily pretreated histories.

e14011 Background: Leptomeningeal metastasis (LM) is the deadliest complication of lung cancer. No standard therapy for the LM harbor non-sensitive epidermal growth factor receptor (EGFR)-mutant|(neither E19 del, E21 p.L858R nor E18 p. G719X mutation ). Previous studies showed cetuximab held the potential for treating the EGFR mutants who had failed 2 or more lines of standard cytotoxic chemotherapy and reversible EGFR TKIs. Methods: We screen the lung cancer patients with LM treated with Cetuximab-based regimen from July 1st, 2020 to Dec 31th 2020. The medical records were retrospectively reviewed and analyzed. Results: Three lung cancer patients with LM were included. All of them were heavily pretreated with various TKIs, chemotherapy, or/and with antiangiogenesis and PD-1 antibodies. When they were referred to our department, all these patients were in severe medical conditions. Case 1 has severe multiple cranial nerve impairment with cauda equina syndrome and massive malignant pleural effusion. Case 2 has intensively violent headaches with vomit and lumbosacral pain due to more than 500mm H2O of intracranial hypertension. Case 3 has acute pancreatitis due to oppressive obstruction of pancreatic duct by multiple metastatic tumors. The molecule test of tumor tissue or liquid from malignant pleural fluid have revealed E20 p.C797S in cis with p.T790M accompanied E19 del of EGFR gene in case 1, E21 p. R831H with E19 p.L747P of EGFR gene in case 2, and E20 p.S768_D770dup of EGFR gene in case 3, respectively. Their therapies were changed to cetuximab combined with TKI of afatinib or osimertinib, and local treatment including local radiation, intraventricular pemetrexed administration, or with intrathoracic drain. The disease control rate (DCR) was 100% of one partial remission (PR) and two stable disease (SD). The intracranial response was also observed in all the 3 patients showing CSF cytology turning negative or enhanced meningeal disappearance in MRI image with obviously relieved headache or/and improved cranial nerve palsy. The performance status of two patients was largely improved from Karnofsky Performance Status (KPS) scoring 20 to 90 and 50, respectively, and that of the other patient was stable with KPS scoring 50. The side effect is manageable skin rashes (grade II-III). Until this abstract was written, all the 3 patients were still alive. Conclusions: Cetuximab-based systemic therapy combined with local treatment demonstrated preliminary clinical activity in the rare EGFR-mutant lung cancer with LM who have already undergone heavily previous therapy, warranting further investigation.

Effect of oxaliplatin plus 5-fluorouracil or capecitabine on circulating and imaging biomarkers in patients with metastatic colorectal cancer: a prospective biomarker study

BackgroundPatients with metastatic colorectal cancer are treated with cytotoxic chemotherapy supplemented by molecularly targeted therapies. There is a critical need to define biomarkers that can optimise the use of these therapies to maximise efficacy and avoid unnecessary toxicity. However, it is important to first define the changes in potential biomarkers following cytotoxic chemotherapy alone. This study reports the impact of standard cytotoxic chemotherapy across a range of circulating and imaging biomarkers.MethodsA single-centre, prospective, biomarker-driven study. Eligible patients included those diagnosed with colorectal cancer with liver metastases that were planned to receive first line oxaliplatin plus 5-fluorouracil or capecitabine. Patients underwent paired blood sampling and magnetic resonance imaging (MRI), and biomarkers were associated with progression-free survival (PFS) and overall survival (OS).ResultsTwenty patients were recruited to the study. Data showed that chemotherapy significantly reduced the number of circulating tumour cells as well as the circulating concentrations of Ang1, Ang2, VEGF-A, VEGF-C and VEGF-D from pre-treatment to cycle 2 day 2. The changes in circulating concentrations were not associated with PFS or OS. On average, the MRI perfusion/permeability parameter, Ktrans, increased in response to cytotoxic chemotherapy from pre-treatment to cycle 2 day 2 and this increase was associated with worse OS (HR 1.099, 95%CI 1.01–1.20, p = 0.025).ConclusionsIn patients diagnosed with colorectal cancer with liver metastases, treatment with standard chemotherapy changes cell- and protein-based biomarkers, although these changes are not associated with survival outcomes. In contrast, the imaging biomarker, Ktrans, offers promise to direct molecularly targeted therapies such as anti-angiogenic agents.

Systemic Options for Malignant Peripheral Nerve Sheath Tumors.

Malignant peripheral nerve sheath tumors (MPNSTs) are rare mesenchymal neoplasms that represent a profound therapeutic challenge due to their high proclivity for recurrence and metastasis and relatively poor response to systemic therapy regimens. While our understanding of the pathophysiology of MPNST is growing, including loss of the tumor suppressor gene neurofibromin and subsequent activation of the Ras pathway, targeted therapy to modify the poor prognosis seen in MPNST patients has thus far been without success. Correspondingly, MPNST patients are treated as per soft tissue sarcoma treatment algorithms with anthracycline-based therapy as the front-line therapy of choice for patients with unresectable, locally advanced, or metastatic MPNST. Beyond first-line anthracycline-based therapy, other standard cytotoxic chemotherapy agents used in advanced MPNST include the alkylating agent ifosfamide and the topoisomerase II inhibitor etoposide. Notably, soft tissue sarcoma regimens are used in MPNST despite distinct systemic therapy sensitivity and prognosis. This is particularly notable for neurofibromatosis type 1 (NF1)-associated MPNST, which is associated with poorer response to systemic therapy and prognosis than sporadic MPNST. As such, NF1-associated MPNST is a particular area in need of novel therapeutic strategies. Given the lack of benefit in the targeting of unique aspects of MPNST disease biology thus far, pre-clinical studies to identify novel rational therapies are critical to inform future clinical trials.

Current treatment and recent progress in gastric cancer.

Gastric cancer is not a top-10 malignancy in the United States but represents one of the most common causes of cancer death worldwide. Biological differences between tumors from Eastern and Western countries add to the complexity of identifying standard-of-care therapy based on international trials. Systemic chemotherapy, radiotherapy, surgery, immunotherapy, and targeted therapy all have proven efficacy in gastric adenocarcinoma; therefore, multidisciplinary treatment is paramount to treatment selection. Triplet chemotherapy for resectable gastric cancer is now accepted and could represent a plateau of standard cytotoxic chemotherapy for localized disease. Classification of gastric cancer based on molecular subtypes is providing an opportunity for personalized therapy. Biomarkers, in particular microsatellite instability (MSI), programmed cell death ligand 1 (PD-L1), human epidermal growth factor receptor 2 (HER2), tumor mutation burden, and Epstein-Barr virus, are increasingly driving systemic therapy approaches and allowing for the identification of populations most likely to benefit from immunotherapy and targeted therapy. Significant research opportunities remain for the less differentiated histologic subtypes of gastric adenocarcinoma and those without markers of immunotherapy activity.

Abstract PD12-06: Treatment-related amenorrhea with T-DM1 plus pertuzumab (KP) is lower than with docetaxel/carboplatin/trastuzumab/pertuzumab (TCHP) in the phase III neoadjuvant KRISTINE trial

Abstract Background: Cytotoxic chemotherapy (CT) in combination with trastuzumab and pertuzumab (HP) is standard of care for patients (pts) diagnosed with HER2-positive early breast cancer (EBC). While highly effective, the toxicity associated with CT is challenging. In KRISTINE/TRIO-021, neoadjuvant T-DM1 was combined with pertuzumab (KP) and compared to standard TCHP. Pts. received six cycles of neoadjuvant treatment followed by adjuvant therapy (KP or HP). Pts. in the KP arm were allowed to receive standard adjuvant CT. Pathologic complete response (pCR) rate was significantly lower with KP versus TCHP and more pts. had disease progression prior to surgery with KP, resulting in a meaningfully lower event-free survival rate vs. the control (85.3% vs 94.2%). However, 3-year invasive disease-free survival was numerically similar in both arms. Neoadjuvant KP demonstrated less toxicity than standard CT, although treatment discontinuation was higher post-surgery. Association of KP and TCHP with treatment-related amenorrhea (TRA) in premenopausal EBC pts. has not been ascertained. Methods: All pts. with premenopausal status at study entry (those not meeting the menopause definition based on National Comprehensive Cancer Network Guidelines v3, 2012) and with menstrual period documented within 3 months of randomization, were independently evaluated for presence or absence of TRA by two reviewers. TRA, a prespecified exploratory endpoint of KRISTINE, was defined as cessation of menstruation for &amp;gt;12 months in the absence of treatment with ovarian suppression or other interventions that can induce amenorrhea. Pts. were followed from the time of study entry through the 3-year follow up period after surgery. For cases with inconsistent determination between the two reviewers, a third reviewer adjudicated. TRA rates were calculated per arm, hormone-receptor (HR) status, adjuvant CT and age group. Proportions were compared by estimating the odds ratio (OR) and the 95% confidence interval. Results: Of 444 pts. enrolled, 205 were excluded based on being post-menopausal per NCCN guidelines. Of 239 pts. remaining, 56 were excluded due to insufficient data. The median age of pts. included was 40 years (range: 22-53) for TCHP and 42.5 (range: 23-52) for KP. TRA was observed in 55% (50/91) of pts. treated with TCHP compared to 30% (28/92) treated with KP (OR=2.79; 95% CI 1.52-5.12). In pts. with HR-positive EBC, TRA occurred in 62% with TCHP vs 35% for KP (OR=2.998; 95% CI 1.44-6.25). In those with HR-negative EBC, TRA was observed in 42% with TCHP vs. 21% with KP (OR=2.77; 95% CI 0.88-8.72). In the KP arm, TRA was observed in 38% (8/21) of pts. treated with standard adjuvant CT vs. 28% (20/71) of those that did not (OR 1.57; 95% CI 0.57-4.36). For women age ≤ 40, the rate of TRA was 38% with TCHP vs. 17% with KP (OR=3.00; 95% CI 1.05-8.60). For those &amp;gt; 40 years, TRA was observed in 74% treated with TCHP vs. 39% of those with KP (OR=4.50; 95% CI 1.88-10.73). Conclusion: The rate of TRA with standard TCHP is nearly double that observed with KP, suggesting that targeted CT with an antibody-drug conjugate regimen is associated with less gonadal toxicity. Rates of TRA are higher in women over the age of 40 for each treatment arm however KP is associated with lower rate of TRA in each age group. Association of TRA with efficacy outcomes (pCR, iDFS) will be presented. Citation Format: Sara A Hurvitz, Rodrigo Fresco, Karen Afenjar, Daniil Stroyakovskiy, Chiun-Sheng Huang, Hans Wildiers, Kyung Hae Jung, Jean-François Boileau, Mario Campone, Miguel Martín, Vicente Valero, Joseph A. Sparano, W. Fraser Symmans, Peter A. Fasching, Alastair M. Thompson, Nadia Harbeck, Vanesa López-Valverde, Chunyan Song, Thomas Boulet, Eleonora Restuccia, Dennis J. Slamon. Treatment-related amenorrhea with T-DM1 plus pertuzumab (KP) is lower than with docetaxel/carboplatin/trastuzumab/pertuzumab (TCHP) in the phase III neoadjuvant KRISTINE trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD12-06.

Systematic Review and Network Meta-Analysis of Immune Checkpoint Inhibitors in Combination with Chemotherapy as a First-Line Therapy for Extensive-Stage Small Cell Carcinoma.

Simple SummaryPatients with extensive-stage small cell lung cancer (ED-SCLC) have a very short survival time even if they receive standard chemotherapy. Currently, the combination of chemotherapy plus immune checkpoint inhibitors (ICIs) as the first line treatment had superior survival than chemotherapy alone in randomized control trials. However, there is a lack of head-to-head comparisons for these combination regimens. We conducted a systematic review and network meta-analysis to provide a treatment ranking of ICIs for ED-SCLC. In summary, the probability of nivolumab was associated with the best ranking for overall survival, followed by atezolizumab, durvalumab, pembrolizumab, and ipilimumab. The ranking of progression free survival from the best to the worst was as follows: nivolumab, pembrolizumab, atezolizumab, durvalumab, and ipilimumab. However, nivolumab had the highest probability of grade 3–4 adverse events in our study. Further head-to head large-scale phase III randomized controlled studies are needed to verify our conclusions.Patients with extensive-stage small cell lung cancer (ED-SCLC) have a very short survival time even if they receive standard cytotoxic chemotherapy with etoposide and platinum (EP). Several randomized controlled trials have shown that patients with ED-SCLC who received a combination of EP plus immune checkpoint inhibitors (ICIs) had superior survival compared with those who received EP alone. We conducted a systematic review and network meta-analysis to provide a ranking of ICIs for our primary endpoints in terms of overall survival (OS), progression free survival (PFS), and objective response rate (ORR), as well as our secondary endpoint in terms of adverse events. The fractional polynomial model was used to evaluate the adjusted hazard ratios for the survival indicators (OS and PFS). Treatment rank was estimated using the surface under the cumulative ranking curve (SUCRA), as well as the probability of being best (Prbest) reference. EP plus nivolumab, atezolizumab or durvalumab had significant benefits compared with EP alone in terms of OS (Hazard Ratio HR = 0.67, 95% Confidence Interval CI = 0.46–0.98 for nivolumab, HR = 0.70, 95% CI = 0.54–0.91 for atezolizumab, HR = 0.73, 95% CI = 0.59–0.90 for durvalumab) but no significant differences were observed for pembrolizumab or ipilimumab. The probability of nivolumab being ranked first among all treatment arms was highest (SCURA = 78.7%, Prbest = 46.7%). All EP plus ICI combinations had a longer PFS compared with EP alone (HR = 0.65, 95% CI = 0.46–0.92 for nivolumab, HR = 0.77, 95% CI = 0.61–0.96 for atezolizumab, HR = 0.78, 95% CI = 0.65–0.94 for durvalumab, HR = 0.75, 95% CI = 0.61–0.92 for pembrolizumab), and nivolumab was ranked first in terms of PFS (SCURA = 85.0%, Prbest = 66.8%). In addition, nivolumab had the highest probability of grade 3–4 adverse events (SUCRA = 84.8%) in our study. We found that nivolumab had the best PFS and OS in all combinations of ICIs and EP, but nivolumab also had the highest probability of grade 3–4 adverse events in our network meta-analysis. Further head-to head large-scale phase III randomized controlled studies are needed to verify our conclusions.

Effects of Maackia amurensis seed lectin (MASL) on oral squamous cell carcinoma (OSCC) gene expression and transcriptional signaling pathways.

Oral cancer causes over 120,000 deaths annually and affects the quality of life for survivors. Over 90% of oral cancers are derived from oral squamous cell carcinoma cells (OSCCs) which are generally resistant to standard cytotoxic chemotherapy agents. OSCC cells often exhibit increased TGFβ and PDPN receptor activity compared to nontransformed oral epithelial cells. Maackia amurensis seed lectin (MASL) can target the PDPN receptor and has been identified as a novel agent that can be used to treat oral cancer. However, mechanisms by which MASL inhibits OSCC progression are not yet clearly defined. Here, we performed cell migration and cytotoxicity assays to assess the effects of MASL on OSCC motility and viability at physiologically relevant concentrations. We then performed comprehensive transcriptome analysis combined with transcription factor reporter assays to investigate the how MASL affects OSCC gene expression at these concentration. Key data were then confirmed by western blotting to evaluate the effects of MASL on gene expression and kinase signaling activity at the protein level. MASL significantly affected the expression of about 27% of approximately 15,000 genes found to be expressed by HSC-2 cells used to model OSCC cells in this study. These genes affected by MASL include members of the TGFβ-SMAD, JAK-STAT, and Wnt-βCTN signaling pathways. In particular, MASL decreased expression of PDPN, SOX2, and SMAD5 at the RNA and protein levels. MASL also inhibited SMAD and MAPK activity, and exhibited potential for combination therapy with doxorubicin and 5-fluorouracil. Taken together, results from this study indicate that MASL decreases activity of JAK-STAT, TGFβ-SMAD, and Wnt-βCTN signaling pathways to inhibit OSCC growth and motility. These data suggest that further studies should be undertaken to determine how MASL may also be used alone and in combination with other agents to treat oral cancer.

Prognostic Value of Measurable Residual Disease after Venetoclax and Decitabine in Acute Myeloid Leukemia

Assessment of measurable residual disease (MRD) provides prognostic information in acute myeloid leukemia (AML). However, the utility of MRD with venetoclax-based lower intensity regimens is unknown. We analyzed the prognostic value of achieving a negative MRD in older/"unfit" patients with AML receiving first-line therapy with 10-day decitabine and venetoclax. MRD was evaluated in bone marrow specimens using multicolor flow cytometry (sensitivity 0.1%). Ninety-seven patients achieving either a complete remission (CR) or CR with incomplete hematologic recovery (CRi) or morphologic leukemia-free state were included. Median age was 72 years (interquartile range, 68-78 years), and 64% had adverse-risk AML. Eighty-three patients achieved CR/CRi, and 52 (54%) became MRD negative. Median time to becoming MRD negative was 2.0 months (interquartile range, 0.9-3.1 months). Patients becoming MRD negative by 2 months had longer relapse-free survival (RFS) compared with those remaining MRD positive (median RFS, not reached vs 5.2 months; hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.12-0.78; P = .004), longer event-free survival (EFS) (median EFS, not reached vs 5.8 months; HR, 0.25; 95% CI, 0.12-0.55; P < .001), as well as longer overall survival (OS) (median OS, 25.1 vs 7.1 months; HR, 0.23; 95% CI, 0.11-0.51; P < .001). Patients achieving an MRD-negative CR had longer OS compared with those with an inferior response (median OS, 25.1 vs 11.6 months; HR, 0.33; 95% CI, 0.19-0.58; P < .0005). Patients becoming MRD negative within 1 month had an improved OS compared with MRD-positive patients (median OS, 25.1 vs 3.4 months; HR, 0.15; 95% CI, 0.03-0.64; P < .0001). Differential impact of MRD status on survival outcomes persisted at a later 4-month time point of evaluation. In conclusion, MRD-negative status at 1, 2, and 4 months after starting therapy confers significantly better survival in older/unfit patients with AML receiving first-line therapy with 10-day decitabine and venetoclax. This trial was registered at www.clinicaltrials.gov as #NCT03404193.

Phase I trial of nedaplatin and S-1 in patients with advanced squamous cell lung cancer.

The platinum doublet is considered to be the standard cytotoxic chemotherapy for advanced lung cancer. It has been previously reported that nedaplatin and S-1 have clinical efficacy against squamous cell lung cancer. As the combination of nedaplatin and S-1 has never been studied for advanced squamous cell lung cancer, a phase I trial of this combination in the first-line setting was conducted. Patients who had not received chemotherapy previously, aged ≤75 years and with advanced squamous cell lung cancer were recruited. Nedaplatin was administered intravenously (day 1), and S-1 was orally administered (days 1-14) at a fixed dose based on the body surface area (BSA) <1.25 m2, 80 mg/day; BSA=1.25-1.5 m2, 100 mg/day; and BSA ≥1.5 m2, 120 mg/day. A total of 9 patients were enrolled. The maximum tolerated dose was 80 mg/m2 for nedaplatin. At this dosage, dose-limiting toxicity was observed in 2 of the 6 patients. A total of one patient experienced grade 3 thrombocytopenia, and the other patient experienced grade 3 anorexia and grade 3 nausea. The recommended dose for phase II studies was determined as being 70 mg/m2 for nedaplatin (clinical trial registration no. UMIN-CTR UMIN000036387).

Combining Systemic Therapy With Radiation: Head and Neck Cancer Treatments in an Era of Targeted Agents and Immunotherapy.

The addition of chemotherapy to radiation therapy (RT) has been established for decades to improve outcomes in patients with head and neck cancer (HNC). Concurrent chemoradiation increases both local control and overall survival but at the cost of significant toxicity, motivating extensive investigations to optimize the balance of clinical efficacy and adverse effects. This review discusses the rationale and seminal studies underlying the concurrent chemoradiation treatment paradigm in HNC, and describes attempts to better tailor systemic therapy beyond standard-of-care cisplatin, such as the use of alternate cytotoxic agents and nonstandard dosing regimens. Modern efforts to incorporate targeted therapies and immunotherapy are then summarized, particularly for patients unable to receive standard cytotoxic chemotherapy. Finally, mechanisms through which RT and systemic therapy cooperate to improve the therapeutic ratio are discussed, with a focus on the interaction between immunotherapy and RT, a rapidly emerging treatment paradigm. With increasing application of novel diagnostic and therapeutic approaches, determining the optimal concurrent systemic program to maximize RT efficacy will continue to evolve. Identification of patient- and tumor-specific factors will offer a unique opportunity to implement personalized oncologic care.

Prognostic role of mismatch repair deficiency (MMR-D) in patients receiving first-line fluoropyrimidine and platinum (FP) doublet chemotherapy for metastatic and locally advanced unresectable gastric cancers (GCs).

4566 Background: Although chemotherapy has been suggested to have the potential to cause a detrimental effect on treatment outcomes of localized GC with MMR-D, it remains unclear whether chemotherapy for metastatic/recurrent/unresectable GC with MMR-D would also adversely affect the survival outcomes. Anti PD-1 antibody (Ab) showed remarkable efficacy in patients with MMR-D and is being actively investigated in combination with cytotoxic chemotherapy. Hence, we aim to evaluate the impact of MMR status on treatment outcomes of advanced GC. Methods: We reviewed our database to identify all patients with HER2 negative, metastatic, recurrent, and locally advanced unresectable GC who received FP doublet chemotherapy from January 2015 to August 2018. For those who had an available tumor tissue, MMR protein expression was assessed by immunohistochemistry (IHC) and correlated with clinical characteristics and treatment outcomes. Results: Out of 895 patients identified from the database, 543 underwent IHC testing for MMR. The median age was 58 years (range, 24 – 86) with male comprising 64.0%. Most patients had initially metastatic disease (n = 382, 70.3%) followed by recurrent (n = 127, 23.3%) and locally advanced unresectable disease (n = 34, 6.3%). MMR-D was found in 4.4% (n = 24) and associated with age ≥ 65 years (50% vs. 29.9%; P = 0.04) and signet ring cell histology (0% vs. 17.7%, P = 0.01). According to our prognostic model (Koo DH et al, 2011), only 4.2% of patients with MMR-D were classified as Poor-risk group (vs. 16.8% of patients with MMR-P, p= 0.10). In the Good-risk group, patients with MMR-D (n = 10) had significantly shorter median progression-free survival (PFS, 6.0 vs. 9.0 months, P = 0.05) and overall survival (OS, 10.1 vs 20.9 months, P = 0.047) compared to those with MMR-P (n = 188), while there was no significant difference in survival outcomes depending on MMR status in the Moderate and Poor-risk groups. In multivariate analysis for OS, MMR status was a significant prognostic factor for OS in Good-risk group GC patients. Conclusions: GC patients with MMR-D had poorer median PFS and OS than those with MMR-P on standard cytotoxic chemotherapy in the Good-risk group. Thus, for Good-risk GC patients with MMR-D, anti PD-1 Ab alone might be considered rather than combining cytotoxic chemotherapy. Further investigation with next-generation sequencing is in process to determine underlying molecular mechanisms and will be presented in ASCO 2020.