ALBERT

Description: Background: Extranodal natural killer/T cell lymphoma, nasal type (ENKTL) is a highly malignant non-Hodgkin lymphoma (NHL), which has no standard treatment available for this subgroup. Conventional treatment approaches (L-asparaginase- or pegaspargase-based regimen) failed to achieve long-term clinical benefit. The prognosis of advanced ENKTL is poor even in newly diagnosed patients (pts) due to a high relapse rate of 70%. Substantial evidences indicate that anti-programmed death-1 (PD-1) monoclonal antibody has achieved promising efficacy in refractory or relapsed ENKTL (Kwong et al. Blood 2017, Li et al. Journal of Hematology & Oncology 2018, Tao et al. JCO 2020). Results from our retrospective study demonstrated a manageable tolerability profile and favorable anti-tumor activity of anti-PD-1 antibody combined with P-GEMOX (pegaspargase, gemcitabine and oxaliplatin) regimen in untreated advanced ENKTL pts (unpublished data). Therefore, a phase 2 trial (NCT04127227) was initiated to evaluate safety and efficacy of sintilimab (a fully human anti-PD-1 monoclonal antibody) plus P-GEMOX regimen as first-line therapy in advanced ENKTL pts. Here, we report the preliminary results of the study. Methods: This study enrolled adult pts with untreated pathologically confirmed ENKTL with at least one measurable lesion. A sample size of 34 pts was preplanned, with 6 pts recruited for a safety run-in cohort. Pts received six 21-day cycles of sintilimab 200 mg, pegaspargase 2000 U/m2 (day 1), gemcitabine 1g/m2 (days 1 and 8), and oxaliplatin 130 mg/m2 (day 1), followed by sintilimab 200 mg maintenance every 3 weeks for up to 2 years or until documented confirmed disease progression or intolerable toxicity. Of the run-in cohort, preliminary safety and dose-limiting toxicity (DLTs) analyses were performed in the first cycle of treatment, primary endpoints were safety and tolerability of the combination therapy. DLTs were defined as grade 4 neutropenia that does not resolve to grade /= 3 nonhematologic toxicity lasting for more than 7 days, and any treatment-related adverse events (TRAEs) that results in a delay for more than 14 days of initiating cycle 2. Of the entire cohort, primary endpoints were complete response (CR) rate and objective response rate (ORR), secondary endpoints included overall survival, progression-free survival, and safety. TRAEs were accessed according to CTCAE 5.0. Response assessments were performed using PET/CT or MRI scans every 6 weeks of the combined treatment and every 3 months of maintenance treatment. Results: Six pts with untreated ENKTL were enrolled between Sept 19, 2019 and Jul 26, 2020. Median age was 56 years (range 52-67). All pts were found to be found to be positive for EBV encoded RNA (EBER) by in situ hybridization. Clinical characteristics of all pts are listed in Table 1. Median number of treatment cycles was 7 (range 4-11). At data cut-off, 5 pts completed 6 cycles of combination therapy and entered the maintenance phase (median: 1, range 1-5). No DLTs were observed. The majority of TRAEs were reported during the first two cycles of the combination treatment. The most common TRAEs were anorexia (6/6, 100%), elevated transaminase (6/6, 100%), neutropenia (5/6, 3.3%), nausea (4/6, 66.7%), anemia (4/6, 66.7%), hypoproteinemia (4/6, 66.7%), vomiting (3/6, 50.0%) and thrombocytopenia (3/6, 33.3%). Grade 3/4 TRAEs occurred in 4 (66.7%) pts, including thrombocytopenia (1/6, 16.7%), anemia (2/6, 33.0%), and neutropenia (1/6, 16.7%). Details of all-grade TRAEs are listed in Table 2. All the TRAEs were manageable and reversible. No immune-related (ir) AE or treatment-related death was observed. Of the 6 pts received response assessments, ORR was 100% (6/6) and CR rate was 33.3% (2/6). After a median follow-up of 7.8 months, 5 pts were still on the planned treatment and maintained favorable outcomes. The updated data will be reported at the ASH conference. Conclusions: Sintilimab plus P-GEMOX regimen demonstrated manageable safety profile and promising anti-tumor activity in pts with untreated advanced ENKTL. The preliminary safety and efficacy profile of combination therapy support further study and the exploration of effective biomarkers for predicting the treatment response is under way. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Sintilimab is medication that is indicated for the treatment of relapsed or refractory classical Hodgkin's lymphoma after failure of at least second-line systemic chemotherapy.

Description: Background: T-cell lymphoblastic lymphoma (T-LBL) is a highly aggressive non-Hodgkin's lymphoma with poor prognosis and lacks of standard treatment approaches. PAK2, a member of the p21 activated kinase (PAKs) family, is a component of the gene-expression-based classifier which made great contributions to prognostic prediction of T-LBL(Cai et al. Leukemia 2020). This study aims to analyze the expression of PAKs in human T-LBL cell lines and tissues to clarify its clinical significance and evaluate the therapeutic activity of PAKs inhibitor in T-LBL. Methods: The mRNA and protein expression levels of PAKs in human T-lymphoid cell lines (H9) and T-LBL cell lines (Jurkat, SUP-T1 and CCRF-CEM) were detected by quantitative real-time PCR and western blot, respectively. We retrospectively collected 69 Formalin-fixed, Paraffin-embedded (FFPE) samples and corresponding clinical information from T -LBL patients between September 2000 and May 2015 at Sun Yat-sen University Cancer Center (SYSUCC). Affymetrix Human Gene 2.0 ST microarray (Thermo Fisher Scientific, Waltham, MA, USA) was used to detect the expression of PAKs. Mann-Whitney U test was used for comparing the expression differences between relapsed and non-relapsed patients. Cumulative relapse-free survival (RFS) time was calculated using the Kaplan-Meier method (Expression level higher than the upper quartile (P75) was defined as PAK1 or PAK 2 high expression. High expression (median as cutoff point) of both PAK1 and PAK2 was defined as PAK1/2 high expression). Pearson's chi-square test and Fisher's exact test were used to compare the distribution of clinical variables. Correlations between PAK1, PAK2 and NOTCH1 were evaluated using Spearman's correlation coefficient. Two PAK inhibitors, PF3758309 (PF) and FRAX597, were used to block PAK kinase activity pharmacologically. Cell viability was determined using the viability assay kit CCK-8. Cell cycle and cell apoptosis were analyzed by flow cytometry. All statistical analyses were performed using SPSS 24.0 software (SPSS, Armonk, NY, USA) or GraphPad Prism 8.0 (GraphPad, La Jolla, CA, USA). A P value 〈 0.05 was considered significant. The study protocol was approved by the Institutional Review Board of SYSUCC. Results: The mRNA and protein expression levels of PAK1 in T-LBL cell lines of Jurkat, SUP-T1 and CCRF-CEM cell lines were significantly higher than those in T-lymphoid cell lines H9 cell line (P

Description: Chimeric antigen receptor (CAR) T cell therapy has made significant progress in the treatment of blood cancers such as leukemia, lymphoma, and myeloma. However, the therapy faces many challenges in treating solid tumors. These challenges include physical barriers, tumor microenvironment immunosuppression, tumor heterogeneity, target specificity, and limited reactive cell expansion in vivo. Conventional CAR T cell therapy has thus far shown weak cell expansion in solid tumor patients and achieved little or no therapeutic responses. Here, we developed CAR T cells based on a novel CoupledCAR® technology to treat solid tumors. In contrast to conventional CAR T cells, CoupledCAR T cells significantly improved the expansion of the CAR T cells in vivo and enhanced the CAR T cells' migration ability and resistance to immunosuppression by the tumor microenvironment. The enhanced migration ability and resistance allow the CAR T cells to infiltrate to tumor tissue sites and increase anti-tumor activities. Specifically, we engineered CoupledCAR T cells with lentiviral vectors encoding an anti-GCC (guanylate cyclase 2C) CAR molecule. Furthermore, anti-GCC CAR T cells showed anti-tumor activities in vitro and in vivo experiments. To verify the safety and efficacy of CoupledCAR T cells for treating solid tumors, we conducted several clinical trials for different solid tumors, including seven patients with colorectal cancer. These seven patients failed multiple rounds of chemotherapy and radiotherapy. In the clinical trial, the patients were infused with autologous anti-GCC CoupledCAR T cells range from 4.9×10^5/kg to 2.9×10^6/kg. All patients using anti-GCC CoupledCAR T cells showed rapid expansion of CoupledCAR T cells and killing of tumor cells. Specifically, we observed that CoupledCAR T cells expanded significantly in the patients and infiltrated tumor tissue sites, demonstrating enhanced anti-tumor activities. PET/CT showed significant tumor shrinkage and SUV max declined, and the ongoing responses were monitored. Patient 3 achieved complete response and the best overall response rate (ORR, include complete remission, complete metabolic response, partial response, and partial metabolic response.) was 71.4% (5/7), complete remission (CR) rate was 14.3% (1/7). The clinical data demonstrated that CoupledCAR T cells effectively expanded, infiltrated tumor tissue sites, and kill tumor cells in patients with colorectal cancer. We used immunotherapy to achieve complete remission in patients with advanced colorectal cancer for the first time. We are recruiting more colorectal cancer patients to further test the safety and efficacy of anti-GCC CoupledCAR T cells. Since our CoupledCAR® technology is a platform technology, we are expanding it to treat other solid tumors using different target tumor markers . Disclosures Xiao: Innovative Cellular Therapeutics: Other: stockholder.

Description: CoupledCAR TM Technology for Treating Thyroid Cancer Chimeric antigen receptor modified T cells (CAR T) have demonstrated remarkable clinical efficacy in the treatment of B cell malignancies and multiple myeloma. Significant challenges restrict their application across solid tumors due to multiple obstacles, including the lack of robust in vivo CAR-T cell expansion and persistence, the immunosuppressive tumor microenvironment, and tumor escape due to heterogeneous tumor cell composition with a potential loss of the targeted tumor antigen. To address these difficulties, we generated CAR T cells using a novel CoupledCARTM technology. Specifically, we engineered CoupledCAR T cells with lentiviral vectors encoding an anti-thyroid stimulating hormone receptor (TSHR) CAR molecule. Immunohistochemistry (IHC) results showed that TSHR was highly expressed in thyroid cancer cells making it an ideal tumor-specific target antigen. In vitro co-culture experiments showed that TSHR CAR T cells specifically recognized and consequently killed TSHR-positive tumor cells. Animal experiments showed that TSHR CAR T cells inhibited the proliferation of TSHR-positive tumor cells. To evaluate the clinical safety and efficacy of anti-TSHR CoupledCAR T cells on refractory or relapsed thyroid cancer, we treated refractory/relapsed post-thyroidectomy thyroid cancer patients according to an IRB approved protocol. We treated two patients using anti-TSHR CoupledCAR T cells and observed the rapid expansion of CAR T cells and enhanced the killing of tumor cells. One patient's best response was complete remission, and the other was near complete remission. Patient Profile: Patient 1 Male, 64Y, Papillary Thyroid Carcinoma. In May 2017, Thyroid cancer was diagnosed, bilateral total thyroidectomy, and right cervical lymph node functional dissection were performed in June, followed by iodine 131 isotope therapy. In December 2018, bilateral multiple cervical lymph nodes were enlarged, especially on the right side. In February 2019, right neck lymphadenectomy was performed. Patient 2 Female, 60Y, Thyroid Carcinoma. In Aug 2013, a "double lobectomy of the thyroid gland" was performed. From Oct 2013 to Jan 2014, she received iodine 131 isotope therapy. In Sep 2014, she was diagnosed with iodine - resistant thyroid cancer. From Sep to Jan 2016, 5 cycles of chemotherapy were performed. In Jun 2016, she enrolled in the Anlotinib experimental group. In Mar 2019, multiple metastases in both lungs and multiple enlarged lymph nodes in the mediastinum were observed. Observations and Results: Patient 1: One month after infusion (M1), the patient was evaluated as PR: lymph node metastasis became undetectable and the size of the thoracic paratracheal tumor nodules decreased significantly. Three months after infusion (M3), the patient was evaluated as CR, and the tumor tissue was substantially smaller than M1. Patient 2: M1, the patient was evaluated as PR (Partial Response): the tumor volume in the right lower lobe of the lung was reduced by approximately 67.51% (decreased from 65*55mm to 42*39mm). Three months after infusion (M3), compared with that before, the tumor volume was reduced by approximately 73.54% and SUV max value decreased from 14.9 to 2.8, therefore, the patient was evaluated as nCR (near complete remission). We show that TSHR is a good target for treating thyroid cancer, and our anti-TSHR CoupledCAR T cells are safe and effective for treating thyroid cancer. Recruitment is ongoing to evaluate the safety and efficacy of our CoupledCAR T cells. Further, since our CoupledCARTM technology is a platform technology, we are developing it to treat other solid tumors using different target markers. Disclosures Xiao: Innovative Cellular Therapeutics: Other: stockholder.