Cara L Haymaker

Immunological biomarkers of response and resistance to treatment with cabozantinib and nivolumab in recurrent endometrial cancer

Background Antiangiogenics combined with immune checkpoint blockade have become standard of care for recurrent endometrial cancer after standard platinum-based chemotherapy. To dissect mechanisms and define biomarkers associated with clinical outcomes to these combinations, we applied multidimensional immune monitoring to peripheral blood specimens collected from a randomized phase 2 trial of nivolumab with or without cabozantinib in 75 evaluable patients with recurrent endometrial cancer (NCI ETCTN 10104, NCT03367741). This trial demonstrated superiority of the combination to nivolumab alone. Methods and results Using Olink proteomics, mass cytometry, tumor antigen-specific ELISA, and whole exome tumor sequencing, we identified longitudinal immune signatures specific to cabozantinib use, including an increase in plasma HO-1 and reduction in plasma vascular endothelial growth factor receptor 2, interleukin-12, and circulating plasmacytoid dendritic cells. Prior exposure to immunotherapy and carcinosarcoma histology had no adverse impact on clinical benefit or biomarkers, and copy-number high tumors were associated with increased plasma granzymes on combination treatment. Higher baseline plasma levels of myeloid-related markers (chemokine ligand 23/CCL23, colony-stimulating factor-1/macrophage colony-stimulating factor/CSF1) were associated with poor overall and progression-free survival, and lack of clinical benefit (defined as progressive or stable disease <6 months) following combination treatment (Kaplan-Meier, multivariate Cox, false discover rate <0.05). Patients with favorable outcomes had higher levels of activated T-cell markers (plasma ICOS-L, CD28) and exhibited spontaneous autoantibody titers to tumor antigen NY-ESO-1. Patients experiencing severe adverse events from the combination therapy had higher baseline levels of neutrophil-derived markers (CXCL1). Conclusions Overall, this study highlights potential resistance and response mechanisms to nivolumab+cabozantinib and suggests prioritizing combination treatment in patients with activated T-cell immunogenicity profiles while exploring future combinatorial therapies targeting myeloid populations to overcome resistance.

Surgical and Blood-Based Minimal Residual Disease in Patients with Ovarian Cancer after First-line Therapy: Clinical Outcomes and Translational Opportunities

Abstract Purpose: Minimal residual disease (MRD) after first-line treatment of advanced-stage ovarian cancer remains a long-standing barrier to cure. We investigated the prognostic and translational value of MRD detection by second-look laparoscopy (SLL) and ctDNA at the completion of first-line therapy. Experimental Design: Patients with high-grade epithelial ovarian cancer who had a complete clinical response to first-line therapy and underwent SLL and plasma collection for ctDNA were included. Progression-free survival (PFS) and overall survival (OS) were estimated based on MRD and clinicopathologic status. Spatial transcriptomics (GeoMx and Visium) and proteomics (CODEX) profiling were performed on serial samples from select patients. Results: Forty of 95 (42.1%) patients had surgically detected MRD, which was associated with worse PFS (median PFS 7.4 vs. 23.8 months; P < 0.001) and OS (median OS 33.9 vs. not reached; P < 0.001). SLL positivity was an independent negative prognostic factor for OS (HR, 4.40; 95% confidence interval, 1.37–14.21; P = 0.013) in multivariable analysis. Among 44 patients who underwent SLL and had ctDNA testing, 34% (15/44) were ctDNA-positive, which was associated with worse PFS (6.4 vs. 28.1 months; P < 0.001) and OS (32.4 months vs. not reached; P = 0.008). We demonstrated the feasibility of spatial multiomics in studying MRD and their ability to provide hypothesis-generating observations, implicating the upregulation of the hypoxia signaling pathway, expression of multiple druggable targets (CDK6, GLS, MSLN, ERBB2), and immune exclusion in MRD lesions. Conclusions: Approximately half of patients in clinical remission after first-line therapy have assessable MRD, which can inform prognosis, therapeutic target discovery, and clinical trials.

Linking Microbiome Diversity and Immune Profiles in Ethiopian Patients With Cervical Cancer

PURPOSE This study investigates the interplay between T-cell receptor (TCR) immune characteristics and microbiome profiles to explore the relationship between immune diversity and microbial composition in cervical samples from Ethiopia. METHODS Cervical specimens were collected from patients at Tikur Anbessa Specialized Hospital in Addis Ababa, and rural Butajira, south-central Ethiopia. Patient data, including age, human papillomavirus status, pathology, and TCR immune characteristics, were analyzed with a focus on the interactions between TCR profiles and microbiome compositions in malignant samples. RESULTS Three distinct TCR profiles were identified: Group 1 (TCR active) exhibited features of active immune engagement, including high diversity, clonal expansion, and repertoire richness. Group 2 (TCR restricted) showed reduced TCR diversity and expansion, suggesting a restricted repertoire. Group 3 (TCR balanced) had moderate diversity and clonal activity. TCR repertoire groups were linked with microbial diversity, with Group 1 (TCR active) showing the highest number of microbes (high operational taxonomic units and microbial diversity). Maximum TCR clonal expansion positivity associated with microbial richness, while Group 3 (TCR balanced) was linked to reduced microbial alpha diversity. Taxonomic analysis revealed specific organisms enriched in TCR repertoire group. CONCLUSION Variations in TCR profiles are linked to distinct microbial environments in cervical cancer with greater microbial richness in patients with greater maximum productive frequency. These findings underscore the interplay between TCR diversity, microbiome composition, and malignancy, offering insights into the potential implications for microbiome-targeted therapies and prognostic biomarkers in cervical cancer.

CRISPR-mediated TGFBR2 knockout renders human ovarian cancer tumor-infiltrating lymphocytes resistant to TGF-β signaling

Background The correlation between elevated T-cell infiltration and improved survival of ovarian cancer (OvCa) patients suggests that endogenous tumor-infiltrating lymphocytes (TIL) possess some degree of antitumor activity that can be harnessed for OvCa immunotherapy. We previously optimized a protocol for ex vivo OvCa TIL expansion for adoptive cell therapy, which is now being tested in a clinical trial at our institution (NCT03610490). Building on this success, we embarked on genetic modification of OvCa TIL to overcome key immunosuppressive factors present in the tumor microenvironment. Here, we present the preclinical optimization of CRISPR/Cas9-mediated knockout of the TGF-β receptor 2 (TGFBR2) in patient-derived OvCa TIL. Methods OvCa TILs were generated from four patients’ tumor samples obtained at surgical resection and subjected to CRISPR/Cas9-mediated knockout of TGFBR2 before undergoing a rapid expansion protocol. TGFBR2-directed gRNAs were comprehensively evaluated for their TGFBR2 knockout efficiency and off-target activity. Furthermore, the impact of TGFBR2 knockout on TIL expansion, function, and downstream signaling was assayed. Results TGFBR2 knockout efficiencies ranging from 59±6% to 100%±0% were achieved using 5 gRNAs tested in four independent OvCa TIL samples. TGFBR2 knockout TIL were resistant to immunosuppressive TGF-β signaling as evidenced by a lack of SMAD phosphorylation, a lack of global transcriptional changes in response to TGF-β stimulation, equally strong secretion of proinflammatory cytokines in the presence and absence of TGF-β, and improved cytotoxicity in the presence of TGF-β. CRISPR-modification itself did not alter the ex vivo expansion efficiency, immunophenotype, nor the TCR clonal diversity of OvCa TIL. Importantly for clinical translation, comprehensive analysis of CRISPR off-target effects revealed no evidence of off-target activity for our top two TGFBR2-targeting gRNAs. Conclusions CRISPR/Cas9-mediated gene knockout is feasible and efficient in patient-derived OvCa TIL using clinically-scalable methods. We achieved efficient and specific TGFBR2 knockout, yielding an expanded OvCa TIL product that was resistant to the immunosuppressive effects of TGF-β. This study lays the groundwork for clinical translation of CRISPR-modified TIL, providing opportunities for engineering more potent TIL therapies not only for OvCa treatment, but for the treatment of other solid cancers as well.

Efficacy and safety of autologous tumor-infiltrating lymphocytes in recurrent or refractory ovarian cancer, colorectal cancer, and pancreatic ductal adenocarcinoma

Background Tumor-infiltrating lymphocyte (TIL) therapy has shown efficacy in metastatic melanoma, non-small cell lung cancer, and other solid tumors. Our preclinical work demonstrated more robust CD8 predominant TIL production when agonistic anti-4-1BB and CD3 antibodies were used in early ex vivo TIL culture. Methods Patients with treatment-refractory metastatic colorectal (CRC), pancreatic (PDAC) and ovarian (OVCA) cancers were eligible. Lymphodepleting chemotherapy was followed by infusion of ex vivo expanded TIL, manufactured at MD Anderson Cancer Center with IL-2 and agonistic stimulation of CD3 and 4-1BB (urelumab). Patients received up to six doses of high-dose IL-2 after TIL infusion. Primary endpoint was evaluation of objective response rate at 12 weeks using Response Evaluation Criteria in Solid Tumors version 1.1 with secondary endpoints including disease control rate (DCR), duration of response, progression-free survival (PFS), overall survival (OS), and safety. Results 17 patients underwent TIL harvest and 16 were treated on protocol (NCT03610490), including 8 CRC, 5 PDAC, and 3 OVCA patients. Median age was 57.5 (range 33–70) and 50% were females. Median number of lines of prior therapy was 2 (range 1–8). No responses were observed at 12 weeks. Ten subjects achieved at least one stable disease (SD) assessment for a DCR of 62.5% (95% CI 35.4% to 84.8%). Best response included prolonged SD in a patient with PDAC lasting 17 months. Median PFS and OS across cohorts were 2.53 months (95% CI 1.54 to 4.11) and 18.86 months (95% CI 4.86 to NR), respectively. Grade 3 or higher toxicities attributable to therapy were seen in 14 subjects (87.5%; 95% CI 61.7% to 98.4%). Infusion product analysis showed the presence of effector memory cells with high expression of CD39 irrespective of tumor type and low expression of checkpoint markers. Conclusions TIL manufactured with assistance of 4-1BB and CD3 agonism is feasible and treatment is associated with no new safety signals. While no responses were observed, a significant portion of patients achieved SD suggesting early/partial immunological effect. Further research is required to identify factors associated with resistance and functionally enhance T cells for a more effective therapy.

Autologous Tumor Infiltrating Lymphocytes MDA-TIL in Treating Patients With Recurrent or Refractory Ovarian Cancer, Colorectal Cancer, or Pancreatic Ductal Adenocarcinoma

This phase II trial studies how well autologous tumor infiltrating lymphocytes MDA-TIL works in treating patients with ovarian cancer, colorectal cancer, or pancreatic ductal adenocarcinoma that has come back (recurrent) or does not respond to treatment (refractory). Autologous tumor infiltrating lymphocytes MDA-TIL, made by collecting and growing specialized white blood cells (called T-cells) from a patient's tumor, may help to stimulate the immune system in different ways to stop tumor cells from growing.