Biomarker Of Response In Patients Research Articles

Evaluation of biomarkers of response in patients with breast cancer with BRCA 1/2 pathogenic variants treated with PARP inhibitors.

e15188 Background: Several prospective studies highlight the pivotal role of PARP inhibitors (PARPi) in treating BRCA-associated breast cancers (BC), demonstrating a significant overall response rate (ORR) of up to 60% in advanced BC patients with BRCA 1/2 germline pathogenic variants (PV). Despite their clinical efficacy, the factors predicting PARPi response, the mechanisms of resistance to PARPi, and the clinical strategies to overcome these challenges are still unknown. The aim of this study is to establish tissue microarrays (TMA) from primary breast tumor tissue from BC patients with BRCA1/2 PVs who were treated with PARPi and identify biomarkers of PARPi resistance. Methods: Stage 4 BC patients with BRCA 1/2 PVs who presented to the University of Texas MD Anderson Cancer Center Breast Medical Oncology clinics and were treated with PARPi between 2008-2023 were identified using our database. Available patient tissue samples were obtained from institutional tumor banks. TMA from breast tumor tissue created and evaluated by our collabrating pathologists for expression of biomarkers:Wee-1, MRE, BP1,and c-Myc. Clinical and tumor characteristics analyzed included:Age at diagnosis, treatment details, tumor characteristics including histological type, hormonal receptor status, Her-2/Neu status, grade, Ki-67 and clinical outcome. Descriptive statistics, the Fisher exact test, and the log rank test were used to report patient characteristics and outcomes. Here we report on initial TMA construct and biomarker analysis. Results: So far TMA from 12 patients treated with PARPi were succesfully constructed. Patient characteristics include: Median age of 36.5 years (29-57). Nine (75%) and 3 (25%) patients had BRCA1 and BRCA2 mutations, respectively. All patients had invasive ductal carcinoma and 9 (75%) had triple negative BC. Most patient (75%) had high nuclear grade BC and median Ki-67 was 75 (15-90). In 11 evaluable patients, the ORR was 72.7%. The median OS was 383.6 months (95% CI 62.5-383.6) and median PFS was 31.5 months (95% CI 10.8-NE). No significant difference in biomarker expression was observed between PARPi-responders and non-responders (Table1). Conclusions: This report presents unique data on novel predictive biomarkers of response and evaluates the evidence for potential biomarkers. Further analysis on a larger TMA cohort is ongoing. [Table: see text]

Dual mTOR1/2 Inhibitor Sapanisertib (FTH-003/TAK-228) in Combination With Weekly Paclitaxel in Patients With Previously Treated Metastatic Urothelial Carcinoma: A Phase II Open-Label Study

BackgroundThe PI3K/AKT/mTOR pathway is frequently altered at genomic level in metastatic urothelial carcinoma (mUC). Since mTOR is the last protein in the PI3K signaling cascade, it may have the largest impact on the pathway and has been a focus of targeted therapies. Sapanisertib (FTH-003/TAK-228) is an oral highly selective mTOR1 and mTOR2 inhibitor. NFE2L2 mutations have been described as predictive biomarkers of response in patients with advanced squamous cell lung cancer treated with sapanisertib. Patients and MethodsThis was an open-label, investigator-initiated phase II study evaluating safety and efficacy of sapanisertib plus paclitaxel in patients with mUC who had progressed to prior platinum therapy, and the correlation with NFE2L2 mutations in responders. Primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS) and safety. Patients were treated with weekly paclitaxel at dose of 80 mg/m2 on days 1, 8, and 15 in combination with sapanisertib 4 mg administered orally 3 days per week on days 2-4, 9-11, 16-18, and 23-25 of a 28-day cycle. NFE2L2 mutations were analyzed by Sanger sequencing in responders. Results22 patients were enrolled from May 2018 to April 2020; the trial was halted early due to slow accrual and the COVID-19 pandemic. ORR was 18.2% (n = 4). Disease control rate was 50% (7 SD and 4 PR). Median PFS was 3.4 months (95% CI: 1.8-6.1) and median OS was 6.1 months (95% CI: 1.8-13.4). Adverse events (AE) of grade 3-4 were seen in 86% of patients, but no patients discontinued treatment due to AEs. NFE2L2 mutations were not found in responders. ConclusionsAlthough the primary endpoint was no met, sapanisertib and paclitaxel combination demonstrated clinical activity in a heavily pretreated population of mUC. This trial generates insight for future combination of sapaniserib with immunotherapy and/or antibody drug conjugates.

Alterations in Peripheral Lymphocyte Subsets under Immunochemotherapy in Stage IV SCLC Patients: Th17 Cells as Potential Early Predictive Biomarker for Response.

UICC stage IV small-cell lung cancer (SCLC) is a highly aggressive malignancy without curative treatment options. Several randomized trials have demonstrated improved survival rates through the addition of checkpoint inhibitors to first-line platin-based chemotherapy. Consequently, a combination of chemo- and immunotherapy has become standard palliative treatment. However, no reliable predictive biomarkers for treatment response exist. Neither PD-L1 expression nor tumor mutational burden have proven to be effective predictive biomarkers. In this study, we compared the cellular immune statuses of SCLC patients to a healthy control cohort and investigated changes in peripheral blood B, T, and NK lymphocytes, as well as several of their respective subsets, during treatment with immunochemotherapy (ICT) using flow cytometry. Our findings revealed a significant decrease in B cells, while T cells showed a trend to increase throughout ICT. Notably, high levels of exhausted CD4+ and CD8+ cells, alongside NK subsets, increased significantly during treatment. Furthermore, we correlated decreases/increases in subsets after two cycles of ICT with survival. Specifically, a decrease in Th17 cells indicated a better overall survival. Based on these findings, we suggest conducting further investigation into Th17 cells as a potential early predictive biomarkers for response in patients receiving palliative ICT for stage IV SCLC.

Abstract 5186: Spatial single-cell deconvolution of the bone marrow microenvironment to define predictive biomarker for response to immunotherapy in patients treated with a check point inhibitor in smoldering multiple myeloma, phase II trial of nivolumab in combination with lenalidomide and low dose dexamethasone

Abstract Background:The immune system is critical for response and resistance in all cancer types and therapies. Patients with Smoldering Multiple Myeloma (SMM) have altered immune cell composition in the bone marrow (BM). However, little is known about the role of BM spatial immune profiling in patients treated with checkpoint inhibitors in MM. Methods: We performed spatial profiling with imaging mass cytometry of trephine biopsies of the BM (n=15; pre-treatment n=7 and post-treatment n=8) from patients with high-risk SMM enrolled in a phase II trial of nivolumab in combination with lenalidomide and low dose dexamethasone (NCT02903381). Patients received 6 cycles of induction therapy of nivolumab (240mg) at days 1 and 15, in combination with lenalidomide (25mg) at days 1-21 and dexamethasone at days 1, 8, and 15. The induction phase was followed by nivolumab (240mg) and lenalidomide (25mg) maintenance for another 6 cycles. A treatment cycle was defined as 28 consecutive days for a total of 12 months period. Event monitoring was performed up to 3 years. The primary efficacy outcome was progression-free survival 2 years after treatment. Results: Eight patients were enrolled on this study from January 2017 to June 2017. The study was put on hold due to the toxicity of checkpoint inhibitors observed in other trials of MM. The median age for all patients at enrolment was 60 years (range 49 to 81), with 5 males (62%) and 3 females (38%). All patients met criteria for high risk SMM disease. Median follow-up for all 8 patients was 38.7 months. Median overall survival was not reached; median progression-free survival was 33.8 months. Seven total patients had a response of Minimal Response (MR) or better, and 4 patients who initially responded eventually progressed. The total number of patients who were followed for at least two years and remained progression-free was 4 of 8 evaluable patients (50%; 90% CI: 19 - 81%).Spatial profiling with a panel of 37 markers on the pre-treatment samples allowed us to assess the states and abundances of multiple immune subpopulations, including rare regulatory NK cells. To assess the accuracy of our cell type annotation, we correlated the proportion of malignant plasma cells identified per patient with the value determined by pathologists for clinical diagnosis. These measures were significantly positively correlated (R=0.92, p<0.01). Spatial neighborhood analysis revealed statistically significant interactions enriched in the responders, even with our small sample size (t-test; p < 0.05). Conclusions and future directions: This pilot study suggests that BM spatial immune profiling before receiving immune check point inhibitors can be a biomarker for response in patients with SMM. Citation Format: Yoshinobu Konishi, Giuseppe Tarantino, Yiwen He, Romanos Sklavenitis-Pistofidis, Sujal I. Shah, Katherine Towle, Christian J. Cea-Curry, Oksana Zavidij, Ruben D. Carrasco, Scott J. Rodig, Jon C. Aster, David Liu, Gad Getz, Irene M. Ghobrial. Spatial single-cell deconvolution of the bone marrow microenvironment to define predictive biomarker for response to immunotherapy in patients treated with a check point inhibitor in smoldering multiple myeloma, phase II trial of nivolumab in combination with lenalidomide and low dose dexamethasone [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5186.

Imaging predictive biomarkers of response in patients with prostate cancer undergoing high-intensity focused ultrasound (HIFU) focal therapy.

288 Background: The current study is designed to evaluate the role of PSMA PET/CT for response prediction in prostate cancer (PCa) patients who are candidates for High-Intensity Focused Ultrasound (HIFU) focal therapy (FT). Methods: BetweenOctober 2020 and June 2023, overall 65 patients have been enrolled in our prospective, single-center study. Inclusion criteria were: PSA<20ng/mL, radiological stage ≤T2bN0M0, ISUP grade 1-3, PSMA PET/CT at baseline and at response evaluation 6-12 months post-treatment. Follow up included: PSA at 3, 6 and 12 months. Post-treatment biopsies were scheduled per-protocol at 12 months or earlier if imaging suspicious. Biochemical response and treatment failure were correlated to mpMRI and PSMA PET data, comprising PI-RADS, Primary score, SUVmax, SUVratio, and their variations after HIFU FT. Results: Median age was 67 years (range 53-80), initial PSA (iPSA) was 6.56ng/mL (range 2.25-13.25) and prostate volume was 45mL (range 20-160). The majority of the patients presented with ISUP 1 (66%). mpMRI results were: 14 patients with PI-RADS 1-2 (21.5%) and 51 with PI-RADS 3-4. Baseline Primary scores were: 30 score 1-2 (45%), and 35 score 3-5. Median baseline SUVmax and SUVratio resulted 5.4 (range 1.5-33.2) and 1.43 (range 0.86-9.39), respectively. At 3 months post-HIFU, 23% of the patients obtained a PSA response ≥50%; whereas at 6 months and 12 months, PSA responses were 26% and 45%, respectively. Post-treatment PSMA PET/CT was available in 40 patients. Median SUVmax and SUVratio post-treatment resulted 3.4 (range 1.4-28.4) and 1.1 (range 0.64-10), respectively, with a median ΔSUVmax of 39% and ΔSUVratio of 42%. There was a moderate negative correlation between post-treatment SUVmax and SUVratio with PSA response at 12 months (rho=-0.504, p=0.0280, and rho=-0.521, p=0.0231, respectively), while a positive moderate correlation was confirmed for ΔSUVmax (rho=0.475, p=0.0383). PET parameters were also statistically significantly correlated to treatment failure at 12months (p=0.020, p=0.048 and p=0,04, respectively for SUVmax, SUVratio and Primary), with Primary scores confirmed as predictive on logistic regression (OR=10.5; 95%CI 1.12-98.9). Conclusions: PSMA PET/CT provides useful information for treatment monitoring in PCa patients undergoing HIFU FT. Baseline and post-treatment SUV parameters and Primary score can predict biochemical response and treatment failure at 12 months post-completion.

Potential biomarkers for treatment response in advanced non-pancreatic neuroendocrine tumors.

599 Background: Well-differentiated NETs are highly vascular and hence, inhibition of angiogenesis is of interest. VEGF, a key molecule in promoting angiogenesis, has also been shown to promote an immunosuppressive tumor microenvironment. Nintedanib, an oral inhibitor of FGFR1–3, VEGFR1–3 and PDGFRA, has previously been evaluated in a phase II clinical trial in well-differentiated, non-pancreatic NETs, where 83% of the evaluable patients were progression-free at 16 weeks and median PFS was 11 months. In preclinical studies, nintedanib has been shown to increase PD-L1 expression in tumor cells, which then results in improved outcomes with immune checkpoint inhibition. There are multiple indicators of T-cell exhaustion, including PD-L1 and LAG-3. LAG-3+ T-cells have been found to correlate with poor response to treatment in neuroendocrine neoplasms. Given these findings, this study evaluates serum VEGF and LAG-3 expression to determine potential biomarkers of response in patients treated with nintedanib. Methods: 27 sets of paired samples collected at baseline and 8-weeks post treatment with nintedanib, from clinical trial NCT02399215 were used for this study. With IRB approval, we tested for serum VEGFa and serum LAG-3 using Luminex test kits: HCKP1-11K-01 (LAG-3) and HCYTA-60K-01 (VEGFa). We compared the baseline, 8-week, and percentage change in serum VEGF and serum LAG-3 levels with Rd Cd8+ pAkt+ T-cells (activated cytotoxic T-cells) as a marker of immune activation, Rd CD25+ pAkt+ T-cells (regulatory T-cells) as a marker of immune suppression, and PFS. Results: The median VEGF levels at baseline and 8-weeks were 10.50 pg/mL and 11.90 pg/mL respectively. The median LAG-3 level at baseline and 8-weeks were 59000 pg/mL and 62900 pg/mL respectively. Higher VEGFa levels in the post-treatment samples were associated with poorer progression free survival (HR= 1.009, 95% HR CI: [0.999, 1.019], with P= 0.0760). Higher levels of VEGF at baseline were also associated with lower numbers of Rd CD8+ pAkt + cells (Pearson coefficient = -0.42, p-value 0.04) at baseline. Increased baseline CD25+ pAkt+ levels were positively correlated with percent change in serum LAG-3 levels between baseline and post-treatment samples. (Pearson Co-efficient: 0.45; p=value: 0.02). Conclusions: Elevated serum VEGFa levels at 8-weeks post treatment correlated with lower PFS. Serum VEGFa level is a potential indicator of effector T-cell suppression, as evidenced by low number of activated cytotoxic T-cells in patients with higher VEGFa levels at baseline. Higher baseline regulatory T-cells were associated with a greater increase in serum LAG-3 levels, suggesting that serum LAG-3 may be an indicator of an immunosuppressive tumor microenvironment.

HMG co-reductase expression and response to intravesical Bacillus Calmette-Guérin in patients with high grade non-muscle invasive urinary bladder cancer receiving statins.

Cardiovascular disease affects over 7 million people in the UK and statins are often prescribed to mitigate cardiovascular risks. The effect of statins on a number of cancers is debated and their effect on Bacillus Calmette-Guérin (BCG) responsiveness in non-muscle invasive urinary bladder cancer (NMIBC) is not fully understood. This study aims to explore the difference in HMG Co-A reductase (HMGCR) expression in NMIBC on immunochemistry in BCG responders and non-responders while on statins. Three hundred and thirty-two cases of intravesical BCG treatment for high-risk NMIBC between November 2003 and December 2017 were identified. Patients taking statins for at least 12 months before the diagnosis of NIMBC and with a follow-up of at least 5 years were included. They were divided into BCG responders and non-responders. Tumour tissue from these patients was immunohistochemically stained and quantitative image analysis carried out to assess and compare HMGCR expression in the groups. This study showed a differential expression of HMGCR in responders vs. non-responders to BCG for high-risk NMIBC on statins. This data should form the basis of a further research and multi-centre study in a larger cohort, using HMGCR as a biomarker of response in patients on statins.

Methotrexate Polyglutamates Exposure - Response Modeling in a Large Cohort of Rheumatoid Arthritis Patients Starting Methotrexate.

Methotrexate polyglutamates (MTX-PG) concentrations in red blood cells (RBCs) have been suggested as a biomarker of response in patients with rheumatoid arthritis (RA) receiving low-dose MTX therapy. We investigated the association and interpatient variability between RBC-MTX-PG3-5 -exposure and response in patients with RA starting MTX. Data of three prospective cohorts were available. The relationship between exposure and Disease Activity Score in 28 joints (DAS28) was analyzed using a population pharmacokinetic-pharmacodynamic model. Relevant covariates were tested using full covariate modeling and backward elimination. From 395 patients, 3,401 MTX-PG concentrations and 1,337 DAS28 measurements were available between 0 and 300 days after MTX treatment onset. The developed model adequately described the time course of MTX-PG3-5 and DAS28. The median MTX-PG3-5 level at month 1 was 30.9 nmol/L (interquartile range (IQR): 23.6-43.7; n = 41) and at month 3: 69.3 nmol/L (IQR: 17.9-41.2; n = 351). Clearance of MTX-PG3-5 from RBCs was 28% lower (95% confidence interval (CI): 23.6-32.8%) in a woman and 10% lower (95% CI: 7.7-12.4%) in a 65-year-old compared with a 35-year-old patient. MTX-PG3-5 concentrations associated with DAS28: half-maximal effective concentration (EC50 ) was 9.14 nmol/L (95% CI: 4.2 nmol/L-14.1 nmol/L). EF at 80% (EC80 ) above 47 nmol/L was regarded as the optimal response. Independent of the MTX-PG 3-5 - response association, co-administration of disease-modifying antirheumatic drugs and corticosteroids improved response (additive effect on maximum effect (Emax )), whereas smoking, high body mass index and low albumin decreased Emax . In patients with RA starting MTX, RBC-MTX-PG3-5 was associated with clinical response. A dose increase is suggested when MTX-PG3-5 at month 1 is below 9.15 nmol/L, continued with the same dose when the concentration is above 47 nmol/L, and consider other treatment options above 78 nmol/L from 3months onwards.

Neoplastic and blood-based biomarkers of response in patients with advanced endometrial cancer: Results from NRG GY012.

5525 Background: NRG GY012 is a randomized, 3-arm phase II study, comparing olaparib (O) and the combination of cediranib and olaparib (CO) to the reference arm cediranib (C) for metastatic pre-treated, endometrial cancer (EC). The trial found a trend towards benefit for CO and no benefit for O compared to C. Archival tumor and prospective blood samples were collected for biomarker analysis. Methods: Targeted next-generation sequencing (BROCA-GO) was used to detect pathogenic variants (PV) and loss of heterozygosity (LOH) in DNA from paired blood and archival cancers. The LOH cut-off was identified at 11% for HRD based on testing ovarian cancers with known HRD. Plasma samples collected at baseline, cycle 2 day 1, and end-of-treatment were analyzed via multiplex ELISA for 25 angiogenic and inflammatory circulating protein biomarkers (Angiome); IL6 was of specific interest. Prognostic associations with PFS and OS were analyzed using proportional hazards models (PhM) stratified by histology and adjusted for treatment assignment. Predictive associations (PFS and OS) were analyzed using PhM stratified by histology and including main effects for both treatment assignment and biomarker group plus an interaction term. Results: In 97 patients (pts) with evaluable tumor, BROCA-GO identified 370 somatic PV; TP53 (61%) was the most commonly mutated gene. PV in homologous recombination repair (HRR) genes were identified in 5 cases (5%). Somatic PVs were identified in BRCA2, RAD51B and PALB2. 1 pt had a germline BRCA1 PV. 2 cases had somatic PV that might restore HRR: 1 case with a somatic BRCA2 PV had somatic PVs in CHD4 and TP53BP1; the TP53BP1 frameshift PV was present only in the recurrent and not primary cancer. LOH was available for 45 cases. LOH high occurred in 16 (35.6%) cases and was exclusive to EC with TP53 mutations (p=0.0003). LOH was not associated with outcome in any of the arms. For the circulating biomarker analysis (N=96), median IL-6 was 4pg/ml. IL-6 levels >4pg/ml were associated with increased risk of progression (HR: 1.59; 95% CI: (1.04-2.42); p-value=0.032). In predictive analyses, pts with IL-6 > 4 pg/ml receiving C or C+O had increased PFS (3.8 mo vs 1.9 mo) and OS (11.9 mo vs 5.7 mo) compared to pts receiving O, the interaction p value did not reach statistical significance. Conclusions: LOH high status was not associated with outcome to O. There were too few cases with HRR PVs to determine their relationship to PARPi response. The restriction of LOH high to cancers with TP53 mutation may suggest that genomic LOH in ECs correlates better with aneuploidy than with HRR function indicating that at least some biomarkers of PARPi response vary between tumor types. IL-6 levels were prognostic of PFS but were not predictive of either OS or PFS for pts receiving C compared to pts receiving O in this small study. Further analysis of the complete Angiome and integration with the BROCA-GO dataset are ongoing. Clinical trial information: NCT03660826 .

Clinical efficacy and biomarker analysis of pucotenlimab (HX008) in patients with previously treated advanced mismatch repair-deficient or microsatellite instability-high solid tumors: A single-arm, multicenter, phase 2 study.

799 Background: Pucotenlimab is a humanized IgG4 anti-PD-1 monoclonal antibody with an engineered Fc domain. We aim to assess the efficacy and safety of pucotenlimab, and potential predictive biomarkers of response in patients with previously treated advanced microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) solid tumors. Methods: In this single-arm, multi-center, phase 2 study, eligible patients had locally advanced or metastatic, centrally confirmed MSI-H or dMMR solid tumors treated with at least one prior systemic therapy. Patients received pucotenlimab 200mg every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR) assessed by the independent review committee (IRC) per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Besides, patients’ PD-L1 expression, blood neutrophil to lymphocyte ratio (NLR), germline HLA-I genotyping, loss of heterozygosity (LOH) of HLA-I genes, tumor mutational burden (TMB), and genetic alterations in the tumor revealed by next-generation sequencing were investigated to identify potential predictors of efficacy. Results: 100 patients with MSI-H or dMMR solid tumors were enrolled. Colorectal cancer (n=71) and gastric cancer (n=10) were the most common cancer types. The median follow-up duration was 22.5 months (range: 0.3-37.4) at data cutoff (December 4, 2021). The ORR was 49.0% (95% CI 38.86%-59.20%), and the 12-month progression-free survival (PFS) rate was 56.1% (95% CI 45.63%-65.24%) based on IRC’s assessment. Both the median PFS and median duration of response were not reached. Pucotenlimab was well tolerated. Grade ≥3 treatment-related adverse events (TRAEs) were reported in 18 patients, most commonly anemia, leukocytopenia, and hypertension. For the biomarker analysis, patients with NLR <4 at the second treatment cycle, TMB≥32.5 muts/Mb (the lower 35th TMB-percentile), or mutations in the KMT2D gene showed significantly higher ORR. Conclusions: Pucotenlimab demonstrated durable antitumor activity and manageable safety for previously treated patients with advanced MSI-H/dMMR solid tumors. KMT2D gene mutation, along with NLR and TMB, warrants further investigation as predictive biomarkers. Clinical trial information: NCT03704246 .

Early Real Time Quantification of CD19. CAR T Cells By Flow Cytometry As a Predictive Biomarker for Response in Patients with R/R LBCL

Introduction: Despite the clinical success of CD19-directed CAR T-cell therapy in relapsed / refractory (r/r) LBCL (large B-cell lymphoma), the majority of patients do not respond or relapse early after treatment. Biomarker analysis within pivotal trials showed the prognostic value of CAR T-cell expansion over time during the early post-transfusion period. We set up a longitudinal immunomonitoring to investigate whether distinct CAR T-cell levels can predict treatment response. Methods: 63 patients with r/r LBCL were treated in third line with the commercially available CD19-directed CAR T-cell products Axicabtagene ciloleucel (Axi-cel) or Tisagenlecleucel (Tisa-cel) between January 2019 and November 2021 at the University Hospitals of Erlangen and the LMU Munich. Aliquots of CAR T-cell products and EDTA-anticoagulated peripheral blood (15cc) were collected at day 4, 7, 14, 28, 60 and 90 post CAR T-cell transfusion. Clinical metadata were assembled prior and post transfusion. CAR T-cells were analyzed with flow cytometry utilizing a two step-staining with a biotinylated CD19 protein. CAR T-cells were detected with a sensitivity of 1:2000 and reported as cells/µl based on differential blood counts. Responders (R, complete or partial remission) were compared to non-responders (NR, stable or progressive disease) according to (PET-) CT scans three months after transfusion. Results: Surprisingly, the CAR T-cell products contained more untransduced T-cells than anti-CD19 expressing CAR T-cells with a median cell number of 5.75x108 Non-CAR T-cells and 1.76x108 CAR T-cells (p<0.0001). Even though a large inter-patient variability was observed, CAR T-cell peak expansion occurred between day 7 to 14 in the majority of patients. Interestingly, differences in the number of CAR T transduced T-cells were observed in Tisa-cel versus Axi-cel: Tisa-cel products contained higher numbers of Non-CAR T-cells compared to Axi-cel products (p<0.0001) followed by greater expansion of Non-CAR T-cells over time after Tisa-cel transfusion compared to Axi-cel transfusion (p=0.0155). However, the absolute number of CAR T transduced T-cells within the product did not impact response rate. More importantly, higher CAR T-cell expansion over time (AUC p=0.0007) and peak expansion (p=0.0009) were associated with treatment response. Moreover, higher CAR T-cell peak expansion in relation to tumor burden at baseline was associated with treatment response (p=0.0011). Comparing the absolute CAR T-cell numbers at the different time points, we identified the CAR T-cell levels at day 7 to be strongly associated with treatment response (p=0.0005). Next, through ROC analysis, we were able to identify 20/µl CAR T-cells on day 7 as a cut-off value, that was associated with treatment response (AUC=0.7656 and p=0.0007) and improved survival (PFS p=0.0001 and OS p=0.0002). Next, we hypothesized, that higher CAR T-cell numbers on day 7 reflect the superior capacity of CAR T-cells to proliferate and expand. This was indeed supported by our findings, that CAR T-cell numbers on day 7 correlated with the absolute number of CAR T-cells in the CAR product of R (r=0.4928, p=0.0144) but not of NR (r=-0.152). Finally, we found patient- (ECOG) and disease-associated (tumor volume, LDH) as well as baseline inflammatory markers (CRP and Ferritin) to be negatively correlated with CAR T-cell kinetics. Conclusion: Longitudinal quantification of CAR-T cells by multiparameter flow cytometry is feasible. Responding patients with r/r LBCL showed greater CAR T-cell expansion over the first 90 days post transfusion. Notably, a cut-off value of 20/µl CAR T-cells at day 7 was associated with both improved radiographic response and survival. Currently the cut-off value is being validated in an external control of 100 patients. Our data suggest that quantification of CAR T-cell levels might serve as a biomarker to predict treatment failure and open up the possibility to modify treatment concepts in these patients at an early time point. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Fecal microbiota transplantation followed by anti–PD-1 treatment in patients with advanced melanoma.

9533 Background: The gut microbiome has been shown to be a biomarker of response in patients (pts) with melanoma. Strategies to modify the microbiome are currently being investigated. We report the effects of Fecal Microbiota Transplantation (FMT) on safety and anti-PD-1 response in pts with melanoma from a phase I trial (NCT03772899). Methods: 20 pts with advanced melanoma with RECIST-evaluable disease, without prior anti-PD-1 treatment for advanced disease, were recruited from 3 Canadian academic centers. Pts with ECOG &gt; 2, autoimmune diseases, immunosuppression or unstable brain metastases were excluded. Pts received 80-100 g of healthy donor stool via oral capsules and were treated with anti-PD-1 one week later. The primary objective was safety of combining FMT with anti-PD-1 therapy. Objective response rate (ORR) by RECIST 1.1 and correlative studies were secondary objectives. Flow cytometry and multiplex ELISA were performed on pts blood samples. Avatar mice were transplanted with stool samples obtained from participants on the trial before and after FMT. Mice were subsequently implanted with B-16 or MCA-205 tumors and received anti-PD-1 antibodies. Results: Median age was 75.5 years, 12 (60%) were male, 18 (90%) had stage 4 disease, and 5 (25%) pts harbored a BRAF mutation. Median follow-up was 11.2 months. FMT-related adverse events included grade 2 diarrhea (2 pts) and hypophosphatemia (1 pt), and 13 pts (65%) experienced grade 1 gastrointestinal toxicities. Grade 3 immune-related adverse events (irAE) were one each of myocarditis, nephritis, and fatigue. Anti-PD-1 therapy was discontinued for toxicity in 2 (10%) pts. No unexpected irAE or death on treatment occurred. ORR was 65% (13/20), of which 3 were CR. Clinical benefit rate (includes SD lasting &gt; 6 months) was 75% (15/20). Median PFS was not reached, and one pt died from their disease. Translational analyses demonstrated upregulation of IL-17 post-FMT in responders, which correlated with upregulation of the frequency of Th17 cells in peripheral blood. In parallel, murine experiments showed that feces from pts pre-FMT did not sensitize tumors to anti-PD-1. In both tumor models, only feces obtained post-FMT from responders restored anti-PD-1 efficacy in mice, providing strong support that FMT contributed to the anti-tumor response observed in pts. Conclusions: FMT followed by anti-PD-1 treatment in melanoma pts undergoing therapy is safe and may lead to improved anti-tumor responses that can be reproduced in tumor mouse models. The gut microbiome plays an important role in responses to anti-PD-1 in patients with advanced melanoma, paving the way for future microbiome-based interventions. Clinical trial information: NCT03772899.

45-OR: Less Favorable Response to Anti-VEGF Therapy in Patients with Diabetic Macular Edema and Decreased Baseline Outer Retinal Layer Thickness

Early identification of patients who are more likely to respond to anti-VEGF therapy for diabetic macular edema (DME) would improve patient management and allow for more rapid assessment of new therapeutic targets. This study evaluated retinal thickness variables and their association with anti-VEGF therapy response in patients with DME. We identified patients at the Joslin Diabetes Center who received their first anti-VEGF injection for DME between 1/2016-12/20 and assessed mean change in visual acuity (VA) and central retinal thickness (RT) at 6 mos. A good VA or RT response to anti-VEGF therapy was defined using thresholds of letter and retinal thickness change as follows: eyes with baseline VA of ≥20/32, ≥5 letters; 20/40-20/70, ≥letters; ≤20/80, ≥15 letters and eyes with baseline RT of &amp;lt;375µm, &amp;gt;10%; 375-449µm, &amp;gt;20%; &amp;gt;449µm, &amp;gt;25%. A total of 151 eyes from 126 patients fell into the following responder groups: both VA and RT response (32.5%) , only VA response (21.9%) or RT response (11.3%) , and neither VA nor RT response (34.4%) , with 57.0% of all eyes exhibiting VA response and 43.7% exhibiting RT response. While diabetes duration, A1c, and blood pressure were not associated with responder group, decreased baseline thickness of the outer retinal layer (ORL) was more likely to be present in eyes with neither VA nor RT response (β=-.018; 95% CI -0.03 to -0.01; P=.006) . Improvement in mean VA was associated with younger age (β=.004; 95% CI 0.001-0.007; P=.01) . Decreased baseline ORL thickness (β=-.003; 95% CI -0.0to -0.001; P=.01) and increased baseline inner retinal layer (IRL) thickness (β=.0004; 95% CI 0.0001-0.0007; P=.02) were associated with less VA gain at 6 mos. These findings suggest that decreased baseline ORL thickness is associated with less favorable outcome after anti-VEGF therapy and may be a potential biomarker for treatment response in patients with DME. Disclosure M.G.Mitzner: None. W.Fickweiler: None. D.B.Robinson: None. T.Boumenna: None. L.P.Aiello: Consultant; KalVista Pharmaceuticals, Inc., Novo Nordisk, Stock/Shareholder; KalVista Pharmaceuticals, Inc. J.Sun: Consultant; American Diabetes Association, American Medical Association, Research Support; Adaptive Sensory Technology, Boehringer Ingelheim International GmbH, Genentech, Inc., Jaeb Center for Health Research, Janssen Pharmaceuticals, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk, Optovue, Incorporated, Physical Sciences, Inc, Roche Pharmaceuticals. Funding American Diabetes Association (7-21-PDF-022) ; National Eye Institute (R01EYE26080-01) ; National Institute of Diabetes and Digestive and Kidney Diseases and National Institutes of Health (DP3-DK-094333-01) ; JDRF (17-2013-310) ; The Dianne Nunnally Hoppes Fund; The Beatson Pledge Fund

The role of biomarkers in drug-resistant trigeminal neuralgia: a prospective study in patients submitted to surgical treatment.

Molecular mechanisms underlying trigeminal neuralgia (TN) have been poorly understood. Recently, different biomarkers have been studied in several chronic neuropathic diseases or in neuronal damage, but their role in TN has not yet been investigated. Here, we firstly analyzed the serum levels of the neuron-specific enolase (NSE) (as an index of neuronal tissue damage) in TN patients submitted to surgical treatment. Different cytokines and interleukins related to inflammation were also studied. Blood samples from 40 patients were prospectively collected preoperatively and after the surgical procedure, namely microvascular decompression (MVD) and percutaneous balloon compression (PBC). Serum levels of uric acid, NSE, ferritin, CRP, IL-2R, and IL-6 were studied. The acute pain relief (APR) and the pre- and postoperative BNI were used to evaluate the clinical outcome. Overall, we obtained an APR in 87.5% of patients and a significant reduction of BNI after surgery (p < 0.0001). We observed a significant reduction of postoperative NSE values in the group of patients undergoing MVD (p = 0.0055) and a significant increase of postoperative NSE values in patients undergoing PBC (p < 0.05). Furthermore, in the group of patients undergoing MVD, we found a significant postoperative increase of CRP (p < 0.0001), ferritin (p = 0.001), and IL-6 (p = 0.01) values. The only patient who did not respond to MVD had NSE levels unchanged. Our results suggest the hypothesis that TN would be related to the neural damage instead of the systemic inflammatory status and indicate NSE as a possible biomarker of response in patients submitted to MVD.

Clinical outcomes in advanced urothelial cancer (UC) patients who experienced immune-related adverse events (irAEs) after immune checkpoint inhibitor monotherapy (ICI).

544 Background: Immune checkpoint inhibitors (ICIs) continue to demonstrate promise in treatment of advanced urothelial carcinoma (UC). Some patients undergoing ICIs experience immune related adverse events (irAEs) and may serve as a marker of response. We investigated the relationship between irAEs and clinical outcomes in UC patients treated with ICIs. Methods: A retrospective study of 70 UC patients treated with ICI monotherapies at Winship Cancer Institute from 2015-2020 was done. Overall survival (OS) and progression-free survival (PFS), defined as time from ICI initiation to death and clinical or radiographic progression, respectively as well as clinical benefit (CB), defined as best radiographic response of complete response, partial response, or stable disease for ≥ 6 months per RECIST v1.1, were used to measure clinical outcomes. Cox proportional hazards and multivariable analyses (MVA) were used to model associations with OS and PFS. Results: Most patients were male (70%) with a median age of 68.7 years (28.0-91.0). Most patients (95%) had urothelial carcinoma and most (81%) received at least 1 prior treatment. One third of patients had ECOG PS greater than or equal to 2. Of patients that experienced an irAE (35%), the most common were dermatologic (12.9%) and arthralgia (0.5%). In addition to significantly longer treatment duration, irAE patients had significantly increased OS (HR:0.38, 95% CI:0.18-0.79, p=0.009), significantly longer PFS (HR:0.27, 95% CI:0.14-0.53, p &lt; 0.001), and significantly greater CB (OR:4.20, 95% CI:1.35-13.06, p=0.013). Patients who experienced dermatologic irAEs had significantly increased OS, PFS, and CB (Table). Conclusions: Our results demonstrate that UC patients undergoing ICI therapy who experience irAEs, especially dermatologic irAEs, had improved clinical outcomes. This suggests that irAEs may serve as a clinical biomarker of advantageous response in patients receiving ICI. Future prospective studies are needed for validation.[Table: see text]

MiRNA Levels as a Biomarker for Anti-VEGF Response in Patients with Diabetic Macular Edema.

Background: The aim of this study was to investigate whether miRNA levels in the circulation could serve as a predictive biomarker for responsiveness to anti-vascular endothelial growth factor (VEGF) therapy in patients with diabetic macular edema. Methods: Whole blood samples were collected at baseline from 135 patients who were included in the BRDME study, a randomized controlled comparative trial of monthly bevacizumab or ranibizumab treatment for 6 months in patients with diabetic macular edema (Trialregister.nl, NTR3247). Best corrected visual acuity letter score (BCVA) and retinal central area thickness (CAT) were measured monthly during the 6-month follow-up. Levels of selected miRNAs were quantified. Results: Following linear regression analysis, the levels of four miRNAs were negatively associated with baseline CAT. Multivariable regression analysis confirmed this association for miR-181a. No associations with changes in CAT after 3 or 6 months of anti-VEGF treatment were found. In addition, no associations with miRNA levels with baseline BCVA or change in BCVA after 3 or 6 months of anti-VEGF treatment were found. Conclusions: Circulating miR-181a levels were negatively associated with CAT at baseline. However, no associations between miRNA levels and the response to anti-VEGF therapy were found.

Discovery and characterization of circulating tumor cell clusters in neuroendocrine tumor patients using nanosubstrate-embedded microchips

Circulating tumor cell (CTC) clusters are present in cancer patients with severe metastasis, resulting in poor clinical outcomes. However, CTC clusters have not been studied as extensively as single CTCs, and the clinical utility of CTC clusters remains largely unknown. In this study, we aim sought to explore the feasibility of NanoVelcro Chips to simultaneously detect both single CTCs and CTC clusters with negligible perturbation to their intrinsic properties in neuroendocrine tumors (NETs). We discovered frequent CTC clusters in patients with advanced NETs and examined their potential roles, together with single NET CTCs, as novel biomarkers of patient response following peptide receptor radionuclide therapy (PRRT). We observed dynamic changes in both total NET CTCs and NET CTC cluster counts in NET patients undergoing PRRT which correlated with clinical outcome. These preliminary findings suggest that CTC clusters, along with single CTCs, offer a potential non-invasive option to monitor the treatment response in NET patients undergoing PRRT.

Systems biology informed neural networks (SBINN) predict response and novel combinations for PD-1 checkpoint blockade

Anti-PD-1 immunotherapy has recently shown tremendous success for the treatment of several aggressive cancers. However, variability and unpredictability in treatment outcome have been observed, and are thought to be driven by patient-specific biology and interactions of the patient’s immune system with the tumor. Here we develop an integrative systems biology and machine learning approach, built around clinical data, to predict patient response to anti-PD-1 immunotherapy and to improve the response rate. Using this approach, we determine biomarkers of patient response and identify potential mechanisms of drug resistance. We develop systems biology informed neural networks (SBINN) to calculate patient-specific kinetic parameter values and to predict clinical outcome. We show how transfer learning can be leveraged with simulated clinical data to significantly improve the response prediction accuracy of the SBINN. Further, we identify novel drug combinations and optimize the treatment protocol for triple combination therapy consisting of IL-6 inhibition, recombinant IL-12, and anti-PD-1 immunotherapy in order to maximize patient response. We also find unexpected differences in protein expression levels between response phenotypes which complement recent clinical findings. Our approach has the potential to aid in the development of targeted experiments for patient drug screening as well as identify novel therapeutic targets.

Oropharyngeal Squamous Cell Carcinoma Treatment in the Era of Immune Checkpoint Inhibitors.

While head and neck squamous cell carcinomas (HNSCC) are marginally decreasing due to the reduction in exposure to the major risk factors, tobacco and alcohol, the incidence of high-risk human papillomavirus (HPV)-positive oropharynx squamous cell carcinomas (OPSCC), especially those in the tonsil and base of tongue subsites, are increasing. Patients with the latter are younger, display a longer overall survival, and show a lower recurrence rate after standard-of-care treatment than those with HPV-negative OPSCC. This may reflect an important role for immune surveillance and control during the natural history of the virally driven tumour development. Immune deviation through acquisition of immune-suppressive factors in the tumour microenvironment (TME) is discussed in relation to treatment response. Understanding how the different immune factors are integrated in the TME battleground offers opportunities for identifying prognostic biomarkers as well as novel therapeutic strategies. OPSCC generally receive surgery or radiotherapy for early-stage tumour treatment, but many patients present with locoregionally advanced disease requiring multimodality therapies which can involve considerable complications. This review focuses on the utilization of newly emerged immune checkpoint inhibitors (PD-1/PD-L1 pathway) for treatment of HNSCC, in particular HPV-positive OPSCC, since they could be less toxic and more efficacious. PD-1/PD-L1 expression in the TME has been extensively investigated as a biomarker of patient response but is yet to provide a really effective means for stratification of treatment. Extensive testing of combinations of therapeutic approaches by types and sequencing will fuel the next evolution of treatment for OPSCC.

TP53 Null Mutations Identify Lung Cancer Cell Lines with Highest Sensitivity to the Nontaxane Microtubule Inhibitor Eribulin.

The nontaxane microtubule inhibitor eribulin is an approved therapeutic for metastatic breast cancer and liposarcoma. Eribulin was previously tested in unselected patients with lung cancer and yielded a modest objective response rate of ∼5%-12%. Because lung cancers represent diverse histologies and driving oncogenic mutations, we postulated that eribulin may exhibit properties of a precision oncology agent with a previously undefined specificity for a molecularly distinct subset of lung cancers. Herein, we screened a panel of 44 non-small cell and small-cell lung cancer cell lines for in vitro growth sensitivity to eribulin. The results revealed a greater than 15,000-fold range in eribulin sensitivity (IC50 = 0.005-89 nM) among the cell lines that was not correlated with their sensitivity to the taxane-based inhibitor paclitaxel. The quartile of cell lines exhibiting the lowest eribulin IC50 values was not enriched for specific histologies, epithelial-mesenchymal differentiation, or specific oncogene drivers but was significantly enriched for nonsense/frameshift TP53 mutations and low-TP53 mRNA but not missense TP53 mutations. By comparison, the mutation status of cyclin-dependent kinase inhibitor 2A, STK11, and KEAP1 was not associated with eribulin sensitivity. Finally, the highest eribulin IC50 quartile (>1 nM) exhibited significantly elevated mRNA expression of the drug pump, ATP binding cassette B1, defined resistance mechanism to eribulin, and paclitaxel. The findings support further investigations into basic mechanisms by which complete lack of TP53 function regulates anticancer activity of eribulin and the potential utility of TP53 null phenotypes distinct from TP53 missense mutations as a biomarker of response in patients with lung cancer. SIGNIFICANCE STATEMENT: Distinct from precision oncology agents that are matched to cancers bearing oncogenically activated versions of their targets, microtubule inhibitors, such as eribulin, are deployed in an unselected manner. The results in this study demonstrate that lung cancer cell lines exhibiting the highest sensitivity to eribulin bear TP53 null phenotypes, supporting a rationale to consider the status of this tumor suppressor in the clinical setting.