Molecular residual disease detection in resected, muscle-invasive urothelial cancer with a tissue-based comprehensive genomic profiling–informed personalized monitoring assay

IntroductionCirculating tumor DNA (ctDNA) detection postoperatively may identify patients with urothelial cancer at a high risk of relapse. Pragmatic tools building off clinical tumor next-generation sequencing (NGS) platforms could have the potential to increase assay accessibility.MethodsWe evaluated the widely available Foundation Medicine comprehensive genomic profiling (CGP) platform as a source of variants for tracking of ctDNA when analyzing residual samples from IMvigor010 (ClinicalTrials.gov identifier NCT02450331), a randomized adjuvant study comparing atezolizumab with observation after bladder cancer surgery. Current methods often involve germline sampling, which is not always feasible or practical. Rather than performing white blood cell sequencing to filter germline and clonal hematopoiesis (CH) variants, we applied a bioinformatic approach to select tumor (non-germline/CH) variants for molecular residual disease detection. Tissue-informed personalized multiplex polymerase chain reaction–NGS assay was used to detect ctDNA postsurgically (Natera).ResultsAcross 396 analyzed patients, prevalence of potentially actionable alterations was comparable with the expected prevalence in advanced disease (13% FGFR2/3, 20% PIK3CA, 13% ERBB2, and 37% with elevated tumor mutational burden ≥10 mutations/megabase). In the observation arm, 66 of the 184 (36%) ctDNA-positive patients had shorter disease-free survival [DFS; hazard ratio (HR) = 5.77; 95% confidence interval (CI), 3.84–8.67; P < 0.0001] and overall survival (OS; HR = 5.81; 95% CI, 3.41–9.91; P < 0.0001) compared with ctDNA-negative patients. ctDNA-positive patients had improved DFS and OS with atezolizumab compared with those in observation (DFS HR = 0.56; 95% CI, 0.38–0.83; P = 0.003; OS HR = 0.66; 95% CI, 0.42–1.05). Clinical sensitivity and specificity for detection of postsurgical recurrence were 58% (60/103) and 93% (75/81), respectively.ConclusionWe present a personalized ctDNA monitoring assay utilizing tissue-based FoundationOne® CDx CGP, which is a pragmatic and potentially clinically scalable method that can detect low levels of residual ctDNA in patients with resected, muscle-invasive bladder cancer without germline sampling

Interrogation of transcriptomic changes associated with drug-induced hepatic sinusoidal dilatation in colorectal cancer

Drug-related sinusoidal dilatation (SD) is a common form of hepatotoxicity associated with oxaliplatin-based chemotherapy used prior to resection of colorectal liver metastases (CRLM). Recently, hepatic SD has also been associated with anti-delta like 4 (DLL4) cancer therapies targeting the NOTCH pathway. To investigate the hypothesis that NOTCH signaling plays an important role in drug-induced SD, gene expression changes were examined in livers from anti-DLL4 and oxaliplatin-induced SD in non-human primate (NHP) and patients, respectively. Putative mechanistic biomarkers of bevacizumab (bev)-mediated protection against oxaliplatin-induced SD were also investigated. RNA was extracted from whole liver sections or centrilobular regions by laser-capture microdissection (LCM) obtained from NHP administered anti-DLL4 fragment antigen-binding (F(ab’)2 or patients with CRLM receiving oxaliplatin-based chemotherapy with or without bev. mRNA expression was quantified using high-throughput real-time quantitative PCR. Significance analysis was used to identify genes with differential expression patterns (false discovery rate (FDR) < 0.05). Eleven (CCL2, CCND1, EFNB2, ERG, ICAM1, IL16, LFNG, NOTCH1, NOTCH4, PRDX1, and TGFB1) and six (CDH5, EFNB2, HES1, IL16, MIK67, HES1 and VWF) candidate genes were differentially expressed in the liver of anti-DLL4- and oxaliplatin-induced SD, respectively. Addition of bev to oxaliplatin-based chemotherapy resulted in differential changes in hepatic CDH5, HEY1, IL16, JAG1, MMP9, NOTCH4 and TIMP1 expression. This work implicates NOTCH and IL16 pathways in the pathogenesis of drug-induced SD and further explains the hepato-protective effect of bev in oxaliplatin-induced SD observed in CRLM patients

C-reactive protein reduction post treatment is associated with improved survival in atezolizumab (anti-PD-L1) treated non-small cell lung cancer patients.

PurposeOverall survival (OS) is the most significant endpoint for evaluation of treatment benefit with checkpoint inhibitors (CPI) in cancer. We evaluated serum C-reactive protein (CRP) in non-small cell lung cancer (NSCLC) trials with atezolizumab (anti-PD-L1) as an early OS surrogate.MethodsSerum from patients enrolled in randomized Phase II (n = 240) and Phase III (n = 701) trials of NSCLC patients (POPLAR, OAK) who progressed on prior-platinum chemotherapy, were analyzed for CRP levels over time. Patients were grouped by changes in CRP levels post-treatment as either increased (≥ 1.5 fold), decreased (≤ 1.5 fold) or unchanged (within +1.5 fold) relative to pre-treatment levels to assess association with progression free survival (PFS) and OS.ResultsDecrease in serum CRP levels at 6 weeks relative to pre-treatment were observed in patients with RECIST1.1 based complete or partial responses (CR/PR) to atezolizumab whereas patients with disease progression (PD) demonstrated an increase in CRP levels in the Phase II POPLAR study, and confirmed in the Phase III OAK study. Decrease in serum CRP as early as six weeks post treatment predicted improved PFS and OS, even in patients who were determined as stable disease (SD) in their first scan. This effect was not observed in the chemotherapy arms.ConclusionModulation of serum CRP correlates with clinical outcome post-atezolizumab treatment. This routine lab test may provide utility in informing OS signals as early as 6 weeks post-initiation of therapy with CPIs in NSCLC

Comparison of PD-L1 protein expression between primary tumors and metastatic lesions in triple negative breast cancers

Programmed Death Ligand 1 (PD-L1) positivity rates differ between different metastatic sites and the primary tumor. Understanding PD-L1 expression characteristics could guide biopsy procedures and motivate research to better understand site-specific differences in the tumor microenvironment. The purpose of this study was to compare PD-L1 positivity on immune cells and tumor cells in primary and metastatic triple negative breast cancer (TNBC) tumors. Retrospective study utilizing the PD-L1 database of Foundation Medicine containing the SP142 companion diagnostic immunohistochemistry assay (SP142 CDx) and Food and Drug Administration guidelines for scoring. 340 TNBC cases (179 primary tumors and 161 unmatched metastatic lesions) were evaluated. The primary outcome measures were PD-L1 positivity rates in immune cells and tumor cells. χ2 test was used for comparisons. Spearman’s correlation coefficient was used for correlations. More primary tumors were positive for PD-L1 expression on immune cells than metastatic lesions (114 (63.7%) vs 68 (42.2%), p&lt;0.0001). This was driven by the lower PD-L1 positivity rates in skin (23.8%, 95% CI: 8.22% to 47.2%), liver (17.4%, 95% CI: 5.00% to 38.8%) and bone (16.7%, 95% CI: 2.10% to 48.4%) metastases. Lung (68.8%, 95% CI: 41.3% to 90.0%), soft tissues (65.2%, 95% CI: 42.7% to 83.6%) and lymph nodes (51.1%, 95% CI: 35.8% to 66.3%) had PD-L1 % positivity rates similar to primary tumors. PD-L1 expression was rare on tumor cells in both the breast and metastatic sites (8.3% vs 4.3%, p=0.13). The rate of PD-L1 positivity varies by metastatic location with substantially lower positivity rates in liver, skin and bone metastases compared with primary breast lesions or lung, soft tissue or lymph node metastases. This difference in PD-L1 positivity rates between primary tumors and different metastatic sites should inform physicians when choosing sites to biopsy and suggests a difference in the immune microenvironment across metastatic sites

Overcoming leukemia heterogeneity by combining T cell engaging bispecific antibodies

Background Leukemia represents about 5% of all human cancers. Despite advances in therapeutics, a substantial number of patients succumb to the disease. Several subtypes of leukemia are inherently more resistant to treatment despite intensive chemotherapy or targeted therapy.Methods Here we describe the generation of T cell engaging (CD3) bispecific antibodies (BsAbs) built on humanized IgG frameworks using the IgG(L)-scFv format against two targets expressed on acute lymphoblastic leukemia (ALL) and on acute myeloid leukemia (AML).Results Each BsAb mediated potent anti-leukemia effect against ALL (CD19) and AML (CD33) in vitro and in xenograft models. Importantly, the CD19-specific BsAb (BC250) was effective against hematogenous spread preventing metastases to liver and kidney in mice bearing ALL and Burkitt’s lymphoma xenografts. BC250 was more potent than the The Food and Drug Administration (FDA)-approved BsAb blinatumomab against ALL xenografts in vivo as measured by tumor bioluminescence and mouse survival. Furthermore, the combination of the CD19 and CD33 BsAbs in two xenograft models of mixed phenotype acute leukemia (biphenotypic and bilineal leukemia) was far superior than monotherapy with either of the BsAbs alone.Conclusions Selective combinations of these leukemia-specific BsAb offer the potential to overcome tumor heterogeneity or clonal escape in the modern era of antibody-based T cell-driven immunotherapy