The 27-gene IO score is associated with efficacy of PD-1/L1 inhibitors independent of FGFR expression in a real-world metastatic urothelial carcinoma cohort.

Multiple targeted therapeutics have been approved by the FDA for mUC, including immune checkpoint inhibitors (ICIs) and more recently targeted agents for both FGFR and Nectin-4. FGFR3-aberrant and Nectin-4 expressing cells have been associated with an immunosuppressed phenotype. Given that less than half of all patients respond to these agents as monotherapies and less than 20% are eligible to receive salvage therapy, effective personalized treatment plans are critical. Typical biomarkers for ICIs such as PD-L1 and TMB have not been definitive in mUC, yet a biomarker-driven optimization of first-line therapy and subsequent sequencing have the potential to achieve higher and more durable response rates. The IO score is a 27-gene tumor immune microenvironment (TIME) classifier that has been associated with the clinical benefits of ICIs in multiple cancer types, including mUC. This study demonstrates that the IO score was associated with both progression-free survival (PFS) and overall survival (OS) in a real-world cohort of mUC patients treated with ICIs. Furthermore, the IO score was independent of and provided information incremental to TMB. Interestingly, the IO score predicted benefit in patients with high FGFR expression, despite conflicting data regarding response rates among the FGFR aberrant population. Taken together, these results demonstrate that the IO score assessment of the TIME is associated with a clinical benefit from ICI therapy and that this novel biomarker may inform therapeutic sequencing decisions in mUC, potentially improving outcomes for this notoriously difficult-to-treat disease.

Homologous Recombination Deficiency: Concepts, Definitions, and Assays.

BACKGROUND: Homologous recombination deficiency (HRD) is a phenotype that is characterized by the inability of a cell to effectively repair DNA double-strand breaks using the homologous recombination repair (HRR) pathway. Loss-of-function genes involved in this pathway can sensitize tumors to poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitors and platinum-based chemotherapy, which target the destruction of cancer cells by working in concert with HRD through synthetic lethality. However, to identify patients with these tumors, it is vital to understand how to best measure homologous repair (HR) status and to characterize the level of alignment in these measurements across different diagnostic platforms. A key current challenge is that there is no standardized method to define, measure, and report HR status using diagnostics in the clinical setting. METHODS: Friends of Cancer Research convened a consortium of project partners from key healthcare sectors to address concerns about the lack of consistency in the way HRD is defined and methods for measuring HR status. RESULTS: This publication provides findings from the group's discussions that identified opportunities to align the definition of HRD and the parameters that contribute to the determination of HR status. The consortium proposed recommendations and best practices to benefit the broader cancer community. CONCLUSION: Overall, this publication provides additional perspectives for scientist, physician, laboratory, and patient communities to contextualize the definition of HRD and various platforms that are used to measure HRD in tumors.

Translation of the 27-gene immuno-oncology test (IO score) to predict outcomes in immune checkpoint inhibitor treated metastatic urothelial cancer patients.

BACKGROUND: The IO Score is a 27-gene immuno-oncology (IO) classifier that has previously predicted benefit to immune checkpoint inhibitor (ICI) therapy in triple negative breast cancer (TNBC) and non-small cell lung cancer (NSCLC). It generates both a continuous score and a binary result using a defined threshold that is conserved between breast and lung. Herein, we aimed to evaluate the IO Score's binary threshold in ICI-naïve TCGA bladder cancer patients (TCGA-BLCA) and assess its clinical utility in metastatic urothelial cancer (mUC) using the IMvigor210 clinical trial treated with the ICI, atezolizumab. METHODS: We identified a list of tumor immune microenvironment (TIME) related genes expressed across the TCGA breast, lung squamous and lung adenocarcinoma cohorts (TCGA-BRCA, TCGA-LUSQ, and TCGA-LUAD, 939 genes total) and then examined the expression of these 939 genes in TCGA-BLCA, to identify patients as having high inflammatory gene expression. Using this as a test of classification, we assessed the previously established threshold of IO Score. We then evaluated the IO Score with this threshold in the IMvigor210 cohort for its association with overall survival (OS). RESULTS: In TCGA-BLCA, IO Score positive patients had a strong concordance with high inflammatory gene expression (p < 0.0001). Given this concordance, we applied the IO Score to the ICI treated IMvigor210 patients. IO Score positive patients (40%) had a significant Cox proportional hazard ratio (HR) of 0.59 (95% CI 0.45-0.78 p < 0.001) for OS and improved median OS (15.6 versus 7.5 months) compared to IO Score negative patients. The IO Score remained significant in bivariate models combined with all other clinical factors and biomarkers, including PD-L1 protein expression and tumor mutational burden. CONCLUSION: The IMvigor210 results demonstrate the potential for the IO Score as a clinically useful biomarker in mUC. As this is the third tumor type assessed using the same algorithm and threshold, the IO Score may be a promising candidate as a tissue agnostic marker of ICI clinical benefit. The concordance between IO Score and inflammatory gene expression suggests that the classifier is capturing common features of the TIME across cancer types.

Clinicopathologic, genomic and protein expression characterization of 356 ROS1 fusion driven solid tumors cases.

Based on the approvals of crizotinib and entrectinib by the Food and Drug Administration for the treatment of ROS1 positive nonsmall cell lung cancer (NSCLC), we sought to examine the mutational profile of a variety of solid tumors (excluding sarcomas) with ROS1 fusions that underwent comprehensive genomic profiling. A review of our database was performed to extract all nonsarcoma patients with ROS1 fusions that were discovered by the hybrid capture-based DNA only sequencing assays. We examined the coalterations representing potentially targetable biomarkers, resistance alterations and other alterations in these cases. In addition, we examined the histologic characteristics and protein expression with immunohistochemistry (IHC). From a series of clinically advanced nonsarcoma solid tumors, 356 unique cases with ROS1 fusions included 275 (77.2%) NSCLC and 81 (22.8%) non-NSCLC. Ten novel ROS1 fusions were discovered. Importantly, the NSCLC ROS1 fusionpos tumors had a higher PD-L1 IHC expression positivity when compared to the NSCLC ROS1 fusionneg population (P = .012, Chi-squared). The frequency of known and likely anti-ROS1 targeted therapy resistance genomic alterations in NSCLC was 7.3% (20/275) and in non-NSCLC was 4.9% (4/81). Overall, the coalteration profile of ROS1 fusionpos NSCLC and non-NSCLC was similar with only three genes altered significantly more frequently in non-NSCLC vs NSCLC: TERT, PTEN, APC. In our study, we characterized a large cohort of ROS1 fusionpos NSCLC and non-NSCLC solid tumors and discovered 10 novel ROS1 fusions.

Comparative Genomic Analysis of Intrahepatic Cholangiocarcinoma: Biopsy Type, Ancestry, and Testing Patterns.

BACKGROUND: At diagnosis, the majority of patients with intrahepatic cholangiocarcinoma (IHCC) present with advanced disease and a poor prognosis. Comprehensive genomic profiling (CGP) early in the disease course may increase access to targeted therapies and clinical trials; however, unresolved issues remain surrounding the optimal biopsy type to submit for CGP. PATIENTS AND METHODS: Mutational frequencies between primary tumor biopsies (Pbx), metastatic biopsies (Mbx), and liquid biopsies (Lbx) in 1,632 patients with IHCC were compared. RESULTS: Potentially actionable alterations were found in 52%, 34%, and 35% of patients in the Pbx, Mbx, and Lbx cohorts, respectively. In Pbx, Mbx, and Lbx, FGFR2 rearrangements were found in 9%, 6%, and 4%, and IDH1 mutations were identified in 16%, 5%, and 9% patients, respectively. Moreover, alterations in FGFR2 and IDH1 were significantly associated with distinct ancestries, including 2.1-fold enrichment for FGFR2 rearrangements in patients with African ancestry and 1.5-fold enrichment for IDH1 mutations in patients with admixed American (Hispanic) ancestry. Finally, the publication of biomarker-driven clinical trials in IHCC correlated with changing CGP testing patterns. Significant correlations between patient characteristics and IHCC trial disclosures were observed, including a significant decrease from time between biopsy and CGP testing, and more frequent testing of primary versus metastatic samples. CONCLUSION: Overall, because of the high likelihood of identifying actionable genomic alterations, CGP should be considered for the majority of patients with inoperable IHCC, and Lbx and Mbx can be considered as part of the diagnostic suite. IMPLICATIONS FOR PRACTICE: Comprehensive genomic profiling (CGP) should be considered for all patients with intrahepatic cholangiocarcinoma (IHCC) or suspected IHCC, as actionable alterations were commonly found in multiple genes and a wide variety of FGFR2 fusion partners were identified. The disclosure of IHCC trial data correlated with increased use of CGP, an encouraging trend that moves new therapeutic options forward for rare cancers with a rare biomarker. Although tissue from the primary lesion may identify actionable alterations at higher rates, CGP of a liquid biopsy or metastatic site can be considered, particularly if the primary tissue block is exhausted.

Clinicopathologic and Genomic Landscape of Breast Carcinoma Brain Metastases.

BACKGROUND: Among patients with breast carcinoma who have metastatic disease, 15%-30% will eventually develop brain metastases. We examined the genomic landscape of a large cohort of patients with breast carcinoma brain metastases (BCBMs) and compared it with a cohort of patients with primary breast carcinomas (BCs). MATERIAL AND METHODS: We retrospectively analyzed 733 BCBMs tested with comprehensive genomic profiling (CGP) and compared them with 10,772 primary breast carcinomas (not-paired) specimens. For a subset of 16 triple-negative breast carcinoma (TNBC)-brain metastasis samples, programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) was performed concurrently. RESULTS: A total of 733 consecutive BCBMs were analyzed. Compared with primary BCs, BCBMs were enriched for genomic alterations in TP53 (72.0%, 528/733), ERBB2 (25.6%, 188/733), RAD21 (14.1%, 103/733), NF1 (9.0%, 66/733), BRCA1 (7.8%, 57/733), and ESR1 (6.3%,46/733) (p < .05 for all comparisons). Immune checkpoint inhibitor biomarkers such as high tumor mutational burden (TMB-high; 16.2%, 119/733); high microsatellite instability (1.9%, 14/733); CD274 amplification (3.6%, 27/733); and apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like mutational signature (5.9%, 43/733) were significantly higher in the BCBM cohort compared with the primary BC cohort (p < .05 for all comparisons). When using both CGP and PD-L1 IHC, 37.5% (6/16) of patients with TNBC brain metastasis were eligible for atezolizumab based on PD-L1 IHC, and 18.8% (3/16) were eligible for pembrolizumab based on TMB-high status. CONCLUSION: We found a high prevalence of clinically relevant genomic alterations in patients with BCBM, suggesting that tissue acquisition (surgery) and/or cerebrospinal fluid for CGP in addition to CGP of the primary tumor may be clinically warranted. IMPLICATIONS FOR PRACTICE: This study found a high prevalence of clinically relevant genomic alterations in patients with breast carcinoma brain metastasis (BCBM), suggesting that tissue acquisition (surgery) and/or cerebrospinal fluid for comprehensive genomic profiling (CGP) in addition to CGP of the primary tumor may be clinically warranted. In addition, this study identified higher positive rates for FDA-approved immunotherapy biomarkers detected by CGP in patients with BCBM, opening a possibility of new on-label treatments. Last, this study noted limited correlation between tumor mutational burden and PD-L1 immunohistochemistry (IHC), which shows the importance of testing patients with triple-negative BCBM for immune checkpoint inhibitor eligibility with both PD-L1 IHC and CGP.

A Phase 1 dose-escalation study of disulfiram and copper gluconate in patients with advanced solid tumors involving the liver using S-glutathionylation as a biomarker.

BACKGROUND: Disulfiram and metals inactivate key oncoproteins resulting in anti-neoplastic activity. The goal of this study was to determine the maximum tolerated dose of copper when administered with disulfiram in patients with advanced solid tumors and liver involvement. METHODS: Disulfiram 250 mg was administered daily in 28-day cycles. Four doses of copper gluconate were tested (2, 4, 6, and 8 mg of elemental copper) in a standard 3 + 3 dose escalation design. Patients were evaluated for dose limiting toxicities and response. Protein S-glutathionylation was evaluated as a pharmacodynamic marker. RESULTS: Twenty-one patients were enrolled and 16 patients were evaluable for dose limiting toxicities. Among the 21 patients, there was a median of 4 lines of prior chemotherapy. Five Grade 3 toxicities were observed (anorexia, elevated aspartate aminotransferase or AST, elevated alkaline phosphatase, fever, and fatigue). Response data was available for 15 patients. Four patients had stable disease with the longest duration of disease control being 116 days. The median duration of treatment for evaluable patients was 55 days (range 28-124). Reasons for discontinuation included functional decline, disease progression, and disease-associated death. Increased S-glutathionylation of serum proteins was observed with treatment. CONCLUSION: Disulfiram 250 mg daily with copper gluconate (8 mg of elemental copper) was well-tolerated in patients with solid tumors involving the liver and was not associated with dose limiting toxicities. While temporary disease stabilization was noted in some patients, no objective responses were observed. Treatment was associated with an increase in S-glutathionylation suggesting that this combination could exert a suppressive effect on cellular growth and protein function. TRIAL REGISTRATION: NCT00742911 , first posted 28/08/2008.

Biomarkers in Breast Cancer: An Integrated Analysis of Comprehensive Genomic Profiling and PD-L1 Immunohistochemistry Biomarkers in 312 Patients with Breast Cancer.

BACKGROUND: We examined the current biomarker landscape in breast cancer when programmed death-ligand 1 (PD-L1) testing is integrated with comprehensive genomic profiling (CGP). MATERIAL AND METHODS: We analyzed data from samples of 312 consecutive patients with breast carcinoma tested with both CGP and PD-L1 (SP142) immunohistochemistry (IHC) during routine clinical care. These samples were stratified into hormone receptor positive (HR+)/human epidermal growth factor receptor negative (HER2-; n = 159), HER2-positive (n = 32), and triple-negative breast cancer (TNBC) cohorts (n = 121). RESULTS: We found that in the TNBC cohort, 43% (52/121) were immunocyte PD-L1-positive, and in the HR+/HER2- cohort, 30% (48/159) had PIK3CA companion diagnostics mutations, and hence were potentially eligible for atezolizumab plus nab-paclitaxel or alpelisib plus fulvestrant, respectively. Of the remaining 212 patients, 10.4% (22/212) had a BRCA1/2 mutation, which, if confirmed by germline testing, would allow olaparib plus talazoparib therapy. Of the remaining 190 patients, 169 (88.9%) were positive for another therapy-associated marker or a marker that would potentially qualify the patient for a clinical trial. In addition, we examined the relationship between immunocyte PD-L1 positivity and different tumor mutation burden (TMB) cutoffs and found that when a TMB cutoff of ≥9 mutations per Mb was applied (cutoff determined based on prior publication), 11.6% (14/121) patients were TMB ≥9 mutations/Mb and of these, TMB ≥9 mutations per Mb, 71.4% (10/14) were also positive for PD-L1 IHC. CONCLUSION: Our integrated PD-L1 and CGP methodology identified 32% of the tested patients as potentially eligible for at least one of the two new Food and Drug Administration approved therapies, atezolizumab or alpelisib, and an additional 61.2% (191/312) had other biomarker-guided potential therapeutic options. IMPLICATIONS FOR PRACTICE: This integrated programmed death-ligand 1 immunohistochemistry and comprehensive genomic profiling methodology identified 32% of the tested patients as eligible for at least one of the two new Food and Drug Administration-approved therapies, atezolizumab or alpelisib, and an additional 61.2% (191/312) had other biomarker-guided potential therapeutic options. These findings suggest new research opportunities to evaluate the predictive utility of other commonly seen PIK3CA mutations in hormone receptor-positive breast cancers and to standardize tumor mutation burden cutoffs to evaluate its potentially predictive role in triple-negative breast cancer.

Phase I/II study of everolimus combined with mFOLFOX-6 and bevacizumab for first-line treatment of metastatic colorectal cancer.

Background This phase I/II trial evaluated toxicity and antitumor activity of everolimus plus mFOLFOX6 + bevacizumab for first-line treatment of metastatic colorectal cancer (mCRC). Methods A phase I, modified 3 + 3 Fibonacci schema determined the maximum tolerated dose (MTD) of everolimus, followed by phase II dose expansion. The phase II primary objective was progression-free survival at 6 months (PFS-6 m). Results The everolimus MTD was 10 mg daily with mFOLFOX6 + bevacizumab based on safety from phase I (n = 22). Twenty-five patients were treated in the phase II at 10 mg everolimus daily. Frequent grade 3-4 adverse events were neutropenia (64%), leukopenia (28%) and hypokalemia (26%). Grade 2 stomatitis was observed in 62% of patients. Two dose-limiting toxicities were observed with one attributed to everolimus 10 mg daily (grade 3 diarrhea, hypokalemia, and anorexia) and grade 3 coronary vasospasm attributed to fluorouracil. The objective response rate was 53% and was higher (86%) in those with PTEN deficiency. PFS-6 m was 96% (95% CI 89-99.9%) at the MTD (n = 35). The everolimus recommended phase II dose of this regimen is 7.5 mg daily due to frequent stomatitis and dose reductions. Conclusions Everolimus plus mFOLFOX-6 + bevacizumab is tolerable and demonstrated preliminary efficacy for first-line mCRC. Further studies are warranted in PTEN deficiency.

Investigational Aurora A kinase inhibitor alisertib (MLN8237) as an enteric-coated tablet formulation in non-hematologic malignancies: phase 1 dose-escalation study.

BACKGROUND: This phase 1b study evaluated an enteric-coated tablet (ECT) formulation of the investigational Aurora A kinase inhibitor, alisertib (MLN8237). METHODS: Patients with advanced, non-hematologic malignancies received oral alisertib ECT for 7 d BID followed by 14 d treatment-free (21-day cycles; 3 + 3 dose escalation schema). Objectives were to assess safety, pharmacokinetics, and antitumor activity, and to define a recommended phase 2 dose (RP2D) of alisertib. RESULTS: 24 patients were treated. Median age was 57 years. Patients received a median of 2 cycles (range 1-12). The RP2D was determined as 50 mg BID for 7 d (21-day cycles). A cycle 1 dose-limiting toxicity of grade 4 febrile neutropenia was observed in 1 of 13 patients at RP2D. The most common drug-related adverse event (AE) was neutropenia (50%). At doses ≥ 40 mg BID, 7 patients had drug-related AEs that were serious but largely reversible/manageable by dose reduction and supportive care, including 3 with febrile neutropenia. Pharmacokinetic data were available in 24 patients. Following administration of alisertib ECT, the plasma peak concentration of alisertib was achieved at ~3 h; systemic exposure increased with increasing dose over 10-60 mg BID. Mean t½ was ~21 h following multiple dosing. Renal clearance was negligible. Nine patients achieved stable disease (3.98*, 5.59, 1.28*, 2.56, 5.45*, 3.48, 3.15, 8.31, and 6.93* months; *censored). CONCLUSIONS: Alisertib ECT was generally well tolerated in adults with advanced, non-hematologic malignancies. The RP2D is 50 mg BID for 7 d and is being evaluated in ongoing phase 2 studies.

The Molecular, Immunologic, and Clinicodemographic Landscape of MYC-Amplified Advanced Prostate Cancer.

BACKGROUND: MYC is a commonly amplified, potentially targetable gene in prostate cancer (PCa). We sought to define the molecular, immunologic, and clinicodemographic landscape of MYC amplification (MYCamp) in advanced PCa to establish a rationale for personalized treatment combinations. METHODS: Hybrid capture-based comprehensive genomic profiling (CGP) was performed on PCa tumor samples. MYCamp = copy number ≥6 (CN). Patients treated between January 2011 and December 2020 were selected from a nationwide deidentified (280 clinics) EHR-derived clinicogenomic database (CGDB). RESULTS: Of 12,528 hormone-sensitive and castrate-resistant (CRPC) samples, MYCamp was detected in 10.6% (median CN = 8). MYCamp was more frequent in men with African versus European ancestry (12.9% vs. 10.2% P = .002), in metastatic vs. primary tissue (15.7% vs. 6.2% P < .001), and enriched in metastatic liver lesions (20.2%), but inversely associated with high microsatellite-instability (0.8% vs. 2.4%, P < .001). MYC CN≥15 was associated with PD-L1 expression (26.1% vs. 9.8%, P = .025). Amplification of AR, RAD21, LYN, CCND1, ZNF703, FGF3/4/19, and FGFR1 was enriched in MYCamp vs. MYCwt (all P < .001). In liquid samples with tumor fraction [TF]>0, MYCamp was detected in 2.0% (28/1,402), and 4.5% (20/445) with TF>20%. In the CGDB, (67 MYCamp and 658 MYCwt), patients received similar treatments; most received hormone therapies (35.8% MYCamp vs. 31.5% MYCwt) or chemotherapy (37.3% MYCamp vs. 27.7% MYCwt) as first therapy after CGP report. CONCLUSION: MYCamp defines a biologically distinct subset of PCa patients and is characterized with multiple proxies of advanced disease. These data suggest that MYCamp may be prognostic; independent cohorts are needed to validate these findings.

Plasma Proteome-Based Test for First-Line Treatment Selection in Metastatic Non-Small Cell Lung Cancer.

PURPOSE: Current guidelines for the management of metastatic non-small cell lung cancer (NSCLC) without driver mutations recommend checkpoint immunotherapy with PD-1/PD-L1 inhibitors, either alone or in combination with chemotherapy. This approach fails to account for individual patient variability and host immune factors and often results in less-than-ideal outcomes. To address the limitations of the current guidelines, we developed and subsequently blindly validated a machine learning algorithm using pretreatment plasma proteomic profiles for personalized treatment decisions. PATIENTS AND METHODS: We conducted a multicenter observational trial (ClinicalTrials.gov identifier: NCT04056247) of patients undergoing PD-1/PD-L1 inhibitor-based therapy (n = 540) and an additional patient cohort receiving chemotherapy (n = 85) who consented to pretreatment plasma and clinical data collection. Plasma proteome profiling was performed using SomaScan Assay v4.1. RESULTS: Our test demonstrates a strong association between model output and clinical benefit (CB) from PD-1/PD-L1 inhibitor-based treatments, evidenced by high concordance between predicted and observed CB (R2 = 0.98, P < .001). The test categorizes patients as either PROphet-positive or PROphet-negative and further stratifies patient outcomes beyond PD-L1 expression levels. The test successfully differentiates between PROphet-negative patients exhibiting high tumor PD-L1 levels (≥50%) who have enhanced overall survival when treated with a combination of immunotherapy and chemotherapy compared with immunotherapy alone (hazard ratio [HR], 0.23 [95% CI, 0.1 to 0.51], P = .0003). By contrast, PROphet-positive patients show comparable outcomes when treated with immunotherapy alone or in combination with chemotherapy (HR, 0.78 [95% CI, 0.42 to 1.44], P = .424). CONCLUSION: Plasma proteome-based testing of individual patients, in combination with standard PD-L1 testing, distinguishes patient subsets with distinct differences in outcomes from PD-1/PD-L1 inhibitor-based therapies. These data suggest that this approach can improve the precision of first-line treatment for metastatic NSCLC.

Potential pathogenic germline variant reporting from tumor comprehensive genomic profiling complements classic approaches to germline testing.

Existing guidance regarding clinically informed germline testing for patients with cancer is effective for evaluation of classic hereditary cancer syndromes and established gene/cancer type associations. However, current screening methods may miss patients with rare, reduced penetrance, or otherwise occult hereditary risk. Secondary finding of suspected germline variants that may confer inherited cancer risk via tumor comprehensive genomic profiling (CGP) has the potential to help address these limitations. However, reporting practices for secondary finding of germline variants are inconsistent, necessitating solutions for transparent and coherent communication of these potentially important findings. A workflow for improved confidence detection and clear reporting of potential pathogenic germline variants (PPGV) in select cancer susceptibility genes (CSG) was applied to a research dataset from real-world clinical tumor CGP of > 125,000 patients with advanced cancer. The presence and patterns of PPGVs identified across tumor types was assessed with a focus on scenarios in which traditional clinical germline evaluation may have been insufficient to capture genetic risk. PPGVs were identified in 9.7% of tumor CGP cases using tissue- and liquid-based assays across a broad range of cancer types, including in a number of "off-tumor" contexts. Overall, PPGVs were identified in a similar proportion of cancers with National Comprehensive Cancer Network (NCCN) recommendations for germline testing regardless of family history (11%) as in all other cancer types (9%). These findings suggest that tumor CGP can serve as a tool that is complementary to traditional germline genetic evaluation in helping to ascertain inherited susceptibility in patients with advanced cancer.

An Immune-Related Gene Expression Signature Predicts Benefit from Adding Atezolizumab to FOLFOXIRI plus Bevacizumab in Metastatic Colorectal Cancer.

PURPOSE: AtezoTRIBE phase II randomized study demonstrated that adding atezolizumab to first-line FOLFOXIRI (5-fluorouracil, oxaliplatin, irinotecan) plus bevacizumab prolongs progression-free survival (PFS) of patients with metastatic colorectal cancer (mCRC), with a modest benefit among proficient mismatch repair (pMMR). DetermaIO is an immune-related 27-gene expression signature able to predict benefit from immune checkpoint inhibition in triple-negative breast cancer. In this analysis of AtezoTRIBE, we investigated the predictive impact of DetermaIO in mCRC. EXPERIMENTAL DESIGN: Patients with mCRC unselected for MMR status were randomly assigned (1:2) to FOLFOXIRI plus bevacizumab (control arm) or the same regimen with atezolizumab (atezolizumab arm). qRT-PCR by DetermaIO was performed on RNA purified from pretreatment tumors of 132 (61%) of 218 enrolled patients. A binary result (IOpos vs. IOneg) adopting the preestablished DetermaIO cut-off point (0.09) was obtained, and an exploratory optimized cut-off point (IOOPT) was computed in the overall population and in pMMR subgroup (IOOPTpos vs. IOOPTneg). RESULTS: DetermaIO was successfully determined in 122 (92%) cases, and 23 (27%) tumors were IOpos. IOpos tumors achieved higher PFS benefit from atezolizumab arm than IOneg (HR: 0.39 vs. 0.83; Pinteraction = 0.066). In pMMR tumors (N = 110), a similar trend was observed (HR: 0.47 vs. 0.93; Pinteraction = 0.139). In the overall population, with the computed IOOPT cut-off point (0.277), 16 (13%) tumors were IOOPTpos and they derived higher PFS benefit from atezolizumab than IOOPTneg (HR: 0.10 vs. 0.85, Pinteraction = 0.004). Similar results were found in the pMMR subgroup. CONCLUSIONS: DetermaIO may be useful to predict benefit of adding atezolizumab to first-line FOLFOXIRI plus bevacizumab in mCRC. The exploratory IOOPT cut-off point should be validated in independent mCRC cohorts.

A phase Ib trial of pembrolizumab plus paclitaxel or flat-dose capecitabine in 1st/2nd line metastatic triple-negative breast cancer.

Chemoimmunotherapy with anti-programmed cell death 1/ligand 1 and cytotoxic chemotherapy is a promising therapeutic modality for women with triple-negative breast cancer, but questions remain regarding optimal chemotherapy backbone and biomarkers for patient selection. We report final outcomes from a phase Ib trial evaluating pembrolizumab (200 mg IV every 3 weeks) with either weekly paclitaxel (80 mg/m2 weekly) or flat-dose capecitabine (2000 mg orally twice daily for 7 days of every 14-day cycle) in the 1st/2nd line setting. The primary endpoint is safety (receipt of 2 cycles without grade III/IV toxicities requiring discontinuation or ≥21-day delays). The secondary endpoint is efficacy (week 12 objective response). Exploratory aims are to characterize immunologic effects of treatment over time, and to evaluate novel biomarkers. The trial demonstrates that both regimens meet the pre-specified safety endpoint (paclitaxel: 87%; capecitabine: 100%). Objective response rate is 29% for pembrolizumab/paclitaxel (n = 4/13, 95% CI: 10-61%) and 43% for pembrolizumab/capecitabine (n = 6/14, 95% CI: 18-71%). Partial responses are observed in two subjects with chemo-refractory metaplastic carcinoma (both in capecitabine arm). Both regimens are associated with significant peripheral leukocyte contraction over time. Response is associated with clinical PD-L1 score, non-receipt of prior chemotherapy, and the H&E stromal tumor-infiltrating lymphocyte score, but also by a novel 27 gene IO score and spatial biomarkers (lymphocyte spatial skewness). In conclusion, pembrolizumab with paclitaxel or capecitabine is safe and clinically active. Both regimens are lymphodepleting, highlighting the competing immunostimulatory versus lymphotoxic effects of cytotoxic chemotherapy. Further exploration of the IO score and spatial TIL biomarkers is warranted. The clinical trial registration is NCT02734290.

Concurrent BRAFV600E and BRCA Mutations in MSS Metastatic Colorectal Cancer: Prevalence and Case Series of mCRC patients with prolonged OS.

BACKGROUND: BRAF V600E+ microsatellite stable (MSS) metastatic colorectal cancer (mCRC) patients comprise up to 10% of advanced CRC. They have a poor prognosis with a median survival typically <1 year. Despite use of multi-agent 1st line chemotherapy regimens and combination targeted therapies, outcomes are still poor. In our Institutional Molecular Tumor Board (MTB) database, we identified 3 mCRC patients with MSS/BRAF V600E who also had a BRCA1 or BRCA2 co-mutation and had relatively long overall survivals. Prior studies suggested that BRCA mutations are uncommon in CRC and we queried the Foundation Medicine (FM) genomic database to evaluate the prevalence of these cases as well as those with co-mutations in other homologous recombination genes. METHODS: 36,966 CRC pts were sequenced by FMI using hybrid capture comprehensive genomic profiling (CGP) to evaluate all classes of genomic alterations (GA) for pathogenic BRAF mutations and/or a mutation in BRCA1/2 or a co-mutation in other homologous recombination (HR) genes (BARD1, CDK12, FANCL, PALB2, ATM, RAD54L, CHEK2, BRAF, BRIP1, RAD51D, RAD51C, RAD51B, CHEK1). Selected cohort analysis of BRAF V600E co-mutated with BRCA1 and BRCA2 were separated into MSI-H and MSS cohorts. The clinicopathological features and genomic loss of heterozygosity (gLOH) of those with a BRAF V600E and a BRCA1/BRCA2 mutation were collected and analyzed. We also describe 3 consecutive cases of mCRC patients, identified through the Inova Schar Cancer Institute (ISCI) MTB registry, whom had prolonged OS. RESULTS: Of 36,966 colorectal cancer pts, 6.6% were BRAF V600E+ and 1.5% had any co-occurring HR gene mutation(s) with 0.6% of the total mCRC population having co-ocurring BRAF V600E and BRCA1/2 alterations. BRCA co-mutations were higher in MSI-High BRAF V600E, however 24.1% of co-occurrences were observed in MSS samples. BRCA1 co-mutation was more commonly associated with MSS BRAF V600E and was associated with a higher gLOH than MSI-H BRAF V600E (18.7% vs 2.8%; p <0.001). In our institutional MTB database, (3/241;1.2%) CRC patients were MSS, BRAF V600E+ with BRCA1 or BRCA2 co-mutations, all somatic in origin, with an average gLOH of 21.4% and overall survivals of 72+(alive), 17+(alive), and 30 months, respectively. CONCLUSION: Co-existence of BRAF V600E/BRCA1/2 may represent a unique subset of advanced MSS CRC that may have a better prognosis and represent an opportunity to test novel targeted therapies. The elevated gLOH in these cases may also be a valuable biomarker for these pts. Larger prospective clinical validation trials in this subset is warranted.

Tissue and liquid biopsy profiling reveal convergent tumor evolution and therapy evasion in breast cancer.

Pathological and genomic profiling have transformed breast cancer care by matching patients to targeted treatments. However, tumors evolve and evade therapeutic interventions often through the acquisition of genomic mutations. Here we examine patients profiled with tissue (TBx) and liquid biopsy (LBx) as part of routine clinical care, to characterize the tumor evolutionary landscape and identify potential vulnerabilities in the relapsed setting. Real-world evidence demonstrates that LBx is utilized later in care and identifies associations with intervening therapy. While driver events are frequently shared, acquired LBx alterations are detected in a majority of patients, with the highest frequency in ER+ disease and in patients with longer biopsy intervals. Acquired mutations are often polyclonal and present at lower allelic fractions, suggesting multi-clonal convergent evolution. In addition to well-characterized resistance mutations (e.g., ESR1, NF1, RB1, ERBB2), we observe a diversity of rarer but potentially targetable mutations (e.g., PIK3CA, HRAS/NRAS/KRAS, FGFR1/2/3, BRAF) and fusions (e.g., FGFR1/2, ERBB2, RET), as well as BRCA1/2 reversions through a variety of mechanisms, including splice alterations and structural deletions. This study provides insights on treatment and selection-driven tumor evolution and identifies potential combinatorial treatment options in advanced breast cancer.

Predictive Biomarkers for Immune Checkpoint Inhibitors in Metastatic Breast Cancer.

We examined a large dataset of female metastatic breast cancers (MBCs) profiled with comprehensive genomic profiling (CGP) to identify the prevalence and distribution of immunotherapy responsiveness-associated biomarkers. DNA was extracted from 3831 consecutive MBCs: 1237 (ERpos /HER2neg ), 1953 ERneg /HER2amp , and 641 triple-negative breast cancer (TNBC). CGP was performed using the FoundationOne® or FoundationOne® CDx NGS assay. Tumor mutational burden (TMB) and microsatellite instability (MSI) were determined in a subset of cases. PD-L1 expression in immunocytes in a subset of cases was determined by immunohistochemistry using the companion diagnostic VENTANA PD-L1 SP142 Assay. The median age of the cohort was 54 years (range 20-89). Genomic alterations (GAs)/tumor were similar (range: 5.9-7.3). Markers of potential immune checkpoint inhibitor (ICPI) benefit included: CD274 (PD-L1) amplification (1%-3%), BRAF GA (1%-4%), TMB of ≥10 mutations/Mb (8%-12%), MSI-high (0.1%-0.4%), PBRM1 GA (1%), and positive PD-L1 staining of immunocytes ranging from 13% in ERpos /HER2neg and 33% in ERneg /HER2amp to 47% in the TNBC group. Potential markers of ICPI resistance included inactivating STK11 GA (1%-2%) and MDM2 amplification (3%-6%). MTOR pathway targets were common with lowest frequency in TNBC. ERBB2 short variant mutations were most frequent ERpos /HER2neg and absent in TNBC. BRCA1/2 GA were least frequent in ERneg /HER2amp . The demonstrations of clinical benefit of immunotherapy in MBC support the need for development and utilization of biomarkers to guide the use of ICPIs for these patients. In addition to guiding therapy selection, CGP shows potential to identify GA linked to response and resistance to ICPI in MBC.

Comprehensive genomic profiling of histologic subtypes of urethral carcinomas.

BACKGROUND: Carcinoma of the urethra (UrthCa) is an uncommon Genitourinary (GU) malignancy that can progress to advanced metastatic disease. METHODS: One hundred twenty-seven metastatic UrthCa underwent hybrid capture-based comprehensive genomic profiling to evaluate all classes of genomic alterations (GA). Tumor mutational burden was determined on up to 1.1 Mbp of sequenced DNA, and microsatellite instability was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). RESULTS: Forty-nine (39%) urothelial (UrthUC), 31 (24%) squamous (UrthSCC), 24 (19%) adenocarcinomas NOS (UrthAC), and 12 (9%) clear cell (UrthCC) were evaluated. UrthUC and UrthSCC are more common in men; UrthAC and UrthCC are more common in women. Ages were similar in all 4 groups. GA in PIK3CA were the most frequent potentially targetable GA; mTOR pathway GA in PTEN were also identified. GA in other potentially targetable genes were also identified including ERBB2 (6% in UrthUC, 3% in UrthSCC, and 12% in UrthAC), FGFR1-3 (3% in UrthSCC), BRAF (3% in UrthAC), PTCH1 (8% in UrthCC), and MET (8% in UrthCC). Possibly reflecting their higher GA/tumor status, potential for immunotherapy benefit associated with higher tumor mutational burden and PD-L1 staining levels were seen in UrthUC and UrthSCC compared to UrthAC and UrthCC. Microsatellite instability high status was absent throughout. CONCLUSIONS: Comprehensive genomic profiling reveals GA that may be predictive of both targeted and immunotherapy benefit in patients with advanced UrthCa and that could potentially be used in future adjuvant, neoadjuvant, and metastatic disease trials.

Landscape of Biomarkers in Non-small Cell Lung Cancer Using Comprehensive Genomic Profiling and PD-L1 Immunohistochemistry.

Comprehensive genomic profiling (CGP) and immunohistochemistry (IHC) are important biomarker tools used for patients with non-small cell lung cancer (NSCLC) given the expanding number of standard-of-care therapies that require companion diagnostic testing. We examined 9450 NSCLC real-world patient samples that underwent both CGP and programmed death-ligand 1 (PD-L1) IHC to understand the biomarker landscape in this patient cohort. By assessing National Comprehensive Cancer Network (NCCN)-recommended biomarkers including genomic alterations, tumor mutational burden (≥10 mutations/Mb cut-off), and PD-L1 expression (Tumor Proportion Score (TPS) ≥ 50% cut-off), we show that CGP + PD-L1 IHC yielded potentially actionable results for 70.5% of the 9,450 patients with NSCLC. Among the remaining 29.5% (2,789/9,450) of patients, 86.7% (2,419/2,789) were potentially eligible for another biomarker-associated therapy and/or clinical trial based on their genomic profile. In addition, in the PD-L1TPS≥50% disease subset, BRAF mutations, MET mutations, MET amplifications, and KRAS mutations were significantly enriched; and in the PD-L1TPS<50%, EGFR mutations, ERBB2 mutations, STK11 mutations, and KEAP1 mutations were enriched. These findings highlight the improved clinical utility of combining CGP with IHC to expand the biomarker-guided therapeutic options available for patients with NSCLC, relative to single biomarker testing alone.