Pooled subgroup analysis of twelve randomized controlled trials of immunotherapy in non-small cell lung cancer

e20639

Background: Multiple randomized controlled trials (RCTs) have shown a robust benefit of immunotherapy with immune checkpoint inhibitors (ICI) in non-small cell lung cancer (NSCLC). We did a meta-analysis to examine the benefit of ICI in various subgroups. Methods: PubMed was searched up to Jan 15, 2019 for RCTs comparing overall survival (OS) between ICI and control (without ICI) arms. Pooled hazard ratio (HR) and 95% confidence interval (CI) was calculated for each subgroup. Interaction tests were done to compare relative benefit between opposed subgroups of interest (eg. men vs women; reported as Pheterogeneity). All analyses were performed with a random effects model in Comprehensive Meta Analysis (v2). Results: Twelve phase 2/3 RCTs involving 7244 patients were included. A significant OS benefit of ICI was found in both squamous and non-squamous histology. Current/former smokers, EGFR wild-type, and KRAS mutant patients had a significant OS benefit from ICI, but never smokers, EGFR mutant, and KRAS wild-type patients did not. An OS benefit of ICI was found in patients with or without baseline brain metastasis, PD-L1 < 1% or ≥1%, men or women, age < 65 or ≥65, and ECOG PS 0 or ≥1. No significant difference of relative benefit from ICI over control was found in patients with different PD-L1 expression, sex, age, or ECOG PS (Table). Conclusions: OS benefit of ICI in NSCLC was associated with a smoking history, wild-type EGFR or KRAS mutation. However, the OS benefit of ICI was seen regardless of histology, PD-L1 expression, sex, age, and ECOG PS. [Table: see text]

Exploring sex differences in small cell lung cancer: Is this a hormonal issue?

e20077

Background: Small cell lung cancer (SCLC) accounts for about 10% to 15% of lung cancers among women and men. Though heavily associated with smoking, its incidence in women is rapidly increasing despite a decline in cigarette exposure. Given the changing demographics of SCLC and hormonal factors associated with other forms of lung cancer, we studied differences between sexes in SCLC. Methods: Utilizing the National Cancer Database, we identified all incident SCLC cases from 2004 to 2014. Patients were classified as limited stage (LS) or extensive stage (ES). Women were stratified by menopausal status (≥55 years = postmenopausal). Kaplan-Meier method and Cox regression were used for overall survival (OS) and multivariable analysis. Results: 161,978 patients were identified. No significant sociodemographic differences were observed between sexes. The majority of patients were non-Hispanic whites (89.1%), followed by non-Hispanic blacks (7.5%). Men were more likely to be diagnosed with ES disease than women (63% vs. 56%). Both sexes initiated treatment within a similar time frame from diagnosis (chemotherapy, median: 18 days, IQR 8-32). Women had better median OS compared to men in both LS (15.2 vs. 12.7 months, HR: 0.85, 95% CI 0.83-0.86, p < 0.0001) and ES (6.4 vs. 5.7 months, HR: 0.88, 95% CI 0.87-0.90, p < 0.0001). No racial or ethnic disparities in OS were observed, overall and when examined within sex and disease stage groups. Differences between sexes in OS were also observed when comparing patients within the same racial/ethnic group (women having better OS). When divided by menopausal status, postmenopausal women with LS and ES had worse OS than premenopausal women (14.7 vs. 22 months, HR: 1.50, 95% CI 1.44-1.56; 6.1 vs. 9.8 months, HR: 1.41, 95% CI: 1.37-1.46, respectively). We also observed worse OS in older men when divided by age ( < 55 years and ≥55 years). In multivariable analysis, older age, postmenopausal status, and Medicaid as primary insurance were associated with worse OS for both LS and ES. Conclusions: In this large cohort, women with SCLC had better OS compared to men. Post-menopausal women had worse OS compared to pre-menopausal women. Since older men had a similar trend of worse survival compared to younger men, age might exert a more significant influence on survival than hormonal status in SCLC. Further studies with data on sexual hormone levels are necessary to better understand their role in women with SCLC.

Is a delay in ALK inhibitor initiation associated with poorer survival? A retrospective analysis based on real-world data

e18240

Background: The time between a patient’s positive biomarker test result and initiation of targeted therapy may vary due to a number of factors, including the use of chemotherapy prior to or after the biomarker test result. The objective of this study was two-fold: first, to investigate the impact of delayed ALK inhibitor (ALKi) therapy on overall survival (OS) and second, to examine the association between the use of chemotherapy prior to or after biomarker testing and OS. Methods: The Flatiron Health EHR-derived database was used to identify patients with ALK-positive (ALK+) advanced NSCLC diagnosed between 1/1/2011 - 9/30/2018. The median time from ALK+ test result to ALKi start was used to separate patients into early versus delayed treatment cohorts. To account for potential immortal time bias, times from ALK+ test result to ALKi start from the delayed cohort were sampled with replacement and used to create modified index dates among the early cohort. Cox proportional hazards models adjusting for baseline characteristics (i.e. ECOG) were used to assess the association between delayed ALKi start and OS and the use of chemotherapy with OS. Results: 422 patients with ALK+ aNSCLC were included in this analysis with a median time from test result to ALKi start of 3 weeks. 88 patients (20.9%) received chemotherapy prior to starting their ALKi. Delayed ALKi use was associated with a 2.3 fold increase in risk of mortality (HR [95% CI]: 2.30 [1.28, 4.15], p < 0.01). There was no difference in survival observed between those who had received chemotherapy prior to initiating their ALKi and those who did not receive chemotherapy (HR [95% CI]: 0.99 [0.62, 1.58]). Among those who initiated chemotherapy prior to their ALK+ test result, the continued use of chemotherapy prior to initiating an ALKi did not result in differences in OS compared to those who switched to an ALKi without continuing chemotherapy (HR [95% CI]: 1.03 [0.44, 2.41]). Conclusions: Delayed initiation of ALKi may result in poor outcomes in patients with ALK+ NSCLC. Receipt of chemotherapy prior to ALKi or the duration of chemotherapy did not impact survival. Future strategies to improve the time to therapy initiation may be useful in improving patient outcomes.

Overestimation of tumor mutational burden (TMB) using algorithms compared to germline subtraction

2621

Background: TMB is an emerging predictor of survival with immunotherapy. TMB is determined by taking the difference between somatic and germline datasets when tumor-normal pairs are available. In the case of commonly utilized tumor-only sequencing, additional steps are needed to estimate the somatic alterations. Computational tools have been developed that determine germline contribution based on sample copy state, purity estimates and occurrence of the variant in population databases. Given the potential bias of population datasets, we hypothesized that tumor-only filtering approaches may overestimate the actual TMB. Methods: We assessed the TMB from 50 tumors in 10 diseases including all missense, indels, and frameshift variants with an allelic fraction (AF) ≥5% and Coverage ≥100X within the tumor. Tumor-only TMB was evaluated against the gold standard of matched germline subtracted TMB at three levels. Level 1 removed all the tumor-only variants with AF in the non-TCGA ExAC database ≥1%. Level 2 removed all variants observed in population databases simulating a naive approach of removing germline variation. Level 3 used an internal tumor-only pipeline for calculating TMB. Results: There were significantly higher estimates of TMB with Level 1, Level 2 and Level 3 tumor-only filtering approaches than that determined by germline subtraction, resulting in significant bias. Whereas there was no correlation between TMB estimates and tumor-germline TMB for Level 1 filtering, there were improvements in correlations for Level 2 and Level 3. Conclusions: The tumor-only approaches that filter variants in population databases overestimate TMB compared to that determined by germline subtraction. Despite improved correlations with more stringent filtering approaches, these falsely elevated estimates may result in the inappropriate categorization of tumor specimens and negatively impact clinical trial results and patient outcomes. [Table: see text]

Retrospective review of 11C-choline detected thoracic lesions in prostate cancer

325

Background: Prostate cancer recurrence is detected by serum measurements of prostate specific antigen (PSA). Upon PSA elevation, locating sites of recurrence is important to guiding treatment and affecting patient outcomes. The imaging modalities in current practice have varying sensitivities and specificities and often miss early recurrent disease. 11C-choline positron emission tomography (11C-PET) may be able to detect occult disease and guide treatment decisions earlier in the clinical course. We assessed a case series of patients who underwent 11C-PET imaging and were identified to have thoracic disease to estimate the benefit of detection with this modality. Methods: Clinical records were retrospectively reviewed of seventy patients from thoracic oncology teams at Mayo Clinic in Rochester, Minnesota. Patients who had thoracic +/- extra-thoracic metastases on 11C-PET imaging were followed, noting changes in treatment and PSA trends to look for biochemical recurrence of disease. Results: Seventy patients with thoracic metastases discovered on 11C-PET imaging were initially identified. Median time to choline-avid disease from original diagnosis was 82 (IQR: 40-129) months with a median PSA at time of choline of 7.4 (IQR: 3.1-15.7). 11C-PET findings showed 28 patients with metastases limited to the thorax and 42 patients with thoracic and extra-thoracic metastases. After 11C-PET imaging, 1 patient underwent localized therapy only (radiation and surgery), 44 patients underwent systemic therapy only (chemotherapy or hormonal therapy), 19 patients underwent both localized (cryotherapy, radiation, or surgery) and systemic therapy, 3 patients underwent no further treatment, and 3 patients were lost to follow up. After a median follow-up of 36.5 (IQR: 13-52) months, 30 patients had no recurrence and 20 had evidence of biochemical recurrence. For those who underwent local therapy (N=21), 11 had no recurrence of disease. Conclusions: Choline-based imaging may earlier identify metastatic disease that is amenable to local therapy. Further studies are needed to validate the effectiveness of 11C-PET in identifying early, responsive metastatic prostate cancer and its utility in affecting patient outcomes.

Immunotherapy-related toxicities: More common than originally reported?

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Background: Population level data regarding incidence of immune-related adverse events (irAE) is lacking. This study evaluated the frequency of irAEs among a large population of patients with non-small cell lung cancer (NSCLC) who received immune checkpoint inhibitors. Methods: Administrative claims data from a large U.S. commercial insurance database (OptumLabs Data Warehouse) were used to retrospectively identify patients with NSCLC who received PD-1 or PD-L1 inhibitors between January 1, 2015 to December 31, 2017. The frequencies of irAEs were reported, identified by having a new medical claim with a corresponding ICD-9 or ICD-10 code during the time period in which the patient was on immunotherapy. Results: Of 2,798 patients with NSCLC (median age at PD-(L)1 initiation: 69 years, interquartile range: 60-75, 1558 male [55.7%], 1240 [44.3%] female), 1,998 (71.4%) received nivolumab, 699 (25.0%) received pembrolizumab, and 101 (3.6%) received atezolizumab. Most patients (1463, 52.3%) received a PD-(L)1 inhibitor as second line therapy; the majority of patients (744) received alkylating agents and antimetabolites prior to receiving PD-(L)1 therapy. See Table 1 for frequencies of irAEs. Conclusions: The current study suggests that the frequencies of some irAEs related to immune checkpoint inhibitor therapies may be higher than those which were reported in the initial trials that led to the FDA approvals for immunotherapies. For example, hypophysitis was noted to occur in 0.6% of patients in the KEYNOTE-024 trial, but was identified in 2.4% of patients in this large cohort. Real world data may refine provider and patient expectations for outcomes beyond what is observed in clinical trials. [Table: see text]

Representation of minorities in oncology clinical trials: Review of the past 14 years

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Background: Many cancer clinical trials (CT) lack appropriate representation of specific patients populations, limiting the generalizability of the evidence obtained. Therefore, we determined the representation of ethnic minorities in oncology CT. Methods: Enrollment data from all therapeutic trials reported as completed in clinicaltrial.gov from 2003 to 2016 were analyzed. CT in rare cancers (< 1% incidence) or with recruitment outside of the US were excluded. Enrollment fraction (EF) was defined as the number of enrollees divided by the 2013 SEER database cancer prevalence. Chi-square test was used to estimate differences in categorical data. Results: Out of 1,012 CT, 310 (31%) reported ethnicity with a total of 55689 enrollees. Distribution by race and comparison with data from 1996-2002, US cancer prevalence and US census are described in the Table. Participation in CT varied significantly across ethnic groups, non-Hispanic Whites (NHW) were more likely to be enrolled in CT (EF of 1.2%) than African Americans (EF of 0.7%, p < 0.001) and Hispanics (EF of 0.4%, p<0.001). A decrease in African Americans (AA) and Hispanics (H) enrollment was observed when compared with historical data from 1996 to 2002. Hispanics were less represented in breast and prostate cancer CT contributing only to 3% and 1.5% of the study population; African Americans were less represented in lung (5.4%) and renal cell carcinoma (3%) trials. Asians were well represented and their recruitment doubled over the past 14 years (2% vs 5.3%). Conclusions: African Americans and Hispanics were less likely to be enrolled in CT. Comparing with historical data; we observed a decrease in minorities’ recruitment in the past 14 years. This change could be attributed to the increased complexity of CT and mandatory molecular testing as many minorities lack access to institutions with genetic testing capacity. Future trials should take extra measures to recruit participants that adequately represent the U.S. cancer population. [Table: see text]

Checkmate 743: A phase 3, randomized, open-label trial of nivolumab (nivo) plus ipilimumab (ipi) vs pemetrexed plus cisplatin or carboplatin as first-line therapy in unresectable pleural mesothelioma

TPS8581

Background: Malignant pleural mesothelioma (MPM) is an aggressive cancer with a 5-year overall survival (OS) rate of < 10%. At diagnosis, most patients (pts) have unresectable disease. Combination chemotherapy of cisplatin (or carboplatin as an alternative) + pemetrexed is the approved first-line standard of care. Phase 1 and 2 data suggest that targeting immune checkpoint pathways (eg, programmed death [PD]-1/PD-ligand 1 [PD-L1] and/or cytotoxic T-lymphocyte antigen-4 [CTLA-4]) may provide benefit with acceptable safety in MPM. In pts with previously treated, malignant mesothelioma, single-agent tremelimumab (a CTLA-4 inhibitor antibody) was active but did not improve OS vs placebo. In a phase 2 study of nivo (a fully human PD-1 immune checkpoint inhibitor antibody) in 34 pts with MPM that progressed after first-line platinum-based chemotherapy, 12-week disease control rate (DCR) was 50%, 5 pts had partial response, and 12 pts had stable disease. Given the data with single-agent CTLA-4 and PD-1 inhibitors and that CTLA-4 inhibition can induce PD-L1 expression, there is reason to anticipate synergy when combining CTLA-4 and PD-1 inhibitors in MPM. A phase 2 study assessing nivo alone and nivo + ipi (a CTLA-4 inhibitor antibody) in MPM is ongoing. CheckMate 743 (NCT02899299) is a phase 3 study that will evaluate the efficacy and safety of first-line nivo + ipi vs chemotherapy for MPM. Methods: Approximately 600 adult pts with unresectable MPM and ECOG performance status 0–1 will be randomized. Pts are ineligible if they have primary peritoneal, pericardial, or tunica vaginalis testis mesotheliomas; have active, untreated CNS metastases; or had received prior systemic therapy for pleural mesothelioma or a prior PD-1/PD-L1 or CTLA-4 checkpoint inhibitor antibody. Pts are randomized 1:1 to receive nivo + ipi or pemetrexed + cisplatin/carboplatin. Primary endpoints are OS and progression-free survival (PFS), assessed by blinded independent central review. Secondary endpoints are objective response rate (ORR), DCR, and correlation of PD-L1 expression level and efficacy (ORR, PFS, and OS). Clinical trial information: NCT02899299.

ATOMIC-Meso: A randomized phase 2/3 trial of ADI-PEG20 or placebo with pemetrexed and cisplatin in patients with argininosuccinate synthetase 1-deficient non-epithelioid mesothelioma

TPS8582

Background: Argininosuccinate synthetase 1 (ASS1)-deficient malignant pleural mesothelioma (MPM) is sensitive to arginine deprivation therapy with pegylated arginine deiminase (ADI-PEG20), which also enhances the cytotoxicity of pemetrexed. The TRAP Phase 1 trial (NCT02029690) of ADI-PEG 20 combined with 1st-line pemetrexed (PEM) and cisplatin (CDDP) chemotherapy revealed a 94% disease control rate in non-epithelioid (biphasic and sarcomatoid) MPM subtypes characterized by a 75% rate of ASS1 loss. Thus, we plan to assess the efficacy of ADI-PEG20 or placebo combined with PEM and CDDP in patients (pts) with poor prognosis MPM in a randomized, placebo-controlled, double-blind phase 2/3 global trial. Methods: Up to 386 good performance (ECOG 0-1) pts with non-epithelioid malignant pleural mesothelioma will be enrolled in a phase 2/3 adaptive, biomarker-driven study design. Biopsies will be required prior to randomization: ASS1-agnostic pts will be enrolled initially (phase 2 stage) with an option to restrict enrolment to ASS1-deficient MPM (phase 3 stage). Pts will be randomized to receive weekly ADI-PEG20 (36 mg/m2 IM) or placebo with standard doses of PEM and CDDP for a maximum of 18 weeks (6 cycles) of treatment. Pts who develop CDDP toxicity may be switched to carboplatin. Pts will be assessed every 6 weeks using modified RECIST (RECIST 1.1 allowed for pts with significant extrathoracic disease). The primary endpoint for the phase 2 stage will be overall response rate (ORR) with secondary endpoints of overall survival (OS), safety and toxicity. The phase 2 will test ORR proportions with the placebo triplet set at 15% vs. 35% for the ADI-PEG 20 triplet, with a 1:1 randomization, 80% power. After recruitment of 176 pts, the phase 2 will convert to a phase 3 study with the primary endpoint of OS. In summary, ATOMIC-Meso is the first triplet chemotherapy study to assess the role of targeted arginine deprivation in aggressive subtypes of mesothelioma. Pt accrual has commenced across the US and Asia, with enrolment due in Europe and Australia by 2nd quarter of 2017. [Trial sponsored by Polaris Group]. Clinical trial information: NCT02709512.

Bim and soluble PD-L1 (sPD-L1) as predictive biomarkers of response to anti-PD-1 therapy in patients with melanoma and lung carcinoma

11534

Background: To date, there are no validated blood-based biomarkers of predicting response to PD-1 blockade. We previously reported that Bim is a downstream signaling molecule of the PD-1 pathway, and that measurement of Bim levels in circulating T-cells may predict and monitor responses to anti–PD-1 therapy in melanoma. We have identified the existence of sPD-L1 in cancer patients and showed that the sPD-L1 is biologically active and capable of triggering apoptosis in activated T-cells. Here we evaluated T cell Bim and sPD-L1 in the peripheral blood (PB) as biomarkers of response in a cohort of patients with metastatic melanoma and lung cancer undergoing anti-PD1 therapy. Methods: 60 pts treated with anti-PD-1 had PB collected at baseline and at radiographic tumor evaluation. Frequencies of Bim+ T cells and Bim median fluorescence intensity (MFI) were measured by flow cytometry in gated tumor-reactive CD11ahighPD1+ CD8+ T cells. We also measured levels of sPD-L1 at baseline and serially during treatment with sPD-L1 ELISA. Baseline Bim and sPD-L1 levels and percent change in Bim levels in patients (pts) who had a radiographic response (CR/PR) were compared to those who had progressive disease (PD) at 12 wks. Results: Similarly to previously reported preliminary data, pts with objective response (CR/PR, 15/60) after 4 cycles of anti-PD1 therapy had higher frequency of Bim T cells at baseline compared to pts with PD (16/60) (mean 43% vs. 30%, P = 0.0484). The frequencies of Bim+ T cells decreased significantly after the first 3 months of treatment in responders compared with progressors (mean -16% vs. + 40% P = 0.0111). High baseline sPD-L1 were associated with progression on anti-PD1 therapy (mean 2.8 ng/mL vs. 0.7 ng/mL, p = 0.07, n = 13) and the levels increased by the first tumor assessment in patients resistant to anti-PD-1. Conclusions: Measurements of Bim and sPD-L1 levels may help to select patients who are likely to benefit from anti-PD1 monotherapy versus combinatorial strategies, and provide a new non-invasive way to monitor response to anti-PD-1 blockade. A larger validation study is underway.

Phase I/III trial of atezolizumab with carboplatin and etoposide in ES-SCLC in first-line setting (IMpower133)

TPS8584

Background: The first-line standard of care for the majority of patients (pts) with extensive-stage small-cell lung cancer (ES-SCLC) is platinum-based chemotherapy with etoposide, but survival outcomes remain poor (median OS, < 1 year) despite initial response rates ranging from 50-70%. Atezolizumab (atezo), an anti–PD-L1 mAb, prevents the binding of PD-L1 with its receptors PD-1 and B7.1 and restores anticancer T-cell activity. Tolerable safety with promising durability of response has been shown with atezo in pts with ES-SCLC: confirmed ORR was 6% (n = 1/17 [partial response]; DOR of 7 mo) by RECIST v1.1 and 24% by immune-related response criteria (irRC; n = 4/17, with 2 pts on atezo for ≥ 12 mo). Preliminary data also indicate the potential synergy between atezo and platinum-based chemotherapy in NSCLC, whereby durable responses may translate into improved survival over atezo alone. IMpower133 (NCT02763579), a global, Phase I/III, randomized, multicenter, double-blinded, placebo-controlled trial will evaluate the efficacy and safety of 1L atezo + carboplatin + etoposide compared with placebo + carboplatin + etoposide in treatment-naive pts with ES-SCLC. Methods: Pts with measurable (RECIST v1.1) ES-SCLC, who have ECOG PS 0-1 and no prior systemic anticancer treatment, are eligible for the study. Exclusion criteria include untreated CNS metastases and history of autoimmune disease. The study requires submission of tumor tissue, but pts will be enrolled regardless of biomarker status. Pts will be stratified by sex, ECOG PS and presence of treated brain metastases. Eligible pts will be randomized 1:1 to receive four 21-day cycles of atezo (1200 mg IV) or placebo in combination with carboplatin (AUC 5 mg/mL/min IV, d 1) and etoposide (100 mg/m2 IV, d 1-3), followed by maintenance therapy with atezo or placebo until PD per RECIST v1.1. Pts can continue with treatment until persistent radiographic PD, symptomatic deterioration or unacceptable toxicity. Co-primary endpoints are investigator-assessed PFS per RECIST v1.1 and OS. Secondary efficacy endpoints include investigator-assessed ORR and DOR. Safety and tolerability will also be assessed. Approximately 400 pts will be enrolled. Clinical trial information: NCT02763579.

Chromoplectic TPM3-ALK rearrangement in a patient with inflammatory myofibroblastic tumor who responded to ceritinib after progression on crizotinib

Ceritinib resulted in a significant, durable response of a metastatic inflammatory myofibroblastic tumor (IMT) after failure of crizotinib. A chromoplectic TPM3–ALK rearrangement involving many known oncogenes was found in the residual IMT. Ceritinib may be useful for patients with IMT after failure of crizotinib, and chromoplexy may have a role in the oncogenesis or treatment resistance of IMTs.

Background

Inflammatory myofibroblastic tumors (IMTs) are rare sarcomas that can occur at any age. Surgical resection is the primary treatment for patients with localized disease; however, these tumors frequently recur. Less commonly, patients with IMTs develop or present with metastatic disease. There is no standard of care for these patients and traditional cytotoxic therapy is largely ineffective. Most IMTs are associated with oncogenic ALK, ROS1 or PDGFRβ fusions and may benefit from targeted therapy.

Patient and methods

We sought to understand the genomic abnormalities of a patient who presented for management of metastatic IMT after progression of disease on crizotinib and a significant and durable partial response to the more potent ALK inhibitor ceritinib.

Results

The residual IMT was resected based on the recommendations of a multidisciplinary tumor sarcoma tumor board and analyzed by whole-genome mate pair sequencing. Analysis of the residual, resected tumor identified a chromoplectic TPM3–ALK rearrangement that involved many other known oncogenes and was confirmed by rtPCR.

Conclusions

In our analysis of the treatment-resistant, residual IMT, we identified a complex pattern of genetic rearrangements consistent with chromoplexy. Although it is difficult to know for certain if these chromoplectic rearrangements preceded treatment, their presence suggests that chromoplexy has a role in the oncogenesis of IMTs. Furthermore, this patient's remarkable response suggests that ceritinib should be considered as an option after progression on crizotinib for patients with metastatic or unresectable IMT and ALK mutations.

Temporal and spatial discordance of programmed cell death-ligand 1 expression and lymphocyte tumor infiltration between paired primary lesions and brain metastases in lung cancer

The tumor microenvironments of paired primary lung cancers and brain metastases are significantly different, such that many of the metastases lose PD-L1 expression, lymphocyte infiltration or both with greater discrepancies over time. The spatial and temporal heterogeneity of PD-L1 expression may limit its use as a tissue-based predictive biomarker in lung cancer.

Background

The dynamics of PD-L1 expression may limit its use as a tissue-based predictive biomarker. We sought to expand our understanding of the dynamics of PD-L1 expression and tumor-infiltrating lymphocytes (TILs) in patients with lung cancer-related brain metastases.

Experimental design

Paired primary lung cancers and brain metastases were identified and assessed for PD-L1 and CD3 expression by immunohistochemistry. Lesions with 5% or greater PD-L1 expression were considered positive. Agreement statistics and the χ² or Fisher's exact test were used for analysis.

Results

We analyzed 146 paired lesions from 73 cases. There was disagreement of tumor cell PD-L1 expression in 10 cases (14%, κ = 0.71), and disagreement of TIL PD-L1 expression in 19 cases (26%, κ = 0.38). Most paired lesions with discordant tumor cell expression of PD-L1 were obtained 6 or more months apart. When specimens were categorized using a proposed tumor microenvironment categorization scheme based on PD-L1 expression and TILs, there were significant changes in the classifications because many of the brain metastases lacked either PD-L1 expression, tumor lymphocyte infiltration or both even when they were present in the primary lung cancer specimens (P = 0.009).

Conclusions

We identified that there are significant differences between the tumor microenvironment of paired primary lung cancers and brain metastases. When physicians decide to treat patients with lung cancer with a PD-1 or PD-L1 inhibitor, they must do so in the context of the spatial and temporal heterogeneity of the tumor microenvironment.

Implications of Programmed Cell Death 1 Ligand 1 Heterogeneity in the Selection of Patients With Non-Small Cell Lung Cancer to Receive Immunotherapy

The use of programmed cell death 1 ligand 1 (PD-L1) as a predictive biomarker to select patients to receive programmed cell death 1 (PD-1) or PD-L1 inhibitors in non-small cell lung cancer (NSCLC) is limited by the definitions of positivity, interassay agreement, and intra- and intertumoral heterogeneity of expression. Although PD-L1 expression enriches for responses, the lack of expression does not exclude clinical benefit.

Prospective evaluation of protein C and factor VIII in prediction of cancer-associated thrombosis

Venous thromboembolism (VTE) is a preventable disease, yet it is one of the leading causes of death among patients with cancer. Improving risk stratification mechanisms will allow us to personalize thrombo-prophylaxis strategies. We sought to evaluate Collagen and Thrombin Activated Platelets (COAT-platelets) as well as protein C and factor VIII as biomarkers predictive of cancer-associated thrombosis in a prospective cohort of patients with cancer. Protein C was selected as a candidate based on bioinformatics prediction. Blood samples were collected before chemotherapy. All specimen processing was blinded to clinical data. Surveillance and adjudication of the main outcome of VTE was performed for up to 1 year. We used Cox proportional hazard regression to measure the association of biomarkers and incident events using SAS 9.2 for all statistical analysis. Death was modeled as a competing event. Among 241 patients followed for an average of 10.4 months, 15% died and 13% developed a VTE. COAT-platelets were not predictive of VTE. Low levels of pre-chemotherapy protein C (<118%) (HR 2.5; 95% CI 1.1-5.5) and high baseline factor VIII (>261% I) (HR 3.0; 95% CI 1.1-8.0) were predictive of VTE after adjusting for age, Khorana prediction risk, metastatic disease and D dimer. In addition, low protein C was predictive of overall mortality independent of age, metastatic disease and functional status (HR 2.8; 95% CI 1.3-6.0). Addition of these biomarkers to cancer-VTE risk prediction models may add to risk stratification and patient selection to optimize thrombo-prophylaxis.

Severe hepatic dysfunction is associated with venous thromboembolic events in phase 1 clinical trials

INTRODUCTION

Venous thromboembolic events (VTEs) are a significant cause of death in patients with cancer. The incidence of VTE is not well characterized in early phase clinical trials of novel antineoplastic agents, or in hepatic dysfunction studies designed for patients with varying degrees of liver test abnormalities. We compared the incidences of VTE in phase 1 clinical trials (P1CTs) and hepatic dysfunction trials (HDCTs) sponsored by the Cancer Therapy Evaluation Program of the National Cancer Institute (NCI) of the United States.

MATERIALS & METHODS

We reviewed individual patient records of 1841 subjects for symptomatic VTE diagnosed while on study: 1328 subjects on 42 P1CTs, and 513 subjects on 9 HDCTs. The NCI's Organ Dysfunction Working Group definitions were used to categorize patients. The incidences of VTEs between patients were compared by the Chi square test. Confounders were evaluated with the Cochran-Mantel-Haenszel method.

RESULTS & CONCLUSIONS

There were 43 VTEs identified among all subjects (2.3%). There were significantly more VTE observed in the subjects on P1CTs (n=38, 2.9%) than in the subjects on HDCTs (n=5, 1.0%; RR 0.341, 95% 0.13-0.86, p=0.015). For patients on HDCTs, those with severe dysfunction had a high incidence of VTE (RR 10.5 (1.12-93.6), p=0.021) that remained significant in a multivariate model. VTEs were observed less frequently in patients who were enrolled in HDCT than those who were enrolled in P1CT; however, patients with severe hepatic dysfunction were more likely to experience VTE. Severe liver test abnormalities may not be protective against VTE in patients with malignancies receiving chemotherapy.