Roel Funke

Atezolizumab in combination with bevacizumab enhances antigen-specific T-cell migration in metastatic renal cell carcinoma

Anti-tumour immune activation by checkpoint inhibitors leads to durable responses in a variety of cancers, but combination approaches are required to extend this benefit beyond a subset of patients. In preclinical models tumour-derived VEGF limits immune cell activity while anti-VEGF augments intra-tumoral T-cell infiltration, potentially through vascular normalization and endothelial cell activation. This study investigates how VEGF blockade with bevacizumab could potentiate PD-L1 checkpoint inhibition with atezolizumab in mRCC. Tissue collections are before treatment, after bevacizumab and after the addition of atezolizumab. We discover that intra-tumoral CD8+ T cells increase following combination treatment. A related increase is found in intra-tumoral MHC-I, Th1 and T-effector markers, and chemokines, most notably CX3CL1 (fractalkine). We also discover that the fractalkine receptor increases on peripheral CD8+ T cells with treatment. Furthermore, trafficking lymphocyte increases are observed in tumors following bevacizumab and combination treatment. These data suggest that the anti-VEGF and anti-PD-L1 combination improves antigen-specific T-cell migration.

Abstract P2-11-06: Safety and clinical activity of atezolizumab (anti-PDL1) in combination with nab-paclitaxel in patients with metastatic triple-negative breast cancer

Background: Metastatic triple-negative breast cancer (mTNBC) is associated with poor prognosis, and chemotherapy remains the mainstay of treatment. Cancer immunotherapy represents a promising treatment approach for mTNBC, which is characterized by a high mutation rate, increased levels of tumor-infiltrating lymphocytes and high programmed death ligand-1 (PD-L1) expression levels. Atezolizumab (atezo; MPDL3280A) is a humanized monoclonal antibody that can restore tumor-specific T-cell immunity by inhibiting the binding of PD-L1 to PD-1. Atezo has demonstrated durable responses as monotherapy in mTNBC (Emens et al, AACR 2015). In addition, high objective response rates (ORRs) and durable responses have been observed with atezo plus chemotherapy in patients with non-small cell lung cancer (Liu et al, ASCO 2015). This study is the first combination trial of a checkpoint inhibitor with chemotherapy in patients with mTNBC. Methods: This arm of a multicenter, multi-arm Phase Ib study (NCT01633970) evaluated atezo in combination with weekly nab-paclitaxel in patients with mTNBC. Primary endpoints were safety and tolerability, with secondary endpoints of PK and clinical activity. Key eligibility criteria included measurable disease, ECOG PS 0/1 and ≤ 2 prior cytotoxic regimens. Patients received atezo 800 mg q2w (days 1 and 15) with nab-paclitaxel 125 mg/m2 q1w (days 1, 8 and 15) for 3 weeks in 4-week cycles, continued until loss of clinical benefit. If nab-paclitaxel was discontinued due to toxicity, atezo could be continued as monotherapy. ORR was assessed by RECIST v1.1. PD-L1 expression was scored at 4 diagnostic levels based on PD-L1 staining on tumor cells and tumor-infiltrating immune cells with the SP142 immunohistochemistry assay. Results: As of February 10, 2015, 11 patients were evaluable for safety. All patients were women with a median age of 58 y (range, 32-75 y). No unexpected or dose-limiting toxicities were observed. The median duration of safety follow-up was 79 days (range, 27-182 days). The efficacy-evaluable population consisted of 5 patients who had ≥ 1 scan and ≥ 3 months follow-up. Four PRs and 1 SD were observed. By the next data cutoff of June 15, 2015, 21 patients will have been enrolled (7 in the safety cohort and 14 in the expansion cohort). All patients in the expansion cohort were required to undergo serial biopsies for correlative analyses. Approximately 21 and 19 patients will be evaluable for safety and efficacy, respectively. Updated safety, efficacy and biomarker data will be presented. Conclusions: Preliminary results indicate that the combination of atezo plus nab-paclitaxel is tolerable with promising activity in patients with mTNBC. Based on these results and the observed activity of single-agent atezo in these patients, the combination of atezo and nab-paclitaxel is being evaluated in a Phase III study (NCT02425891) of patients with previously untreated mTNBC. Sponsor: Genentech, Inc. ClinicalTrials.gov: NCT01633970. Citation Format: Adams S, Diamond J, Hamilton E, Pohlmann P, Tolaney S, Molinero L, Zou W, Liu B, Waterkamp D, Funke R, Powderly J. Safety and clinical activity of atezolizumab (anti-PDL1) in combination with nab-paclitaxel in patients with metastatic triple-negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-06.

1049OSAFETY AND EFFICACY OF MPDL3280A (ANTI-PDL1) IN COMBINATION WITH BEVACIZUMAB (BEV) AND/OR CHEMOTHERAPY (CHEMO) IN PATIENTS (PTS) WITH LOCALLY ADVANCED OR METASTATIC SOLID TUMORS

ABSTRACT Aim: PD-L1 mediates cancer immune evasion, and blocking PD-L1 represents a cancer immunotherapy strategy that can restore tumor-specific T-cell immunity. MPDL3280A, a human monoclonal antibody containing an engineered Fc-domain, targets PD-L1, preventing binding to its receptors PD-1 and B7.1 on activated T cells. MPDL3280A does not disrupt the PD-L2/PD-1 interaction, which may mitigate autoimmune lung toxicity. As VEGF blockade is proposed to synergize with immunotherapy, and certain chemos may augment immune responses, we examined MPDL3280A with bev and/or chemo. Methods: This open-label, multicenter phase Ib study evaluated the safety and preliminary efficacy of MPDL3280A with bev (Arm A, refractory tumors or 1L renal cell carcinoma [RCC]) and bev + FOLFOX (Arm B, oxaliplatin-naive tumors) in pts with locally advanced or metastatic solid malignancies. Pts received MPDL3280A 20 mg/kg q3w (Arm A) or 15 mg/kg q2w (Arm B), and bev 15 mg/kg q3w (Arm A) or 10 mg/kg q2w (Arm B). Chemo was given at standard doses. Objective responses were assessed by RECIST 1.1. Results: As of Jan 21, 2014, 33 pts in Arm A and 29 pts in Arm B were treated; Arm A 1L RCC patients had short follow-up. Most pts had CRC (39% and 79% in Arms A and B, respectively). Grade 3/4 AEs regardless of attribution occurred in 42% of Arm A pts, including abdominal pain, hyperbilirubinemia, pneumonia and tumor pain (6% each), and in 52% of Arm B pts, including neutropenia (31%) and diarrhea (14%). No MPDL3280A-related infusion reactions occurred. SAEs occurred in 30% and 17% of pts in Arms A and B, respectively. RECIST responses were observed in 3 Arm A pts (CRC, melanoma, breast cancer) and 11 Arm B pts (10 CRC, 1 breast cancer). One Arm B pt (RCC) had a CR. Updated results will be presented. Conclusions: MPDL3280A + bev ± chemo was well tolerated and no unexpected toxicity was observed. Responses were observed in a variety of tumors. Further evaluation of MPDL3280A combination regimens in pts with advanced or metastatic solid tumors is warranted. Disclosure: C. Lieu: Sanofi Aventis consultant; J.D. Powderly: : Leadership position: Biologics Human Application Lab. Advisor: Genentech, BMS, Amplimmune, and Merck. BMS. Research funding: Genentech, BMS, Amplimmune, Merck, AstraZeneca, ImClone, and Eli Lilly. Speaker and advisor: BMS; H. Hochster: Genentech consultant; R. Funke, C. Rossi and D. Waterkamp: is an employee of Genentech, Inc.;H. Hurwitz: Research funding from Genentech, Roche, Bristol-Myers Squibb, Pfizer, Sanofi, Regeneron, GlaxoSmithKline, and Amgen. Advisor to Genentech, Roche, Bristol-Myers Squibb, Pfizer, Sanofi, Regeneron, GlaxoSmithKline, and Amgen. All other authors have declared no conflicts of interest.

Randomized Phase II Trial of Parsatuzumab (Anti‐EGFL7) or Placebo in Combination with FOLFOX and Bevacizumab for First‐Line Metastatic Colorectal Cancer

Abstract Lessons Learned. These negative phase II results for parsatuzumab highlight the challenges of developing an agent intended to enhance the efficacy of vascular endothelial growth factor inhibition without the benefit of validated pharmacodynamic biomarkers or strong predictive biomarker hypotheses. Any further clinical development of anti‐EGFL7 is likely to require new mechanistic insights and biomarker development for antiangiogenic agents. Background. EGFL7 (epidermal growth factor‐like domain 7) is a tumor‐enriched vascular extracellular matrix protein that supports endothelial cell survival. This phase II trial evaluated the efficacy of parsatuzumab (also known as MEGF0444A), a humanized anti‐EGFL7 IgG1 monoclonal antibody, in combination with modified FOLFOX6 (mFOLFOX6) (folinic acid, 5‐fluorouracil, and oxaliplatin) bevacizumab in patients with previously untreated metastatic colorectal cancer (mCRC). Methods. One‐hundred twenty‐seven patients were randomly assigned to parsatuzumab, 400 mg, or placebo, in combination with mFOLFOX6 plus bevacizumab, 5 mg/kg. Treatment cycles were repeated every 2 weeks until disease progression or unacceptable toxicity for a maximum of 24 months, with the exception of oxaliplatin, which was administered for up to 8 cycles. Results. The progression‐free survival (PFS) hazard ratio was 1.17 (95% confidence interval [CI], 0.71–1.93; p = .548). The median PFS was 12 months for the experimental arm versus 11.9 months for the control arm. The hazard ratio for overall survival was 0.97 (95% CI, 0.46–2.1; p = .943). The overall response rate was 59% in the parsatuzumab arm and 64% in the placebo arm. The adverse event profile was similar in both arms. Conclusions. There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first‐line mCRC.

Abstract 2651: Clinical activity and immune correlates from a phase Ib study evaluating atezolizumab (anti-PDL1) in combination with FOLFOX and bevacizumab (anti-VEGF) in metastatic colorectal carcinoma

Genetic and epigenetic alterations can distinguish cancer cells from their normal counterparts, allowing tumors to be recognized as foreign by the immune system. The immune system9s ability to detect and destroy these abnormal cells is the foundation of cancer immunotherapy. In order for this to occur immune cells must traffic and persist in the tumors. Programmed death-ligand 1 (PD-L1; also called B7-H1 or CD274), which is expressed on many cancer and tumor-infiltrating immune cells, plays an important part in blocking immune-mediated tumor cell destruction by binding B7.1 (CD80) and programmed death-1 (PD-1), which is a negative regulator of T-lymphocyte activation. PD-L1 blockade has previously been shown to increase CD8+ T cell infiltration and PD-L1 protein levels, as well as the expression levels of immune genes in tumors. Vascular endothelial growth factor A (VEGF-A) is a secreted factor that specifically acts on endothelial cells to stimulate angiogenesis and has also been shown to exert immunosuppressive effects. Although some cytotoxic agents have been proposed to induce immunogenic cell death, the effects of chemotherapy and anti-angiogenic therapy on the tumor immune milieu have not been extensively studied. This study was designed to evaluate the safety, activity and biomarkers of combined FOLFOX treatment combined with PD-L1 and VEGF-A inhibition in 1L colorectal (CRC) patients using the humanized antibodies atezolizumab (anti-PD-L1) and bevacizumab (anti-VEGF-A), respectively. RECIST (v1.1) responses by the cutoff date of 09/01/2015 were observed in 52% (95% CI 30.6-73.2) of the patients (n = 23) with a median progression free survival of 14.1 months (95% CI 8.7-17.1) and a median duration of response of 11.4 months (95% CI 7.6-15.9). No unexpected toxicities were observed. We found that CD8+ T cells and PD-L1 expression by IHC were increased in tumors following administration of FOLFOX alone as well as after combined administration of FOLFOX, atezolizumab and bevacizumab. Elevations in cytotoxic T-cell signatures (e.g. CD8A, IFNγ, GZMB, EOMES) with treatment were also noted in several of the patient tumors. Patients with elevations in tumor-infiltrating CD8+ T cells consistent with increased expression of cytotoxic T-cell signatures and PD-L1 exhibited sustained responses or prolonged disease control. These data suggest that the combination of FOLFOX, atezolizumab, and bevacizumab promote immune-related activity in CRC potentially resulting in enhanced efficacy. Citation Format: Jeffrey Wallin, Michael J. Pishvaian, Genevive Hernandez, Mahesh Yadav, Suchit Jhunjhunwala, Lelia Delamarre, Xian He, John Powderly, Christopher Lieu, S Gail Eckhardt, Herbert Hurwitz, Howard S. Hochster, Janet Murphy, Vincent Leveque, Edward Cha, Roel Funke, Daniel Waterkamp, Priti Hegde, Johanna Bendell. Clinical activity and immune correlates from a phase Ib study evaluating atezolizumab (anti-PDL1) in combination with FOLFOX and bevacizumab (anti-VEGF) in metastatic colorectal carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2651.

FIR: Efficacy, Safety, and Biomarker Analysis of a Phase II Open-Label Study of Atezolizumab in PD-L1–Selected Patients With NSCLC

Introduction: The FIR phase II study (NCT01846416) evaluated the efficacy and safety of anti–programmed death‐ligand 1 (PD‐L1) atezolizumab in advanced NSCLC selected by tumor cell (TC) or tumor‐infiltrating immune cell (IC) PD‐L1 expression. Methods: Patients with PD‐L1 TC2/3 (PD‐L1 staining on ≥5% of TC) or IC2/3 tumors (PD‐L1 staining on ≥5% of IC; determined by SP142 PD‐L1 immunohistochemistry assay) with paired fresh and archival histology samples were recruited into cohort 1 (chemotherapy‐naive/>6 months between adjuvant chemotherapy and recurrence), cohort 2 (≥ second‐line without brain metastases), or cohort 3 (≥ second‐line with treated brain metastases). Patients received 1200 mg atezolizumab on day 1 (21‐day cycles). Primary endpoint was investigator‐assessed modified Response Evaluation Criteria in Solid Tumors, objective response rate (Response Evaluation Criteria in Solid Tumors v1.1). Secondary endpoints were overall survival, progression‐free survival, duration of response, and safety. Results: Patients (N = 138) were enrolled (137 evaluable for response: cohort 1, n = 31; cohort 2, n = 93; and cohort 3, n = 13). Investigator‐assessed objective response rate was 32%, 21%, and 23% for cohorts 1, 2, and 3, respectively. Treatment‐related adverse events were reported in 81%, 67%, and 69% of patients, respectively, including grade 3–4 treatment‐related adverse events in 16%, 19%, and 15%, respectively. Moreover, 88.6% (86 of 97) paired baseline tumor samples had <5% change in TC/IC PD‐L1 expression over time. Conclusions: Atezolizumab monotherapy showed clinical activity in patients with NSCLC, including those with brain metastases; safety was consistent with previous trials. Atezolizumab has completed phase III monotherapy studies in second‐line. Front‐line trials are ongoing, confirming these favorable results.

Atezolizumab and Nab-Paclitaxel in Advanced Triple-Negative Breast Cancer

Background Unresectable locally advanced or metastatic triple‐negative (hormone‐receptor–negative and human epidermal growth factor receptor 2 [HER2]–negative) breast cancer is an aggressive disease with poor outcomes. Nanoparticle albumin‐bound (nab)–paclitaxel may enhance the anticancer activity of atezolizumab. Methods In this phase 3 trial, we randomly assigned (in a 1:1 ratio) patients with untreated metastatic triple‐negative breast cancer to receive atezolizumab plus nab‐paclitaxel or placebo plus nab‐paclitaxel; patients continued the intervention until disease progression or an unacceptable level of toxic effects occurred. Stratification factors were the receipt or nonreceipt of neoadjuvant or adjuvant taxane therapy, the presence or absence of liver metastases at baseline, and programmed death ligand 1 (PD‐L1) expression at baseline (positive vs. negative). The two primary end points were progression‐free survival (in the intention‐to‐treat population and PD‐L1–positive subgroup) and overall survival (tested in the intention‐to‐treat population; if the finding was significant, then it would be tested in the PD‐L1–positive subgroup). Results Each group included 451 patients (median follow‐up, 12.9 months). In the intention‐to‐treat analysis, the median progression‐free survival was 7.2 months with atezolizumab plus nab‐paclitaxel, as compared with 5.5 months with placebo plus nab‐paclitaxel (hazard ratio for progression or death, 0.80; 95% confidence interval [CI], 0.69 to 0.92; P=0.002); among patients with PD‐L1–positive tumors, the median progression‐free survival was 7.5 months and 5.0 months, respectively (hazard ratio, 0.62; 95% CI, 0.49 to 0.78; P<0.001). In the intention‐to‐treat analysis, the median overall survival was 21.3 months with atezolizumab plus nab‐paclitaxel and 17.6 months with placebo plus nab‐paclitaxel (hazard ratio for death, 0.84; 95% CI, 0.69 to 1.02; P=0.08); among patients with PD‐L1–positive tumors, the median overall survival was 25.0 months and 15.5 months, respectively (hazard ratio, 0.62; 95% CI, 0.45 to 0.86). No new adverse effects were identified. Adverse events that led to the discontinuation of any agent occurred in 15.9% of the patients who received atezolizumab plus nab‐paclitaxel and in 8.2% of those who received placebo plus nab‐paclitaxel. Conclusions Atezolizumab plus nab‐paclitaxel prolonged progression‐free survival among patients with metastatic triple‐negative breast cancer in both the intention‐to‐treat population and the PD‐L1–positive subgroup. Adverse events were consistent with the known safety profiles of each agent. (Funded by F. Hoffmann–La Roche/Genentech; IMpassion130 ClinicalTrials.gov number, NCT02425891.)

Differential regulation of PD-L1 expression by immune and tumor cells in NSCLC and the response to treatment with atezolizumab (anti–PD-L1)

Significance Programmed death-ligand 1 (PD-L1) expression on tumor cells and tumor-infiltrating immune cells is regulated by distinct mechanisms and has nonredundant roles in regulating anticancer immunity, and PD-L1 on both cell types is important for predicting best response to atezolizumab in non-small cell lung cancer. Programmed death-ligand 1 (PD-L1) expression on tumor cells (TCs) by immunohistochemistry is rapidly gaining importance as a diagnostic for the selection or stratification of patients with non-small cell lung cancer (NSCLC) most likely to respond to single-agent checkpoint inhibitors. However, at least two distinct patterns of PD-L1 expression have been observed with potential biological and clinical relevance in NSCLC: expression on TC or on tumor-infiltrating immune cells (ICs). We investigated the molecular and cellular characteristics associated with PD-L1 expression in these distinct cell compartments in 4,549 cases of NSCLC. PD-L1 expression on IC was more prevalent and likely reflected IFN-γ–induced adaptive regulation accompanied by increased tumor-infiltrating lymphocytes and effector T cells. High PD-L1 expression on TC, however, reflected an epigenetic dysregulation of the PD-L1 gene and was associated with a distinct histology described by poor immune infiltration, sclerotic/desmoplastic stroma, and mesenchymal molecular features. Importantly, durable clinical responses to atezolizumab (anti–PD-L1) were observed in patients with tumors expressing high PD-L1 levels on either TC alone [40% objective response rate (ORR)] or IC alone (22% ORR). Thus, PD-L1 expression on TC or IC can independently attenuate anticancer immunity and emphasizes the functional importance of IC in regulating the antitumor T cell response.

Atezolizumab Plus nab-Paclitaxel in the Treatment of Metastatic Triple-Negative Breast Cancer With 2-Year Survival Follow-up: A Phase 1b Clinical Trial

Importance The humanized monoclonal antibody atezolizumab targets programmed death-ligand 1 and has demonstrated durable single-agent activity in a subset of metastatic triple-negative breast cancers. To extend the observed activity, combinatorial approaches are being tested with standard cytotoxic chemotherapies known to induce immunogenic tumor cell death. Objective To examine the safety, tolerability, and preliminary clinical activity of atezolizumab plus nab-paclitaxel in metastatic triple-negative breast cancers. Design, Setting, and Participants This phase 1b multicohort study enrolled 33 women with stage IV or locally recurrent triple-negative breast cancers and 0 to 2 lines of prior chemotherapy in the metastatic setting from December 8, 2014, to April 30, 2017, at 11 sites in the United States. The median follow-up was 24.4 months (95% CI, 22.1-28.8 months). Interventions Patients received concurrent intravenous atezolizumab and intravenous nab-paclitaxel (minimum 4 cycles). Main Outcomes and Measures The primary end point was safety and tolerability. Secondary end points included best overall response rate by Response Evaluation Criteria in Solid Tumors, version 1.1; objective response rate; duration of response; disease control rate; progression-free survival; overall survival; and biomarker analyses. Results The 33 women had a median age of 55 years (range, 32-84 years) and received 1 or more doses of atezolizumab. All patients (100%) experienced at least 1 treatment-related adverse event, 24 patients (73%) experienced grade 3/4 adverse events, and 7 patients (21%) had grade 3/4 adverse events of special interest. No deaths were related to study treatment. The objective response rate was 39.4% (95% CI, 22.9%-57.9%), and the median duration of response was 9.1 months (95% CI, 2.0-20.9 months). The disease control rate was 51.5% (95% CI, 33.5%-69.2%). Median progression-free survival and overall survival were 5.5 months (95% CI, 5.1-7.7 months) and 14.7 months (95% CI, 10.1-not estimable), respectively. Concurrent nab-paclitaxel neither significantly changed biomarkers of the tumor immune microenvironment (programmed death-ligand 1, tumor-infiltrating lymphocytes, CD8) nor impaired atezolizumab systemic immune activation (expansion of proliferating CD8+ T cells, increase of CXCL10 chemokine). Conclusions and Relevance In this phase 1b trial for metastatic triple-negative breast cancers, the combination of atezolizumab plus nab-paclitaxel had a manageable safety profile. Antitumor responses were observed, including in patients previously treated with a taxane. Trial Registration ClinicalTrials.gov identifier: NCT01633970

Abstract A017: PD-L1 as a predictive biomarker for atezolizumab (MPDL3280A; anti-PDL1) in non-small cell lung cancer (NSCLC)

Background: Programmed death ligand-1 (PD-L1), a ligand for PD-1 and B7.1, is broadly expressed on tumor cells (TC) and tumor-infiltrating immune cells (IC) in many human cancers. PD-L1 expression on either TC or IC can negatively regulate antitumor T-cell function within the tumor microenvironment (TME). Consistent with this, the ORR, PFS and OS benefit of atezolizumab (atezo) across PhI and PhII studies appeared to correlate with increasing baseline PD-L1 expression levels on TC and/or IC. Therefore, we explored the biologic reasons for PD-L1 expression on TC and IC, the association with response to atezo and the intrapatient heterogeneity of PD-L1 expression in NSCLC. Methods: Tumor specimens were obtained from patients (pts) prescreened and/or enrolled in NSCLC atezo trials (PhI PCD4989g, PhII POPLAR and FIR [n=1360]) and from pts treated at MSKCC (n=39). Samples included 14 synchronous and 106 metachronous pairs collected in FIR or at MSKCC. Using the SP142 IHC assay, which has been optimized to detect PD-L1 on both TC and IC, PD-L1 expression was scored at 4 levels (TC0-3 and IC0-3) based on increasing expression. A subset of samples was further characterized by histopathologic review and gene expression by RNAseq. CD8 expression (clone C8/144B) was assessed in the tumor center, invasive margin and periphery by IHC. Results: PD-L1 was expressed on IC only, on TC only or on both TC and IC within the TME. Tumors with the highest (TC3 or IC3), moderate/high (TC2/3 or IC2/3) and any (TC1/2/3 or IC1/2/3) PD-L1 expression represented ≈15%, ≈38% and ≈70% of NSCLC, respectively. PD-L1 expression was similar across all paired synchronous and metachronous tissues. At the TC3 or IC3 cutoff, PD-L1 status remained unchanged in 86% of paired synchronous specimens and in 78% of metachronous pairs. Analysis of PD-L1 expression patterns revealed the existence of exclusive TC and IC subpopulations at each PD-L1 expression level, unique to NSCLC and not seen in other cancers, e.g. UBC. Strikingly, TC3 and IC3 tumors represented 2 distinct populations, with Conclusions: These data demonstrated that NSCLC has unique PD-L1 expression patterns. High expression of PD-L1 on TC and/or IC in NSCLC confers sensitivity to atezo, despite exhibiting distinct immunologic profiles. These results further our understanding of how atezo promotes responses in tumors expressing PD-L1 on TC and/or IC and emphasizes the need to assess PD-L1 on both TC and IC in NSCLC. In addition, intrapatient heterogeneity in PD-L1 expression was relatively low in both synchronous and metachronous tissues, indicating that various types of tumor samples (e.g. primary or metastatic, fresh or archival) can be reliably used to assess PD-L1 expression with the SP142 assay. Citation Format: Marcin Kowanetz, Hartmut Koeppen, Wei Zou, Sanjeev Mariathasan, Matthew Hellmann, Mark Kockx, Colombe Chappey, Edward Kadel, Dustin Smith, Natasha Miley, Vincent Leveque, Roel Funke, Alan Sandler, Ian McCaffery, Lukas Amler, Daniel Chen, Priti Hegde. PD-L1 as a predictive biomarker for atezolizumab (MPDL3280A; anti-PDL1) in non-small cell lung cancer (NSCLC). [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A017.