Marcella Fasso

Atezolizumab, an Anti–Programmed Death-Ligand 1 Antibody, in Metastatic Renal Cell Carcinoma: Long-Term Safety, Clinical Activity, and Immune Correlates From a Phase Ia Study

PURPOSE The objective was to determine the safety and clinical activity of atezolizumab (MPDL3280A), a humanized programmed death-ligand 1 (PD-L1) antibody, in renal cell carcinoma (RCC). Exploratory biomarkers were analyzed and associated with outcomes. PATIENTS AND METHODS Seventy patients with metastatic RCC, including clear cell (ccRCC; n = 63) and non-clear cell (ncc; n = 7) histologies, received atezolizumab intravenously every 3 weeks. PD-L1 expression was scored at four diagnostic levels (0/1/2/3) that were based on PD-L1 staining on tumor cells and tumor-infiltrating immune cells (IC) with the SP142 assay. Primary end points were safety and toxicity; secondary end points assessed clinical activity per Response Evaluation Criteria in Solid Tumors version 1.1 and immune-related response criteria. Plasma and tissue were analyzed for potential biomarkers of atezolizumab response. RESULTS Grade 3 treatment-related and immune-mediated adverse events occurred in 17% and 4% of patients, respectively, and there were no grade 4 or 5 events. Sixty-three patients with ccRCC were evaluable for overall survival (median, 28.9 months; 95% CI, 20.0 months to not reached) and progression-free survival (median, 5.6 months; 95% CI, 3.9 to 8.2 months), and 62 patients were evaluable for objective response rate (ORR; 15%; 95% CI, 7% to 26%). ORR was evaluated on the basis of PD-L1 IC expression (IC1/2/3: n = 33; 18%; 95% CI, 7% to 35%; and IC0: n = 22; 9%; 95% CI, 1% to 29%). The ORR for patients with Fuhrman grade 4 and/or sarcomatoid histology was 22% (n = 18; 95% CI, 6% to 48%). Decreases in circulating plasma markers and acute-phase proteins and an increased baseline effector T-cell-to-regulatory T-cell gene expression ratio correlated with response to atezolizumab. CONCLUSION Atezolizumab demonstrated a manageable safety profile and promising antitumor activity in patients with metastatic RCC. Correlative studies identified potential predictive and pharmacodynamic biomarkers. These results have guided ongoing studies and combinations with atezolizumab in RCC.

Abstract 2859: Inhibition of PD-L1 by MPDL3280A leads to clinical activity in patients with metastatic triple-negative breast cancer (TNBC)

Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA Introduction: TNBC is a mutationally complex breast cancer subtype with poor prognosis and no current targeted therapy options. Compared with other intrinsic breast cancer subtypes, TNBC has higher programmed death-ligand 1 (PD-L1) expression levels, which may hinder antitumor T-cell responses. MPDL3280A is a monoclonal anti-PDL1 antibody, engineered for optimized efficacy and safety, that blocks signaling through the PD-L1/PD-1 and PD-L1/B7.1 pathways. Methods: MPDL3280A was tested in a metastatic TNBC expansion cohort as part of a multicenter Phase Ia study. Pts received MPDL3280A at 15 mg/kg, 20 mg/kg or 1200 mg flat dose IV q3w. AEs were summarized for the safety follow-up duration from the first dose to 30 days after the last dose before the clinical cutoff on Sept 2, 2014. Responses were assessed by RECIST v1.1 criteria in pts who received MPDL3280A by Jul 21, 2014, evaluable for efficacy (≥ 6-wk follow-up). PD-L1 expression on tumor-infiltrating immune cells (ICs) at baseline was centrally evaluated by IHC in archival or fresh biopsies, and pts were scored as PD-L1 IHC (IC) 0, 1, 2 or 3. Peripheral biomarkers were assayed using FACS and multiplex immunoassays. Results: In the TNBC cohort, 27 pts were selectively enrolled. These pts had a median age of 48 y (29-82 y) and were evaluable for safety; 52% had ECOG PS 0 and 44% had ECOG PS 1. Visceral and bone metastases were present at baseline in 59% and 11% of pts, respectively. In addition, 85% received ≥ 4 prior systemic regimens (neoadjuvant, adjuvant or metastatic), including anthracyclines (78%), taxanes (82%) and platinum agents (15% cisplatin, 41% carboplatin). All-grade treatment-related AEs occurred in 67% of pts, most frequently fatigue (22%), pyrexia (15%), neutropenia (15%) and nausea (15%). 11% of pts experienced a Grade 3-5 related AE (5 Grade 3 events: adrenal insufficiency, neutropenia, nausea, vomiting, decreased WBC count; 1 Grade 5 pulmonary hypertension event in a pt with an atrial septal defect). Among 21 efficacy-evaluable PD-L1 IHC 2 or 3 pts (13 IHC 2 and 8 IHC 3), the unconfirmed RECIST ORR was 24% (95% CI, 8% to 47%); 3 PRs and 2 CRs were observed. Response duration ranged from 0.1+ to 41.6+ wks, with the median not yet reached. Pts with evidence of durable nonclassical responses suggestive of pseudoprogression were also observed. Overall, the 24-wk PFS rate was 33% (95% CI, 12% to 53%). Biomarker analysis revealed transient elevation of plasma cytokines and proliferating CD8 cells following MPDL3280A treatment. Updated clinical data, including PD-L1-negative pts, will be presented. Conclusions: MPDL3280A was generally well tolerated and demonstrated promising efficacy in pretreated metastatic PD-L1 IHC 2 or 3 TNBC pts. Furthermore, circulating biomarker analyses revealed pharmacodynamic responses to MPDL3280A. Clinical evaluation of MPDL3280A in metastatic PD-L1 IHC 0 or 1 TNBC is ongoing ([NCT01375842][1]). Citation Format: Leisha A. Emens, Fadi S. Braiteh, Philippe Cassier, Jean-Pierre Delord, Joseph Paul Eder, Marcella Fasso, Yuanyuan Xiao, Yan Wang, Luciana Molinero, Daniel S. Chen, Ian Krop. Inhibition of PD-L1 by MPDL3280A leads to clinical activity in patients with metastatic triple-negative breast cancer (TNBC). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2859. doi:10.1158/1538-7445.AM2015-2859 [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01375842&atom=%2Fcanres%2F75%2F15_Supplement%2F2859.atom

Abstract 2986: Atezolizumab in metastatic TNBC (mTNBC): Long-term clinical outcomes and biomarker analyses

Introduction. Triple negative breast cancer (TNBC) has a poor prognosis and limited treatment options. Atezolizumab (atezo) is a humanized mAb that inhibits the binding of PD-L1 to PD-1 and B7.1, thus restoring tumor-specific T-cell immunity. Atezo was evaluated in an expansion cohort of mTNBC patients (pts) in a Phase Ia study (NCT01375842). Methods. Enrollment was initially limited to TNBC pts with PD-L1 on ≥5% of tumor-infiltrating immune cells (IC2/3), then opened to pts regardless of PD-L1 status. Pts received atezo IV in 1L or 2L+ q3w at 15 or 20 mg/kg or 1200 mg for 1 y with option to be retreated at PD, or until loss of clinical benefit. ORR was assessed by RECIST v1.1 and irRC, to capture non-conventional responses. Baseline PD-L1 expression on IC was centrally scored as IC0/1/2/3 (VENTANA SP142 assay). Pretreatment tumors and on-therapy biopsies were evaluated for TILs, CD8 T cells and macrophages by IHC. Results. As of Mar 31, 2016, 115 mTNBC pts were safety evaluable; atezo was generally well tolerated. There were no additional safety signals from prior report (Emens AACR 2015). 112 pts with FU ≥12 wk were evaluable for response. Based on irRC, ORR in 1L and 2L+ pts were 26% and 11%, respectively. ORR for PD-L1 IC2/3 pts were 17% vs 8% in IC0/1. mDoR was 21.1 mo (3 to 34+). mOS of responders (n=15) was not reached (4+ to 37+ mo) with no deaths as of data cutoff. mOS of non-responders who lived ≥ 6 wk (n=87) was 9 mo (1+ to 19+ mo). OS rates in all pts at 1, 2, and 3 y were 41%, 22% and 22%, respectively. OS rates at 1, 2, and 3 y for PD-L1 IC2/3 were 45%, 28% and 28%, respectively. Pts whose tumors had >10% TILs or ≥1.35% CD8 in the tumor center trended toward higher ORR and longer OS. Atezo increased intratumoral TILs, CD8, macrophages and IC PD-L1 expression, but no response association was observed. Conclusions. In mTNBC, atezo was well tolerated. Responders showed durable clinical benefit. Response rates were higher in 1L or PD-L1 IC2/3 pts. Baseline TILs and CD8 were associated with greater clinical benefit. Citation Format: Peter Schmid, Cristina Cruz, Fadi S. Braiteh, Joseph Paul Eder, Sara Tolaney, Irene Kuter, Rita Nanda, Cathie Chung, Philippe Cassier, Jean-Pierre Delord, Michael Gordon, Yijin Li, Bo Liu, Carol O’Hear, Marcella Fasso, Luciana Molinero, Leisha A. Emens. Atezolizumab in metastatic TNBC (mTNBC): Long-term clinical outcomes and biomarker analyses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2986. doi:10.1158/1538-7445.AM2017-2986

Atezolizumab (MPDL3280A) Monotherapy for Patients With Metastatic Urothelial Cancer: Long-term Outcomes From a Phase 1 Study

Importance Atezolizumab (anti–programmed death ligand 1) has demonstrated safety and activity in advanced and metastatic urothelial carcinoma, but its long-term clinical profile remains unknown. Objective To report long-term clinical outcomes with atezolizumab therapy for patients with metastatic urothelial carcinoma. Design, Setting, and Participants Patients were enrolled in an expansion cohort of an ongoing, open-label, phase 1 study. Median follow-up was 37.8 months (range, >0.7 to 44.4 months). Enrollment occurred between March 2013 and August 2015 at US and European academic medical centers. Eligible patients had measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1, Eastern Cooperative Oncology Group performance status 0 to 1, and a representative tumor sample. Programmed death ligand 1 expression on immune cells was assessed (VENTANA SP142 assay). Interventions Atezolizumab was given intravenously every 3 weeks until unacceptable toxic effects, protocol nonadherence, or loss of clinical benefit. Main Outcomes and Measures Primary outcome was safety. Secondary outcomes included objective response rate, duration of response, and progression-free survival. Response and overall survival were assessed in key baseline subgroups. Results Ninety-five patients were evaluable (72 [76%] male; median age, 66 years [range, 36-89 years]). Forty-five (47%) received atezolizumab as third-line therapy or greater. Nine patients (9%) had a grade 3 to 4 treatment-related adverse event, mostly within the first treatment year; no serious related adverse events were observed thereafter. One patient (1%) discontinued treatment due to a related event. No treatment-related deaths occurred. Responses occurred in 26% (95% CI, 18%-36%) of patients. Median duration of response was 22.1 months (range, 2.8 to >41.0 months), and median progression-free survival was 2.7 months (95% CI, 1.4-4.3 months). Median overall survival was 10.1 months (95% CI, 7.3-17.0 months); 3-year OS rate was 27% (95% CI, 17%-36%). Response occurred in 40% (95% CI, 26%-55%; n = 40) and 11% (95% CI, 4%-25%; n = 44) of patients with programmed death ligand 1 expression of at least 5% tumor-infiltrating immune cells (IC2/3) or less than 5% (IC0/1), respectively. Median overall survival in patients with IC2/3 and IC0/1 was 14.6 months (95% CI, 9.0 months to not estimable) and 7.6 months (95% CI, 4.7 to 13.9 months), respectively. Conclusions and Relevance Atezolizumab remained well tolerated and provided durable clinical benefit to a heavily pretreated metastatic urothelial carcinoma population in this long-term study. Trial Registration clinicaltrials.gov Identifier: NCT01375842

Immune biomarkers associated with clinical benefit from atezolizumab (MPDL3280a; anti-PD-L1) in advanced urothelial bladder cancer (UBC)

Meeting abstracts Atezolizumab (anti-PD-L1) has demonstrated robust clinical activity in UBC [[1][1]]. Elevated PD-L1 expression on tumor-infiltrating immune cells (IC) is associated with increased clinical efficacy; however, the contribution of other immune biomarkers is unknown. In this study, we

PS01.62: Long-Term Safety and Clinical Activity of Atezolizumab Monotherapy in Metastatic NSCLC: Final Results from a Phase Ia Study: Topic: Medical Oncology.

provide information on the current management and outcomes of patients diagnosed with NSCLC who are eligible for their first systemic therapy. REVOLUTION has two primary objectives: 1) characterize current practice patterns in patients with NSCLC, with a special emphasis on pharmacotherapy (ie, chemotherapy, targeted agents, immunotherapy), and epidermal growth factor receptor mutated disease); 2) compare progression-free survival, overall survival, and duration of response in patients treated with cytotoxic chemotherapy, targeted therapies, and immune checkpoint inhibitors. Secondary objectives include assessment of which patients undergo molecular testing, sequence of treatments, toxicities, treatmentand toxicity-related costs, quality of life (QOL), and how decision-making is influenced by these factors from the patient, payer, and provider perspectives. Methods: Approximately 2500 patients will be enrolled across 25 US academic and community-based centers. Detailed patient demographic and clinical data will be collected at baseline and every 3 months via electronic portal. Patients (or their proxies) will complete 3 outcome scales (QoL EORTC-QLQ C30, symptom-specific EORTC-QLQ LC13). Additional treatment, outcome, and healthcare utilization data will be collected by electronic medical record abstraction for 5 years or until patient death or withdrawal of consent. Medicare claims data for the first year will be linked. Archived and residual specimens will be collected for genomic testing and biomarker evaluation. REVOLUTION is expected to begin accrual in July 2016 (NCT02835599). Results: Not Applicable. Conclusion: REVOLUTION will be the most comprehensive US registry of patients with NSCLC treated in the real-world environment in the era of targeted and immunotherapy, allowing analyses of clinical practice, treatment choice and effects, safety, QOL, and economic and efficacy outcomes.

Long-term Clinical Outcomes and Biomarker Analyses of Atezolizumab Therapy for Patients With Metastatic Triple-Negative Breast Cancer: A Phase 1 Study

Importance Atezolizumab (anti–programmed cell death ligand 1 [PD-L1]) is well tolerated and clinically active in multiple cancer types. Its safety and clinical activity in metastatic triple-negative breast cancer (mTNBC) has not been reported. Objective To evaluate the safety, clinical activity, and biomarkers associated with the use of single-agent atezolizumab in patients with mTNBC. Design, Setting, and Participants Women with mTNBC (defined by investigator assessment) were enrolled between January 2013 and February 2016 in a multicohort open-label, phase 1 study at US and European academic medical centers. Median follow-up was 25.3 months (range, 0.4-45.6 months). Eligible patients regardless of line of therapy had measurable disease by Response Evaluation Criteria in Solid Tumors, version 1.1; Eastern Cooperative Oncology Group performance status of 0 to 1; and a representative tumor sample for assessment of immune cell (IC) PD-L1 expression. Interventions Atezolizumab was given intravenously every 3 weeks until unacceptable toxic effects or loss of clinical benefit. Main Outcomes and Measures Primary outcome was safety and tolerability. Activity and exploratory outcomes included objective response rate (ORR), duration of response, progression-free survival (PFS), and overall survival (OS). Outcomes were assessed in all patients and in key patient subgroups. Results Among 116 evaluable patients (median age, 53 years [range, 29-82 years]), treatment-related adverse events occurred in 73 (63%); 58 (79%) were grade 1 to 2. Most adverse events occurred within the first treatment year. The ORRs were numerically higher in first-line (5 of 21 [24%]) than in second-line or greater patients (6 of 94 [6%]). Median duration of response was 21 months (range, 3 to ≥38 months). Median PFS was 1.4 (95% CI, 1.3-1.6) months by RECIST and 1.9 (95% CI, 1.4-2.5) months by irRC. In first-line patients, median OS was 17.6 months (95% CI, 10.2 months to not estimable). Patients with PD-L1 expression of at least 1% tumor-infiltrating ICs had higher ORRs and longer OS (12% [11 of 91]; 10.1 [95% CI, 7.0-13.8] months, respectively) than those with less than 1% ICs (0 of 21; 6.0 [95% CI, 2.6-12.6] months, respectively). High levels of ICs (>10%) were independently associated with higher ORRs and longer OS. Conclusions and Relevance Single-agent atezolizumab was well tolerated and provided durable clinical benefit in patients with mTNBC with stable or responding disease and in earlier lines of treatment. Trial Registration ClinicalTrials.gov identifier: NCT01375842

Safety and clinical activity of atezolizumab in head and neck cancer: results from a phase I trial

Background Head and neck cancer (HNC) has a poor prognosis at advanced stages. Given the immunosuppressive tumor microenvironment in HNC, inhibition of the programmed death-ligand 1/programmed death-1 (PD-L1/PD-1) signaling pathway represents a promising therapeutic approach. Atezolizumab (anti-PD-L1) is efficacious against many tumor types. Here we report the clinical safety and activity from the HNC cohort of the phase Ia PCD4989g clinical trial. Patients and methods Patients with previously treated, advanced HNC received atezolizumab i.v. every 3 weeks for 16 cycles, up to 1 year or until loss of clinical benefit. Patients were monitored for safety and tolerability and evaluated for response at least every 6 weeks. Baseline PD-L1 expression level and human papillomavirus (HPV) status were evaluated. Results Thirty-two patients were enrolled; 7 patients (22%) had a primary tumor in the oral cavity, 18 (56%) in the oropharynx, 1 (3%) in the hypopharynx, 2 (6%) in the larynx, and 4 (13%) in the nasopharynx. Seventeen patients (53%) had ≥2 prior lines of therapy. Twenty-one patients (66%) experienced a treatment-related adverse event (TRAE), with three experiencing grade 3 TRAEs and one experiencing a grade 4 TRAE (per CTCAE v4.0). No grade 5 TRAEs were reported. Objective responses by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) occurred in 22% of patients, with a median duration of response of 7.4 months (range 2.8-45.8 months). Median progression-free survival was 2.6 months (range 0.5-48.4 months), and median overall survival was 6.0 months (range 0.5-51.6+ months). Responses showed no association with HPV status or PD-L1 expression level. Conclusions In this heavily pre-treated advanced HNC cohort, atezolizumab had a tolerable safety profile and encouraging activity, with responses observed regardless of HPV status and PD-L1 expression level. These findings warrant further investigation of atezolizumab in HNC. ClinicalTrials.gov number: NCT01375842.