John D. Powderly

Predictive correlates of response to the anti-PD-L1 antibody MPDL3280A in cancer patients

The development of human cancer is a multistep process characterized by the accumulation of genetic and epigenetic alterations that drive or reflect tumour progression. These changes distinguish cancer cells from their normal counterparts, allowing tumours to be recognized as foreign by the immune system. However, tumours are rarely rejected spontaneously, reflecting their ability to maintain an immunosuppressive microenvironment. Programmed death-ligand 1 (PD-L1; also called B7-H1 or CD274), which is expressed on many cancer and immune cells, plays an important part in blocking the ‘cancer immunity cycle’ by binding programmed death-1 (PD-1) and B7.1 (CD80), both of which are negative regulators of T-lymphocyte activation. Binding of PD-L1 to its receptors suppresses T-cell migration, proliferation and secretion of cytotoxic mediators, and restricts tumour cell killing. The PD-L1–PD-1 axis protects the host from overactive T-effector cells not only in cancer but also during microbial infections. Blocking PD-L1 should therefore enhance anticancer immunity, but little is known about predictive factors of efficacy. This study was designed to evaluate the safety, activity and biomarkers of PD-L1 inhibition using the engineered humanized antibody MPDL3280A. Here we show that across multiple cancer types, responses (as evaluated by Response Evaluation Criteria in Solid Tumours, version 1.1) were observed in patients with tumours expressing high levels of PD-L1, especially when PD-L1 was expressed by tumour-infiltrating immune cells. Furthermore, responses were associated with T-helper type 1 (TH1) gene expression, CTLA4 expression and the absence of fractalkine (CX3CL1) in baseline tumour specimens. Together, these data suggest that MPDL3280A is most effective in patients in which pre-existing immunity is suppressed by PD-L1, and is re-invigorated on antibody treatment.

Phase I Study of Single-Agent Anti–Programmed Death-1 (MDX-1106) in Refractory Solid Tumors: Safety, Clinical Activity, Pharmacodynamics, and Immunologic Correlates

PURPOSE Programmed death-1 (PD-1), an inhibitory receptor expressed on activated T cells, may suppress antitumor immunity. This phase I study sought to determine the safety and tolerability of anti-PD-1 blockade in patients with treatment-refractory solid tumors and to preliminarily assess antitumor activity, pharmacodynamics, and immunologic correlates. PATIENTS AND METHODS Thirty-nine patients with advanced metastatic melanoma, colorectal cancer (CRC), castrate-resistant prostate cancer, non-small-cell lung cancer (NSCLC), or renal cell carcinoma (RCC) received a single intravenous infusion of anti-PD-1 (MDX-1106) in dose-escalating six-patient cohorts at 0.3, 1, 3, or 10 mg/kg, followed by a 15-patient expansion cohort at 10 mg/kg. Patients with evidence of clinical benefit at 3 months were eligible for repeated therapy. RESULTS Anti-PD-1 was well tolerated: one serious adverse event, inflammatory colitis, was observed in a patient with melanoma who received five doses at 1 mg/kg. One durable complete response (CRC) and two partial responses (PRs; melanoma, RCC) were seen. Two additional patients (melanoma, NSCLC) had significant lesional tumor regressions not meeting PR criteria. The serum half-life of anti-PD-1 was 12 to 20 days. However, pharmacodynamics indicated a sustained mean occupancy of > 70% of PD-1 molecules on circulating T cells > or = 2 months following infusion, regardless of dose. In nine patients examined, tumor cell surface B7-H1 expression appeared to correlate with the likelihood of response to treatment. CONCLUSION Blocking the PD-1 immune checkpoint with intermittent antibody dosing is well tolerated and associated with evidence of antitumor activity. Exploration of alternative dosing regimens and combinatorial therapies with vaccines, targeted therapies, and/or other checkpoint inhibitors is warranted.

Survival, Durable Tumor Remission, and Long-Term Safety in Patients With Advanced Melanoma Receiving Nivolumab

PURPOSE Programmed cell death 1 (PD-1) is an inhibitory receptor expressed by activated T cells that downmodulates effector functions and limits the generation of immune memory. PD-1 blockade can mediate tumor regression in a substantial proportion of patients with melanoma, but it is not known whether this is associated with extended survival or maintenance of response after treatment is discontinued. PATIENTS AND METHODS Patients with advanced melanoma (N = 107) enrolled between 2008 and 2012 received intravenous nivolumab in an outpatient setting every 2 weeks for up to 96 weeks and were observed for overall survival, long-term safety, and response duration after treatment discontinuation. RESULTS Median overall survival in nivolumab-treated patients (62% with two to five prior systemic therapies) was 16.8 months, and 1- and 2-year survival rates were 62% and 43%, respectively. Among 33 patients with objective tumor regressions (31%), the Kaplan-Meier estimated median response duration was 2 years. Seventeen patients discontinued therapy for reasons other than disease progression, and 12 (71%) of 17 maintained responses off-therapy for at least 16 weeks (range, 16 to 56+ weeks). Objective response and toxicity rates were similar to those reported previously; in an extended analysis of all 306 patients treated on this trial (including those with other cancer types), exposure-adjusted toxicity rates were not cumulative. CONCLUSION Overall survival following nivolumab treatment in patients with advanced treatment-refractory melanoma compares favorably with that in literature studies of similar patient populations. Responses were durable and persisted after drug discontinuation. Long-term safety was acceptable. Ongoing randomized clinical trials will further assess the impact of nivolumab therapy on overall survival in patients with metastatic melanoma.

Overall Survival and Long-Term Safety of Nivolumab (Anti–Programmed Death 1 Antibody, BMS-936558, ONO-4538) in Patients With Previously Treated Advanced Non–Small-Cell Lung Cancer

PURPOSE Programmed death 1 is an immune checkpoint that suppresses antitumor immunity. Nivolumab, a fully human immunoglobulin G4 programmed death 1 immune checkpoint inhibitor antibody, was active and generally well tolerated in patients with advanced solid tumors treated in a phase I trial with expansion cohorts. We report overall survival (OS), response durability, and long-term safety in patients with non-small-cell lung cancer (NSCLC) receiving nivolumab in this trial. PATIENTS AND METHODS Patients (N = 129) with heavily pretreated advanced NSCLC received nivolumab 1, 3, or 10 mg/kg intravenously once every 2 weeks in 8-week cycles for up to 96 weeks. Tumor burden was assessed by RECIST (version 1.0) after each cycle. RESULTS Median OS across doses was 9.9 months; 1-, 2-, and 3-year OS rates were 42%, 24%, and 18%, respectively, across doses and 56%, 42%, and 27%, respectively, at the 3-mg/kg dose (n = 37) chosen for further clinical development. Among 22 patients (17%) with objective responses, estimated median response duration was 17.0 months. An additional six patients (5%) had unconventional immune-pattern responses. Response rates were similar in squamous and nonsquamous NSCLC. Eighteen responding patients discontinued nivolumab for reasons other than progressive disease; nine (50%) of those had responses lasting > 9 months after their last dose. Grade 3 to 4 treatment-related adverse events occurred in 14% of patients. Three treatment-related deaths (2% of patients) occurred, each associated with pneumonitis. CONCLUSION Nivolumab monotherapy produced durable responses and encouraging survival rates in patients with heavily pretreated NSCLC. Randomized clinical trials with nivolumab in advanced NSCLC are ongoing.

Phase I/II Study of Ipilimumab for Patients With Metastatic Melanoma

PURPOSE The primary objective of this phase I/II study was to determine the safety and pharmacokinetic profile of either transfectoma- or a hybridoma-derived ipilimumab. Secondary objectives included determination of a maximum-tolerated dose and assessment of clinical activity. PATIENTS AND METHODS Eighty-eight patients with unresectable stage III or IV melanoma with at least one measurable lesion were treated. Mean age was 59 years, with 65% male and 35% female patients, and 79% of patients had received prior systemic therapy. Single doses of ipilimumab up to 20 mg/kg (group A, single dose), multiple doses up to 5 mg/kg (group A, multiple dose), and multiple doses up to 10 mg/kg (group B) were administered. RESULTS Single dosing up to 20 mg/kg of transfectoma antibody was well tolerated, as were multiple doses up to 10 mg/kg without a maximum-tolerated dose. In group B, dose-limiting toxicity was seen in six of 23 melanoma patients. Grade 3 or 4 immune-related adverse events (irAEs) were observed in 14% of patients (12 of 88 patients), and grade 1 or 2 irAEs were seen in an additional 58%. The half-life of ipilimumab was 359 hours. In group B, there was one partial response (23+ months), one complete response (21+ months), and seven patients with stable disease (SD), for a disease control rate of 39%. Two patients in group B with SD had slow, steady decline in tumor burden that was ongoing at 1 year of observation. CONCLUSION Ipilimumab has activity in patients with metastatic melanoma. Late responses were observed in patients with prolonged SD.

Survival, Durable Response, and Long-Term Safety in Patients With Previously Treated Advanced Renal Cell Carcinoma Receiving Nivolumab

PURPOSE Blockade of the programmed death-1 inhibitory cell-surface molecule on immune cells using the fully human immunoglobulin G4 antibody nivolumab mediates tumor regression in a portion of patients with advanced treatment-refractory solid tumors. We report clinical activity, survival, and long-term safety in patients with advanced renal cell carcinoma (RCC) treated with nivolumab in a phase I study with expansion cohorts. PATIENTS AND METHODS A total of 34 patients with previously treated advanced RCC, enrolled between 2008 and 2012, received intravenous nivolumab (1 or 10 mg/kg) in an outpatient setting once every two weeks for up to 96 weeks and were observed for survival and duration of response after treatment discontinuation. RESULTS Ten patients (29%) achieved objective responses (according to RECIST [version 1.0]), with median response duration of 12.9 months; nine additional patients (27%) demonstrated stable disease lasting > 24 weeks. Three of five patients who stopped treatment while in response continued to respond for ≥ 45 weeks. Median overall survival in all patients (71% with two to five prior systemic therapies) was 22.4 months; 1-, 2-, and 3-year survival rates were 71%, 48%, and 44%, respectively. Grade 3 to 4 treatment-related adverse events occurred in 18% of patients; all were reversible. CONCLUSION Patients with advanced treatment-refractory RCC treated with nivolumab demonstrated durable responses that in some responders persisted after drug discontinuation. Overall survival is encouraging, and toxicities were generally manageable. Ongoing randomized clinical trials will further assess the impact of nivolumab on overall survival in patients with advanced RCC.

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.

Induction of Antigen-Specific Immunity with a Vaccine Targeting NY-ESO-1 to the Dendritic Cell Receptor DEC-205

Dendritic cell targeting safely leads to integrated humoral and cellular immunity when combined with TLR agonists in cancer patients. Start Spreading the News Dendritic cells are the matchmakers of the immune system: They introduce T cells to antigen, providing the right context for the T cell to react. However, tumor alters the nearby microenvironment in such a way as to block immune activation. Dhodapkar et al. attempt to overcome this inhibition by targeting a tumor antigen directly to dendritic cells. The authors tested a vaccine that consisted of a human antibody targeted to the dendritic cell receptor DEC-205 fused with the tumor antigen NY-ESO-1 in a cohort of patients with tumors refractory to other therapies. They also added Toll-like receptor ligands as adjuvants in a dose-escalating study. They found that treatment induced both humoral and cellular immunity in these patients, with no dose-limiting toxicities. What’s more, a subset of patients had either stable disease or disease regression, particularly those who had received immune checkpoint inhibitors. If these data can be reproduced in larger trials, this study suggests that targeting antigen to dendritic cells could be an additional avenue to boost the immune response to cancer. Immune-based therapies for cancer are generating substantial interest because of the success of immune checkpoint inhibitors. This study aimed to enhance anticancer immunity by exploiting the capacity of dendritic cells (DCs) to initiate T cell immunity by efficient uptake and presentation of endocytosed material. Delivery of tumor-associated antigens to DCs using receptor-specific monoclonal antibodies (mAbs) in the presence of DC-activating agents elicits robust antigen-specific immune responses in preclinical models. DEC-205 (CD205), a molecule expressed on DCs, has been extensively studied for its role in antigen processing and presentation. CDX-1401 is a vaccine composed of a human mAb specific for DEC-205 fused to the full-length tumor antigen NY-ESO-1. This phase 1 trial assessed the safety, immunogenicity, and clinical activity of escalating doses of CDX-1401 with the Toll-like receptor (TLR) agonists resiquimod (TLR7/8) and Hiltonol (poly-ICLC, TLR3) in 45 patients with advanced malignancies refractory to available therapies. Treatment induced humoral and cellular immunity to NY-ESO-1 in patients with confirmed NY-ESO-1–expressing tumors across various dose levels and adjuvant combinations. No dose-limiting or grade 3 toxicities were reported. Thirteen patients experienced stabilization of disease, with a median duration of 6.7 months (range, 2.4+ to 13.4 months). Two patients had tumor regression (~20% shrinkage in target lesions). Six of eight patients who received immune-checkpoint inhibitors within 3 months after CDX-1401 administration had objective tumor regression. This first-in-human study of a protein vaccine targeting DCs demonstrates its feasibility, safety, and biological activity and provides rationale for combination immunotherapy strategies including immune checkpoint blockade.

Survival and long-term follow-up of safety and response in patients (pts) with advanced melanoma (MEL) in a phase I trial of nivolumab (anti-PD-1; BMS-936558; ONO-4538).

CRA9006^ Background: The monoclonal antibody nivolumab blocks PD-1, an inhibitory immune checkpoint receptor expressed by activated T cells. Pts with previously treated MEL or other tumors received nivolumab IV Q2W during dose escalation and/or cohort expansion in a phase I trial (Topalian et al., NEJM 2012;366:2443). METHODS Pts received ≤12 cycles (4 doses/cycle) of treatment until discontinuation criteria were met. Cohorts of MEL pts were expanded at 0.1, 0.3, 1, 3, and 10 mg/kg. We report overall survival data and long-term safety and response data from the MEL pts treated on this study. RESULTS 107 MEL pts received nivolumab as of July 2012. 103/107 pts (97%) were ECOG PS ≤1 and approximately 25% received ≥3 prior therapies. Median OS was 16.8 months across doses and 20.3 months at the 3 mg/kg dose selected for phase III trials. 44% and 40% of pts were alive at 2 and 3 yrs (Table). ORs were observed at all doses (highest at 3 mg/kg) (Table). Of 29 responders who initiated treatment ≥1 year prior to data analysis, 16 had responses lasting ≥1 year. Drug-related AEs (any grade) occurred in 82% of pts, with Gr 3-4 drug-related AEs in 21% of pts; the most common included lymphopenia (3%), fatigue, and increased lipase (2%). Gr 3-4 drug-related diarrhea (2%), endocrine disorders (2%), and hepatitis (1%) was observed. No Gr ≥3 drug-related pneumonitis was observed in the MEL cohort. CONCLUSIONS In this large cohort of pretreated MEL pts, nivolumab produced durable OS and responses with an acceptable safety profile. OS compares favorably with historical data. Data updated as of Feb 2013 will be reported. Phase III registration trials have been initiated. CLINICAL TRIAL INFORMATION NCT00730639. [Table: see text].

Abstract CT001: Durable, long-term survival in previously treated patients with advanced melanoma (MEL) who received nivolumab (NIVO) monotherapy in a phase I trial

Background: In previously treated MEL patients (pts), the results of an early phase I trial with NIVO monotherapy (CA209-003) demonstrated tumor responses that were durable even after treatment discontinuation (Topalian et al. J Clin Oncol 2014;32:1020). We report extended follow-up with 5-year overall survival (OS) data from this study. Methods: IPI-naive pts (N = 107) who had received 1-5 prior systemic therapies for MEL were treated with NIVO (0.1, 0.3, 1, 3, or 10 mg/kg) every 2 weeks for ?96 weeks. Pts were followed for OS, progression-free survival (PFS), long-term safety, and response duration after discontinuing NIVO treatment. Pts began treatment in October 2008, and current data were analyzed in October 2015 with a minimum follow-up of 45 months (time from when the last pt received his or her first dose of NIVO). Results: Median age of the pts was 61 years, 67% were male, 97% had an ECOG performance status of 0 or 1, 62% had received ?2 prior systemic therapies, and 36% had elevated lactate dehydrogenase levels at baseline. In all 107 pts, the 60-month OS rate was 34% (95% confidence interval [CI]: 25-43) and median OS was 17.3 months (95% CI: 12.5-37.8) (Table). OS rates appeared to plateau at ∼48 months, although further follow-up is needed. Similar results were observed with NIVO at 3 mg/kg, the currently approved monotherapy dose (Table). At the last timepoint for tumor assessment, PFS rates at 30 months were 18.6% and 25.7% for all pts and those who received NIVO at 3 mg/kg, respectively. Conclusions: This analysis represents the longest survival follow-up of pts who received anti-PD-1 therapy in a clinical study. In this heavily pretreated population of MEL pts, these results suggest durable, long-term survival following NIVO monotherapy, with 34% of pts alive at 5 years. Characteristics of long-term survivors and updated safety data will also be presented. Citation Format: F. Stephen Hodi, Harriet Kluger, Mario Sznol, Richard Carvajal, Donald Lawrence, Michael Atkins, John Powderly, William Sharfman, Igor Puzanov, David Smith, Philip Leming, Evan Lipson, Janis Taube, Robert Anders, Christine Horak, Joel Jiang, David McDermott, Jeffrey Sosman, Julie Brahmer, Drew Pardoll, Suzanne Topalian. Durable, long-term survival in previously treated patients with advanced melanoma (MEL) who received nivolumab (NIVO) monotherapy in a phase I trial. [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 CT001.