The immune suppressive molecule programmed death-1 (PD-1) is upregulated in activated T lymphocytes and inhibits T-cell function upon binding to its ligands B7-H1 (PD-L1, CD274) and B7-DC (PD-L2, ...CD273). Substantial experimental data from in vitro cell culture systems and animal models, and more recently from clinical trials, indicate that PD-1/PD-1-ligand interactions are a major mechanism of immune suppression within the tumor microenvironment. Initial clinical studies of antibodies directed against PD-1 and B7-H1 showed both an encouraging safety profile and remarkable antitumor activity in subsets of patients with metastatic disease, including malignancies--such as lung cancer--which were previously thought to be unresponsive to immunotherapy. Preliminary data have suggested a correlation between tumor membrane B7-H1 expression and clinical response to anti-PD-1 antibodies. Several key challenges remain to optimize development of PD-1/B7-H1 pathway blockade, including defining the biologic significance of all potential ligand-receptor interactions in the tumor microenvironment, developing more accurate predictive biomarkers of response, determining the breadth of activity in human malignancies, and developing rational combinations of therapy that address key mechanisms involved in positive and negative regulation of antitumor immune responses.
Melanoma is among the most sensitive of malignancies to immune modulation. Although multiple trials conducted over decades with vaccines, cytokines, and cell therapies demonstrated meaningful ...responses in a small subset of patients with metastatic disease, a true increase in overall survival (OS) within a randomized phase III trial was not observed until the development of anti-CTLA-4 (ipilimumab). Further improvements in OS for metastatic disease were observed with the anti-PD-1-based therapies (nivolumab, pembrolizumab) as single agents or combined with ipilimumab. A lower bound for expected 5-year survival for metastatic melanoma is currently approximately 35% and could be as high as 50% for the nivolumab/ipilimumab combination among patients who would meet criteria for clinical trials. Moreover, a substantial fraction of long-term survivors will likely remain progression-free without continued treatment. The hope and major challenge for the future is to understand the immunobiology of tumors with primary or acquired resistance to anti-PD-1 or anti-PD-1/anti-CTLA-4 and to develop effective immune therapies tailored to individual patient subsets not achieving long-term clinical benefit. Additional goals include optimal integration of immune therapy with nonimmune therapies, the development and validation of predictive biomarkers in the metastatic setting, improved prognostic and predictive biomarkers for the adjuvant setting, understanding mechanisms of and decreasing toxicity, and optimizing the duration of therapy.
Combination checkpoint blockade (CCB) targeting inhibitory CTLA4 and PD1 receptors holds promise for cancer therapy. Immune-related adverse events (IRAEs) remain a major obstacle for the optimal ...application of CCB in cancer. Here, we analyzed B cell changes in patients with melanoma following treatment with either anti-CTLA4 or anti-PD1, or in combination. CCB therapy led to changes in circulating B cells that were detectable after the first cycle of therapy and characterized by a decline in circulating B cells and an increase in CD21lo B cells and plasmablasts. PD1 expression was higher in the CD21lo B cells, and B cell receptor sequencing of these cells demonstrated greater clonality and a higher frequency of clones compared with CD21hi cells. CCB induced proliferation in the CD21lo compartment, and single-cell RNA sequencing identified B cell activation in cells with genomic profiles of CD21lo B cells in vivo. Increased clonality of circulating B cells following CCB occurred in some patients. Treatment-induced changes in B cells preceded and correlated with both the frequency and timing of IRAEs. Patients with early B cell changes experienced higher rates of grade 3 or higher IRAEs 6 months after CCB. Thus, early changes in B cells following CCB may identify patients who are at increased risk of IRAEs, and preemptive strategies targeting B cells may reduce toxicities in these patients.
Severe immune-related adverse events (irAEs) occur in up to 60% of patients with melanoma treated with immune checkpoint inhibitors (ICIs). However, it is unknown whether a common baseline ...immunological state precedes irAE development. Here we applied mass cytometry by time of flight, single-cell RNA sequencing, single-cell V(D)J sequencing, bulk RNA sequencing and bulk T cell receptor (TCR) sequencing to study peripheral blood samples from patients with melanoma treated with anti-PD-1 monotherapy or anti-PD-1 and anti-CTLA-4 combination ICIs. By analyzing 93 pre- and early on-ICI blood samples and 3 patient cohorts (n = 27, 26 and 18), we found that 2 pretreatment factors in circulation-activated CD4 memory T cell abundance and TCR diversity-are associated with severe irAE development regardless of organ system involvement. We also explored on-treatment changes in TCR clonality among patients receiving combination therapy and linked our findings to the severity and timing of irAE onset. These results demonstrate circulating T cell characteristics associated with ICI-induced toxicity, with implications for improved diagnostics and clinical management.
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.
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.
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.
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.
Summary Background Immunotherapy targeting the PD-1 axis has activity in several tumour types. We aimed to establish the activity and safety of the PD-1 inhibitor pembrolizumab in patients with ...untreated brain metastases from melanoma or non-small-cell lung cancer (NSCLC). Methods In this non-randomised, open-label, phase 2 trial, we enrolled patients aged 18 years or older with melanoma or NSCLC with untreated brain metastases from the Yale Cancer Center. Patients had at least one untreated or progressive brain metastasis between 5 and 20 mm in diameter without associated neurological symptoms or the need for corticosteroids. Patients with NSCLC had tumour tissue positive for PD-L1 expression; this was not required for patients with melanoma. Patients were given 10 mg/kg pembrolizumab every 2 weeks until progression. The primary endpoint was brain metastasis response assessed in all treated patients. The trial is ongoing and here we present an early analysis. The study is registered with ClinicalTrials.gov , number NCT02085070. Findings Between March 31, 2014, and May 31, 2015, we screened 52 patients with untreated or progressive brain metastases (18 with melanoma, 34 with NSCLC), and enrolled 36 (18 with melanoma, 18 with NSCLC). A brain metastasis response was achieved in four (22%; 95% CI 7–48) of 18 patients with melanoma and six (33%; 14–59) of 18 patients with NSCLC. Responses were durable, with all but one patient with NSCLC who responded showing an ongoing response at the time of data analysis on June 30, 2015. Treatment-related serious and grade 3–4 adverse events were grade 3 elevated aminotransferases (n=1 6%) in the melanoma cohort, and grade 3 colitis (n=1 6%), grade 3 pneumonitis (n=1 6%), grade 3 fatigue (n=1 6%), grade 4 hyperkalemia (n=1 6%), and grade 2 acute kidney injury (n=1 6%) in the NSCLC cohort. Clinically significant neurological adverse events included transient grade 3 cognitive dysfunction and grade 1–2 seizures (n=3 17%) in the melanoma cohort. Interpretation Pembrolizumab shows activity in brain metastases in patients with melanoma or NSCLC with an acceptable safety profile, which suggests that there might be a role for systemic immunotherapy in patients with untreated or progressive brain metastases. Funding Merck and the Yale Cancer Center.
Urelumab is an agonist antibody to CD137 with potential application as an immuno-oncology therapeutic. Data were analyzed to assess safety, tolerability, and pharmacodynamic activity of urelumab, ...including the dose selected for ongoing development in patients with advanced solid tumors and lymphoma.
A total of 346 patients with advanced cancers who had progressed after standard treatment received at least one dose of urelumab in one of three dose-escalation, monotherapy studies. Urelumab was administered at doses ranging from 0.1 to 15 mg/kg. Safety analyses included treatment-related and serious adverse events (AEs), as well as treatment-related AEs leading to discontinuation and death, with a focus on liver function test abnormalities and hepatic AEs.
Urelumab doses between 1 and 15 mg/kg given every 3 weeks resulted in a higher frequency of treatment-related AEs than 0.1 or 0.3 mg/kg every 3 weeks. Dose was the single most important factor contributing to transaminitis development, which was more frequent and severe at doses ≥1 mg/kg. At the MTD of 0.1 mg/kg every 3 weeks, urelumab was relatively well tolerated, with fatigue (16%) and nausea (13%) being the most common treatment-related AEs, and was associated with immunologic and pharmacodynamic activity demonstrated by the induction of IFN-inducible genes and cytokines.
Integrated evaluation of urelumab safety data showed significant transaminitis was strongly associated with doses of ≥1 mg/kg. However, urelumab 0.1 mg/kg every 3 weeks was demonstrated to be safe, with pharmacodynamic activity supporting continued clinical evaluation of this dose as monotherapy and in combination with other immuno-oncology agents.
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This phase Ib study (NCT02179918) evaluated the safety, antitumor activity, pharmacokinetics, and pharmacodynamics of utomilumab, a fully human IgG2 mAb agonist of the T-cell costimulatory receptor ...4-1BB/CD137 in combination with the humanized, PD-1-blocking IgG4 mAb pembrolizumab in patients with advanced solid tumors.
Utomilumab (0.45-5.0 mg/kg) and pembrolizumab (2 mg/kg) were administered intravenously every 3 weeks. Utomilumab dose escalation was conducted using the time-to-event continual reassessment method.
Twenty-three patients received combination treatment with no dose-limiting toxicities. Treatment-emergent adverse events were mostly grades 1 to 2, without any treatment-related discontinuations. Six patients (26.1%) had confirmed complete or partial responses. Pharmacokinetics and immunogenicity of utomilumab and pembrolizumab were similar when administered alone or in combination. A trend toward higher levels of activated memory/effector peripheral blood CD8
T cells was observed in responders versus nonresponders.
The safety, tolerability, and clinical activity demonstrated by utomilumab in combination with pembrolizumab support further investigation in patients with advanced solid tumors.
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