***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND We assessed the efficacy and safety of programmed cell death 1 ( PD-1 ) inhibition with pembrolizumab in patients with advanced non-small-cell lung cancer enrolled in a phase 1 study . We also sought to define and vali date an expression level of the PD-1 lig and 1 ( PD-L1 ) that is associated with the likelihood of clinical benefit . METHODS We assigned 495 patients receiving pembrolizumab ( at a dose of either 2 mg or 10 mg per kilogram of body weight every 3 weeks or 10 mg per kilogram every 2 weeks ) to either a training group ( 182 patients ) or a validation group ( 313 patients ) . We assessed PD-L1 expression in tumor sample s using immunohistochemical analysis , with results reported as the percentage of neoplastic cells with staining for membranous PD-L1 ( proportion score ) . Response was assessed every 9 weeks by central review . RESULTS Common side effects that were attributed to pembrolizumab were fatigue , pruritus , and decreased appetite , with no clear difference according to dose or schedule . Among all the patients , the objective response rate was 19.4 % , and the median duration of response was 12.5 months . The median duration of progression-free survival was 3.7 months , and the median duration of overall survival was 12.0 months . PD-L1 expression in at least 50 % of tumor cells was selected as the cutoff from the training group . Among patients with a proportion score of at least 50 % in the validation group , the response rate was 45.2 % . Among all the patients with a proportion score of at least 50 % , median progression-free survival was 6.3 months ; median overall survival was not reached . CONCLUSIONS Pembrolizumab had an acceptable side-effect profile and showed antitumor activity in patients with advanced non-small-cell lung cancer . PD-L1 expression in at least 50 % of tumor cells correlated with improved efficacy of pembrolizumab . ( Funded by Merck ; KEYNOTE-001 Clinical Trials.gov number , NCT01295827 . ) BACKGROUND Blockade of programmed death 1 ( PD-1 ) , an inhibitory receptor expressed by T cells , can overcome immune resistance . We assessed the antitumor activity and safety of BMS-936558 , an antibody that specifically blocks PD-1 . METHODS We enrolled patients with advanced melanoma , non-small-cell lung cancer , castration-resistant prostate cancer , or renal-cell or colorectal cancer to receive anti-PD-1 antibody at a dose of 0.1 to 10.0 mg per kilogram of body weight every 2 weeks . Response was assessed after each 8-week treatment cycle . Patients received up to 12 cycles until disease progression or a complete response occurred . RESULTS A total of 296 patients received treatment through February 24 , 2012 .  Grade 3 or 4 drug-related adverse events occurred in 14 % of patients ; there were three deaths from pulmonary toxicity . No maximum tolerated dose was defined . Adverse events consistent with immune-related causes were observed . Among 236 patients in whom response could be evaluated , objective responses ( complete or partial responses ) were observed in those with non-small-cell lung cancer , melanoma , or renal-cell cancer .  Cumulative response rates ( all doses ) were 18 % among patients with non-small-cell lung cancer ( 14 of 76 patients ) , 28 % among patients with melanoma ( 26 of 94 patients ) , and 27 % among patients with renal-cell cancer ( 9 of 33 patients ) . Responses were durable ; 20 of 31 responses lasted 1 year or more in patients with 1 year or more of follow-up . To assess the role of intratumoral PD-1 lig and ( PD-L1 ) expression in the modulation of the PD-1-PD-L1 pathway , immunohistochemical analysis was performed on pretreatment tumor specimens obtained from 42 patients . Of 17 patients with PD-L1-negative tumors , none had an objective response ; 9 of 25 patients ( 36 % ) with PD-L1-positive tumors had an objective response ( P=0.006 ) . CONCLUSIONS Anti-PD-1 antibody produced objective responses in approximately one in four to one in five patients with non-small-cell lung cancer , melanoma , or renal-cell cancer ; the adverse-event profile does not appear to preclude its use . Preliminary data suggest a relationship between PD-L1 expression on tumor cells and objective response . ( Funded by Bristol-Myers Squibb and others ; Clinical Trials.gov number , NCT00730639 . ) Therapies that target the programmed death-1 ( PD-1 ) receptor have shown unprecedented rates of durable clinical responses in patients with various cancer types . One mechanism by which cancer tissues limit the host immune response is via upregulation of PD-1 lig and ( PD-L1 ) and its ligation to PD-1 on antigen-specific CD8 + T cells ( termed adaptive immune resistance ) . Here we show that pre-existing CD8 + T cells distinctly located at the invasive tumour margin are associated with expression of the PD-1/PD-L1 immune inhibitory axis and may predict response to therapy . We analysed sample s from 46 patients with metastatic melanoma obtained before and during anti-PD-1 therapy ( pembrolizumab )  using quantitative immunohistochemistry , quantitative multiplex immunofluorescence , and next-generation sequencing for T-cell antigen receptors ( TCRs ) . In serially sample d tumours , patients responding to treatment showed proliferation of intratumoral CD8 + T cells that directly correlated with radiographic reduction in tumour size . Pre-treatment sample s obtained from responding patients showed higher numbers of CD8- , PD-1- and PD-L1-expressing cells at the invasive tumour margin and inside tumours , with close proximity between PD-1 and PD-L1 , and a more clonal TCR repertoire . Using multivariate analysis , we established a predictive model based on CD8 expression at the invasive margin and vali date d the model in an independent cohort of 15 patients . Our findings indicate that tumour regression after therapeutic PD-1 blockade requires pre-existing CD8 + T cells that are negatively regulated by PD-1/PD-L1-mediated adaptive immune resistance 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-lig and 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 design ed 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 BACKGROUND Nivolumab was associated with higher rates of objective response than chemotherapy in a phase 3 study involving patients with ipilimumab-refractory metastatic melanoma . The use of nivolumab in previously untreated patients with advanced melanoma has not been tested in a phase 3 controlled study . METHODS We r and omly assigned 418 previously untreated patients who had metastatic melanoma without a BRAF mutation to receive nivolumab ( at a dose of 3 mg per kilogram of body weight every 2 weeks and dacarbazine-matched placebo every 3 weeks ) or dacarbazine ( at a dose of 1000 mg per square meter of body-surface area every 3 weeks and nivolumab-matched placebo every 2 weeks ) . The primary end point was overall survival . RESULTS At 1 year , the overall rate of survival was 72.9 % ( 95 % confidence interval [ CI ] , 65.5 to 78.9 ) in the nivolumab group , as compared with 42.1 % ( 95 % CI , 33.0 to 50.9 ) in the dacarbazine group ( hazard ratio for death , 0.42 ; 99.79 % CI , 0.25 to 0.73 ; P<0.001 ) . The median progression-free survival was 5.1 months in the nivolumab group versus 2.2 months in the dacarbazine group ( hazard ratio for death or progression of disease , 0.43 ; 95 % CI , 0.34 to 0.56 ; P<0.001 ) . The objective response rate was 40.0 % ( 95 % CI , 33.3 to 47.0 ) in the nivolumab group versus 13.9 % ( 95 % CI , 9.5 to 19.4 ) in the dacarbazine group ( odds ratio , 4.06 ; P<0.001 ) . The survival benefit with nivolumab versus dacarbazine was observed across prespecified subgroups , including subgroups defined by status regarding the programmed death lig and 1 ( PD-L1 ) . Common adverse events associated with nivolumab included fatigue , pruritus , and nausea . Drug-related adverse events of grade 3 or 4 occurred in 11.7 % of the patients treated with nivolumab and 17.6 % of those treated with dacarbazine . CONCLUSIONS Nivolumab was associated with significant improvements in overall survival and progression-free survival , as compared with dacarbazine , among previously untreated patients who had metastatic melanoma without a BRAF mutation . ( Funded by Bristol-Myers Squibb ; CheckMate 066 Clinical Trials.gov number , NCT01721772 . ) 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 r and omized clinical trials will further assess the impact of nivolumab on overall survival in patients with advanced RCC BACKGROUND Patients with melanoma that progresses on ipilimumab and , if BRAF(V600 ) mutant-positive , a BRAF or MEK inhibitor or both , have few treatment options . We assessed the efficacy and safety of two pembrolizumab doses versus investigator-choice chemotherapy in patients with ipilimumab-refractory melanoma . METHODS We carried out a r and omised phase 2 trial of patients 
    Output:
    
Squamous NSCLC and RCC did not show any significant difference in response according to the PD-L1 status .
PD-L1 expression is significantly associated with mortality and clinical response to anti-PD-1/PD-L1 antibodies in MM patients and with clinical response in patients with non-squamous NSCLC