***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: 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 . ) Introduction The significance of programmed death lig and 1 ( PD-L1 ) expression in the prognosis of patients with colorectal cancer remains to be determined . Methods We assessed the levels of PD-L1 expression  in tumor-infiltrating immune cells as well as tumor cells , and evaluated the association between  PD-L1 expression  and clinical outcome in 262 colorectal cancer patients . Results In univariate analysis , TNM stage ( p < 0.001 ) , PD-L1 expression in tumor-infiltrating immune cells ( p = 0.016 ) , tumor location ( p = 0.033 ) , and tumor size ( p = 0.019 ) were associated with survival . In multivariate analysis , PD-L1 expression in tumor infiltrating immune cells and TNM stage were independent prognostic factors ( HR 1.83 , 95 % CI 1.09–3.05 , p = 0.021 ; HR 2.49 , 95 % CI 1.51–4.12 , p < 0.001 , respectively ) . Eight percent of patients had positive PD-L1 expression in tumor cells . In contrast , PD-L1 expression in tumor cells was not significantly associated with patient clinical outcome . Conclusions Our data indicate that PD-L1 status in tumor-infiltrating immune cells is a significant prognostic factor in colorectal cancer patients . There is a need for r and omized studies that evaluate the role of PD-L1 expression in colorectal cancer in treatment decision protocol s for novel immunotherapy The efficacy of immune response to control human cancer remains controversial . It is particularly debated whether and to what extent the capacity of tumor-infiltrating dendritic cells ( DC ) to drive immunization can be turned off by transformed cells , leading to tumor-specific tolerance rather than immunization . To address this issue , we have characterized the DC isolated from human non-small cell lung cancer ( NSCLC ) . These biopsy specimens contained CD11chigh myeloid DC ( mDC ) , but also CD11c− plasmacytoid DC ( pDC ) and a third DC subset expressing intermediate level of CD11c . Compared with peripheral blood , CD11chigh tumor-infiltrating DC ( TIDC ) displayed a “ semi-mature ” phenotype , and TLR4 or TLR8 stimulation drove them to mature partially and to secrete limited amounts of cytokines . In contrast , most tumor-infiltrating pDC were immature but underwent partial maturation after TLR7 activation , whereas TLR9 ligation triggered low secretion of IFN-α . CD11cint mDC represented ∼25 % of total DC in tumoral and peritumoral tissues and expressed low levels of costimulatory molecules contrasting with high levels of the immunoinhibitory molecule B7-H1 . Finally , the poor APC function of total TIDC even after TLR stimulation and the migratory response of both tumor-infiltrating mDC and pDC toward CCL21 and SDF-1 in vitro suggested their ability to compromise the tumor-specific immune response in draining lymph nodes in vivo . Further studies will be required to establish the specific role of the three TIDC subsets in tumor immunity and to draw conclusions for the design of therapeutic strategies 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 population s. Responses were durable and persisted after drug discontinuation . Long-term safety was acceptable . Ongoing r and omized clinical trials will further assess the impact of nivolumab therapy on overall survival in patients with metastatic melanoma BACKGROUND The programmed death 1 ( PD-1 ) receptor is a negative regulator of T-cell effector mechanisms that limits immune responses against cancer . We tested the anti-PD-1 antibody lambrolizumab ( previously known as MK-3475 ) in patients with advanced melanoma . METHODS We administered lambrolizumab intravenously at a dose of 10 mg per kilogram of body weight every 2 or 3 weeks or 2 mg per kilogram every 3 weeks in patients with advanced melanoma , both those who had received prior treatment with the immune checkpoint inhibitor ipilimumab and those who had not .  Tumor responses were assessed every 12 weeks . RESULTS A total of 135 patients with advanced melanoma were treated . Common adverse events attributed to treatment were fatigue , rash , pruritus , and diarrhea ; most of the adverse events were low grade . The confirmed response rate across all dose cohorts , evaluated by central radiologic review according to the Response Evaluation Criteria in Solid Tumors ( RECIST ) , version 1.1 , was 38 % ( 95 % confidence interval [ CI ] , 25 to 44 ) , with the highest confirmed response rate observed in the cohort that received 10 mg per kilogram every 2 weeks ( 52 % ; 95 % CI , 38 to 66 ) . The response rate did not differ significantly between patients who had received prior ipilimumab treatment and those who had not ( confirmed response rate , 38 % [ 95 % CI , 23 to 55 ] and 37 % [ 95 % CI , 26 to 49 ] , respectively ) . Responses were durable in the majority of patients ( median follow-up , 11 months among patients who had a response ) ; 81 % of the patients who had a response ( 42 of 52 ) were still receiving treatment at the time of analysis in March 2013 . The overall median progression-free survival among the 135 patients was longer than 7 months . CONCLUSIONS In patients with advanced melanoma , including those who had had disease progression while they had been receiving ipilimumab , treatment with lambrolizumab result ed in a high rate of sustained tumor regression , with mainly grade 1 or 2 toxic effects . ( Funded by Merck Sharp and Dohme ; Clinical Trials.gov number , NCT01295827 . ) BACKGROUND Pre clinical studies suggest that Reed-Sternberg cells exploit the programmed death 1 ( PD-1 ) pathway to evade immune detection . In classic Hodgkin 's lymphoma , alterations in chromosome 9p24.1 increase the abundance of the PD-1 lig and s , PD-L1 and PD-L2 , and promote their induction through Janus kinase (JAK)-signal transducer and activator of transcription ( STAT ) signaling . We hypothesized that nivolumab , a PD-1-blocking antibody , could inhibit tumor immune evasion in patients with relapsed or refractory Hodgkin 's lymphoma . METHODS In this ongoing study , 23 patients with relapsed or refractory Hodgkin 's lymphoma that had already been heavily treated received nivolumab ( at a dose of 3 mg per kilogram of body weight ) every 2 weeks until they had a complete response , tumor progression , or excessive toxic effects . Study objectives were measurement of safety and efficacy and assessment of the PDL1 and PDL2 ( also called CD274 and PDCD1LG2 , respectively ) loci and PD-L1 and PD-L2 protein expression . RESULTS Of the 23 study patients , 78 % were enrolled in the study after a relapse following autologous stem-cell transplantation and 78 % after a relapse following the receipt of  brentuximab vedotin .  Drug-related adverse events of any grade and of grade 3 occurred in 78 % and 22 % of patients , respectively . An objective response was reported in 20 patients ( 87 % ) , including 17 % with a complete response and 70 % with a partial response ; the remaining 3 patients ( 13 % ) had stable disease . The rate of progression-free survival at 24 weeks was 86 % ; 11 patients were continuing to participate in the study . Reasons for discontinuation included stem-cell transplantation ( in 6 patients ) , disease progression ( in 4 patients ) , and drug toxicity ( in 2 patients ) . Analyses of pretreatment tumor specimens from 10 patients revealed copy-number gains in PDL1 and PDL2 and increased expression of these lig and s. Reed-Sternberg cells showed nuclear positivity of phosphorylated STAT3 , indicative of active JAK-STAT signaling . CONCLUSIONS Nivolumab had substantial therapeutic activity and an acceptable safety profile in patients with previously heavily treated relapsed or refractory Hodgkin 's lymphoma . ( Funded by Bristol-Myers Squibb and others ; Clinical Trials.gov number , NCT01592370 . ) BACKGROUND Patients with squamous non-small-cell lung cancer that is refractory to multiple treatments have poor outcomes . We assessed the activity of nivolumab , a fully human IgG4 PD-1 immune checkpoint inhibitor antibody , for patients with advanced , refractory , squamous non-small-cell lung cancer . METHODS We did this phase 2 , single-arm trial at 27 sites ( academic , hospital , and private cancer centres ) in France , Germany , Italy , and USA . Patients who had received two or more previous treatments received intravenous nivolumab ( 3 mg/kg ) every 2 weeks until progression or unacceptable toxic effects . The primary endpoint was the proportion of patients with a confirmed objective response 
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Conclusion : This meta- analysis revealed that PD-L1 can serve as a significant biomarker for negative prognosis and the adverse clinicopathological features of colorectal cancer and could facilitate the better management of individual patients