Antibodies to PD-1 protein and to one of its ligands, PD-L1, have shown antitumor activity. Unleashing T cells from inhibitory signals may be a strategy to treat cancers. Autoimmune side effects from ...anti–PD-L1 antibody seem less severe than those from anti–CTLA-4 antibody.
Passive cancer immunotherapy that uses tumor-targeted monoclonal antibodies has achieved broad therapeutic efficacy.
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However, T-cell directed immunotherapy has been less successful.
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Despite the large number of tumor antigens induced by genetic and epigenetic changes found in all cancers, tumors resist immune attack by inducing tolerance among tumor-specific T cells and by expressing ligands that engage inhibitory receptors and dampen T-cell functions within the tumor microenvironment.
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Preclinical and clinical data show that antibody blockade of these immune checkpoints can significantly enhance antitumor immunity.
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Cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4), an inhibitory receptor that down-modulates the initial stages of T-cell activation, was the . . .
Traditional treatment modalities for advanced cancer (radiotherapy, chemotherapy, or targeted agents) act directly on tumors to inhibit or destroy them. Along with surgery, these modalities are ...predominantly palliative, with toxicity and only modest improvements in survival in patients with advanced solid tumors. Accordingly, long‐term survival rates for most patients with advanced cancer remain low, thus there is a need for cancer treatments with favorable benefit and toxicity profiles that can potentially result in long‐term survival. The immune system plays a critical role in the recognition and eradication of tumor cells (“immune surveillance”), and immunotherapies based on this concept have been used for decades with some success against a few tumor types; however, most immunotherapies were limited by a lack of either substantial efficacy or specificity, resulting in toxicity. We now have a greater understanding of the complex interactions between the immune system and tumors and have identified key molecules that govern these interactions. This information has revitalized the interest in immunotherapy as an evolving treatment modality using immunotherapeutics designed to overcome the mechanisms exploited by tumors to evade immune destruction. Immunotherapies have potentially complementary mechanisms of action that may allow them to be combined with other immunotherapeutics, chemotherapy, targeted therapy, or other traditional therapies. This review discusses the concepts and data behind immunotherapies, with a focus on the checkpoint inhibitors and their responses, toxicities, and potential for long‐term survival, and explores promising single‐agent and combination therapies in development.
Implications for Practice:
Immunotherapy is an evolving treatment approach based on the role of the immune system in eradicating cancer. An example of an immunotherapeutic is ipilimumab, an antibody that blocks cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) to augment antitumor immune responses. Ipilimumab is approved for advanced melanoma and induced long‐term survival in a proportion of patients. The programmed death‐1 (PD‐1) checkpoint inhibitors are promising immunotherapies with demonstrated sustained antitumor responses in several tumors. Because they harness the patient's own immune system, immunotherapies have the potential to be a powerful weapon against cancer.
Immunotherapy is an evolving treatment approach based on the role of the immune system in eradicating cancer. This review discusses the concepts and data behind immunotherapies, with a focus on the checkpoint inhibitors and their responses, toxicities, and potential for long‐term survival, and explores promising single‐agent and combination therapies in development.
The efficacy and safety of biological molecules in cancer therapy, such as peptides and small interfering RNAs (siRNAs), could be markedly increased if high concentrations could be achieved and ...amplified selectively in tumour tissues versus normal tissues after intravenous administration. This has not been achievable so far in humans. We hypothesized that a poxvirus, which evolved for blood-borne systemic spread in mammals, could be engineered for cancer-selective replication and used as a vehicle for the intravenous delivery and expression of transgenes in tumours. JX-594 is an oncolytic poxvirus engineered for replication, transgene expression and amplification in cancer cells harbouring activation of the epidermal growth factor receptor (EGFR)/Ras pathway, followed by cell lysis and anticancer immunity. Here we show in a clinical trial that JX-594 selectively infects, replicates and expresses transgene products in cancer tissue after intravenous infusion, in a dose-related fashion. Normal tissues were not affected clinically. This platform technology opens up the possibility of multifunctional products that selectively express high concentrations of several complementary therapeutic and imaging molecules in metastatic solid tumours in humans.
Tumor-associated PD-L1 expression is predictive of clinical response to PD-1-directed immunotherapy. However, PD-L1-negative patients may also respond to PD-1 checkpoint blockade, suggesting that ...other PD-1 ligands may be relevant to the clinical activity of these therapies. The prevalence of PD-L2, the other known ligand of PD-1, and its relationship to response to anti-PD-1 therapy were evaluated.
PD-L2 expression was assessed in archival tumor tissue from seven indications using a novel immunohistochemical assay. In addition, relationships between clinical response and PD-L2 status were evaluated in tumor tissues from patients with head and neck squamous cell carcinoma (HNSCC) with recurrent or metastatic disease, treated with pembrolizumab.
PD-L2 expression was observed in all tumor types and present in stromal, tumor, and endothelial cells. The prevalence and distribution of PD-L2 correlated significantly with PD-L1 (
= 0.0012-<0.0001); however, PD-L2 was detected in the absence of PD-L1 in some tumor types. Both PD-L1 and PD-L2 positivity significantly predicted clinical response to pembrolizumab on combined tumor, stromal and immune cells, with PD-L2 predictive independent of PD-L1. Response was greater in patients positive for both PD-L1 and PD-L2 (27.5%) than those positive only for PD-L1 (11.4%). PD-L2 status was also a significant predictor of progression-free survival (PFS) with pembrolizumab independent of PD-L1 status. Longer median times for PFS and overall survival were observed for PD-L2-positive than PD-L2-negative patients.
Clinical response to pembrolizumab in patients with HNSCC may be related partly to blockade of PD-1/PD-L2 interactions. Therapy targeting both PD-1 ligands may provide clinical benefit in these patients.
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Sunitinib (SU011248) is an oral small molecular tyrosine kinase inhibitor that exhibits potent antiangiogenic and antitumor activity. Tyrosine kinase inhibitors such as SU6668 and SU5416 (semaxanib) ...demonstrated poor pharmacologic properties and limited efficacy; therefore, sunitinib was rationally designed and chosen for its high bioavailability and its nanomolar-range potency against the antiangiogenic receptor tyrosine kinases (RTKs)--vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR). Sunitinib inhibits other tyrosine kinases including, KIT, FLT3, colony-stimulating factor 1 (CSF-1), and RET, which are involved in a number of malignancies including small-cell lung cancer, GI stromal tumors (GISTs), breast cancer, acute myelogenous leukemia, multiple endocrine neoplasia types 2A and 2B, and familial medullary thyroid carcinoma. Sunitinib demonstrated robust antitumor activity in preclinical studies resulting not only in tumor growth inhibition, but tumor regression in models of colon cancer, non-small-cell lung cancer, melanoma, renal carcinoma, and squamous cell carcinoma, which were associated with inhibition of VEGFR and PDGFR phosphorylation. Clinical activity was demonstrated in neuroendocrine, colon, and breast cancers in phase II studies, whereas definitive efficacy has been demonstrated in advanced renal cell carcinoma and in imatinib-refractory GISTs, leading to US Food and Drug Administration approval of sunitinib for treatment of these two diseases. Studies investigating sunitinib alone in various tumor types and in combination with chemotherapy are ongoing. The clinical benchmarking of this small-molecule inhibitor of members of the split-kinase domain family of RTKs will lead to additional insights regarding the biology, potential biomarkers, and clinical utility of agents that target multiple signaling pathways in tumor, stromal, and endothelial compartments.
Immunotherapy has revolutionized the treatment of advanced non-small-cell lung cancer (NSCLC). In two phase III trials (CheckMate 017 and CheckMate 057), nivolumab showed an improvement in overall ...survival (OS) and favorable safety versus docetaxel in patients with previously treated, advanced squamous and nonsquamous NSCLC, respectively. We report 5-year pooled efficacy and safety from these trials.
Patients (N = 854; CheckMate 017/057 pooled) with advanced NSCLC, ECOG PS ≤ 1, and progression during or after first-line platinum-based chemotherapy were randomly assigned 1:1 to nivolumab (3 mg/kg once every 2 weeks) or docetaxel (75 mg/m
once every 3 weeks) until progression or unacceptable toxicity. The primary end point for both trials was OS; secondary end points included progression-free survival (PFS) and safety. Exploratory landmark analyses were investigated.
After the minimum follow-up of 64.2 and 64.5 months for CheckMate 017 and 057, respectively, 50 nivolumab-treated patients and nine docetaxel-treated patients were alive. Five-year pooled OS rates were 13.4% versus 2.6%, respectively; 5-year PFS rates were 8.0% versus 0%, respectively. Nivolumab-treated patients without disease progression at 2 and 3 years had an 82.0% and 93.0% chance of survival, respectively, and a 59.6% and 78.3% chance of remaining progression-free at 5 years, respectively. Treatment-related adverse events (TRAEs) were reported in 8 of 31 (25.8%) nivolumab-treated patients between 3-5 years of follow-up, seven of whom experienced new events; one (3.2%) TRAE was grade 3, and there were no grade 4 TRAEs.
At 5 years, nivolumab continued to demonstrate a survival benefit versus docetaxel, exhibiting a five-fold increase in OS rate, with no new safety signals. These data represent the first report of 5-year outcomes from randomized phase III trials of a programmed death-1 inhibitor in previously treated, advanced NSCLC.
Ceritinib is 20 times as potent as crizotinib at inhibiting anaplastic lymphoma kinase (ALK) in vitro. In patients, ceritinib produced antitumor responses in 56% of those who had resistance to ...crizotinib.
Genetic alterations in the anaplastic lymphoma kinase gene (
ALK
) are implicated in the pathogenesis of several human cancers.
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ALK can be aberrantly activated by mutation, gene amplification, or chromosomal rearrangement, leading to the expression of a potent oncogenic driver. In non–small-cell lung cancer (NSCLC),
ALK
rearrangement occurs in approximately 5% of cases.
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–
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ALK
-rearranged tumors depend on ALK for growth and survival and show marked sensitivity to ALK inhibitors such as crizotinib. Among patients with advanced,
ALK
-rearranged NSCLC, crizotinib has been associated with response rates of approximately 60% across multiple studies and a median progression-free survival . . .
Summary Background PD-1 and its ligands are expressed in urothelial cancer, and findings have shown that inhibition of the PD-1 pathway has clinical benefit. We aimed to assess the safety and ...activity of an anti-PD-1 antibody pembrolizumab in patients with locally advanced or metastatic urothelial cancer. Methods This study was part of the non-randomised, multi-cohort, open-label, phase 1b KEYNOTE-012 basket trial. We enrolled patients aged 18 years and older with a histologically or cytologically confirmed diagnosis of locally advanced or metastatic urothelial cancer, including cancers of the renal pelvis, ureter, bladder, or urethra, from eight hospitals in the USA and Israel. Patients were required to have at least 1% PD-L1 expression detected on the tumour cells or in tumour stroma, as determined by immunohistochemistry. Patients were given 10 mg/kg intravenous pembrolizumab every 2 weeks until disease progression, unacceptable toxic effects, or the end of the study (ie, 24 months of treatment). Primary endpoints were safety and overall response (defined by Response Evaluation Criteria In Solid Tumors RECIST version 1.1), as assessed by a masked, independent central review. Safety was assessed in patients who received one or more doses of pembrolizumab (all-patients-as-treated population); activity was assessed in patients who received pembrolizumab, had measurable disease at baseline, and had one or more post-baseline scans, or discontinued because of progressive disease or treatment-related adverse events (full analysis set). This study is registered with ClinicalTrials.gov , number NCT01848834 , and is no longer enrolling patients; follow-up is ongoing. Findings Between May 14, 2013, and Dec 10, 2013, 115 patients were tissue pre-screened as part of a two-part consent process. 61 (53%) patients were PD-L1 positive, of whom 33 were enrolled in this study. All enrolled patients received at least one dose of pembrolizumab and were included in the safety analyses. 27 patients comprised the full analysis set and were deemed assessable for activity. Six patients were not assessable: three discontinued study drug because of a non-treatment-related adverse event before the first post-baseline scan, two withdrew before the first post-baseline scan, and one had no measurable disease at baseline. The most common treatment-related adverse events were fatigue (six 18% of 33 patients) and peripheral oedema (4 12%). Five (15%) patients had 11 grade 3 treatment-related adverse events; no single event occurred in more than one patient. Three (9%) patients experienced five serious treatment-related adverse events. After median follow-up of 13 months (range 1–26, IQR 5–23), an overall response was achieved in seven (26% 95% CI 11–46) of 27 assessable patients, with three (11% 2–29) complete and four (15% 4–34) partial responses. Of the four deaths that occurred during the study (cardiac arrest, pneumonia, sepsis, and subarachnoid haemorrhage), none were deemed treatment related. Interpretation Pembrolizumab showed anti-tumour activity and acceptable safety in patients with advanced urothelial cancer, supporting ongoing phase 2 and 3 studies of pembrolizumab in this population. Funding Merck & Co., Inc.
Immune checkpoint inhibition has been demonstrated to be an effective anticancer strategy. Several lines of evidence support the study of immunotherapy in triple-negative breast cancer (TNBC). We ...assessed the safety and antitumor activity of the programmed cell death protein 1 (PD-1) inhibitor pembrolizumab in patients with advanced TNBC.
KEYNOTE-012 (ClinicalTrials.gov identifier: NCT01848834) was a multicenter, nonrandomized phase Ib trial of single-agent pembrolizumab given intravenously at 10 mg/kg every 2 weeks to patients with advanced PD-L1-positive (expression in stroma or ≥ 1% of tumor cells by immunohistochemistry) TNBC, gastric cancer, urothelial cancer, and head and neck cancer. This report focuses on the TNBC cohort.
Among 111 patients with TNBC whose tumor samples were screened for PD-L1 expression, 58.6% had PD-L1-positive tumors. Thirty-two women (median age, 50.5 years; range, 29 to 72 years) were enrolled and assessed for safety and antitumor activity. The median number of doses administered was five (range, 1 to 36 doses). Common toxicities were mild and similar to those observed in other tumor cohorts (eg, arthralgia, fatigue, myalgia, and nausea), and included five (15.6%) patients with grade ≥ 3 toxicity and one treatment-related death. Among the 27 patients who were evaluable for antitumor activity, the overall response rate was 18.5%, the median time to response was 17.9 weeks (range, 7.3 to 32.4 weeks), and the median duration of response was not yet reached (range, 15.0 to ≥ 47.3 weeks).
This phase Ib study describes preliminary evidence of clinical activity and a potentially acceptable safety profile of pembrolizumab given every 2 weeks to patients with heavily pretreated, advanced TNBC. A single-agent phase II study examining a 200-mg dose given once every 3 weeks (ClinicalTrials.gov identifier: NCT02447003) is ongoing.
Immuno-oncology (I-O) has required a shift in the established paradigm of toxicity and response assessment in clinical research. The design and interpretation of cancer clinical trials has been ...primarily driven by conventional toxicity and efficacy patterns observed with chemotherapy and targeted agents, which are insufficient to fully inform clinical trial design and guide therapeutic decisions in I-O. Responses to immune-targeted agents follow nonlinear dose-response and dose-toxicity kinetics mandating the development of novel response evaluation criteria. Biomarker-driven surrogate endpoints may better capture the mechanism of action and biological response to I-O agents and could be incorporated prospectively in early-phase I-O clinical trials. While overall survival remains the gold standard for evaluation of clinical efficacy of I-O agents in late-phase clinical trials, exploration of potential novel surrogate endpoints such as objective response rate and milestone survival is to be encouraged. Patient-reported outcomes should also be assessed to help redefine endpoints for I-O clinical trials and drive more efficient drug development. This paper discusses endpoints used in I-O trials to date and potential optimal endpoints for future early- and late-phase clinical development of I-O therapies.
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