Within the past decade, the field of immunotherapy has revolutionized the treatment of many cancers with the development and regulatory approval of various immune-checkpoint inhibitors and chimeric ...antigen receptor T cell therapies in diverse indications. Another promising approach to cancer immunotherapy involves the use of personalized vaccines designed to trigger de novo T cell responses against neoantigens, which are highly specific to tumours of individual patients, in order to amplify and broaden the endogenous repertoire of tumour-specific T cells. Results from initial clinical studies of personalized neoantigen-based vaccines, enabled by the availability of rapid and cost-effective sequencing and bioinformatics technologies, have demonstrated robust tumour-specific immunogenicity and preliminary evidence of antitumour activity in patients with melanoma and other cancers. Herein, we provide an overview of the complex process that is necessary to generate a personalized neoantigen vaccine, review the types of vaccine-induced T cells that are found within tumours and outline strategies to enhance the T cell responses. In addition, we discuss the current status of clinical studies testing personalized neoantigen vaccines in patients with cancer and considerations for future clinical investigation of this novel, individualized approach to immunotherapy.
Cancer vaccines, which are designed to amplify tumour-specific T cell responses through active immunization, have long been envisioned as a key tool of effective cancer immunotherapy. Despite a clear ...rationale for such vaccines, extensive past efforts were unsuccessful in mediating clinically relevant antitumour activity in humans. Recently, however, next-generation sequencing and novel bioinformatics tools have enabled the systematic discovery of tumour neoantigens, which are highly desirable immunogens because they arise from somatic mutations of the tumour and are therefore tumour specific. As a result of the diversity of tumour neoepitopes between individuals, the development of personalized cancer vaccines is warranted. Here, we review the emerging field of personalized cancer vaccination and discuss recent developments and future directions for this promising treatment strategy.
Summary Background Few effective treatments exist for patients with advanced urothelial carcinoma that has progressed after platinum-based chemotherapy. We assessed the activity and safety of ...nivolumab in patients with locally advanced or metastatic urothelial carcinoma whose disease progressed after previous platinum-based chemotherapy. Methods In this phase 1/2, multicentre, open-label study, we enrolled patients (age ≥18 years) with urothelial carcinoma of the renal pelvis, ureter, bladder, or urethra at 16 sites in Finland, Germany, Spain, the UK, and the USA. Patients were not selected by PD-L1 expression, but tumour PD-L1 membrane expression was assessed retrospectively. Patients received nivolumab 3 mg/kg intravenously every 2 weeks until disease progression or treatment discontinuation because of unacceptable toxicity or other protocol-defined reasons, whichever occurred later. The primary endpoint was objective response by investigator assessment. All patients who received at least one dose of the study drug were included in the analyses. We report an interim analysis of this ongoing trial. CheckMate 032 is registered with ClinicalTrials.gov , NCT01928394. Findings Between June 5, 2014, and April 24, 2015, 86 patients with metastatic urothelial carcinoma were enrolled in the nivolumab monotherapy group and 78 received at least one dose of treatment. At data cutoff (March 24, 2016), the minimum follow-up was 9 months (median 15·2 months, IQR 12·9–16·8). A confirmed investigator-assessed objective response was achieved in 19 (24·4%, 95% CI 15·3–35·4) of 78 patients. Grade 3–4 treatment-related adverse events occurred in 17 (22%) of 78 patients; the most common were elevated lipase (four 5%), elevated amylase (three 4%), and fatigue, maculopapular rash, dyspnoea, decreased lymphocyte count, and decreased neutrophil count (two 3% each). Serious adverse events were reported in 36 (46%) of 78 patients and eight (10%) had a serious adverse event judged to be treatment related. Two (3%) of 78 patients discontinued because of treatment-related adverse events (grade 4 pneumonitis and grade 4 thrombocytopenia) and subsequently died. Interpretation Nivolumab monotherapy was associated with a substantial and durable clinical response and a manageable safety profile in previously treated patients with locally advanced or metastatic urothelial carcinoma. These data support further investigation of nivolumab monotherapy in advanced urothelial carcinoma. Funding Bristol-Myers Squibb.
Programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1) checkpoint blockade immunotherapy elicits durable antitumor effects in multiple cancers, yet not all patients ...respond. We report the evaluation of >300 patient samples across 22 tumor types from four KEYNOTE clinical trials. Tumor mutational burden (TMB) and a T cell-inflamed gene expression profile (GEP) exhibited joint predictive utility in identifying responders and nonresponders to the PD-1 antibody pembrolizumab. TMB and GEP were independently predictive of response and demonstrated low correlation, suggesting that they capture distinct features of neoantigenicity and T cell activation. Analysis of The Cancer Genome Atlas database showed TMB and GEP to have a low correlation, and analysis by joint stratification revealed biomarker-defined patterns of targetable-resistance biology. These biomarkers may have utility in clinical trial design by guiding rational selection of anti-PD-1 monotherapy and combination immunotherapy regimens.
As reported recently in Science Translational Medicine, intra-tumoral administration of mRNAs that encode four cytokines formulated in saline mediates regression of injected and distant murine ...tumors. The anti-tumor effect, which is also seen in the anti-PD-1-resistant setting and enhanced by checkpoint blockade, is mediated by tumor-specific T cells and natural killer cells.
As reported recently in Science Translational Medicine, intra-tumoral administration of mRNAs that encode four cytokines formulated in saline mediates regression of injected and distant murine tumors. The anti-tumor effect, which is also seen in the anti-PD-1-resistant setting and enhanced by checkpoint blockade, is mediated by tumor-specific T cells and natural killer cells.
Purpose The safety and efficacy of pembrolizumab, a humanized monoclonal antibody against programmed death 1 (PD-1), were assessed in patients with programmed death ligand 1 (PD-L1)-expressing ...extensive-stage small-cell lung cancer (SCLC) in the multicohort, phase Ib open-label KEYNOTE-028 study ( ClinicalTrials.gov identifier: NCT02054806). Methods Patients with SCLC received pembrolizumab 10 mg/kg every 2 weeks for 24 months or until disease progression or intolerable toxicity occurred. PD-L1 expression was assessed by immunohistochemistry. PD-L1-positive patients had membranous PD-L1 expression in ≥ 1% of tumor and associated inflammatory cells or positive staining in stroma. Response was assessed by investigator per Response Evaluation Criteria in Solid Tumors version 1.1 every 8 weeks for the first 6 months and every 12 weeks thereafter. Adverse events (AEs) were reported per the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. Primary end points were safety, tolerability, and objective response rate (ORR). Secondary end points included progression-free survival, overall survival, and duration of response. Results Twenty-four patients with PD-L1-expressing SCLC were enrolled and received at least one pembrolizumab dose. At the data cutoff date (June 20, 2016), the median follow-up duration was 9.8 months (range, 0.5 to 24 months). All 24 patients experienced AEs; the most common were asthenia (n = 7), fatigue (n = 7), and cough (n = 6). Two patients experienced grade 3 to 5 treatment-related AEs: one patient had elevated bilirubin, and one patient had asthenia, grade 5 colitis, and intestinal ischemia. One patient had a complete response, and seven patients had partial responses, resulting in an ORR of 33% (95% CI, 16% to 55%). Conclusion The safety of pembrolizumab was consistent with the known safety profile in other tumor types. Pembrolizumab demonstrated promising antitumor activity in patients with pretreated, PD-L1-expressing SCLC.
Checkpoint inhibitors are revolutionizing treatment options and expectations for patients with melanoma. Ipilimumab, a monoclonal antibody against cytotoxic T-lymphocyte-associated antigen 4 ...(CTLA-4), was the first approved checkpoint inhibitor. Emerging long-term data indicate that approximately 20% of ipilimumab-treated patients achieve long-term survival. The first programmed death 1 (PD-1) inhibitor, pembrolizumab, was recently approved by the United States Food and Drug Administration for the treatment of melanoma; nivolumab was previously approved in Japan. PD-1 inhibitors are also poised to become standard of care treatment for other cancers, including non-small cell lung cancer, renal cell carcinoma and Hodgkin's lymphoma. Immunotherapy using checkpoint inhibition is a different treatment approach to chemotherapy and targeted agents: instead of directly acting on the tumor to induce tumor cell death, checkpoint inhibitors enhance or de novo stimulate antitumor immune responses to eliminate cancer cells. Initial data suggest that objective anti-tumor response rates may be higher with anti-PD-1 agents compared with ipilimumab and the safety profile may be more tolerable. This review explores the development and next steps for PD-1 pathway inhibitors, including discussion of their novel mechanism of action and clinical data to-date, with a focus on melanoma.
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