PD-L1 (B7-H1) and PD-1 pathway blockade for cancer therapy: Mechanisms, response biomarkers, and combinations.

PD-L1 and PD-1 (PD) pathway blockade is a highly promising therapy and has elicited durable antitumor responses and long-term remissions in a subset of patients with a broad spectrum of cancers. How to improve, widen, and predict the clinical response to anti-PD therapy is a central theme in the field of cancer immunology and immunotherapy. Oncologic, immunologic, genetic, and biological studies focused on the human cancer microenvironment have yielded substantial insight into this issue.

Autoimmune Bullous Skin Disorders with Immune Checkpoint Inhibitors Targeting PD-1 and PD-L1.

Monoclonal antibodies (mAb) targeting immune checkpoint pathways such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death 1 (PD-1) may confer durable disease control in several malignancies. In some patients, immune checkpoint mAbs cause cutaneous immune-related adverse events. Although the most commonly reported cutaneous toxicities are mild, a subset may persist despite therapy and can lead to severe or life-threatening toxicity.

Combinatorial Cancer Immunotherapies.

T cell checkpoint blockade therapies are revolutionizing the treatment of patients with cancer. Highlighted by the recent success of PD-1 plus CTLA-4 blockade in patients with melanomas, synergistic immunotherapy combinations of modalities represent an important opportunity to improve responses and outcomes for patients. We review the rationale and experience with T cell checkpoint blockade in combination with targeting of other coinhibitory or costimulatory checkpoints, immunomodulatory molecules in the tumor microenvironment, and other anticancer modalities such as vaccines, chemotherapy, and radiation.

Intestinal microbiome analyses identify melanoma patients at risk for checkpoint-blockade-induced colitis.

The composition of the intestinal microbiota influences the development of inflammatory disorders. However, associating inflammatory diseases with specific microbial members of the microbiota is challenging, because clinically detectable inflammation and its treatment can alter the microbiota's composition. Immunologic checkpoint blockade with ipilimumab, a monoclonal antibody that blocks cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) signalling, is associated with new-onset, immune-mediated colitis.

A phase 2 trial of everolimus and pasireotide long-acting release in patients with metastatic uveal melanoma.

The aim of this study was to test the hypothesis that inhibiting mammalian target of rapamycin and insulin-like growth factor-1 receptor would be efficacious in metastatic uveal melanoma. This was a phase 2 trial of everolimus 10 mg daily plus pasireotide long-acting release 60 mg every 28 days enrolling patients with progressive, metastatic uveal melanoma to treatment until progression by Response Evaluation Criteria In Solid Tumors 1.1 (RECIST 1.

Clonal Abundance of Tumor-Specific CD4(+) T Cells Potentiates Efficacy and Alters Susceptibility to Exhaustion.

Current approaches to cancer immunotherapy aim to engage the natural T cell response against tumors. One limitation is the elimination of self-antigen-specific T cells from the immune repertoire. Using a system in which precursor frequency can be manipulated in a murine melanoma model, we demonstrated that the clonal abundance of CD4(+) T cells specific for self-tumor antigen positively correlated with antitumor efficacy.

Baseline Peripheral Blood Biomarkers Associated with Clinical Outcome of Advanced Melanoma Patients Treated with Ipilimumab.

Purpose: To identify baseline peripheral blood biomarkers associated with clinical outcome following ipilimumab treatment in advanced melanoma patients.

Experimental Design: Frequencies of myeloid-derived suppressor cells (MDSC) and regulatory T cells (Treg), serum lactate dehydrogenase (LDH), routine blood counts, and clinical characteristics were assessed in 209 patients. Endpoints were overall survival (OS) and best overall response.

The PTEN pathway in Tregs is a critical driver of the suppressive tumor microenvironment.

The tumor microenvironment is profoundly immunosuppressive. We show that multiple tumor types create intratumoral immune suppression driven by a specialized form of regulatory T cell (Treg) activation dependent on the PTEN (phosphatase and tensin homolog) lipid phosphatase. PTEN acted to stabilize Tregs in tumors, preventing them from reprogramming into inflammatory effector cells.

CCR 20th Anniversary Commentary: Immune-Related Response Criteria--Capturing Clinical Activity in Immuno-Oncology.

To evaluate antitumor responses to chemotherapeutic agents, investigators would typically rely upon Response Evaluation Criteria in Solid Tumors (RECIST) or modified WHO criteria, which do not comprehensively capture responses with immunotherapeutic agents. In the December 1, 2009, issue of Clinical Cancer Research, Wolchok and colleagues reported their development of novel criteria, designated "Immune-related Response Criteria" (irRC), designed to better capture the response patterns observed with immunotherapies. Broad use of the irRC since then has allowed for a more comprehensive evaluation of immunotherapies in clinical trials, indicating that their concepts can be used in conjunction with either RECIST or WHO, and has shown irRC to be a powerful tool for improved clinical investigation.

Phase I Clinical Trial of Ipilimumab in Pediatric Patients with Advanced Solid Tumors.

Purpose: Ipilimumab is a first-in-class immune checkpoint inhibitor approved for treatment of metastatic melanoma but not studied in children until this phase I protocol.

Experimental Design: This study examined safety, pharmacokinetics, and immunogenicity, and immune correlates of ipilimumab administered to subjects ≤21 years old with recurrent or progressive solid tumors. Dose escalation cohorts received 1, 3, 5, or 10 mg/m(2) intravenously every 3 weeks in a 3 + 3 design.

Genetics and immunology: reinvigorated.

Immune checkpoint blockade therapy is changing oncology by improving the outcome of patients with advanced malignancies. Our research has revealed the genetic features of tumors present in patients who initiate a successful antitumor immune response and derive clinical benefit from immune checkpoint blockade therapy versus non-responders.

Tumor-Expressed IDO Recruits and Activates MDSCs in a Treg-Dependent Manner.

Indoleamine 2,3-dioxygenase (IDO) has been described as a major mechanism of immunosuppression in tumors, though the mechanisms of this are poorly understood. Here, we find that expression of IDO by tumor cells results in aggressive tumor growth and resistance to T-cell-targeting immunotherapies. We demonstrate that IDO orchestrates local and systemic immunosuppressive effects through recruitment and activation of myeloid-derived suppressor cells (MDSCs), through a mechanism dependent on regulatory T cells (Tregs).

Immunotherapy of Melanoma.

The history of immunotherapy is rooted in the treatment of melanoma and therapy with immune checkpoint-blocking agents is now a cornerstone for the treatment of metastatic melanoma. The first effective immunotherapies approved by the US Food and Drug Administration in melanoma included interleukin-2 for metastatic disease and interferon alpha in the adjuvant setting. These were followed by a group of new therapies, including checkpoint-blocking antibodies targeting cytotoxic T lymphocyte-associated protein 4 and programmed cell death protein 1.

Clinical Activity, Toxicity, Biomarkers, and Future Development of CTLA-4 Checkpoint Antagonists.

Evidence that the immune system can recognize, and in some cases control or even eliminate tumors, is increasingly clear. Encouraging T-cell activation by blocking regulatory or "checkpoint" molecules is a potent way to amplify anti-tumor immune responses. Successfully exploiting this concept, a new class of anti-cancer therapies, "checkpoint-blocking" antibodies has emerged.

Inhibiting DNA Methylation Causes an Interferon Response in Cancer via dsRNA Including Endogenous Retroviruses.

We show that DNA methyltransferase inhibitors (DNMTis) upregulate immune signaling in cancer through the viral defense pathway. In ovarian cancer (OC), DNMTis trigger cytosolic sensing of double-stranded RNA (dsRNA) causing a type I interferon response and apoptosis. Knocking down dsRNA sensors TLR3 and MAVS reduces this response 2-fold and blocking interferon beta or its receptor abrogates it.

PD-1 Blockers.

Nivolumab and pembrolizumab are monoclonal antibodies that block the programmed death-1 receptor (PD-1, CD279), resulting in dis-inhibition of tumor-specific immune responses. Both are recently approved for use in the treatment of metastatic melanoma, and nivolumab as well for non-small cell lung cancer.

Immune-Related Adverse Events, Need for Systemic Immunosuppression, and Effects on Survival and Time to Treatment Failure in Patients With Melanoma Treated With Ipilimumab at Memorial Sloan Kettering Cancer Center.

Purpose: Ipilimumab is a standard treatment for metastatic melanoma, but immune-related adverse events (irAEs) are common and can be severe. We reviewed our large, contemporary experience with ipilimumab treatment outside of clinical trials to determine the frequency of use of systemic corticosteroid or anti-tumor necrosis factor α (anti-TNFα) therapy and the effect of these therapies on overall survival (OS) and time to treatment failure (TTF).

Patients And Methods: We reviewed retrospectively the medical records of patients with melanoma who had received treatment between April 2011 and July 2013 with ipilimumab at the standard dose of 3 mg/kg.

The New Era of Cancer Immunotherapy: Manipulating T-Cell Activity to Overcome Malignancy.

Using the immune system to control cancer has been investigated for over a century. Yet it is only over the last several years that therapeutic agents acting directly on the immune system have demonstrated improved overall survival for cancer patients in phase III clinical trials. Furthermore, it appears that some patients treated with such agents have been cured of metastatic cancer.

Efficacy and Safety of Nivolumab in Patients With BRAF V600 Mutant and BRAF Wild-Type Advanced Melanoma: A Pooled Analysis of 4 Clinical Trials.

Importance: The anti-PD-1 therapeutic antibody, nivolumab, has demonstrated clinical activity in patients with advanced melanoma. The activity of nivolumab in subgroups of patients with tumors which have wild-type BRAF kinase vs patients with tumors having mutant BRAF has not systematically been explored in a large dataset.

Objective: To evaluate the efficacy and safety of nivolumab in patients with wild-type BRAF and mutant BRAF metastatic melanoma.

Safety of Infusing Ipilimumab Over 30 Minutes.

Purpose: The approved dose of ipilimumab is 3 mg/kg infused over 90 minutes; however, in clinical trials, 10 mg/kg has also been infused over 90 minutes. At this higher dose, patients receive 3 mg/kg within the first 27 minutes of treatment. We sought to determine whether the standard dose of 3 mg/kg could be safely infused over 30 minutes.