Immune Checkpoint Blockade: A New Paradigm in Treating Advanced Cancer

Delayed Separation of Kaplan-Meier Curves is Commonly Observed in Studies of Advanced/Metastatic Solid Tumors Treated with Anti-PD-(L)1 Therapy: Systematic Review and Meta-Analysis

BACKGROUND

Immune checkpoint inhibitor (ICI) Kaplan-Meier (KM) curves often show delayed survival benefit followed by long-term survival in a subgroup of patients. Such outcomes can violate the proportional hazards assumption, leading to a loss of statistical power.

OBJECTIVE

We aimed to determine common trends in delayed separation to inform future ICI clinical trials.

PATIENTS AND METHODS

A literature search was performed using Trialtrove® to identify phase III trials of antiprogrammed cell death (ligand)-1 (anti-PD-[L]1) agents in locally advanced/metastatic solid tumors published between January 2010 and September 2021. The frequency of delayed separation of overall survival (OS) and progression-free survival (PFS) KM curves, correlation between duration of delayed separation in OS/PFS KM curves, and correlation between duration of delayed separation in OS/PFS KM curves with corresponding hazard ratios (HRs) were assessed in all-comer and PD-L1 enriched populations.

RESULTS

Eighty-five studies with OS/PFS KM curves were identified. Most studies showed delayed separation of OS (> 67.9%) and PFS (> 54.5%) KM curves. The correlation between the duration of delayed separation in OS/PFS KM curves was strongest in the PD-L1 enriched population (adjusted R2 = 0.66). No correlation was seen between the duration of delayed separation of OS KM curves and OS HR. A modest correlation was seen between the duration of delayed separation of PFS KM curves and PFS HR in all-comer and PD-L1 enriched populations (adjusted R2 = 0.24 and 0.31, respectively).

CONCLUSIONS

Delayed separation of KM curves was common in clinical trials of anti-PD-(L)1 agents. Understanding delayed separation is key to clinical study designs and assessing outcomes with ICIs.

Thyroid Storm and Type 1 Diabetes Mellitus Induced by Combined Ipilimumab and Nivolumab Immunotherapy: A Case Report

Immune checkpoint inhibitors have revolutionised the management of cancer, and they are being used in combination to improve survival outcomes. Combination therapy is, however, associated with an increase in the frequency and severity of immune-related adverse events such as endocrine disorders. We report a case of simultaneous onset thyroid storm and type 1 diabetes mellitus induced by ipilimumab and nivolumab therapy in a patient with advanced melanoma. This case report suggests that combination immunotherapy can trigger a robust immune reaction leading to the development of multiple life-threatening endocrinopathies, including rapid onset destructive thyroiditis and insulitis. Prompt identification and management are essential to prevent morbidity and mortality.

Treatment-free survival after discontinuation of immune checkpoint inhibitors in mNSCLC: a systematic review and meta-analysis

Background

Recent research has suggested that patients with metastatic non-small cell lung cancer (mNSCLC) can achieve ongoing response after discontinuation of immune checkpoint inhibitor (ICI), but the best time to discontinue and the factors influencing efficacy remain unknown.

Method

A systematic search was performed for prospective clinical trials in patients with mNSCLC treated with ICIs published up to July 10, 2022. Eligible studies reported treatment-free survival (TFS) after discontinuation of ICI in partial objective responders. We calculated objective response rate (ORR) and TFS using random-effects models with respective 95% confidence intervals (Cis), and performed subgroup analyses to discuss the specific associations between ORR and TFS and the associated influencing factors.

Results

Across the 26 cohorts (3833 patients) included, the weighted mean ORR for all patients was 29.30% (95% CI 24.28% to 34.57%), with ICI plus chemotherapy (48.83%, 95% CI 44.36% to 53.30%) significantly higher than monotherapy (23.40%, 95% CI 18.53% to 28.62%). 395 patients were all patients who were complete or partial responders in the study, 194 discontinued ICI treatment, and nearly 35.5% achieved a durable response. No significant differences in TFS were found between subgroups according to the ICI regimen classification. Four cohorts of patients who completed 35 courses of treatment showed high levels of pooled TFS at 6 (80.18%, 95% CI 53.03% to 97.87%) and 12 months (66.98%, 95% CI 46.90% to 84.47%). Three cohorts of patients discontinued ICI treatment due to treatment-related adverse events (TRAEs) with the TFS rates at 6 (76.98%, 95% CI 65.79% to 86.65%) and 12 months (64.79%, 95% CI 50.20% to 78.19%).

Conclusion

Patients with mNSCLC were able to achieve ongoing responses after discontinuation of ICI. In conclusion, the results of this meta-analysis indicate that different treatment regimens, different drugs or different treatment durations may have an impact on TFS.

Transient Thyroiditis Followed by Exacerbation of Hypothyroidism After Immune Checkpoint Inhibitor Therapy (Nivolumab and Ipilimumab) in a Patient With Pre-existing Autoimmune Hypothyroidism: A Case Report

Treatment with immune checkpoint inhibitors has improved the prognosis of solid tumors. However, immune-related adverse events (IRAEs), including exacerbation of pre-existing autoimmune disease, are common and have become more frequent with combination therapy. The literature is scanty regarding reports of the use of combination immune checkpoint therapy in patients with pre-existing autoimmune hypothyroidism. We report a case of a man with a history of hypothyroidism, who developed transient thyroiditis, characterized by a thyrotoxic phase followed by a severe hypothyroid phase soon after receiving combination therapy (nivolumab and ipilimumab) for the treatment of a malignant pleural mesothelioma. He had been on a stable low dose of levothyroxine for 12 years prior to this episode. His levothyroxine requirement markedly increased soon after the episode of immune checkpoint inhibitor-induced thyroiditis. Immune checkpoint inhibitors can cause destructive thyroiditis followed by exacerbation of hypothyroidism in patients with pre-existing autoimmune hypothyroidism, such that patients end up on a higher dose of levothyroxine. This case will add to the growing literature regarding thyroid IRAEs associated with the use of immune checkpoint inhibitors in patients with pre-existing autoimmune thyroid disease.

Molecular Mechanisms of Resistance to Immunotherapy and Antiangiogenic Treatments in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype arising from renal cell carcinomas. This tumor is characterized by a predominant angiogenic and immunogenic microenvironment that interplay with stromal, immune cells, and tumoral cells. Despite the obscure prognosis traditionally related to this entity, strategies including angiogenesis inhibition with tyrosine kinase inhibitors (TKIs), as well as the enhancement of the immune system with the inhibition of immune checkpoint proteins, such as PD-1/PDL-1 and CTLA-4, have revolutionized the treatment landscape. This approach has achieved a substantial improvement in life expectancy and quality of life from patients with advanced ccRCC. Unfortunately, not all patients benefit from this success as most patients will finally progress to these therapies and, even worse, approximately 5 to 30% of patients will primarily progress. In the last few years, preclinical and clinical research have been conducted to decode the biological basis underlying the resistance mechanisms regarding angiogenic and immune-based therapy. In this review, we summarize the insights of these molecular alterations to understand the resistance pathways related to the treatment with TKI and immune checkpoint inhibitors (ICIs). Moreover, we include additional information on novel approaches that are currently under research to overcome these resistance alterations in preclinical studies and early phase clinical trials.

Treatment-free survival over extended follow-up of patients with advanced melanoma treated with immune checkpoint inhibitors in CheckMate 067

BACKGROUND

Treatment-free survival (TFS) characterizes disease control after discontinuation of immune checkpoint inhibitors (ICIs) until subsequent therapy or death. We previously evaluated TFS in a pooled analysis of the CheckMate 067 and CheckMate 069 trials of the ICIs nivolumab and ipilimumab, alone or in combination, in patients with advanced melanoma after minimum follow-up of 36 months. This analysis investigated TFS differences between treatments in CheckMate 067 after a minimum follow-up of 60 months, and their relation to overall survival (OS) differences.

METHODS

Data were from 937 patients who initiated treatment (nivolumab plus ipilimumab, nivolumab, or ipilimumab) in CheckMate 067 (NCT01844505). TFS was defined as the area between the Kaplan-Meier curves for time to protocol therapy cessation and time to subsequent systemic therapy initiation or death, each measured from randomization. TFS was partitioned as time with and without toxicity. Toxicity included persistent and late-onset grade ≥2 select treatment-related adverse events (ie, those of potential immunologic etiology). The area between Kaplan-Meier curves was estimated by the difference in 60-month restricted-mean times of the endpoints. Between-group differences were estimated with bootstrapped 95% CIs.

RESULTS

At 60 months from randomization, 39%, 24%, and 11% of patients assigned to treatment with nivolumab plus ipilimumab, nivolumab, and ipilimumab, respectively, had survived and were treatment-free. The 60-month mean TFS was approximately twice as long with the combination (19.7 months) than with nivolumab (9.9 months; absolute difference, 9.8 (95% CI 6.7 to 12.8)) or ipilimumab (11.9 months; absolute difference, 7.8 (95% CI 4.6 to 11.0)). In the respective groups, mean TFS represented 33% (8% with and 25% without toxicity), 17% (2% and 14%), and 20% (3% and 17%) of the 60-month period. Compared with 36-month estimates, mean TFS over the 60-month period represented slightly greater percentages of time in the nivolumab-containing regimen groups and a lesser percentage in the ipilimumab group. TFS differences between the combination and either monotherapy increased with longer follow-up.

CONCLUSIONS

Along with improved long-term OS with the nivolumab-containing regimens versus ipilimumab, TFS without toxicity was sustained with nivolumab plus ipilimumab versus either monotherapy, demonstrating larger between-group differences with extended follow-up.

Atezolizumab-Induced Hypothyroidism in a Patient With Pre-existing Triiodothyronine (T3) Thyrotoxicosis Due to Graves' Disease: A Case Report and Literature Review

The use of immune checkpoint inhibitors has improved the management and prognosis of many solid tumors. Because of their mechanism of action, and as checks on the immune systems are reduced, immune-related adverse events are common, including the exacerbation of the pre-existing autoimmune disease. The literature is scanty regarding reports of the use of immune checkpoint inhibitors in patients with pre-existing Graves' disease. We report a case of a woman with pre-existing triiodothyronine (T3) thyrotoxicosis (hyperthyroidism) secondary to Graves' disease, who developed thyroiditis followed by severe hypothyroidism after receiving an immune checkpoint inhibitor (atezolizumab) for the treatment of small-cell lung cancer. She had been on an anti-thyroid drug for Graves' disease for two and a half years and was on the waiting list for a total thyroidectomy. However, the discovery of the severe hypothyroidism following atezolizumab-induced thyroiditis resulted in the need for long-term thyroid replacement therapy, and the planned surgery was no longer required. This case is one of the very few published reports of the use of atezolizumab in a patient with pre-existing Graves' disease, resulting in the conversion from pre-existing T3-thyrotoxicosis to overt hypothyroidism. A multidisciplinary team approach is required when using immune checkpoint inhibitors in patients with pre-existing Graves' disease or any other autoimmune disease.

Discovery of secondary sulphonamides as IDO1 inhibitors with potent antitumour effects in vivo

Indoleamine 2,3-dioxygenase 1 (IDO1) as a key rate-limiting enzyme in the kynurenine pathway of tryptophan metabolism plays an important role in tumour immune escape. Herein, a variety of secondary sulphonamides were synthesised and evaluated in the HeLa cell-based IDO1/kynurenine assay, leading to the identification of new IDO1 inhibitors. Among them, compounds 5d, 5l and 8g exhibited the strongest inhibitory effect with significantly improved activity over the hit compound BS-1. The in vitro results showed that these compounds could restore the T cell proliferation and inhibit the differentiation of naïve CD4⁺ T cell into highly immunosuppressive FoxP3⁺ regulatory T (Treg) cell without affecting the viability of HeLa cells and the expression of IDO1 protein. Importantly, the pharmacodynamic assay showed that compound 5d possessed potent antitumour effect in both CT26 and B16F1 tumours bearing immunocompetent mice but not in immunodeficient mice. Functionally, subsequent experiments demonstrated that compound 5d could effectively inhibit tumour cell proliferation, induce apoptosis, up-regulate the expression of IFN-γ and granzyme B, and suppress FoxP3⁺ Treg cell differentiation, thereby activate the immune system. Thus, compound 5d could be a potential and efficacious agent for further evaluation.

Hematopoietic versus Solid Cancers and T Cell Dysfunction: Looking for Similarities and Distinctions

Simple Summary

Dysfunction of the immune T cell compartment occurs in many hematopoietic as well as solid cancers and hampers successful application of new immunotherapeutic approaches. A complete understanding of T cell dysfunction might improve the outcome of such therapies, but an overview in the various cancers is still lacking. We aim to map areas of similarities and differences in solid versus hematopoietic malignancies, providing a high-level rather than a detailed perspective on T cell dysfunction in those tumors.

Abstract

Cancer cells escape, suppress and exploit the host immune system to sustain themselves, and the tumor microenvironment (TME) actively dampens T cell function by various mechanisms. Over the last years, new immunotherapeutic approaches, such as adoptive chimeric antigen receptor (CAR) T cell therapy and immune checkpoint inhibitors, have been successfully applied for refractory malignancies that could only be treated in a palliative manner previously. Engaging the anti-tumor activity of the immune system, including CAR T cell therapy to target the CD19 B cell antigen, proved to be effective in acute lymphocytic leukemia. In low-grade hematopoietic B cell malignancies, such as chronic lymphocytic leukemia, clinical outcomes have been tempered by cancer-induced T cell dysfunction characterized in part by a state of metabolic lethargy. In multiple myeloma, novel antigens such as BCMA and CD38 are being explored for CAR T cells. In solid cancers, T cell-based immunotherapies have been applied successfully to melanoma and lung cancers, whereas application in e.g., breast cancer lags behind and is modestly effective as yet. The main hurdles for CAR T cell immunotherapy in solid tumors are the lack of suitable antigens, anatomical inaccessibility, and T cell anergy due to immunosuppressive TME. Given the wide range of success and failure of immunotherapies in various cancer types, it is crucial to comprehend the underlying similarities and distinctions in T cell dysfunction. Hence, this review aims at comparing selected, distinct B cell-derived versus solid cancer types and at describing means by which malignant cells and TME might dampen T cell anti-tumor activity, with special focus on immunometabolism. Drawing a meaningful parallel between the efficacy of immunotherapy and the extent of T cell dysfunction will shed light on areas where we can improve immune function to battle cancer.

Immune manifestations with checkpoint inhibitors in a single Brazilian center: experience and literature review

Objectives

The presence of autoimmune events were recorded in patients receiving immune checkpoint inhibitors.

Materials & Methods

Retrospective study in patients receiving immune checkpoint inhibitors (ICIs) during the period of 2012-2019.

Results

A total of 554 patients received ICIs of which 123 developed an immune related adverse event. Twenty one (17%) with toxicity were identified as having a pre-existing autoimmune disease and 88 required treatment with corticosteroids or hormone replacement. Thirty two (26%) out of 123 had to temporarily discontinue ICIs due to autoimmune manifestations. Endocrine and skin manifestations were the most prevalent immune disorders in our cohort. In melanoma better efficacy was seen in patients with immune toxicity.

Conclusion

Autoimmune diseases appear in patients receiving ICIs in this real world experience. Our results differ from other series on the frequency of autoimmunity. Complete discontinuation of ICIs due to autoimmunity was rare.

Thyroid Dysfunctions Due to Immune Checkpoint Inhibitors: A Review

Aim

Immune checkpoint inhibitors are anti-cancer drugs associated with adverse events that result from releasing the immune system against self-antigens while attacking cancer cells. Thyroid dysfunctions are among the most common associated adverse events.

Materials and Methods

We conducted a systematic search of the literature in 2 databases: PubMed and Medline. Articles that reported thyroid adverse events of immune checkpoint inhibitors were reviewed. Thyroid disorders include hyperthyroidism and hypothyroidism and are most commonly seen with programmed cell death protein 1 and programmed death-ligand 1 inhibitors.

Conclusions

Thyroid disorders are common side effects seen with check point inhibitors and are treated, depending on the clinical situation, by adequate hormonal replacement, thionamides, corticosteroids or observation only. The use of high dose corticosteroids has not been established as a treatment of thyroid toxicities. Thyroid function tests screening should be a part of baseline laboratory testing of all patients undergoing treatment with immune checkpoint inhibitors.

Blocking the PD-1/PD-L1 axis enhanced cisplatin chemotherapy in osteosarcoma in vitro and in vivo

Background

The blocking of the programmed cell death protein (PD-1)/programmed death-ligand 1 (PD-L1) axis has been found to have an anticancer activity against various types of cancer by enhancing T cell immunity, while there are no studies linking the PD-1/PD-L1 axis to chemotherapy drugs in osteosarcoma (OS). The present study aimed to investigate the effects of blocking PD-1/PD-L1 axis on the cisplatin chemotherapy in OS in vitro and in vivo.

Methods

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to detect PD-L1 mRNA in OS tissues. Cell proliferation and apoptosis were measured by Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. In vivo, the syngeneic mice were treated with cisplatin and anti-PD-1 antibody alone or jointly.

Results

In this study, it revealed that PD-L1 mRNA was highly expressed in OS tissues. Further inhibitory evaluation showed that the K7M2-LV cells (PD-L1 overexpression) co-cultured with PD-1⁺ lymphocytes could promote K7M2 cell proliferation. Meanwhile, the combination of anti-PD-1 antibody and cisplatin significantly decreased the proliferation and increased the apoptosis of K7M2 cells in a co-culture system. In vivo, the combination of anti-PD-1 antibody and cisplatin significantly inhibited tumor growth, while the mechanisms did not involve regulatory T cells.

Conclusion

The present data suggested that the blocking of PD-1/PD-L1 axis had a positive prognostic value, which can enhance the chemotherapeutic effect of cisplatin in OS. These findings provide a rationale for utilizing PD1/PD-L1 blocking antibodies as a single agent to cure refractory OS in patients receiving cisplatin treatment.

Treatment-Free Survival: A Novel Outcome Measure of the Effects of Immune Checkpoint Inhibition-A Pooled Analysis of Patients With Advanced Melanoma

PURPOSE

Outcome measures that comprehensively capture attributes of immuno-oncology agents, including prolonged treatment-free time and persistent treatment-related adverse events (TRAEs), are needed to complement conventional survival end points.

METHODS

We pooled data from the CheckMate 067 and 069 clinical trials of nivolumab and ipilimumab, as monotherapies or in combination, for patients with advanced melanoma. Treatment-free survival (TFS) was defined as the area between Kaplan-Meier curves for two conventional time-to-event end points, each defined from random assignment: time to immune checkpoint inhibitor (ICI) protocol therapy cessation and time to subsequent systemic therapy initiation or death. TFS was partitioned as time with and without toxicity by a third end point, time to cessation of both ICI therapy and toxicity. Toxicity included persistent and late-onset grade 3 or higher TRAEs. The area under each Kaplan-Meier curve was estimated by the 36-month restricted mean time.

RESULTS

At 36 months, many of the 1,077 patients who initiated ICI therapy were surviving free of subsequent therapy initiation (47% nivolumab plus ipilimumab, 37% nivolumab, 15% ipilimumab). The restricted mean TFS was longer for nivolumab plus ipilimumab (11.1 months) compared with nivolumab (4.6 months; difference, 6.5 months; 95% CI, 5.0 to 8.0 months) or ipilimumab (8.7 months; difference, 2.4 months; 95% CI, 0.8 to 4.1 months); restricted mean TFS represented 31% (3% with and 28% without toxicity), 13% (1% and 11%), and 24% (less than 1% and 23%) of the 36-month period, respectively, in the three treatment groups. TFS without toxicity was longer for nivolumab plus ipilimumab than nivolumab (difference, 6.0 months) or ipilimumab (difference, 1.7 months).

CONCLUSION

The analysis of TFS between ICI cessation and subsequent therapy initiation revealed longer TFS without toxicity for patients with advanced melanoma who received nivolumab plus ipilimumab compared with nivolumab or ipilimumab. Regardless of treatment, a small proportion of the TFS involved grade 3 or higher TRAEs.

The Advanced Practice Provider Perspective: Treating Patients With Immuno-Oncology Combination Therapy Across Tumor Types

A number of immune checkpoint inhibitors (ICIs) have been approved by the U.S. Food and Drug Administration (FDA) as immuno-oncology (IO) monotherapy for multiple solid and hematologic tumor types across various lines of therapy. Furthermore, evidence shows some patients may derive additional benefit from IO combination therapy. Three IO combination regimens, nivolumab plus ipilimumab, and pembrolizumab or atezolizumab plus chemotherapy, are approved by the FDA as of April 2019. Because peripheral immune surveillance via T-cell activity is increased to attack malignant cells, the antitumor effects of ICIs may be accompanied by immune-mediated adverse reactions (IMARs). Although potentially more efficacious than monotherapy, IO combination therapies are associated with increased incidences of IMARs vs. IO monotherapy. Advanced practice providers (APPs) are uniquely placed within the multidisciplinary team to counsel patients with cancer on their IO treatment and educate them about identifying manifestations of IMARs. Advanced practice providers should be aware of the presentation and time to onset of IMARs, appropriate management to reduce risk of organ dysfunction, and guidelines for treating these patients. This article reviews IO/IO and IO/chemotherapy combination regimens with respect to clinical efficacy and safety, and discusses the role of the APP in managing IMARs associated with IO combination therapy.

Radiofrequency ablation of liver metastasis: potential impact on immune checkpoint inhibitor therapy

Percutaneous radiofrequency ablation (RFA), a generally accepted alternative therapy for patients with liver metastases, is a minimally invasive approach with a favorable safety profile and a lower rate of major complications. The use of RFA or combined RFA plus resection can produce total tumor clearance in patients with unresectable liver metastases. However, the relatively high rate of local tumor progression has prevented the widespread use of RFA. Furthermore, its efficacy is controversial because there have been no comparisons for its effect on overall survival compared with standard options such as systemic chemotherapy. Meanwhile, immunotherapy has become a major research focus for oncology based on the recent successes reported for immune checkpoint inhibitors for melanoma, non-small cell lung cancer, gastric cancer, and other cancers. Immune checkpoints negatively regulate T cell function, and inhibition prevents the blockade of the immune system by cancer cells to prevent their destruction. Unfortunately, only some patients (< 25%) respond to immuno-oncology drugs, whereas other patients acquire resistance. However, RFA can induce massive necrotic cell death which might activate immunity and the presentation of cryptic antigens to induce tumor-specific T cell response. Because RFA can induce the rapid release of large amounts of tumor antigens, it can potentially stimulate transient immune responses to much tumor antigens. Combination therapies have induced synergistic enhancement of anticancer immune response in preclinical studies, indicating great promise for the future of oncologic treatment.Key Points • Only some patients respond to immuno-oncology drugs. • RFA causes the release of large amounts of cellular debris, a source of tumor antigens that elicit immune responses against tumors. • Combination RFA for liver metastases and immune checkpoint inhibitor therapies might synergistically enhance antitumor immunity.

Comparative efficacy and safety of first-line treatments for advanced non-small cell lung cancer with immune checkpoint inhibitors: A systematic review and meta-analysis

BACKGROUND

Non-small cell lung cancer (NSCLC) is the predominant type of lung cancer, and most clinically curable patients are diagnosed with locally advanced disease. Although the efficacy of standard platinum-based chemotherapy doublets is relatively limited. The effect of immune checkpoint inhibitors (ICIs) remains controversial, and its role in the first-line treatment of advanced NSCLC is obscure. Thus, we carried out a systematic review and meta-analysis to compare the efficacy and safety of ICIs for advanced NSCLC.

METHODS

The PubMed, Cochrane Central Register Trial, and American Society of Clinical Oncology databases were searched from inception to 30 April 2018. We searched for randomized controlled trials comparing single-agent programmed cell death protein 1/programmed death-ligand 1 inhibitors (nivolumab, pembrolizumab, or atezolizumab) or cytotoxic T-lymphocyte-associated antigen 4 inhibitor (ipilimumab) with chemotherapy in NSCLC patients. Progression-free survival, overall survival, objective response rate, and adverse events were pooled for meta-analysis by Review Manager (RevMan version 5.3) software.

RESULTS

After exclusion of ineligible studies, 12 eligible randomized controlled trials were included. Data showed that ICIs significantly improved progression-free survival (HR 0.66, 95% CI 0.57-0.77, P < 0.00001), overall survival (HR 0.77, 95% CI 0.64-0.91, P = 0.003), and but not objective response rate (RR 1.97, 95% CI 1.25-3.13, P = 0.004) in all unselected NSCLC populations. However, they failed to increase the OS of programmed death-ligand 1 = 1-49% subgroup (HR 0.78, 95% CI 0.51-1.19, P = 0.25) and PFS of programmed death-ligand 1<1% subgroup (HR 0.85; 95%CI 0.70 to 1.03, P=0.09) in ICIs+chemotherapy over chemotherapy. Meanwhile, OS of programmed death-ligand =1-49% subgroup (HR 0.92; 95%CI 0.77 to 1.10, P=0.36) and PFS of programmed death-ligand 1≥50% subgroup (HR 0.76; 95%CI 0.52 to 1.11, P=0.15) showed no significant differences in ICIs over chemotherapy. Furthermore, fewer adverse events were observed in the ICIs groups than control groups.

CONCLUSION

ICIs are overall better tolerated than chemotherapy. Our results provide further evidence supporting the favorable risk/benefit ratio for ICIs.

Baseline antibody profiles predict toxicity in melanoma patients treated with immune checkpoint inhibitors

Background

Immune checkpoint inhibitors (anti-CTLA-4, anti-PD-1, or the combination) enhance anti-tumor immune responses, yielding durable clinical benefit in several cancer types, including melanoma. However, a subset of patients experience immune-related adverse events (irAEs), which can be severe and result in treatment termination. To date, no biomarker exists that can predict development of irAEs.

Methods

We hypothesized that pre-treatment antibody profiles identify a subset of patients who possess a sub-clinical autoimmune phenotype that predisposes them to develop severe irAEs following immune system disinhibition. Using a HuProt human proteome array, we profiled baseline antibody levels in sera from melanoma patients treated with anti-CTLA-4, anti-PD-1, or the combination, and used support vector machine models to identify pre-treatment antibody signatures that predict irAE development.

Results

We identified distinct pre-treatment serum antibody profiles associated with severe irAEs for each therapy group. Support vector machine classifier models identified antibody signatures that could effectively discriminate between toxicity groups with > 90% accuracy, sensitivity, and specificity. Pathway analyses revealed significant enrichment of antibody targets associated with immunity/autoimmunity, including TNFα signaling, toll-like receptor signaling and microRNA biogenesis.

Conclusions

Our results provide the first evidence supporting a predisposition to develop severe irAEs upon immune system disinhibition, which requires further independent validation in a clinical trial setting.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1452-4) contains supplementary material, which is available to authorized users.

A Phase I study of the novel immunomodulatory agent PG545 (pixatimod) in subjects with advanced solid tumours

Background

PG545 (pixatimod) is a novel immunomodulatory agent, which has been demonstrated to stimulate innate immune responses against tumours in preclinical cancer models.

Methods

This Phase I study investigated the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary efficacy of PG545 monotherapy. Escalating doses of PG545 were administered to patients with advanced solid malignancies as a weekly 1-h intravenous infusion.

Results

Twenty-three subjects were enrolled across four cohorts (25, 50, 100 and 150 mg). Three dose-limiting toxicities (DLTs)—hypertension (2), epistaxis (1)—occurred in the 150 mg cohort. No DLTs were noted in the 100 mg cohort, which was identified as the maximum-tolerated dose. No objective responses were reported. Best response was stable disease up to 24 weeks, with the disease control rate in evaluable subjects of 38%. Exposure was proportional up to 100 mg and mean half-life was 141 h. The pharmacodynamic data revealed increases in innate immune cell activation, plasma IFNγ, TNFα, IP-10 and MCP-1.

Conclusion

PG545 demonstrated a tolerable safety profile, proportional PK, evidence of immune cell stimulation and disease control in some subjects. Taken together, these data support the proposed mechanism of action, which represents a promising approach for use in combination with existing therapies.

HLA class I loss in metachronous metastases prevents continuous T cell recognition of mutated neoantigens in a human melanoma model

T lymphocytes against tumor-specific mutated neoantigens can induce tumor regression. Also, the size of the immunogenic cancer mutanome is supposed to correlate with the clinical efficacy of checkpoint inhibition. Herein, we studied the susceptibility of tumor cell lines from lymph node metastases occurring in a melanoma patient over several years towards blood-derived, neoantigen-specific CD8⁺ T cells. In contrast to a cell line established during early stage III disease, all cell lines generated at later time points from stage IV metastases exhibited partial or complete loss of HLA class I expression. Whole exome and transcriptome sequencing of the four tumor lines and a germline control were applied to identify expressed somatic single nucleotide substitutions (SNS), insertions and deletions (indels). Candidate peptides encoded by these variants and predicted to bind to the patient's HLA class I alleles were synthesized and tested for recognition by autologous mixed lymphocyte-tumor cell cultures (MLTCs). Peptides from four mutated proteins, HERPUD1^G161S, INSIG1^S238F, MMS22L^S437F and PRDM10^S1050F, were recognized by MLTC responders and MLTC-derived T cell clones restricted by HLA-A*24:02 or HLA-B*15:01. Intracellular peptide processing was verified with transfectants. All four neoantigens could only be targeted on the cell line generated during early stage III disease. HLA loss variants of any kind were uniformly resistant. These findings corroborate that, although neoantigens represent attractive therapeutic targets, they also contribute to the process of cancer immunoediting as a serious limitation to specific T cell immunotherapy.

Detection of ABCB5 tumour antigen-specific CD8+ T cells in melanoma patients and implications for immunotherapy

ATP binding cassette subfamily B member 5 (ABCB5) has been identified as a tumour-initiating cell marker and is expressed in various malignancies, including melanoma. Moreover, treatment with anti-ABCB5 monoclonal antibodies has been shown to inhibit tumour growth in xenotransplantation models. Therefore, ABCB5 represents a potential target for cancer immunotherapy. However, cellular immune responses against ABCB5 in humans have not been described so far. Here, we investigated whether ABCB5-reactive T cells are present in human melanoma patients and tested the applicability of ABCB5-derived peptides for experimental induction of human T cell responses. Peripheral blood mononuclear cells (PBMNC) isolated from blood samples of melanoma patients (n = 40) were stimulated with ABCB5 peptides, followed by intracellular cytokine staining (ICS) for interferon (IFN)-γ and tumour necrosis factor (TNF)-α. To evaluate immunogenicity of ABCB5 peptides in naive healthy donors, CD8 T cells were co-cultured with ABCB5 antigen-loaded autologous dendritic cells (DC). ABCB5 reactivity in expanded T cells was assessed similarly by ICS. ABCB5-reactive CD8⁺ T cells were detected ex vivo in 19 of 29 patients, melanoma antigen recognised by T cells (MART-1)-reactive CD8⁺ T cells in six of 21 patients. In this small, heterogeneous cohort, reactivity against ABCB5 was significantly higher than against MART-1. It occurred significantly more often and independently of clinical characteristics. Reactivity against ABCB5 could be induced in 14 of 16 healthy donors in vitro by repeated stimulation with peptide-loaded autologous DC. As ABCB5-reactive CD8 T cells can be found in the peripheral blood of melanoma patients and an ABCB5-specific response can be induced in vitro in naive donors, ABCB5 could be a new target for immunotherapies in melanoma.

Immunological and histopathological changes in sheep affected with cutaneous squamous cell carcinoma and treated immunotherapeutically

BACKGROUND AND AIM

Recently, it has been recorded unexpected percentage of cutaneous squamous cell carcinoma (cSCC) in sheep. Despite the improvement in surgical treatment, the outcome of animals remains limited by metastatic relapse. Although antibodies for cancer treatment have been practiced for many decades, the use of this methodology in animals is deficient. This study aimed to establish cSCC therapy by tumor cell protein antibody (Ab1) or secondary antibody (Ab2) raised by two series of immunization in the same strain of rabbits.

MATERIALS AND METHODS

A total of 19 Ossimi sheep were used (14 sheep suffered from cSCC and 5 were apparently healthy). Each animal from control healthy group (n=5) and control cSCC (n=4) group was treated with a course of eight injections of normal globulins. Animals in the third (n=5) and the last (n=5) groups received a course of eight injections of Ab1and Ab2, respectively. Each tumor was measured before and after treatment. The eight injections were applied at 1st, 3rd, 5th, 7th, and 9th week and the remaining three injections were at 1 week interval. Tissue specimens and blood samples were taken for histological and immunological studies.

RESULTS

The obtained results revealed that injection of Ab1 might prevent the bad prognostic picture of polymorph infiltration without any criteria of regression % of tumor. Treatment with Ab2 showed regression of tumor size ranged between minimum of 8.99% and maximum of 78.12%, however, the measurements in most cases reached the maximum regression after the past two injections. In additions, infiltration of lymphocytes to tumor site, normalization of leukocytes picture and also increase of antibody titer were observed.

CONCLUSION

This profile might confirm that Ab2 could act as an antigen and encourage us to use it as a tumor vaccine. Extensive studies are needed to isolate the idiotypic portion of Ab1 for raising Ab2 as an anti-idiotypic antibody to be used as tumor vaccine. The question of how lymphocyte traffic to the tumor site as a result of Ab2 injection needs further investigation.

Tumor immunotherapy: drug-induced neoantigens (xenogenization) and immune checkpoint inhibitors

More than 40 years ago, we discovered that novel transplantation antigens can be induced in vivo or in vitro by treating murine leukemia with dacarbazine. Years later, this phenomenon that we called "Chemical Xenogenization" (CX) and more recently, "Drug-Induced Xenogenization" (DIX), was reproduced by Thierry Boon with a mutagenic/carcinogenic compound (i.e. N-methyl-N'-nitro-N-nitrosoguanidine). In both cases, the molecular bases of DIX rely on mutagenesis induced by methyl adducts to oxygen-6 of DNA guanine. In the present review we illustrate the main DIX-related immune-pharmacodynamic properties of triazene compounds of clinical use (i.e. dacarbazine and temozolomide).In recent years, tumor immunotherapy has come back to the stage with the discovery of immune checkpoint inhibitors (ICpI) that show an extraordinary immune-enhancing activity. Here we illustrate the salient biochemical features of some of the most interesting ICpI and the up-to-day status of their clinical use. Moreover, we illustrate the literature showing the direct relationship between somatic mutation burden and susceptibility of cancer cells to host's immune responses.When DIX was discovered, we were not able to satisfactorily exploit the possible presence of triazene-induced neoantigens in malignant cells since no device was available to adequately enhance host's immune responses in clinical settings. Today, ICpI show unprecedented efficacy in terms of survival times, especially when elevated mutation load is associated with cancer cells. Therefore, in the future, mutation-dependent neoantigens obtained by appropriate pharmacological intervention appear to disclose a novel approach for enhancing the therapeutic efficacy of ICpI in cancer patients.

Effectiveness and safety of PD-1/PD-L1 inhibitors in the treatment of solid tumors: a systematic review and meta-analysis

Background

PD-1/PD-L1 inhibitors have been implicated as potentially effective anti-cancer therapies. Some clinical randomized controlled trials (RCTs) have been completed for a variety of PD-1/PD-L1 inhibitors to treat various malignancies, and more RCTs are still under way. We carried out this systematic meta-analysis to evaluate the efficacy and safety of PD-1/PD-L1 inhibitors in the treatment of solid tumors.

Methods

We searched PubMed, EMBASE, clinical trial registers, conference reports, and related reviews. Eligible RCTs that compared PD-1/PD-L1 inhibitors with other chemotherapy agents or placebo in solid tumor patients were included. For each RCT, progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), stable disease rate (SDR), progressive disease rate (PDR), and adverse events (AEs) were pooled for meta-analysis.

Findings

Based on an analysis of 10 eligible RCTs, PD-1/PD-L1 inhibitors were found to significantly improve PFS (Hazard ratio (HR), 0.65; 95% confidence interval (CI) 0.53 to 0.79, P<0.001), OS (HR, 0.69; 95%CI 0.62 to 0.76, P<0.001), and ORR (Risk Ratio (RR) 292; 95% confidence interval (CI) 2.06 to 4.15, P<0.00001) in all populations, including melanoma and NSCLC subgroups. However, they failed to increase the DCR of cancer patients (RR 1.15; 95%CI 0.91 to 1.45, P=0.25). Furthermore, less AEs were observed in the PD-1/PD-L1 inhibitor groups than the control groups.

Interpretation

PD-1 inhibitors are more effective for improving the PFS, OS, and ORR of cancer patients with little toxicity, despite having little effect on increasing of the DCR.

First-in-Human Phase I Study of the Oral Inhibitor of Indoleamine 2,3-Dioxygenase-1 Epacadostat (INCB024360) in Patients with Advanced Solid Malignancies

Purpose: Indoleamine 2,3-dioxygenase-1 (IDO1) catalyzes the degradation of tryptophan to N-formyl-kynurenine. Overexpressed in many solid malignancies, IDO1 can promote tumor escape from host immunosurveillance. This first-in-human phase I study investigated the maximum tolerated dose, safety, pharmacokinetics, pharmacodynamics, and antitumor activity of epacadostat (INCB024360), a potent and selective inhibitor of IDO1.Experimental Design: Fifty-two patients with advanced solid malignancies were treated with epacadostat [50 mg once daily or 50, 100, 300, 400, 500, 600, or 700 mg twice daily (BID)] in a dose-escalation 3 + 3 design and evaluated in 28-day cycles. Treatment was continued until disease progression or unacceptable toxicity.Results: One dose-limiting toxicity (DLT) occurred at the dose of 300 mg BID (grade 3, radiation pneumonitis); another DLT occurred at 400 mg BID (grade 3, fatigue). The most common adverse events in >20% of patients overall were fatigue, nausea, decreased appetite, vomiting, constipation, abdominal pain, diarrhea, dyspnea, back pain, and cough. Treatment produced significant dose-dependent reductions in plasma kynurenine levels and in the plasma kynurenine/tryptophan ratio at all doses and in all patients. Near maximal changes were observed at doses of ≥100 mg BID with >80% to 90% inhibition of IDO1 achieved throughout the dosing period. Although no objective responses were detected, stable disease lasting ≥16 weeks was observed in 7 of 52 patients.Conclusions: Epacadostat was generally well tolerated, effectively normalized kynurenine levels, and produced maximal inhibition of IDO1 activity at doses of ≥100 mg BID. Studies investigating epacadostat in combination with other immunomodulatory drugs are ongoing. Clin Cancer Res; 23(13); 3269-76. ©2017 AACR.

Gemcitabine reduces MDSCs, tregs and TGFβ-1 while restoring the teff/treg ratio in patients with pancreatic cancer

Background

Cancer immunotherapy can be potentiated by conditioning regimens such as cyclophosphamide, which reduces the level of regulatory T cells (tregs). However, myeloid suppressive cells are still remaining. Accordingly to previous reports, gemcitabine improves immune status of cancer patients. In this study, the role of gemcitabine was further explored to map its immunological target cells and molecules in patients with pancreatic cancer.

Methods

Patient blood was investigated by flow cytometry and cytokine arrays at different time points during gemcitabine treatment.

Results

The patients had elevated myeloid-derived suppressor cells (MDSCs), and Tregs at diagnosis. Myeloid cells were in general decreased by gemcitabine. The granulocytic MDSCs were significantly reduced while monocytic MDSCs were not affected. In vitro, monocytes responding to IL-6 by STAT3 phosphorylation were prevented to respond in gemcitabine medium. However, gemcitabine could not prevent STAT3 phosphorylation in IL-6-treated tumor cell lines. TGFβ-1 was significantly reduced after only one treatment and continued to decrease. At the same time, the effector T cell:Treg ratio was increased and the effector T cells had full proliferative capacity during the gemcitabine cycle. However, after a resting period, the level of suppressor cells and TGFβ-1 had been restored showing the importance of continuous conditioning.

Conclusions

Gemcitabine regulates the immune system in patients with pancreatic cancer including MDSCs, Tregs and molecules such as TGFβ-1 but does not hamper the ability of effector lymphocytes to expand to stimuli. Hence, it may be of high interest to use gemcitabine as a conditioning strategy together with immunotherapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-1037-z) contains supplementary material, which is available to authorized users.

Changing perspective on oncometabolites: from metabolic signature of cancer to tumorigenic and immunosuppressive agents

During tumorigenesis, the shift from oxidative phosphorylation to glycolysis in ATP production accounts for the dramatic change in the cellular metabolism and represents one of the major steps leading to tumour formation. The so-called Warburg effect is currently considered something more than a mere modification in the cellular metabolism. The paradox that during cancer cell proliferation the increase in energy need is supplied by glycolysis can be only explained by taking into account the many roles that intermediates of glycolysis or TCA cycle play in cellular physiology, besides energy production. Recent studies have shown that metabolic intermediates induce changes in chromatin structure or drive neo-angiogenesis. In this review, we present some of the latest findings in the study of cancer metabolism with particular attention to how tumour metabolism and its microenvironment can favour tumour growth and aggressiveness, by hijacking and dampening the anti-tumoral immune response.

How Checkpoint Inhibitors Are Changing the Treatment Paradigm in Solid Tumors: What Advanced Practitioners in Oncology Need to Know

The immune system plays an active role in controlling and eradicating cancer. T cells, an essential component of the adaptive immune system, have a number of surface receptors (called "checkpoints") that can help either to sustain activation or suppress T-cell function. Many malignancies have developed ways to exploit these receptors to suppress T-cell function, enabling them to continue to grow. Anticancer immunotherapy in general, and checkpoint inhibitor therapy specifically, is a unique approach to cancer treatment that strives to harness the body's own immune system to generate an adequate response against cancer cells. Several checkpoint inhibitors are approved for the treatment of metastatic melanoma, non-small cell lung cancer, and renal cell carcinoma. These and other agents in this class are being investigated for their safety and efficacy in a variety of solid and hematologic malignancies. Advanced practitioners (APs) play a critical role in caring for patients treated with checkpoint inhibitors. It is essential for APs to be aware of the mechanism of action of these agents, patterns of response seen with this type of therapy, and presentation of immune-related adverse events related to these agents to ensure timely and successful treatment. Rapid evaluation/diagnostics and treatment are essential for optimal management and prevention of end-organ disease, and treatment of immune-related adverse effects requires a multidisciplinary approach.

Structurally Enabled Discovery of Adenosine A2A Receptor Antagonists

Over the past decade there has been a revolution in the field of G protein-coupled receptor (GPCR) structural biology. Many years of innovative research from different areas have come together to fuel this significant change in the fortunes of this field, which for many years was characterized by the paucity of high-resolution structures. The determination to succeed has been in part due to the recognized importance of these proteins as drug targets, and although the pharmaceutical industry has been focusing on these receptors, it can be justifiably argued and demonstrated that many of the approved and commercially successful GPCR drugs can be significantly improved to increase efficacy and/or reduce undesired side effects. In addition, many validated targets in this class remain to be drugged. It is widely recognized that application of structure-based drug design approaches can help medicinal chemists a long way toward discovering better drugs. The achievement of structural biologists in providing high-resolution insight is beginning to transform drug discovery efforts, and there are a number of GPCR drugs that have been discovered by use of structural information that are in clinical development. This review aims to highlight the key developments that have brought success to GPCR structure resolution efforts and exemplify the practical application of structural information for the discovery of adenosine A_2A receptor antagonists that have potential to treat multiple conditions.

Timing and type of immune checkpoint therapy affect the early radiographic response of melanoma brain metastases to stereotactic radiosurgery

BACKGROUND

Growing evidence suggests that immunotherapy and radiation therapy can be synergistic in the treatment of cancer. This study was performed to determine the effect of the relative timing and type of immune checkpoint therapy on the response of melanoma brain metastases (BrMets) to treatment with stereotactic radiosurgery (SRS).

METHODS

Seventy-five melanoma patients with 566 BrMets were treated with both SRS and immune checkpoint therapy between 2007 and 2015 at a single institution. Immunotherapy and radiosurgery treatment of any single lesion were considered concurrent if SRS was administered within 4 weeks of immunotherapy. The impact of the timing and type of immunotherapy on the lesional response was determined with the Wilcoxon rank-sum test, which was used to compare the median percent lesion volume change 1.5, 3, and 6 months after SRS treatment, with significance determined by P = .0167 according to the Bonferroni correction for multiple comparisons.

RESULTS

Concurrent use of immunotherapy and SRS resulted in a significantly greater median percent reduction in the lesion volume at 1.5 (-63.1% vs -43.2%, P < .0001), 3 (-83.0% vs -52.8%, P < .0001), and 6 months (-94.9% vs -66.2%, P < .0001) in comparison with nonconcurrent therapy. The median percent reduction in the lesion volume was also significantly greater for anti-programmed cell death protein 1 (anti-PD-1) than anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA-4) at 1.5 (-71.1% vs -48.2%, P < .0001), 3 (-89.3% vs -66.2%, P < .0001), and 6 months (-95.1% vs -75.9%, P = .0004).

CONCLUSIONS

The administration of immunotherapy within 4 weeks of SRS results in an improved lesional response of melanoma BrMets in comparison with treatment separated by longer than 4 weeks. Anti-PD-1 therapy also results in a greater lesional response than anti-CTLA-4 after SRS. Cancer 2016;122:3051-3058. © 2016 American Cancer Society.

Regulation of Natural Killer Cell Function by STAT3

Natural killer (NK) cells, key members of a distinct hematopoietic lineage, innate lymphoid cells, are not only critical effectors that mediate cytotoxicity toward tumor and virally infected cells but also regulate inflammation, antigen presentation, and the adaptive immune response. It has been shown that NK cells can regulate the development and activation of many other components of the immune response, such as dendritic cells, which in turn, modulate the function of NK cells in multiple synergistic feed back loops driven by cell–cell contact, and the secretion of cytokines and chemokines that control effector function and migration of cells to sites of immune activation. The signal transducer and activator of transcription (STAT)-3 is involved in driving almost all of the pathways that control NK cytolytic activity as well as the reciprocal regulatory interactions between NK cells and other components of the immune system. In the context of tumor immunology, NK cells are a first line of defense that eliminates pre-cancerous and transformed cells early in the process of carcinogenesis, through a mechanism of “immune surveillance.” Even after tumors become established, NK cells are critical components of anticancer immunity: dysfunctional NK cells are often found in the peripheral blood of cancer patients, and the lack of NK cells in the tumor microenvironment often correlates to poor prognosis. The pathways and soluble factors activated in tumor-associated NK cells, cancer cells, and regulatory myeloid cells, which determine the outcome of cancer immunity, are all critically regulated by STAT3. Using the tumor microenvironment as a paradigm, we present here an overview of the research that has revealed fundamental mechanisms through which STAT3 regulates all aspects of NK cell biology, including NK development, activation, target cell killing, and fine tuning of the innate and adaptive immune responses.

Taking up Cancer Immunotherapy Challenges: Bispecific Antibodies, the Path Forward?

As evidenced by the recent approvals of Removab (EU, Trion Pharma) in 2009 and of Blincyto (US, Amgen) in 2014, the high potential of bispecific antibodies in the field of immuno-oncology is eliciting a renewed interest from pharmaceutical companies. Supported by rapid advances in antibody engineering and the development of several technological platforms such as Triomab or bispecific T cell engagers (BiTEs), the “bispecifics” market has increased significantly over the past decade and may occupy a pivotal space in the future. Over 30 bispecific molecules are currently in different stages of clinical trials and more than 70 in preclinical phase. This review focuses on the clinical potential of bispecific antibodies as immune effector cell engagers in the onco-immunotherapy field. We summarize current strategies targeting various immune cells and their clinical interests. Furthermore, perspectives of bispecific antibodies in future clinical developments are addressed.