Guidelines for the evaluation of immune therapy activity in solid tumors: immune-related response criteria

Imaging approaches and radiomics: toward a new era of ultraprecision radioimmunotherapy?

Strong rationale and a growing number of preclinical and clinical studies support combining radiotherapy and immunotherapy to improve patient outcomes. However, several critical questions remain, such as the identification of patients who will benefit from immunotherapy and the identification of the best modalities of treatment to optimize patient response. Imaging biomarkers and radiomics have recently emerged as promising tools for the non-invasive assessment of the whole disease of the patient, allowing comprehensive analysis of the tumor microenvironment, the spatial heterogeneity of the disease and its temporal changes. This review presents the potential applications of medical imaging and the challenges to address, in order to help clinicians choose the optimal modalities of both radiotherapy and immunotherapy, to predict patient’s outcomes and to assess response to these promising combinations.

A Decade of Success in Melanoma Immunotherapy and Targeted Therapy: What Every Radiologist Should Know

ABSTRACT

Treatment strategies for malignant melanoma have rapidly evolved over the past decade. Because of its propensity to develop advanced stage and metastatic disease, melanoma has contributed to the majority of mortalities among patients with skin cancer. The development of novel therapeutics such as immunotherapy and targeted molecular therapies has revolutionized the treatment of patients with advanced stage and metastatic malignant melanoma. Immune checkpoint inhibitors, BRAF/MEK inhibitors, and other revolutionary therapies have demonstrated remarkable success in the treatment of this common malignancy. Along with these advancements in systemic therapies, imaging has continued to play a critical role in the diagnosis and follow-up of patients with malignant melanoma. As the use of these novel therapies continues to expand, knowledge of the evolving therapeutic landscape of melanoma is becoming critical for radiologists. In this review, we provide a primer for radiologists outlining the evolution of immunotherapy and targeted therapy in the treatment of melanoma. We discuss the critical role of imaging in evaluation of treatment response, including a summary of current imaging response guidelines. Last, we summarize the essential role of imaging in the evaluation of potential adverse events seen in patients with malignant melanoma undergoing treatment with immune checkpoint inhibitors.

Safety and Activity of PolyPEPI1018 Combined with Maintenance Therapy in Metastatic Colorectal Cancer: an Open-Label, Multicenter, Phase Ib Study

PURPOSE

Although chemotherapy is standard of care for metastatic colorectal cancer (mCRC), immunotherapy has no role in microsatellite stable (MSS) mCRC, a "cold" tumor. PolyPEPI1018 is an off-the-shelf, multi-peptide vaccine derived from 7 tumor-associated antigens (TAA) frequently expressed in mCRC. This study assessed PolyPEPI1018 combined with first-line maintenance therapy in patients with MSS mCRC.

PATIENTS AND METHODS

Eleven patients with MSS mCRC received PolyPEPI1018 and Montanide ISA51VG adjuvant subcutaneously, combined with fluoropyrimidine/biologic following first-line induction with chemotherapy and a biologic (NCT03391232). In Part A of the study, 5 patients received a single dose; in Part B, 6 patients received up to three doses of PolyPEPI1018 every 12 weeks. The primary objective was safety; secondary objectives were preliminary efficacy, immunogenicity at peripheral and tumor level, and immune correlates.

RESULTS

PolyPEPI1018 vaccination was safe and well tolerated. No vaccine-related serious adverse event occurred. Eighty percent of patients had CD8+ T-cell responses against ≥3 TAAs. Increased density of tumor-infiltrating lymphocytes were detected post-treatment for 3 of 4 patients' liver biopsies, combined with increased expression of immune-related gene signatures. Three patients had objective response according to RECISTv1.1, and 2 patients qualified for curative surgery. Longer median progression-free survival for patients receiving multiple doses compared with a single dose (12.5 vs. 4.6 months; P = 0.017) suggested a dose-efficacy correlation. The host HLA genotype predicted multi-antigen-specific T-cell responses (P = 0.01) indicative of clinical outcome.

CONCLUSIONS

PolyPEPI1018 added to maintenance chemotherapy for patients with unresectable, MSS mCRC was safe and associated with specific immune responses and antitumor activity warranting further confirmation in a randomized, controlled setting.

Precision Medicine in Solid Tumors: How Far We Traveled So Far?

The future of disease management in solid tumors will rely heavily on how effectively we understand precision medicine and how successfully we can deliver personalized medicine [...]

18FDG PET Assessment of Therapeutic Response in Patients with Advanced or Metastatic Melanoma Treated with First-Line Immune Checkpoint Inhibitors

Simple Summary

In a retrospective study of patients with advanced or metastatic melanoma treated with first-line immune checkpoint inhibitors, we investigated the value of metabolic criteria, PERCIST 5 (criteria used for conventional chemotherapy), and imPERCIST5 (criteria adapted for immunotherapy therapeutic evaluation). Responding patients according to both criteria had better overall survival than that of not-responding patients, with a 2 years OS of 91% versus 39%, respectively. Combining different approaches to assess response could help improve the confidence in the test aiming at evaluating the response to immunotherapy.

Abstract

Background: Immune checkpoint inhibitors (ICI) are currently the first-line treatment for patients with metastatic melanoma. We investigated the value of positron emission tomography (PET) response criteria to assess the therapeutic response to first-line ICI in this clinical context and explore the potential contribution of total tumor metabolic volume (TMTV) analysis. Methods: We conducted a retrospective study in patients treated with first-line ICI for advanced or metastatic melanoma, with 18F-FDG PET/CT performed at baseline and 3 months after starting treatment. Patients’ metabolic response was classified according to PERCIST5 and imPERCIST 5 criteria. TMTV was recorded for each examination. Results: Twenty-nine patients were included. The median overall survival (OS) was 51.2 months (IQR 13.6—not reached), and the OS rate at 2 years was 58.6%. Patients classified as responders (complete and partial response) had a 90.9% 2-year OS rate versus 38.9% for non-responders (stable disease and progressive disease) (p = 0.03), for PERCIST5 and imPERCIST 5 criteria. The median change in metabolic volume was 9.8% (IQR −59–+140%). No significant correlation between OS and changes in TMTV was found. Conclusion: The evaluation of response to immunotherapy using metabolic imaging with PERCIST5 and imPERCIST5 was significantly associated with OS in patients with advanced or metastatic melanoma.

Application of molecular imaging in immune checkpoints therapy: From response assessment to prognosis prediction

Recently, immune checkpoint therapy (ICT) represented by programmed cell death1 (PD-1) and its major ligands, programmed death ligand 1 (PD-L1), has achieved significant success. Detection of PD-L1 by immunohistochemistry (IHC) is a classic method to guide the treatment of ICT patients. However, PD-L1 expression in the tumor microenvironment is highly complex. Thus, PD-L1 IHC is inadequate to fully understand the relevance of PD-L1 levels in the whole body and their dynamics to improve therapeutic outcomes. Intriguingly, numerous studies have revealed that molecular imaging technologies could potentially meet this need. Therefore, the purpose of this narrative review is to summarize the preclinical and clinical application of ICT guided by molecular imaging technology, and to explore the future opportunities and practical difficulties of these innovations.

Evaluation of cancer outcome assessment using MRI: A review of deep-learning methods

Accurate evaluation of tumor response to treatment is critical to allow personalized treatment regimens according to the predicted response and to support clinical trials investigating new therapeutic agents by providing them with an accurate response indicator. Recent advances in medical imaging, computer hardware, and machine-learning algorithms have resulted in the increased use of these tools in the field of medicine as a whole and specifically in cancer imaging for detection and characterization of malignant lesions, prognosis, and assessment of treatment response. Among the currently available imaging techniques, magnetic resonance imaging (MRI) plays an important role in the evaluation of treatment assessment of many cancers, given its superior soft-tissue contrast and its ability to allow multiplanar imaging and functional evaluation. In recent years, deep learning (DL) has become an active area of research, paving the way for computer-assisted clinical and radiological decision support. DL can uncover associations between imaging features that cannot be visually identified by the naked eye and pertinent clinical outcomes. The aim of this review is to highlight the use of DL in the evaluation of tumor response assessed on MRI. In this review, we will first provide an overview of common DL architectures used in medical imaging research in general. Then, we will review the studies to date that have applied DL to magnetic resonance imaging for the task of treatment response assessment. Finally, we will discuss the challenges and opportunities of using DL within the clinical workflow.

Clinical significance and molecular annotation of cellular morphometric subtypes in lower-grade gliomas discovered by machine learning

BACKGROUND

Lower-grade gliomas (LGG) are heterogeneous diseases by clinical, histological, and molecular criteria. We aimed to personalize the diagnosis and therapy of LGG patients by developing and validating robust cellular morphometric subtypes (CMS) and to uncover the molecular signatures underlying these subtypes.

METHODS

Cellular morphometric biomarkers (CMBs) were identified with artificial intelligence technique from TCGA-LGG cohort. Consensus clustering was used to define CMS. Survival analysis was performed to assess the clinical impact of CMBs and CMS. A nomogram was constructed to predict 3- and 5-year overall survival (OS) of LGG patients. Tumor mutational burden (TMB) and immune cell infiltration between subtypes were analyzed using the Mann-Whitney U test. The double-blinded validation for important immunotherapy-related biomarkers was executed using immunohistochemistry (IHC).

RESULTS

We developed a machine learning (ML) pipeline to extract CMBs from whole-slide images of tissue histology; identifying and externally validating robust CMS of LGGs in multicenter cohorts. The subtypes had independent predicted OS across all three independent cohorts. In the TCGA-LGG cohort, patients within the poor-prognosis subtype responded poorly to primary and follow-up therapies. LGGs within the poor-prognosis subtype were characterized by high mutational burden, high frequencies of copy number alterations, and high levels of tumor-infiltrating lymphocytes and immune checkpoint genes. Higher levels of PD-1/PD-L1/CTLA-4 were confirmed by IHC staining. In addition, the subtypes learned from LGG demonstrate translational impact on glioblastoma (GBM).

CONCLUSIONS

We developed and validated a framework (CMS-ML) for CMS discovery in LGG associated with specific molecular alterations, immune microenvironment, prognosis, and treatment response.

Automated detection and segmentation of non-small cell lung cancer computed tomography images

Detection and segmentation of abnormalities on medical images is highly important for patient management including diagnosis, radiotherapy, response evaluation, as well as for quantitative image research. We present a fully automated pipeline for the detection and volumetric segmentation of non-small cell lung cancer (NSCLC) developed and validated on 1328 thoracic CT scans from 8 institutions. Along with quantitative performance detailed by image slice thickness, tumor size, image interpretation difficulty, and tumor location, we report an in-silico prospective clinical trial, where we show that the proposed method is faster and more reproducible compared to the experts. Moreover, we demonstrate that on average, radiologists & radiation oncologists preferred automatic segmentations in 56% of the cases. Additionally, we evaluate the prognostic power of the automatic contours by applying RECIST criteria and measuring the tumor volumes. Segmentations by our method stratified patients into low and high survival groups with higher significance compared to those methods based on manual contours.

Correct interpretation of computer tomography (CT) scans is important for the correct assessment of a patient’s disease but can be subjective and timely. Here, the authors develop a system that can automatically segment the non-small cell lung cancer on CT images of patients and show in an in silico trial that the method was faster and more reproducible than clinicians.

Emerging Management Approach for the Adverse Events of Immunotherapy of Cancer

Immunotherapy, which stimulates the body’s immune system, has received a considerable amount of press in recent years because of its powerful benefits. Cancer immunotherapy has shown long-term results in patients with advanced disease that are not seen with traditional chemotherapy. Immune checkpoint inhibitors, cytokines like interleukin 2 (IL-2) and interferon-alpha (IFN), and the cancer vaccine sipuleucel-T have all been licensed and approved by the FDA for the treatment of various cancers. These immunotherapy treatments boost anticancer responses by stimulating the immune system. As a result, they have the potential to cause serious, even fatal, inflammatory and immune-related side effects in one or more organs. Immune checkpoint inhibitors (ICPIs) and chimeric antigen receptor (CAR) T-cell therapy are two immunotherapy treatments that are increasingly being used to treat cancer. Following their widespread usage in the clinic, a wave of immune-related adverse events (irAEs) impacting virtually every system has raised concerns about their unpredictability and randomness. Despite the fact that the majority of adverse effects are minimal and should be addressed with prudence, the risk of life-threatening complications exists. Although most adverse events are small and should be treated with caution, the risk of life-threatening toxicities should not be underestimated, especially given the subtle and unusual indications that make early detection even more difficult. Treatment for these issues is difficult and necessitates a multidisciplinary approach involving not only oncologists but also other internal medicine doctors to guarantee quick diagnosis and treatment. This study’s purpose is to give a fundamental overview of immunotherapy and cancer-related side effect management strategies.

Double Trouble: Immunotherapy Doublets in Melanoma-Approved and Novel Combinations to Optimize Treatment in Advanced Melanoma

Immune checkpoint inhibitors, particularly anti-PD-1-based immune checkpoint inhibitors, have dramatically improved outcomes for patients with advanced melanoma and are currently deemed a standard of care. Ipilimumab/nivolumab is the first combination of immune checkpoint inhibitors to improve progression-free survival and overall survival in the first-line setting, with durable responses and the longest median overall survival, 72.1 months, of any drug therapy approved for advanced melanoma. However, its use is limited by the high rate of severe (grade 3-4) treatment-related adverse events. More recently, the novel immune checkpoint inhibitor combination of nivolumab/relatlimab (anti-PD-1/anti-LAG3) showed improved progression-free survival compared with nivolumab alone in the first-line setting and was well tolerated; thus, it is likely this combination will be added to the armamentarium as a first-line treatment for advanced melanoma. These changes in the treatment landscape have several treatment implications for decision-making. The choice of first-line systemic drug therapy, and the decision between immune checkpoint inhibitor monotherapy or combination therapy, requires a comprehensive assessment of disease-related factors and patient characteristics. Despite this striking progress, many patients' disease still progresses. Several new agents and therapeutic approaches are under investigation in clinical trials. Intralesional treatments hold promise for accessible metastases, although their broad application in the clinic will be limited. Prognostic and predictive biomarkers, as well as strategies to reduce treatment-related toxicities and overcome resistance, are required and are now the focus of clinical and translational research.

Pembrolizumab activity in patients with Fanconi anemia repair pathway competent and deficient tumors

Background

Given the observed antitumor activity of immune-checkpoint-inhibitors in patients with mismatch-repair deficient (MSI-H) tumors, we hypothesized that deficiency in homologous-recombination-repair (HRR) can also influence susceptibility.

Methods

Patients with disease progression on standard of care and for whom pembrolizumab had no FDA approved indication received pembrolizumab. Patients with MSI-H tumors were excluded. Objectives included immune-related objective response rate (iORR), progression-free survival (PFS) and 20-weeks-PFS. Pembrolizumab was given every 3 weeks and scans performed every six. We evaluated a triple-stain (FANCD2foci/DAPI/Ki67) functional assay of the Fanconi Anemia (FA) pathway: FATSI, in treated patients’ archived tumors. The two-stage sample size of 20/39 patients evaluated an expected iORR≥20% in the whole population vs. the null hypothesis of an iORR≤5%, based on an assumed iORR≥40% in patients with functional FA deficiency, and < 10% in patients with intact HRR. An expansion cohort of MSI stable endometrial cancer (MS-EC) followed. Exploratory stool microbiome analyses in selected patients were performed.

Results

Fifty-two patients (45F,7M;50-evaluable) were enrolled. For the 39 in the two-stage cohort, response evaluation showed 2CR,5PR,11SD,21PD (iORR-18%). FATSI tumor analyses showed 29 competent (+) and 10 deficient (−). 2PR,9SD,17PD,1NE occurred among the FATSI+ (iORR-7%) and 2CR,3PR,2SD,3PD among the FATSI(−) patients (iORR-50%). mPFS and 20w-PFS were 43 days and 21% in FATSI+, versus 202 days and 70% in FATSI(−) patients. One PR occurred in the MS-EC expansion cohort.

Conclusions

Pembrolizumab has meaningful antitumor activity in malignancies with no current FDA approved indications and FA functional deficiency. The results support further evaluation of FATSI as a discriminatory biomarker for population-selected studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-022-00386-0.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of lung cancer and mesothelioma

Immunotherapy has transformed lung cancer care in recent years. In addition to providing durable responses and prolonged survival outcomes for a subset of patients with heavily pretreated non-small cell lung cancer (NSCLC), immune checkpoint inhibitors (ICIs)— either as monotherapy or in combination with other ICIs or chemotherapy—have demonstrated benefits in first-line therapy for advanced disease, the neoadjuvant and adjuvant settings, as well as in additional thoracic malignancies such as small-cell lung cancer (SCLC) and mesothelioma. Challenging questions remain, however, on topics including therapy selection, appropriate biomarker-based identification of patients who may derive benefit, the use of immunotherapy in special populations such as people with autoimmune disorders, and toxicity management. Patient and caregiver education and support for quality of life (QOL) is also important to attain maximal benefit with immunotherapy. To provide guidance to the oncology community on these and other important concerns, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline (CPG). This CPG represents an update to SITC’s 2018 publication on immunotherapy for the treatment of NSCLC, and is expanded to include recommendations on SCLC and mesothelioma. The Expert Panel drew on the published literature as well as their clinical experience to develop recommendations for healthcare professionals on these important aspects of immunotherapeutic treatment for lung cancer and mesothelioma, including diagnostic testing, treatment planning, immune-related adverse events, and patient QOL considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers using immunotherapy to treat patients with lung cancer or mesothelioma.

Joint EANM/SNMMI/ANZSNM practice guidelines/procedure standards on recommended use of [18F]FDG PET/CT imaging during immunomodulatory treatments in patients with solid tumors version 1.0

PURPOSE

The goal of this guideline/procedure standard is to assist nuclear medicine physicians, other nuclear medicine professionals, oncologists or other medical specialists for recommended use of [18F]FDG PET/CT in oncological patients undergoing immunotherapy, with special focus on response assessment in solid tumors.

METHODS

In a cooperative effort between the EANM, the SNMMI and the ANZSNM, clinical indications, recommended imaging procedures and reporting standards have been agreed upon and summarized in this joint guideline/procedure standard.

CONCLUSIONS

The field of immuno-oncology is rapidly evolving, and this guideline/procedure standard should not be seen as definitive, but rather as a guidance document standardizing the use and interpretation of [18F]FDG PET/CT during immunotherapy. Local variations to this guideline should be taken into consideration.

PREAMBLE

The European Association of Nuclear Medicine (EANM) is a professional non-profit medical association founded in 1985 to facilitate worldwide communication among individuals pursuing clinical and academic excellence in nuclear medicine. The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote science, technology and practical application of nuclear medicine. The Australian and New Zealand Society of Nuclear Medicine (ANZSNM), founded in 1969, represents the major professional society fostering the technical and professional development of nuclear medicine practice across Australia and New Zealand. It promotes excellence in the nuclear medicine profession through education, research and a commitment to the highest professional standards. EANM, SNMMI and ANZSNM members are physicians, technologists, physicists and scientists specialized in the research and clinical practice of nuclear medicine. All three societies will periodically put forth new standards/guidelines for nuclear medicine practice to help advance the science of nuclear medicine and improve service to patients. Existing standards/guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner, if indicated. Each standard/guideline, representing a policy statement by the EANM/SNMMI/ANZSNM, has undergone a thorough consensus process, entailing extensive review. These societies recognize that the safe and effective use of diagnostic nuclear medicine imaging requires particular training and skills, as described in each document. These standards/guidelines are educational tools designed to assist practitioners in providing appropriate and effective nuclear medicine care for patients. These guidelines are consensus documents based on current knowledge. They are not intended to be inflexible rules or requirements of practice, nor should they be used to establish a legal standard of care. For these reasons and those set forth below, the EANM, SNMMI and ANZSNM caution against the use of these standards/guidelines in litigation in which the clinical decisions of a practitioner are called into question. The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by medical professionals considering the unique circumstances of each case. Thus, there is no implication that an action differing from what is laid out in the guidelines/procedure standards, standing alone, is below standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the standards/guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources or advances in knowledge or technology subsequent to publication of the guidelines/procedure standards. The practice of medicine involves not only the science, but also the art of dealing with the prevention, diagnosis, alleviation and treatment of disease. The variety and complexity of human conditions make it impossible for general guidelines to consistently allow for an accurate diagnosis to be reached or a particular treatment response to be predicted. Therefore, it should be recognized that adherence to these standards/ guidelines will not ensure a successful outcome. All that should be expected is that practitioners follow a reasonable course of action, based on their level of training, current knowledge, clinical practice guidelines, available resources and the needs/context of the patient being treated. The sole purpose of these guidelines is to assist practitioners in achieving this objective. The present guideline/procedure standard was developed collaboratively by the EANM, the SNMMI and the ANZSNM, with the support of international experts in the field. They summarize also the views of the Oncology and Theranostics and the Inflammation and Infection Committees of the EANM, as well as the procedure standards committee of the SNMMI, and reflect recommendations for which the EANM and SNMMI cannot be held responsible. The recommendations should be taken into the context of good practice of nuclear medicine and do not substitute for national and international legal or regulatory provisions.

New Challenges in Evaluating Outcomes after Immunotherapy in Recurrent and/or Metastatic Head and Neck Squamous Cell Carcinoma

In many recurrent and/or metastatic cancers, the advent of immunotherapy opens up new scenarios of treatment response, with new phenomena, such as pseudoprogression and hyperprogression. Because of this, different immune-related response criteria have been developed, and new therapeutic strategies adopted, such as treatment beyond progression. Moreover, the role of progression-free survival as a surrogate has been questioned, and new surrogate endpoint hypotheses have arisen. A proper understanding of radiological imaging, an assessment of the biological events triggered by therapy, and the clinical evolution of the lesions and of the patient performance status are all factors that should be considered to guide the oncologist’s treatment choice. The primary aim of this article is to discuss how all these concepts apply to recurrent/metastatic head and neck squamous cell carcinoma patients when treated with immunotherapy.

iRECIST and atypical patterns of response to immuno-oncology drugs

With the advent of immunotherapy as one of the keystones of the treatment of our patients with cancer, a number of atypical patterns of response to these agents has been identified. These include pseudoprogression, where the tumor initially shows objective growth before decreasing in size, and hyperprogression, hypothesized to be a drug-induced acceleration of the tumor burden. Despite it being >10 years since the first immune-oncology drug was approved, neither the biology behind these paradoxical responses has been well understood, nor their incidence, identification criteria, predictive biomarkers, or clinical impact have been fully described. Immune-based Response Evaluation Criteria in Solid Tumors (iRECIST) guidelines have been published as a revision to the RECIST V.1.1 criteria for use in trials of immunotherapeutics, and the iRECIST subcommittee (of the RECIST Working Group) is working on elucidating these aspects, with data sharing a current major challenge to move forward with this unmet need in immuno-oncology.

Pseudoprogression of lung large cell neuroendocrine carcinoma resembling pancreatic cancer during durvalumab therapy

A 74-year-old Asian man was referred for numb and painful sensation in the right upper limb. He was diagnosed with lung large cell neuroendocrine carcinoma and started receiving durvalumab therapy as second-line treatment. Sixteen days after the first dose, laboratory examination revealed increased liver enzyme levels and a marked inflammatory response. Contrast-enhanced computed tomography revealed an unenhanced tumor measuring approximately 25 mm in the head of pancreas and dilation of the intra- and extra-hepatic bile ducts. Magnetic resonance cholangiopancreatography confirmed stricture in the lower common bile duct and main pancreatic duct. We suspected acute cholangitis caused by a pancreatic cancer and performed an endoscopic biliary drainage. Two weeks after the procedure, computed tomography revealed significant shrinkage of the tumor. The tumor gradually reduced and pseudoprogression in lung large cell neuroendocrine carcinoma was ultimately diagnosed. Acute cholangitis caused by pseudoprogression resembling pancreatic cancer during immune therapy has not yet been reported. We are mindful that pseudoprogression should be considered as a differential diagnosis if a rapidly developing pancreatic tumor is observed during immunotherapy.

Radiopharmaceuticals as Novel Immune System Tracers

Immune checkpoint inhibitors (ICIs) have transformed the treatment paradigms for multiple cancers. However, ICI therapy often fails to generate measurable and sustained antitumor responses, and clinically meaningful benefits remain limited to a small proportion of overall patients. A major obstacle to development and effective application of novel therapeutic regimens is optimized patient selection and response assessment. Noninvasive imaging using novel immunoconjugate radiopharmaceuticals (immuno–positron emission tomography and immuno-single-photon emission computed tomography) can assess for expression of cell surface immune markers, such as programmed cell death protein ligand-1 (PD-L1), akin to a virtual biopsy. This emerging technology has the potential to provide clinicians with a quantitative, specific, real-time evaluation of immunologic responses relative to cancer burden in the body. We discuss the rationale for using noninvasive molecular imaging of the programmed cell death protein-1 and PD-L1 axis as a biomarker for immunotherapy and summarize the current status of preclinical and clinical studies examining PD-L1 immuno–positron emission tomography. The strategies described in this review provide insight for future clinical trials exploring the use of immune checkpoint imaging as a biomarker for both ICI and radiation therapy, and for the rational design of combinatorial therapeutic regimens.

Immune Cells in Hyperprogressive Disease under Immune Checkpoint-Based Immunotherapy

Immunotherapy, an antitumor therapy designed to activate antitumor immune responses to eliminate tumor cells, has been deeply studied and widely applied in recent years. Immune checkpoint inhibitors (ICIs) are capable of preventing the immune responses from being turned off before tumor cells are eliminated. ICIs have been demonstrated to be one of the most effective and promising tumor treatments and significantly improve the survival of patients with multiple tumor types. However, low effective rates and frequent atypical responses observed in clinical practice limit their clinical applications. Hyperprogressive disease (HPD) is an unexpected phenomenon observed in immune checkpoint-based immunotherapy and is a challenge facing clinicians and patients alike. Patients who experience HPD not only cannot benefit from immunotherapy, but also experience rapid tumor progression. However, the mechanisms of HPD remain unclear and controversial. This review summarized current findings from cell experiments, animal studies, retrospective studies, and case reports, focusing on the relationships between various immune cells and HPD and providing important insights for understanding the pathogenesis of HPD.

A Role for PET/CT in response assessment of malignant pleural mesothelioma

Malignant pleural mesothelioma is a rare type of cancer, whose incidence, however, is increasing and will presumably continue to rise in the coming years. Key features of this disease comprise its mantle-shaped, pleura-associated, often multifocal growth, which cause diagnostic challenges. A growing number of mesotheliomas are being treated with novel immunotherapies for which no image derived general response criteria have been established. However, recent studies indicate that FDG-PET/CT could be superior for response assessment compared to CT-based criteria. This article aims at providing an overview of response assessment criteria dedicated to malignant pleural mesothelioma, such as mRECIST, iRECIST, and PERCIST. In addition, the potential future role of PET/CT in the management of malignant pleural mesothelioma will also be discussed.

Analysis of Spatial Heterogeneity of Responses in Metastatic Sites in Renal Cell Carcinoma Patients Treated with Nivolumab

Background: The purpose was to determine whether tumor response to CPI varies by organ and to characterize response patterns in a group of surgically treated metastatic RCC patients treated with Nivolumab. Methods: A retrospective analysis was undertaken between January 2016 and March 2020 on patients receiving Nivolumab for metastatic RCC, following first-line therapy and having at least one baseline and two follow-up scans. A Fisher’s exact test was used to compare categorical variables, and a Kruskal–Wallis test was used to compare continuous variables. Results: Twenty-one out of thirty patients evaluated were eligible, and they were divided into two groups: responders (n = 11) and non-responders (n = 10). According to all iRECIST standards, 18 (85.7 percent) of the 21 patients had PD (10 patients), PR (3 patients), or SD (8 patients). At baseline, 7, 15, 4, 13, 7, and 7 patients, respectively, had detectable hepatic metastasis and lung, brain, lymph node, soft tissue, and other intra-abdominal metastases; these patients were evaluated for organ-specific response. The ORRs for hepatic metastasis and lung, brain, lymph node, soft tissue, adrenals, and other intraperitoneal metastases were correspondingly 10%, 20%, 35%, 0%, and 25%. In total, 13 (61.9%) of them demonstrated varied responses to CPI therapy, with 6 (28.5%) demonstrating intra-organ differential responses. The lymph nodes (35%) had the best objective response (BOR), followed by the adrenals and peritoneum (both 25%), the brain (20%), and the lung (20%). The response rate was highest in adrenal gland lesions (2/4; 50%), followed by lymph nodes (13/19; 68.4 percent) and liver (5/10; 50%), whereas rates were lowest for lesions in the lung (9/25; 36%), intraperitoneal metastases (1/4; 25%), and brain (1/5; 20%). Conclusions: In renal cell carcinoma, checkpoint inhibitors have a variable response at different metastatic sites, with the best response occurring in lymph nodes and the least occurring in soft tissue.

A pathological complete response after nivolumab plus ipilimumab therapy for DNA mismatch repair‑deficient/microsatellite instability‑high metastatic colon cancer: A case report

The standard treatment for colorectal cancer has always been surgery and chemotherapy, which may be used in combination to treat patients. Immune checkpoint inhibitors have been a significant advancement in the standard treatment of metastatic, unresectable colorectal cancer with deficient mismatch repair. However, little information is available about their use in neoadjuvant and conversion settings with only a few case reports and only one phase 2 trial. The present study reports the case of a large, locally advanced right-sided metastatic deficient mismatch repair/microsatellite instability-high colon cancer, which showed a pathological complete response after combination treatment with nivolumab and ipilimumab. To the best of our knowledge, resected metastatic colon cancer with a pathological complete response after treatment using dual immune checkpoint inhibitors has not been previously reported. Overall, this case report suggests the use of immune checkpoint inhibitors before colorectal surgery.

HLA Class I Downregulation in Progressing Metastases of Melanoma Patients Treated With Ipilimumab

Characterization of the molecular mechanisms underlying antitumor immune responses and immune escape mechanisms has resulted in the development of more effective immunotherapeutic strategies, including immune checkpoint inhibitor (ICI) therapy. ICIs can induce durable responses in patients with advanced cancer in a wide range of cancer types, however, the majority of the patients fail to respond to this therapy or develop resistance in the course of the treatment. Information about the molecular mechanisms underlying primary and acquired resistance is limited. Although HLA class I molecules are crucial in the recognition of tumor antigens by cytotoxic T lymphocytes, only a few studies have investigated the role of their expression level on malignant cells in ICI resistance. To address this topic, utilizing immunohistochemical staining with monoclonal antibodies (mAbs) we analyzed HLA class I expression level in pre-treatment and post-treatment tumor samples from melanoma patients treated with ipilimumab. Twenty-nine metastases removed from six patients were available for the study, including 18 pre-treatment and 11 post-treatment lesions. Compared to metastases excised before ipilimumab therapy, post-treatment lesions displayed a significantly lower HLA class I expression level on melanoma cells; HLA class I downregulation was most marked in progressing metastases from nonresponding patients. We also evaluated the level of infiltration by CD8⁺ T cells and NK cells but did not find consistent changes between pre- and post-treatment samples. Our results indicate the potential role of HLA class I downregulation as a mechanism of ICI resistance.

Immunotherapy-Based Treatments of Hepatocellular Carcinoma: AJR Expert Panel Narrative Review

The advent of immunotherapy for patients with hepatocellular carcinoma (HCC) has changed the treatment landscape and conferred survival benefit for patients with advanced HCC who typically have a very poor prognosis. The most pronounced improvements in response, as documented by standardized response criteria based on CT or MRI, have been achieved when immunotherapy is combined with other systemic or locoregional therapies. Immune checkpoint inhibitor treatments result in unique patterns on CT and MRI that challenge the application of conventional response criteria such as RECIST, modified RECIST, and European Association for the Study of the Liver criteria. Thus, newer criteria have been developed to gauge therapy response or disease progression for patients on immunotherapy, including immune-related RECIST (iRECIST) and immune-modified RECIST (imRECIST), though these remain unvalidated. In this review, we describe the current landscape of immunotherapeutic agents used for HCC, summarize results of published studies, review pathobiological mechanisms that provide a rationale for the use of these agents, and report on the status of response assessment for immunotherapy, either alone or in combination with other treatment options. Finally, consensus statements are provided to inform radiologists on essential considerations in the era of a rapidly changing treatment paradigm for patients with HCC.

Phase IB Study of GITR Agonist Antibody TRX518 Singly and in Combination with Gemcitabine, Pembrolizumab or Nivolumab in Patients with Advanced Solid Tumors

Purpose: TRX518 is a monoclonal antibody engaging the glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR). This open-label, phase I study (TRX518-003) evaluated the safety and efficacy of repeated dose TRX518 monotherapy and combination with gemcitabine, pembrolizumab or nivolumab in advanced solid tumors. Experimental Design: TRX518 monotherapy was dose-escalated (Part A) and expanded (Part B) up to 4 mg/kg load, 1 mg/kg Q3W. Parts C-E included dose-escalation (2mg/kg and 4 mg/kg loading followed by 1mg/kg) and dose-expansion (4mg/kg load) phases with gemcitabine (Part C), pembrolizumab (Part D) or nivolumab (Part E). Primary endpoints included incidence of dose-limiting toxicities (DLTs), serious adverse events (SAEs), and pharmacokinetics. Secondary endpoints were efficacy and pharmacodynamics. Results:109 patients received TRX518: 43 (Parts A+B), 30 (Part C), 26 (Part D), and 10 (Part E) respectively. 67% of patients in Parts D+E had received prior anti-PD(L)1 or anti-CTLA-4. No DLTs, treatment-related SAEs and/or G4/5 AEs were observed with TRX518 monotherapy. In Parts C-E, no DLTs were observed, although TRX518-related SAEs were reported in 3.3% (Part C) and 10.0% (Part E) respectively. Objective response rate was 3.2%, 3.8%, 4% and 12.5% in Parts A+B, C, D and E respectively. TRX518 affected peripheral and intratumoral regulatory T cells (Tregs) with different kinetics depending on the combination regimen. Responses with TRX518 monotherapy+anti-PD1 combination were associated with intratumoral Treg reductions and CD8 increases and activation after treatment. Conclusions:TRX518 showed an acceptable safety profile with pharmacodynamic activity. Repeated dose TRX518 monotherapy and in combination resulted in limited clinical responses associated with immune activation.

The Impact of Surveillance Imaging Frequency on the Detection of Distant Disease for Patients with Resected Stage III Melanoma

BACKGROUND

It is not known whether there is a survival benefit associated with more frequent surveillance imaging in patients with resected American Joint Committee on Cancer stage III melanoma.

OBJECTIVE

The aim of this study was to investigate distant disease-free survival (DDFS), melanoma-specific survival (MSS), post distant recurrence MSS (dMSS), and overall survival for patients with resected stage III melanoma undergoing regular computed tomography (CT) or positron emission tomography (PET)/CT surveillance imaging at different intervals.

PATIENTS AND METHODS

A closely followed longitudinal cohort of patients with resected stage IIIA-D disease treated at a tertiary referral center underwent 3- to 4-monthly, 6-monthly, or 12-monthly surveillance imaging between 2000 and 2017. Survival outcomes were estimated using the Kaplan-Meier method, and log-rank tests assessed the significance of survival differences between imaging frequency groups.

RESULTS

Of 473 patients (IIIA, 19%; IIIB, 31%; IIIC, 49%; IIID, 1%) 30% underwent 3- to 4-monthly imaging, 10% underwent 6-monthly imaging, and 60% underwent 12-monthly imaging. After a median follow-up of 6.2 years, distant recurrence was recorded in 252 patients (53%), with 40% detected by surveillance CT or PET/CT, 43% detected clinically, and 17% with another imaging modality. Median DDFS was 5.1 years (95% confidence interval 3.9-6.6). Among 139 IIIC patients who developed distant disease, the median dMSS was 4.4 months shorter in those who underwent 3- to 4-monthly imaging than those who underwent 12-monthly imaging.

CONCLUSION

Selecting patients at higher risk of distant recurrence for more frequent surveillance imaging yields a higher proportion of imaging-detected distant recurrences but is not associated with improved survival. A randomized comparison of low versus high frequency imaging is needed.

A Phase 2 Study of S-588410 Maintenance Monotherapy for Platinum-Treated Advanced or Metastatic Urothelial Carcinoma

BACKGROUND: Effective maintenance therapy for urothelial carcinoma (UC) is needed to delay progression after first-line chemotherapy. OBJECTIVE: To evaluate S-588410, a cancer peptide vaccine containing five human leukocyte antigen (HLA)-A *24:02-restricted epitope peptides derived from five cancer-testis antigens (DEPDC1, MPHOSPH1, URLC10, CDCA1, and KOC1) in chemotherapy-treated, clinically stable patients with advanced or metastatic UC MATERIALS AND METHODS: This open-label, international, phase 2 trial enrolled patients with UC who had completed≥4 cycles of first-line platinum-containing chemotherapy without disease progression. Forty-five HLA-A *24:02-positive patients received subcutaneous injections of S-588410 (Montanide ISA 51 VG with 1 mg/mL of each peptide) weekly for 12 weeks then once every 2 weeks thereafter for up to 24 months. Thirty-six HLA-A *24:02-negative patients did not receive S-588410 (observation group). The primary endpoint was the rate of cytotoxic T-lymphocyte (CTL) induction against≥1 of the peptides at 12 weeks. RESULTS: The CTL induction rate in the S-588410 group was 93.3% (p <  0.0001, one-sided binomial test with a rate of≤50% as the null hypothesis). The antitumor response rate was 8.9% in the S-588410 group and 0% in the observation group; median progression-free survival was 18.1 versus 12.5 weeks and median overall survival was 71.0 versus 99.0 weeks, respectively. The most frequent treatment-emergent adverse event was injection-site reactions (47 events, grades 1–3) reported in 93.3% (n = 42/45) of participants. CONCLUSIONS: S-588410 demonstrated a high CTL induction rate, acceptable safety profile, and modest clinical response, as maintenance therapy in participants with advanced or metastatic UC who had received first-line platinum-based chemotherapy (EudraCT 2013-005274-22).

Brain radiotherapy, tremelimumab-mediated CTLA-4-directed blockade +/- trastuzumab in patients with breast cancer brain metastases

Breast cancer brain metastases (BCBM) are a common and devastating complication of metastatic breast cancer with conventional systemic therapies demonstrating limited effectiveness. Consequently, radiotherapy (RT) ± surgery remains the cornerstone of BCBM management. Because preclinical and clinical evidence indicate that immune checkpoint blockade (ICB) may synergize with RT to promote systemic tumor regression, we explored the safety and efficacy of RT and concurrent tremelimumab-mediated cytotoxic T-lymphocyte associated protein 4 (CTLA-4) ICB with tremelimumab ± HER2-directed therapy with trastuzumab for BCBM. Eligible patients had BCBM indicated for brain RT. A Simon two-stage design was adopted to evaluate the efficacy of tremelimumab and RT in 20 patients with human epidermal growth factor receptor normal (HER2−) BCBM. The safety of concurrent RT, tremelimumab, and trastuzumab was evaluated in a cohort of 6 HER2+ patients. The primary endpoint was 12-week non-central nervous system (CNS) disease control rate (DCR). Secondary endpoints included safety, survival, and CNS response. Exploratory correlatives included characterization of peripheral blood immune responses among exceptional responders. Tremelimumab plus RT ± trastuzumab was tolerated with no treatment-related grade 4 adverse events reported. The 12-week non-CNS DCR was 10% (2/20) in the HER2− cohort and 33% (2/6) in the HER2+ cohort. One patient with HER2+ disease experienced a durable partial response with evidence of peripheral T-cell activation. Thus, tremelimumab and RT ± trastuzumab was tolerated. Although modest clinical activity was observed in the HER2- efficacy cohort, encouraging responses were observed in the HER2+ safety cohort. Consequently, a trial to determine efficacy in HER2+ BCBM is planned.

Clinical Trial Registration Number: NCT02563925.

Dual checkpoint targeting of B7-H3 and PD-1 with enoblituzumab and pembrolizumab in advanced solid tumors: interim results from a multicenter phase I/II trial

BACKGROUND

Availability of checkpoint inhibitors has created a paradigm shift in the management of patients with solid tumors. Despite this, most patients do not respond to immunotherapy, and there is considerable interest in developing combination therapies to improve response rates and outcomes. B7-H3 (CD276) is a member of the B7 family of cell surface molecules and provides an alternative immune checkpoint molecule to therapeutically target alone or in combination with programmed cell death-1 (PD-1)-targeted therapies. Enoblituzumab, an investigational anti-B7-H3 humanized monoclonal antibody, incorporates an immunoglobulin G1 fragment crystallizable (Fc) domain that enhances Fcγ receptor-mediated antibody-dependent cellular cytotoxicity. Coordinated engagement of innate and adaptive immunity by targeting distinct members of the B7 family (B7-H3 and PD-1) is hypothesized to provide greater antitumor activity than either agent alone.

METHODS

In this phase I/II study, patients received intravenous enoblituzumab (3-15 mg/kg) weekly plus intravenous pembrolizumab (2 mg/kg) every 3 weeks during dose-escalation and cohort expansion. Expansion cohorts included non-small cell lung cancer (NSCLC; checkpoint inhibitor [CPI]-naïve and post-CPI, programmed death-ligand 1 [PD-L1] <1%), head and neck squamous cell carcinoma (HNSCC; CPI-naïve), urothelial cancer (post-CPI), and melanoma (post-CPI). Disease was assessed using Response Evaluation Criteria in Solid Tumors version 1.1 after 6 weeks and every 9 weeks thereafter. Safety and pharmacokinetic data were provided for all enrolled patients; efficacy data focused on HNSCC and NSCLC cohorts.

RESULTS

Overall, 133 patients were enrolled and received ≥1 dose of study treatment. The maximum tolerated dose of enoblituzumab with pembrolizumab at 2 mg/kg was not reached. Intravenous enoblituzumab (15 mg/kg) every 3 weeks plus pembrolizumab (2 mg/kg) every 3 weeks was recommended for phase II evaluation. Treatment-related adverse events occurred in 116 patients (87.2%) and were grade ≥3 in 28.6%. One treatment-related death occurred (pneumonitis). Objective responses occurred in 6 of 18 (33.3% [95% CI 13.3 to 59.0]) patients with CPI-naïve HNSCC and in 5 of 14 (35.7% [95% CI 12.8 to 64.9]) patients with CPI-naïve NSCLC.

CONCLUSIONS

Checkpoint targeting with enoblituzumab and pembrolizumab demonstrated acceptable safety and antitumor activity in patients with CPI-naïve HNSCC and NSCLC.

TRIAL REGISTRATION NUMBER

NCT02475213.

Applications of Circulating Tumor DNA in Immune Checkpoint Inhibition: Emerging Roles and Future Perspectives

Immune checkpoint inhibitors (ICIs), especially anti-programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) antibodies, have made dramatic progress in the treatment of lung cancer, especially for patients with cancers not driven by oncogenes. However, responses are limited to a subset of patients, and which subset of patients will optimally benefit from ICI remains unknown. With the advantage of being minimally invasive and dynamic, noninvasive biomarkers are promising candidates to predict response, monitor resistance, and track the evolution of lung cancer during ICI treatment. In this review, we focus on the application of circulating tumor DNA (ctDNA) in plasma in immunotherapy. We examine the potential of pre- and on-treatment features of ctDNA as biomarkers, and following multiparameter analysis, we determine the potential clinical value of integrating predictive liquid biomarkers of ICIs to optimize patient management. We further discuss the role of ctDNA in monitoring treatment resistance, as well as challenges in clinical translation.

Spatially mapping the immune landscape of melanoma using imaging mass cytometry

Melanoma is an immunogenic cancer with a high response rate to immune checkpoint inhibitors (ICIs). It harbors a high mutation burden compared with other cancers and, as a result, has abundant tumor-infiltrating lymphocytes (TILs) within its microenvironment. However, understanding the complex interplay between the stroma, tumor cells, and distinct TIL subsets remains a substantial challenge in immune oncology. To properly study this interplay, quantifying spatial relationships of multiple cell types within the tumor microenvironment is crucial. To address this, we used cytometry time-of-flight (CyTOF) imaging mass cytometry (IMC) to simultaneously quantify the expression of 35 protein markers, characterizing the microenvironment of 5 benign nevi and 67 melanomas. We profiled more than 220,000 individual cells to identify melanoma, lymphocyte subsets, macrophage/monocyte, and stromal cell populations, allowing for in-depth spatial quantification of the melanoma microenvironment. We found that within pretreatment melanomas, the abundance of proliferating antigen-experienced cytotoxic T cells (CD8⁺CD45RO⁺Ki67⁺) and the proximity of antigen-experienced cytotoxic T cells to melanoma cells were associated with positive response to ICIs. Our study highlights the potential of multiplexed single-cell technology to quantify spatial cell-cell interactions within the tumor microenvironment to understand immune therapy responses.

First-in-human phase 1 dose-escalation study of CAN04, a first-in-class interleukin-1 receptor accessory protein (IL1RAP) antibody in patients with solid tumours

BACKGROUND

Interleukin-1 (IL-1) signalling is involved in various protumoural processes including proliferation, immune evasion, metastasis and chemoresistance. CAN04 is a first-in-class monoclonal antibody that binds IL-1 receptor accessory protein (IL1RAP), required for IL-1 signalling. In this first-in-human phase 1 study, we assessed safety, recommended phase 2 dose (RP2D), pharmacokinetics, pharmacodynamics and preliminary anti-tumour activity of CAN04 monotherapy.

METHODS

Patients with advanced solid tumours known to express IL1RAP and refractory to standard treatments were enrolled in a dose-escalation study with 5 dose levels (1.0-10.0 mg/kg) of weekly CAN04.

RESULTS

Twenty-two patients were enrolled. Most common adverse events were infusion-related reactions (41%), fatigue (32%), constipation (27%), diarrhoea (27%), decreased appetite (23%), nausea (23%) and vomiting (23%). One dose limiting toxicity was reported. No maximum tolerated dose was identified. Pharmacokinetics analyses indicate higher exposures and slower elimination with increasing doses. Decreases in serum IL-6 and CRP were observed in most patients. Twenty-one patients were evaluable for response, 43% had stable disease per immune-related response criteria with no partial/complete responses.

CONCLUSIONS

The IL1RAP targeting antibody CAN04 can be safely administered to patients up to 10.0 mg/kg weekly, which was defined as the RP2D. Serum biomarkers supported target engagement and IL-1 pathway inhibition.

CLINICAL TRIAL REGISTRATION

NCT03267316.

Equivocal evaluation of progressive disease in patients treated with immune checkpoint inhibitors: a challenge for clinical trials and biomarker research

We present two patient cases (one with bladder carcinoma and one with renal cell carcinoma) who consulted our department of General Medical Oncology, after having been treated in other hospitals in two clinical trials with immune checkpoint inhibitors and having been dismissed from the trials after 5 months of therapy for progressive disease. They consulted to discuss consecutive treatment opportunities. However, longer follow-up has shown that both patients were dismissed equivocally from both trials. We are worried that equivocal response evaluation in the context of clinical trials with immune checkpoint inhibitors, due to pseudo-progression or delayed responses, can negatively impact trial outcomes as well as biomarker research.

Elevated tumor markers for monitoring tumor response to immunotherapy

BACKGROUND

As the immune-related response evaluation criteria in solid tumors (irRECIST) by imaging greatly underestimated the objective response to immunotherapy, we established the response evaluation criteria in solid tumors based on tumor markers (RecistTM) to explore whether RecistTM can compensate for the deficiencies of the irRECIST criteria.

METHODS

This was an observational study, which consisted of two parts. The first part (Group A) was a retrospective study including the patients with malignant solid tumors. The second part (Group B) was a prospective study, which were EGFR-negative and ALK-negative patients with stage IIIB-IV non-small cell lung cancer receiving first-line treatment. From January 2017 to September 2020, one hundred and ten patients with a three-time increase in tumor markers receiving immunotherapy were recruited. The treatment response to immunotherapy was evaluated by irRECIST and RecistTM. Efficacy, overall survival (OS), first evaluation time and earliest response time under the different evaluation criteria were compared by statistics.

FINDINGS

The treatment response evaluated by the RecistTM criteria was not consistent with that evaluated by the irRECIST criteria (Kappa = 0.386, p < 0.001). RecistTM had a higher completed response (CR) rate compared to irRECIST criteria (20.9% vs 1.8%, p < 0.001). The earliest response time under the RecistTM criteria was 3.42 weeks earlier than that under the irRECIST criteria (u = -5.233, p < 0.001). There were significant differences in median OS between tumor marker-related complete response (tmCR) and tumor marker-related partial response (tmPR), as well as between tmPR and tumor marker-related stable disease (tmSD) (χ² = 15.572, p < 0.001; χ² = 7.720, p = 0.005), but not between tmSD and tumor marker-related progressive disease (tmPD) (χ² = 1.596, p = 0.206). When applying both criteria together, for patients with immune-related CR / immune-related PR (irCR/irPR) (n = 54) under irRECIST criteria, there was a significant difference in median OS between achieving tmCR (n = 22) and tmPR (n = 32) (χ² = 14.011, p < 0.001). RecistTM criteria can predict 1-year and 2-year OS more accurately than irRECIST criteria (AUCs:0.862 vs 0.552, 0.649 vs 0.521, respectively;both p < 0.001). In RecistTM, 4 patients had been observed with pseudoprogression in tumor markers.

INTERPRETATION

The RecistTM criteria could effectively distinguish CR, PR, and SD, which may help resolve the shortcomings of the RECIST criteria in evaluating the treatment response to immunotherapy, especially in assessing whether patients can achieve deep or even complete response as soon as possible.

FUNDING

This work was supported by the Key projects of Chongqing Health and Family Planning Commission (to Xueqin Yang, 2019ZDXM011).

Navigate Towards the Immunotherapy Era: Value of Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer Patients With Brain Metastases

Brain metastases (BMs) in non-small-cell lung cancer (NSCLC) patients are associated with significant morbidity and poor prognosis. Immune checkpoint inhibitors (ICIs) have resulted in a paradigm shift in the management of advanced NSCLC. However, the value of ICIs in NSCLC patients with BMs remains unclear because patients with BMs are routinely excluded in numerous prospective trials on ICIs. Here, starting from the mechanisms of ICIs for BMs, we will reveal the value of ICIs by reviewing the efficacy and adverse effects of ICIs monotherapy as well as promising combination strategies, such as combinations with chemotherapy, radiotherapy, and anti-angiogenic drugs, etc. In addition, the methods of patient selection and response assessment will be summarized to assist clinical practice and further studies.

Organ-Specific and Mixed Responses to Pembrolizumab in Patients with Unresectable or Metastatic Urothelial Carcinoma: A Multicenter Retrospective Study

To investigate the organ-specific response and clinical outcomes of mixed responses (MRs) to immune checkpoint inhibitors (ICIs) for unresectable or metastatic urothelial carcinoma (ur/mUC), we retrospectively analyzed 136 patients who received pembrolizumab. The total objective response rate (ORR) and organ-specific ORR were determined for each lesion according to the Response Evaluation Criteria in Solid Tumors version 1.1 as follows: (i) complete response (CR), (ii) partial response (PR), (iii) stable disease (SD), and (iv) progressive disease (PD). Most of the organ-specific ORR was 30−40%, but bone metastasis was only 5%. There was a significant difference in overall survival (OS) between responders and non-responders with locally advanced lesions and lymph node, lung, or liver metastases (HR 9.02 (3.63−22.4) p < 0.0001; HR 3.63 (1.97−6.69), p < 0.0001; HR 2.75 (1.35−5.59), p = 0.0053; and HR 3.17 (1.00−10.0), p = 0.049, respectively). MR was defined as occurring when PD happened in one lesion plus either CR or PR occurred in another lesion simultaneously, and 12 cases were applicable. MR was significantly associated with a poorer prognosis than that of the responder group (CR or PR; HR 0.09 (0.02−0.35), p = 0.004). Patients with bone metastases benefitted less. Care may be needed to treat patients with MR as well as patients with pure PD. Further studies should be conducted in the future.

Stereotactic radiosurgery for melanoma brain metastases: Concurrent immune checkpoint inhibitor therapy associated with superior clinicoradiological response outcomes

INTRODUCTION/PURPOSE

This study assessed long-term clinical and radiological outcomes following treatment with combination stereotactic radiosurgery (SRS) and immunotherapy (IT) for melanoma brain metastases (BM).

METHODS

A retrospective review was performed in a contemporary cohort of patients with melanoma BM at a single tertiary institution receiving Gamma Knife^® SRS for melanoma BM. Multivariate Cox proportional-hazards modelling was performed with a P <0.05 for significance.

RESULTS

101 patients (435 melanoma BM) were treated with SRS between January-2015 and June-2019. 68.3% of patients received IT within 4 weeks of SRS (concurrent) and 31.7% received SRS alone or non-concurrently with IT. Overall, BM local control rate was 87.1% after SRS. Median progression free survival was 8.7 months. Median follow-up was 29.2 months. On multivariate analysis (MVA), patients receiving concurrent SRS-IT maintained a higher chance of achieving a complete (CR) or partial response (PR) [HR 2.6 (95% CI: 1.2-5.5, P = 0.012)] and a reduced likelihood of progression of disease (PD) [HR 0.52 (95% CI: 0.16-0.60), P = 0.048]. Any increase in BM volume on the initial MRI 3 months after SRS predicted a lower likelihood of achieving long-term CR or PR on MVA accounting for concurrent IT, BRAF status and dexamethasone use [HR = 0.048 (95% CI: 0.007-0.345, P = 0.0026)]. Stratified volumetric change demonstrated a sequential relationship with outcomes on Kaplan-Meier analysis.

CONCLUSION

Concurrent SRS-IT has favourable clinical and radiological outcomes with respect to CR, PR and a reduced likelihood of PD. Changes in BM volume on the initial MRI 3 months after SRS were predictive of long-term outcomes for treatment response.

Teaching cancer imaging in the era of precision medicine: Looking at the big picture

The role of imaging in cancer diagnosis and treatment has evolved at the same rapid pace as cancer management. Over the last twenty years, with the advancement of technology, oncology has become a multidisciplinary field that allows for researchers and clinicians not only to create individualized treatment options for cancer patients, but also to evaluate patients’ response to therapy with increasing precision. Familiarity with these concepts is a requisite for current and future radiologists, as cancer imaging studies represent a significant and growing component of any radiology practice, from tertiary cancer centers to community hospitals.

In this review we provide the framework to teach cancer imaging in the era of genomic oncology. After reading this article, readers should be able to illustrate the basics cancer genomics, modern cancer genomics, to summarize the types of systemic oncologic therapies available, their patterns of response and their adverse events, to discuss the role of imaging in oncologic clinical trials and the role of tumor response criteria and to display the future directions of oncologic imaging.

MRI Response Assessment in Glioblastoma Patients Treated with Dendritic-Cell-Based Immunotherapy

Introduction: In this post hoc analysis we compared various response-assessment criteria in newly diagnosed glioblastoma (GB) patients treated with tumor lysate-charged autologous dendritic cells (Audencel) and determined the differences in prediction of progression-free survival (PFS) and overall survival (OS). Methods: 76 patients enrolled in a multicenter phase II trial receiving standard of care (SOC, n = 40) or SOC + Audencel vaccine (n = 36) were included. MRI scans were evaluated using MacDonald, RANO, Vol-RANO, mRANO, Vol-mRANO and iRANO criteria. Tumor volumes (T1 contrast-enhancing as well as T2/FLAIR volumes) were calculated by semiautomatic segmentation. The Kruskal-Wallis-test was used to detect differences in PFS among the assessment criteria; for correlation analysis the Spearman test was used. Results: There was a significant difference in median PFS between mRANO (8.6 months) and Vol-mRANO (8.6 months) compared to MacDonald (4.0 months), RANO (4.2 months) and Vol-RANO (5.4 months). For the vaccination arm, median PFS by iRANO was 6.2 months. There was no difference in PFS between SOC and SOC + Audencel. The best correlation between PFS/OS was detected for mRANO (r = 0.65) and Vol-mRANO (r = 0.69, each p < 0.001). A total of 16/76 patients developed a pure T2/FLAIR progressing disease, and 4/36 patients treated with Audencel developed pseudoprogression. Conclusion: When comparing different response-assessment criteria in GB patients treated with dendritic cell-based immunotherapy, the best correlation between PFS and OS was observed for mRANO and Vol-mRANO. Interestingly, iRANO was not superior for predicting OS in patients treated with Audencel.

Molecular Response Assessment with Immune Adaptive PERCIST in Lung Cancer Patients Treated with Nivolumab: Is It Better Than iRECIST?

Aims  We compared the immune response evaluation criteria in solid tumors (iRECIST) with immune adaptive positron emission tomography response criteria in solid tumors (imPERCIST) in lung cancer patients treated with nivolumab.

Materials and Methods  Twenty lung cancer patients underwent fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scan at baseline (PET-0), after four cycles (PET-1) and six to eight cycles (PET-2) of nivolumab were included. Kappa coefficient ( k ) was derived to see the level of agreement in two response criteria. Progression-free survival (PFS) curves were computed by the Kaplan–Meier method and compared with the Log Rank test. Univariate and multivariate regression for the percentage change in the sum of diameters (SoD), standard uptake value maximum (SUVmax), sum of metabolic tumor volume (SoMTV), and sum of total lesion glycolysis (SoTLG) was computed. A p -value less than 0.05 was considered significant.

Results  Kappa coefficient showed a substantial level of agreement (k 0.769) in two response criteria. Mean PFS in partial response, stable disease, and progressive disease (PD) patients in iRECIST and imPERCIST was 27.3, 17.7, 4.2, and 23.3, 18.8, 3.8 months, respectively. The Kaplan–Meier method with the log rank test showed a significant difference in PFS on intracomparison within both criteria; however, it was not significant on intercomparison. On univariate analysis, the percentage change in SoD, SoMTV, SoTLG was significant. However, on multivariate analysis, only percentage change in SoD was a significant predictor.

Conclusions  We concluded that imPERCIST was equally effective as currently recommended criteria iRECIST for response evaluation of nivolumab in lung cancer patients.

Progress and pitfalls in the use of immunotherapy for patients with triple negative breast cancer

INTRODUCTION

Triple negative breast cancer (TNBC) is an area of high unmet medical need in terms of new effective treatment strategies. Although breast cancer is traditionally considered a 'cold' tumor type, TNBC is the most appropriate subtype for immunotherapeutic strategies; this is due to the high level of tumor infiltrating lymphocytes, PD-L1 expression and tumor mutational burden relative to other breast cancer subtypes.

AREAS COVERED

This review examines the use of immunotherapeutic strategies in early and advanced TNBC. The paper summarizes data on novel promising immunomodulatory approaches that have been explored in early phase trials and discusses the pitfalls and limitations often encountered in clinical research.

EXPERT OPINION

PD-1-blockade is approved for stage II/III TNBC and for first-line treatment of PD-L1-positive TNBC patients with metastatic disease and should be considered standard of care. However, question marks and difficulties remain; these include the identification of predictive biomarkers to select patients who benefit from the addition of PD1-blockade and the balance between efficacy and long-term toxicity for an individual patient. Numerous treatment combinations and new immunotherapeutic strategies beyond PD1 blockade are being evaluated, thus reflecting a promising evolution of a more personalized approach, and extended clinical benefit in TNBC.

Comparison of tumor assessments using RECIST 1.1 and irRECIST, and association with overall survival

Background

Patients treated with immune checkpoint inhibitors (ICIs) may experience pseudoprogression, which can be classified as progressive disease (PD) by Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1 and could lead to inappropriate treatment discontinuation. Immune-response criteria were developed to better capture novel response patterns seen with ICIs.

Methods

We pooled data from 1765 patients with 12 types of advanced solid tumors treated with avelumab (an anti-programmed death ligand 1 (PD-L1) monoclonal antibody) monotherapy in the JAVELIN Solid Tumor and JAVELIN Merkel 200 trials, conducted a comparative analysis of tumor assessments by investigators according to RECIST 1.1 and immune-related RECIST (irRECIST), and evaluated the correlation between progression-free survival (PFS) and overall survival (OS).

Results

In total, 147 patients (8.3%) had a best overall response (BOR) of PD by RECIST 1.1 but had immune-related disease control by irRECIST (defined as immune-related BOR (irBOR) of immune-related stable disease or better). This discordance was seen irrespective of PD-L1 status and observed across all tumor types. Overall, PFS and immune-related PFS showed similar imputed rank correlations with OS.

Conclusions

The use of irRECIST identified a subset of patients with a BOR of PD by RECIST 1.1 but an irBOR of immune-related disease control by irRECIST with a distinctive survival curve, thereby providing more clinically relevant information than RECIST 1.1 alone. However, as a surrogate endpoint for OS in the whole population, immune-related PFS by irRECIST did not show improved predictive value compared with PFS by RECIST 1.1.

Efficacy and Prognostic Factors for Response to PD-1 Inhibitors in Advanced Cervical Carcinoma: A Retrospective Study

Purpose

Programmed cell death protein 1 (PD-1) inhibitors have shown a therapeutic effect in the treatment of advanced cervical cancer in clinical trials. However, the clinical characteristics associated with response remain undetermined. This study aimed to evaluate the efficacy and prognostic factors of PD-1 inhibitors in patients with advanced cervical cancer in clinical practice.

Patients and Methods

The study enrolled patients with recurrent or metastatic cervical cancer treated with PD-1 inhibitors at our center between March 2018 and November 2020. The primary outcomes were the objective response rate (ORR) and progression-free survival (PFS). Secondary endpoints were overall survival (OS) and safety. In addition, independent prognostic factors were identified by multivariate regression analysis.

Results

A total of 102 patients were included, and the ORR and disease control rate (DCR) were 51.0% and 66.7%, respectively. Median PFS was 11.0 months (95% CI, 1.7–20.4), while median OS was not achieved. Multivariate analysis indicated that factors associated with a better prognosis (ORR and PFS) included squamous cell carcinoma, a time to recurrence >6 months, and PD-1 plus chemotherapy and anti-angiogenic drugs (p < 0.05). Lines of therapy were independent factors for ORR but not for PFS. We also observed a tendency for longer PFS in patients with lung metastases and lymph node metastases only. Treatment-related adverse events (AEs) were well tolerated and primarily included thrombocytopenia, hepatic dysfunction, anemia, and leukopenia.

Conclusion

PD-1 inhibitors demonstrated beneficial efficacy and safety in advanced cervical cancer, particularly for patients with squamous cell carcinoma, a time to recurrence >6 months, or PD-1 plus chemotherapy and anti-angiogenic drugs. Further studies are needed to confirm the long-term outcomes.

Phase I/II study of the LAG-3 inhibitor ieramilimab (LAG525) ± anti-PD-1 spartalizumab (PDR001) in patients with advanced malignancies

Background

Lymphocyte-activation gene 3 (LAG-3) is an inhibitory immunoreceptor that negatively regulates T-cell activation. This paper presents preclinical characterization of the LAG-3 inhibitor, ieramilimab (LAG525), and phase I data for the treatment of patients with advanced/metastatic solid tumors with ieramilimab ±the anti-programmed cell death-1 antibody, spartalizumab.

Methods

Eligible patients had advanced/metastatic solid tumors and progressed after, or were unsuitable for, standard-of-care therapy, including checkpoint inhibitors in some cases. Patients received ieramilimab ±spartalizumab across various dose-escalation schedules. The primary objective was to assess the maximum tolerated dose (MTD) or recommended phase II dose (RP2D).

Results

In total, 255 patients were allocated to single-agent ieramilimab (n=134) and combination (n=121) treatment arms. The majority (98%) had received prior antineoplastic therapy (median, 3). Four patients experienced dose-limiting toxicities in each treatment arm across various dosing cohorts. No MTD was reached. The RP2D on a 3-week schedule was declared as 400 mg ieramilimab plus 300 mg spartalizumab and, on a 4-week schedule (once every 4 weeks; Q4W), as 800 mg ieramilimab plus 400 mg spartalizumab; tumor target (LAG-3) suppression with 600 mg ieramilimab Q4W was predicted to be similar to the Q4W, RP2D schedule. Treatment-related adverse events (TRAEs) occurred in 75 (56%) and 84 (69%) patients in the single-agent and combination arms, respectively. Most common TRAEs were fatigue, gastrointestinal, and skin disorders, and were of mild severity; seven patients experienced at least one treatment-related serious adverse event in the single-agent (5%) and combination group (5.8%). Antitumor activity was observed in the combination arm, with 3 (2%) complete responses and 10 (8%) partial responses in a mixed population of tumor types. In the combination arm, eight patients (6.6%) experienced stable disease for 6 months or longer versus six patients (4.5%) in the single-agent arm. Responding patients trended towards having higher levels of immune gene expression, including CD8 and LAG3, in tumor tissue at baseline.

Conclusions

Ieramilimab was well tolerated as monotherapy and in combination with spartalizumab. The toxicity profile of ieramilimab in combination with spartalizumab was comparable to that of spartalizumab alone. Modest antitumor activity was seen with combination treatment.

Trial registration number

NCT02460224.

Multi-Level Analysis and Identification of Tumor Mutational Burden Genes across Cancer Types

Tumor mutational burden (TMB) is considered a potential biomarker for predicting the response and effect of immune checkpoint inhibitors (ICIs). However, there are still inconsistent standards of gene panels using next-generation sequencing and poor correlation between the TMB genes, immune cell infiltrating, and prognosis. We applied text-mining technology to construct specific TMB-associated gene panels cross various cancer types. As a case exploration, Pearson’s correlation between TMB genes and immune cell infiltrating was further analyzed in colorectal cancer. We then performed LASSO Cox regression to construct a prognosis predictive model and calculated the risk score of each sample for receiver operating characteristic (ROC) analysis. The results showed that the assessment of TMB gene panels performed well with fewer than 500 genes, highly mutated genes, and the inclusion of synonymous mutations and immune regulatory and drug-target genes. Moreover, the analysis of TMB differentially expressed genes (DEGs) suggested that JAKMIP1 was strongly correlated with the gene expression level of CD8⁺ T cell markers in colorectal cancer. Additionally, the prognosis predictive model based on 19 TMB DEGs reached AUCs of 0.836, 0.818, and 0.787 in 1-, 3-, and 5-year OS models, respectively (C-index: 0.810). In summary, the gene panel performed well and TMB DEGs showed great potential value in immune cell infiltration and in predicting survival.

Cost-Effectiveness of PET/CT Surveillance Schedules to Detect Distant Recurrence of Resected Stage III Melanoma

Objective: To estimate the cost-effectiveness of three surveillance imaging strategies using whole-body positron emission tomography (PET) with computed tomography (CT) (PET/CT) in a follow-up program for adults with resected stage III melanoma. Methods: An analytic decision model was constructed to estimate the costs and benefits of PET/CT surveillance imaging performed 3-monthly, 6-monthly, or 12-monthly compared with no surveillance imaging. Results: At 5 years, 3-monthly PET/CT surveillance imaging incurred a total cost of AUD 88,387 per patient, versus AUD 77,998 for 6-monthly, AUD 52,560 for 12-monthly imaging, and AUD 51,149 for no surveillance imaging. When compared with no surveillance imaging, 12-monthly PET/CT imaging was associated with a 4% increase in correctly diagnosed and treated distant disease; a 0.5% increase with 6-monthly imaging and 1% increase with 3-monthly imaging. The incremental cost-effectiveness ratio (ICER) of 12-monthly PET/CT surveillance imaging was AUD 34,362 for each additional distant recurrence correctly diagnosed and treated, compared with no surveillance imaging. For the outcome of cost per diagnostic error avoided, the no surveillance imaging strategy was the least costly and most effective. Conclusion: With the ICER for this strategy less than AUD 50,000 per unit of health benefit, the 12-monthly surveillance imaging strategy is considered good value for money.

Detection of clinical progression through plasma ctDNA in metastatic melanoma patients: a comparison to radiological progression

BACKGROUND

The validity of circulating tumour DNA (ctDNA) as an indicator of disease progression compared to medical imaging in patients with metastatic melanoma requires detailed evaluation.

METHODS

Here, we carried out a retrospective ctDNA analysis of 108 plasma samples collected at the time of disease progression. We also analysed a validation cohort of 66 metastatic melanoma patients monitored prospectively after response to systemic therapy.

RESULTS

ctDNA was detected in 62% of patients at the time of disease progression. For 67 patients that responded to treatment, the mean ctDNA level at progressive disease was significantly higher than at the time of response (P < 0.0001). However, only 30 of these 67 (45%) patients had a statistically significant increase in ctDNA by Poisson test. A validation cohort of 66 metastatic melanoma patients monitored prospectively indicated a 56% detection rate of ctDNA at progression, with only two cases showing increased ctDNA prior to radiological progression. Finally, a correlation between ctDNA levels and metabolic tumour burden was only observed in treatment naïve patients but not at the time of progression in a subgroup of patients failing BRAF inhibition (N = 15).

CONCLUSIONS

These results highlight the low efficacy of ctDNA to detect disease progression in melanoma when compared mainly to standard positron emission tomography imaging.

Promise and challenges of clinical non-invasive T-cell tracking in the era of cancer immunotherapy

In the last decades, our understanding of the role of the immune system in cancer has significantly improved and led to the discovery of new immunotherapeutic targets and tools, which boosted the advances in cancer immunotherapy to fight a growing number of malignancies. Approved immunotherapeutic approaches are currently mainly based on immune checkpoint inhibitors, antibody-derived targeted therapies, or cell-based immunotherapies. In essence, these therapies induce or enhance the infiltration and function of tumor-reactive T cells within the tumors, ideally resulting in complete tumor eradication. While the clinical application of immunotherapies has shown great promise, these therapies are often accompanied either by a variety of side effects as well as partial or complete unresponsiveness of a number of patients. Since different stages of disease progression elicit different local and systemic immune responses, the ability to longitudinally interrogate the migration and expansion of immune cells, especially T cells, throughout the whole body might greatly facilitate disease characterization and understanding. Furthermore, it can serve as a tool to guide development as well as selection of appropriate treatment regiments. This review provides an overview about a variety of immune-imaging tools available to characterize and study T-cell responses induced by anti-cancer immunotherapy. Moreover, challenges are discussed that must be taken into account and overcome to use immune-imaging tools as predictive and surrogate markers to enhance assessment and successful application of immunotherapies.

Exploring the Interobserver Agreement in Computer-Aided Radiologic Tumor Measurement and Evaluation of Tumor Response

The accurate, objective, and reproducible evaluation of tumor response to therapy is indispensable in clinical trials. This study aimed at investigating the reliability and reproducibility of a computer-aided contouring (CAC) tool in tumor measurements and its impact on evaluation of tumor response in terms of RECIST 1.1 criteria. A total of 200 cancer patients were retrospectively collected in this study, which were randomly divided into two sets of 100 patients for experiential learning and testing. A total of 744 target lesions were identified by a senior radiologist in distinctive body parts, of which 278 lesions were in data set 1 (learning set) and 466 lesions were in data set 2 (testing set). Five image analysts were respectively instructed to measure lesion diameter using manual and CAC tools in data set 1 and subsequently tested in data set 2. The interobserver variability of tumor measurements was validated by using the coefficient of variance (CV), the Pearson correlation coefficient (PCC), and the interobserver correlation coefficient (ICC). We verified that the mean CV of manual measurement remained constant between the learning and testing data sets (0.33 vs. 0.32, p = 0.490), whereas it decreased for the CAC measurements after learning (0.24 vs. 0.19, p < 0.001). The interobserver measurements with good agreement (CV < 0.20) were 29.9% (manual) vs. 49.0% (CAC) in the learning set (p < 0.001) and 30.9% (manual) vs. 64.4% (CAC) in the testing set (p < 0.001). The mean PCCs were 0.56 ± 0.11 mm (manual) vs. 0.69 ± 0.10 mm (CAC) in the learning set (p = 0.013) and 0.73 ± 0.07 mm (manual) vs. 0.84 ± 0.03 mm (CAC) in the testing set (p < 0.001). ICCs were 0.633 (manual) vs. 0.698 (CAC) in the learning set (p < 0.001) and 0.716 (manual) vs. 0.824 (CAC) in the testing set (p < 0.001). The Fleiss’ kappa analysis revealed that the overall agreement was 58.7% (manual) vs. 58.9% (CAC) in the learning set and 62.9% (manual) vs. 74.5% (CAC) in the testing set. The 80% agreement of tumor response evaluation was 55.0% (manual) vs. 66.0% in the learning set and 60.6% (manual) vs. 79.7% (CAC) in the testing set. In conclusion, CAC can reduce the interobserver variability of radiological tumor measurements and thus improve the agreement of imaging evaluation of tumor response.