Coming of Age: Human Genomics and the Cancer-Immune Set Point

Correlation of safety and efficacy of atezolizumab therapy across indications

BACKGROUND

The association between safety and efficacy of immune checkpoint inhibitors is known, but the correlation between severity and impact of specific organ involvement by immune-related adverse events (irAE) and cancer outcomes is poorly understood. Most irAEs are mild-to-moderate but severe irAEs may pose clinical management challenges and affect patient outcomes.

METHODS

We assessed the association between irAE grade (G) and specific organ involvement with overall survival (OS) in 9,521 patients across 14 studies involving atezolizumab as mono (IO) or with chemo/targeted (C-IO) therapy as compared with chemo/targeted therapy (C) in advanced non-small cell lung, small-cell lung, renal cell, urothelial, and triple-negative breast cancers. We used a mixed-effect Cox proportional hazard model for time-varying covariates to address immortal-time bias; adjusted for baseline factors associated with irAEs and OS to control for confounding bias; and focused on five common irAEs (dermatologic, thyroid dysfunction, hepatitis, pneumonitis, and colitis) to avoid low statistical power for rare events.

RESULTS

For patients treated with IO or C-IO, G1-2 irAEs were associated with improved OS (HR=0.65, p<0.01) and G3-4 irAEs showed a slight increased risk of death (HR=1.18, p=0.10) versus patients without irAEs. By specific irAE, G1-2 cutaneous irAEs, thyroid dysfunction, or pneumonitis were associated with improved OS (p<0.05), while G3-4 pneumonitis and colitis were associated with worse OS (p<0.01). There was no association between hepatitis and OS by any grade. Findings were consistent across indications.

CONCLUSIONS

This analysis demonstrates a correlation between irAEs and improved OS with atezolizumab by severity grade and the most common irAEs by organ involvement. Low-grade irAEs are significantly associated with improved OS, while specific high-grade irAEs are associated with poorer OS, underscoring the importance of early recognition and management of toxicity to optimize benefit/risk balance.

Germline mechanisms of immunotherapy toxicities in the era of genome-wide association studies

Cancer immunotherapy has revolutionized the treatment of advanced cancers and is quickly becoming an option for early-stage disease. By reactivating the host immune system, immunotherapy harnesses patients' innate defenses to eradicate the tumor. By putatively similar mechanisms, immunotherapy can also substantially increase the risk of toxicities or immune-related adverse events (irAEs). Severe irAEs can lead to hospitalization, treatment discontinuation, lifelong immune complications, or even death. Many irAEs present with similar symptoms to heritable autoimmune diseases, suggesting that germline genetics may contribute to their onset. Recently, genome-wide association studies (GWAS) of irAEs have identified common germline associations and putative mechanisms, lending support to this hypothesis. A wide range of well-established GWAS methods can potentially be harnessed to understand the etiology of irAEs specifically and immunotherapy outcomes broadly. This review summarizes current findings regarding germline effects on immunotherapy outcomes and discusses opportunities and challenges for leveraging germline genetics to understand, predict, and treat irAEs.

Outcomes in breast cancer-does ethnicity matter?

Ethnic or racial differences in breast cancer (BC) survival outcomes have been reported, but current data are largely restricted to comparisons between African Americans and non-Hispanic whites. Most analyses have traditionally been based on self-reported race which may not always be accurate, or are oversimplified in their classification. With increasing globalization, quantification of the genetic ancestry from genomic data may offer a solution to infer the complex makeup from admixture of races. Focusing on the larger and the latest studies, we will discuss recent findings on the differing host and tumor biology that may be driving these disparities, in addition to the extrinsic environmental or lifestyle factors. Socioeconomic disparities with lower cancer literacy may lead to late presentation, poorer adherence to treatment, and other lifestyle factors such as unhealthy diet, obesity, and inadequate physical activity. These hardships may also result in greater allostatic load, which is in turn associated with aggressive BC features in disadvantaged populations. Epigenetic reprogramming may mediate the effects of the environment or lifestyle factors on gene expression, with ensuing differences in BC characteristics and outcome. There is increasing evidence that germline genetics can influence somatic gene alterations or expression, as well as modulate the tumor or immune microenvironment. Although the precise mechanisms remain elusive, this may account for the varying distribution of different BC subtypes across ethnicities. These gaps in our knowledge highlight the need to interrogate the multiomics landscape of BC in diverse populations, ideally in large-scale collaborative settings with standardized methodology for the comparisons to be statistically robust. Together with improving BC awareness and access to good quality health care, a holistic approach with insights of the biological underpinnings is much needed to eradicate ethnic disparities in BC outcomes.

Differential organ-specific tumor response to first-line immune checkpoint inhibitor therapy in non-small cell lung cancer-a retrospective cohort study

Background

Immune checkpoint inhibitors (ICIs) possess remarkable clinical effectiveness in non-small cell lung cancer (NSCLC). Different immune profiles of tumors may play a key role in the efficacy of treatment with ICIs. This article aimed to determine the differential organ responses to ICI in individuals with metastatic NSCLC.

Methods

This research analyzed data of advanced NSCLC patients receiving first-line treatment with ICIs. Major organs such as the liver, lung, adrenal glands, lymph nodes and brain were assessed using the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and RECIST-improved organ-specific response criteria.

Results

A retrospective analysis was conducted on a total of 105 individuals with advanced NSCLC with programmed death ligand-1 (PD-L1) expression ≥50% who received single agent anti-programmed cell death protein 1 (PD-1)/PD-L1 monoclonal antibodies as first-line therapy. Overall, 105 (100%), 17 (16.2%), 15 (14.3%), 13 (12.4%), and 45 (42.8%) individuals showed measurable lung tumors and liver, brain, adrenal, and other lymph node metastases at baseline. The median size of the lung, liver, brain, adrenal gland, and lymph nodes were 3.4, 3.1, 2.8, 1.9, and 1.8 cm, respectively. The results recorded mean response times of 2.1, 3.4, 2.5, 3.1, and 2.3 months, respectively. Organ-specific overall response rates (ORRs) were 67%, 30.6%, 34%, 39%, and 59.1%, respectively, with the liver having the lowest remission rate and lung lesions having the highest remission rate. There were 17 NSCLC patients with liver metastasis at baseline, and 6 had different responses to ICI treatment, with remission in the primary lung site and progressive disease (PD) in the metastatic liver site. At baseline, the mean progression-free survival (PFS) of the 17 patients with liver metastasis and 88 patients without liver metastasis was 4.3 and 7 months, respectively (P=0.02, 95% CI: 0.691 to 3.033).

Conclusions

The liver metastases of NSCLC may be less responsive to ICIs than other organs. The lymph nodes respond most favorably to ICIs. Further strategies may include additional local treatment in case of oligoprogression in these organs in patients with otherwise sustained treatment benefit.

Oncolytic virus driven T-cell-based combination immunotherapy platform for colorectal cancer

Colorectal cancer is the third most diagnosed cancer and the second leading cause of cancer mortality worldwide, highlighting an urgent need for new therapeutic options and combination strategies for patients. The orchestration of potent T cell responses against human cancers is necessary for effective antitumour immunity. However, regression of a limited number of cancers has been induced by immune checkpoint inhibitors, T cell engagers (TCEs) and/or oncolytic viruses. Although one TCE has been FDA-approved for the treatment of hematological malignancies, many challenges exist for the treatment of solid cancers. Here, we show that TCEs targeting CEACAM5 and CD3 stimulate robust activation of CD4 and CD8-positive T cells in in vitro co-culture models with colorectal cancer cells, but in vivo efficacy is hindered by a lack of TCE retention in the tumour microenvironment and short TCE half-life, as demonstrated by HiBiT bioluminescent TCE-tagging technology. To overcome these limitations, we engineered Bispecific Engager Viruses, or BEVirs, a novel tumour-targeted vaccinia virus platform for intra-tumour delivery of these immunomodulatory molecules. We characterized virus-mediated TCE-secretion, TCE specificity and functionality from infected colorectal cancer cells and patient tumour samples, as well as TCE cytotoxicity in spheroid models, in the presence and absence of T cells. Importantly, we show regression of colorectal tumours in both syngeneic and xenograft mouse models. Our data suggest that a different profile of cytokines may contribute to the pro-inflammatory and immune effects driven by T cells in the tumour microenvironment to provide long-lasting immunity and abscopal effects. We establish combination regimens with immune checkpoint inhibitors for aggressive colorectal peritoneal metastases. We also observe a significant reduction in lung metastases of colorectal tumours through intravenous delivery of our oncolytic virus driven T-cell based combination immunotherapy to target colorectal tumours and FAP-positive stromal cells or CTLA4-positive Treg cells in the tumour microenvironment. In summary, we devised a novel combination strategy for the treatment of colorectal cancers using oncolytic vaccinia virus to enhance immune-payload delivery and boost T cell responses within tumours.