Is there a role for Gallium-67 SPECT in distinguishing progression and pseudoprogresion in oncologic patients receiving immunotherapy?

Immuno-oncology (IO) with immune checkpoint inhibitors (ICIs) is the new landmark in cancer treatment. However, due to its economical-related burden and the possibility of tumor pseudoprogression with late response patterns, it is imperative to find new ways for early discrimination of patients with IO-sensitive versus IO-resistant disease. ICI-mediated antitumor responses depend on tumor immune infiltration by T-cells capable of recognizing and killing tumor cells. Nevertheless, patients may experience different responses to immunotherapy according to their tumor microenvironment and inflammatory infiltration. T-cell infiltrated tumors are referred to as 'hot' and are potential candidates for a good response to ICIs, whereas 'cold' are those tumors lacking T-cell infiltration and exhibit a narrow likelihood of response to IO therapy. Gallium-67 (⁶⁷Ga) scintigraphy may hold potential for separating 'hot' from 'cold' tumors, thus providing an imaging tool to distinguish 'hot' ICI-induced pseudoprogression from real early 'cold' progression. Even so, various tumors (lymphomas, lung cancer, breast cancer, hepatoma, malignant melanoma) exhibit an inherent affinity for ⁶⁷Ga that is independent of the ICI-induced immune infiltration, and this raises issues about false positivity. For that reason, future investigational studies to evaluate the prospective role of this radiotracer in the early prediction of ICI response should be confined to tumors with an inherently low ⁶⁷Ga affinity (thyroid carcinoma, gastrointestinal and genitourinary tract tumors). We describe our experience with a patient with recurrent metastatic lung adenocarcinoma under ICI therapy that was submitted to ⁶⁷Ga scanning for a fever of unknown origin and we discuss the aforementioned topics, alongside current imaging trends and future perspectives in the field.

An Integrated Analysis of Dostarlimab Immunogenicity

Monoclonal antibodies that block the interaction between programmed cell death 1 (PD-1) and its ligand (PD-L1) have revolutionized cancer immunotherapy. However, immunogenic responses to these new therapies—such as the development of antidrug antibodies (ADAs) and neutralizing antibodies (NAbs)—may represent a significant challenge to both efficacy and safety in some patients. Dostarlimab (TSR-042) is an approved, humanized, anti-PD-1 monoclonal antibody that has shown efficacy in multiple solid tumor types. Here, we report the results of an immunogenicity analysis of dostarlimab monotherapy in patients enrolled in the GARNET trial, a multicenter, open-label, single-arm phase 1 study. Overall, 477 of 478 patients (99.8%) were included in the analysis of dostarlimab antibody prevalence, and 349 out of 478 enrolled patients (73.0%) were evaluable for treatment-emergent antibodies to dostarlimab. The incidence of treatment-emergent ADAs was 2.5% at the recommended therapeutic dose (500 mg Q3W for the first 4 doses, 1000 mg Q6W until discontinuation), which is comparable to other anti-PD-(L)1 drugs. NAbs were detected in only 1.3% of patients. In the small percentage of patients who developed ADAs, there was no evidence of altered efficacy or safety of dostarlimab at the recommended dosing regimen. These findings demonstrated that treatment with dostarlimab was associated with a low risk of eliciting clinically meaningful ADAs over the course of this study, and dostarlimab is already approved by health authorities.

Impact of open-label versus blinded study design on patient-reported outcomes data in randomized clinical trials of immunotherapy in advanced or metastatic cancer patients: a systematic review

AIM

A systematic literature review of immuno-oncology trials was conducted to assess the potential impact of open-label vs double-blind trial design on patient-reported outcome (PRO) data.

METHODS

A systematic search of indexed literature published from January 2009 to May 2019 was conducted using PubMed/MEDLINE, Cochrane Library, and EMBASE database. All randomized clinical trials (RCTs) of immuno-oncology therapies on advanced cancer patients reporting PRO data were identified. Descriptive analyses were performed to quantify differences at baseline and over time, by the type of study, regarding questionnaire completion rate and PRO scores.

RESULTS

In total, 23 studies were retained (15 open-label, 8 blinded). At baseline, no difference in completion rate was observed between arms irrespective of trial design (absolute mean difference of 2.8% and 2.2% for open label and blinded studies, respectively). No clinically significant difference in baseline PRO scores was observed between arms. Over time, impact on PRO scores could not be identified due to the limited number of studies, heterogeneity of questionnaires and tumor types.

CONCLUSIONS

Trial design had no impact on PRO completion rate or baseline scores. Future research should involve analyses by specific cancer types and ideally compare individual data from two similar RCTs (blinded vs. open-label).

Autologous dendritic cell-based immunotherapy (DCVAC/LuCa) and carboplatin/paclitaxel in advanced non-small cell lung cancer: A randomized, open-label, phase I/II trial

PURPOSE

To investigate the efficacy and safety of an active cellular immunotherapy (DCVAC/LuCa) and chemotherapy in patients with stage IV non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

SLU01 was a multicenter, open-label, parallel-group, randomized, phase I/II trial. NSCLC patients were randomized in a ratio of 1:1:1 to receive: DCVAC/LuCa and chemotherapy (carboplatin and paclitaxel; Group A); DCVAC/LuCa, chemotherapy, pegylated interferon-α2b, and hydroxychloroquine (Group B); or chemotherapy alone (Group C). DCVAC/LuCa was administered subcutaneously every 3-6 weeks (up to 15 doses). The primary endpoint was overall survival (OS). During the study, enrollment into Group B was discontinued for strategic reasons.

RESULTS

Forty-five patients were randomized to Group A, 29 patients to Group B, and 38 patients to Group C. The median OS in the modified intention-to-treat (mITT) population was 3.7 months longer in Group A than in Group C (15.5 vs. 11.8 months; p = 0.0179; hazard ratio = 0.54; 95% confidence interval: 0.32-0.91). This OS effect was consistent across subgroups of the mITT population (females, males, current smokers, former smokers, and patients with non-squamous and squamous cell histology). The most common treatment-emergent adverse events of any grade reported in Groups A, B, and C, respectively, were neutropenia (50.0%, 29.6%, and 20.6%), fatigue (40.0%, 18.5%, and 20.6%), anemia (35.0%, 44.4%, and 32.4%), paresthesia (27.5%, 25.9%, and 17.6%), and alopecia (25.0%, 29.6%, and 41.2%).

CONCLUSION

DCVAC/LuCa in combination with carboplatin and paclitaxel extended OS and was well tolerated.

Preclinical Evaluation of 89Zr-Df-IAB22M2C PET as an Imaging Biomarker for the Development of the GUCY2C-CD3 Bispecific PF-07062119 as a T Cell Engaging Therapy

Purpose

A sensitive and specific imaging biomarker to monitor immune activation and quantify pharmacodynamic responses would be useful for development of immunomodulating anti-cancer agents. PF-07062119 is a T cell engaging bispecific antibody that binds to CD3 and guanylyl cyclase C, a protein that is over-expressed by colorectal cancers. Here, we used ⁸⁹Zr-Df-IAB22M2C (⁸⁹Zr-Df-Crefmirlimab), a human CD8-specific minibody to monitor CD8+ T cell infiltration into tumors by positron emission tomography. We investigated the ability of ⁸⁹Zr-Df-IAB22M2C to track anti-tumor activity induced by PF-07062119 in a human CRC adoptive transfer mouse model (with injected activated/expanded human T cells), as well as the correlation of tumor radiotracer uptake with CD8+ immunohistochemical staining.

Procedures

NOD SCID gamma mice bearing human CRC LS1034 tumors were treated with four different doses of PF-07062119, or a non-targeted CD3 BsAb control, and imaged with ⁸⁹Zr-Df-IAB22M2C PET at days 4 and 9. Following PET/CT imaging, mice were euthanized and dissected for ex vivo distribution analysis of ⁸⁹Zr-Df-IAB22M2C in tissues on days 4 and 9, with additional data collected on day 6 (supplementary). Data were analyzed and reported as standard uptake value and %ID/g for in vivo imaging and ex vivo tissue distribution. In addition, tumor tissues were evaluated by immunohistochemistry for CD8+ T cells.

Results

The results demonstrated substantial mean uptake of ⁸⁹Zr-Df-IAB22M2C (%ID/g) in PF-07062119-treated tumors, with significant increases in comparison to non-targeted BsAb-treated controls, as well as PF-07062119 dose-dependent responses over time of treatment. A moderate correlation was observed between tumor tissue radioactivity uptake and CD8+ cell density, demonstrating the value of the imaging agent for non-invasive assessment of intra-tumoral CD8+ T cells and the mechanism of action for PF-07062119.

Conclusion

Immune-imaging technologies for quantitative cellular measures would be a valuable biomarker in immunotherapeutic clinical development. We demonstrated a qualification of ⁸⁹Zr-IAB22M2C PET to evaluate PD responses (mice) to a novel immunotherapeutic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11307-021-01621-0.

Genomic stratification based on microenvironment immune types and PD-L1 for tailoring therapeutic strategies in bladder cancer

Background

The tumour microenvironment (TME) not only plays a role during tumour progression and metastasis but also profoundly influences treatment efficacy. Environment-mediated drug resistance is a result of crosstalk between tumour cells and stroma. The presence of a “stromal exhaustion” response is suggested by the T cell exhaustion signature and PD-L1 expression. The prognostic role of PD-L1 in bladder cancer has been investigated in previous studies, but the results remain inconclusive. For a more comprehensive study, we discuss potential strategies to improve effectiveness in patients with various TME statuses and PD-L1 expression levels.

Methods

We estimated the prognostic role of PD-L1 using immunohistochemistry and identified four immune subtypes according to the type of stromal immune modulation and PD-L1 expression status.

Results

Patients in the PD-L1-low-exhausted group had the worst prognosis and showed the worst antigen-presenting cell (APC) immunosuppression status. The PD-L1-low-exhausted group showed the highest amount of infiltration by macrophage M2 cells, naïve B cells and resting mast cells. The TMB and the effectiveness of anti-PD-1 treatment were significantly increased in the PD-L1-high expression groups compared with the PD-L1-low expression groups. In the PD-L1-high groups, patients who underwent chemotherapy exhibited better overall survival rates than patients who did not undergo chemotherapy, whereas there was no significant difference in the PD-L1-low groups. We performed gene set enrichment analysis (GSEA) to explore the critical pathways that were active in the PD-L1-low-exhausted group, including the myogenesis, epithelial-mesenchymal transition and adipogenesis pathways. Copy number variations (CNVs) were related to the expression levels of differentially expressed genes upregulated in the PD-L1-low-exhausted group, including LCNL1, FBP1 and RASL11B. In addition, RASL11B played a role in predicting overall survival according to The Cancer Genome Atlas data, and this finding was validated in the PD-L1-low-exhausted group in the Gene Expression Omnibus database (GEO).

Conclusion

The immune environment of tumours plays an important role in the therapeutic response rate, and defining the immune groups plays a critical role in predicting disease outcome and strategy effectiveness.

Single-cell transcriptomics reveals the effect of PD-L1/TGF-β blockade on the tumor microenvironment

BACKGROUND

The anti-tumor activity of anti-PD-1/PD-L1 therapies correlates with T cell infiltration in tumors. Thus, a major goal in oncology is to find strategies that enhance T cell infiltration and efficacy of anti-PD-1/PD-L1 therapy. TGF-β has been shown to contribute to T cell exclusion, and anti-TGF-β improves anti-PD-L1 efficacy in vivo. However, TGF-β inhibition has frequently been shown to induce toxicity in the clinic, and the clinical efficacy of combination PD-L1 and TGF-β blockade has not yet been proven. To identify strategies to overcome resistance to PD-L1 blockade, the transcriptional programs associated with PD-L1 and/or TGF-β blockade in the tumor microenvironment should be further elucidated.

RESULTS

We used single-cell RNA sequencing in a mouse model to characterize the transcriptomic effects of PD-L1 and/or TGF-β blockade on nearly 30,000 single cells in the tumor and surrounding microenvironment. Combination treatment led to upregulation of immune response genes, including multiple chemokine genes such as CCL5, in macrophages, and downregulation of extracellular matrix genes in fibroblasts. Analysis of publicly available tumor transcriptome profiles showed that the chemokine CCL5 was strongly associated with immune cell infiltration in various human cancers. Further investigation with in vivo models showed that intratumorally administered CCL5 enhanced cytotoxic lymphocytes and the anti-tumor activity of anti-PD-L1.

CONCLUSIONS

Taken together, our data could be leveraged translationally to complement or find alternatives to anti-PD-L1 plus anti-TGF-β combination therapy, for example through companion biomarkers, and/or to identify novel targets that could be modulated to overcome resistance.

Real-world Clinical Effectiveness of Lenvatinib/Everolimus in a Heavily Pretreated Advanced/Metastatic Renal Cell Carcinoma Population in the US Community Oncology Setting

INTRODUCTION

Few studies have evaluated real-world effectiveness of lenvatinib (Len)/everolimus (Eve) for advanced/metastatic renal cell carcinoma (a/mRCC). This study evaluated patient profiles and clinical outcomes of second- and subsequent-line (≥ 2L) Len/Eve for a/mRCC.

PATIENTS AND METHODS

A longitudinal retrospective study examined adult patients initiating ≥ 2L Len/Eve for a/mRCC from May 13, 2016, to July 31, 2019. Len/Eve clinical trial participants or those treated for other primary tumors were excluded. Outcomes included objective response rate, duration of response, progression-free survival (PFS), time to treatment discontinuation, and overall survival. Time-to-event outcomes were estimated using Kaplan-Meier methods.

RESULTS

Seventy-nine patients were assessed: the median age was 64.8 years, 78.5% were Caucasian, 73.4% were male, 78.5% had an Eastern Cooperative Oncology Group performance status score of 0/1, 29.1% received 2L/3L Len/Eve, and the median number of prior lines of therapy was 3 (range, 1-8). At initial diagnosis, 55.7% had stage IV disease, 65.8% had International Metastatic risk scores of intermediate/poor, 19.0% favorable, and 15.2% with missing score. Thirty-one (39.2%) patients received immuno-oncology-based regimens, and 50.6% received tyrosine kinase inhibitors directly before Len/Eve initiation. The median time to treatment discontinuation was 5.7 months (95% CI, 3.3-6.9). The physician-assessed objective response rate was 55.7% (1.6% complete response and 54.1% with some degree of tumor shrinkage). The median duration of response was 9.7 months (95% CI, 5.8-17.1). The median PFS was 6.1 months (95% CI, 4.4-9.0). The median PFS for patients receiving Len/Eve post-immuno-oncology was 6.4 months (95% CI, 4.1-10.8) and for post-tyrosine kinase inhibitor 5.7 months (95% CI, 4.1-10.5). Median overall survival was 14.8 months (95% CI, 10.2-23.9).

CONCLUSION

In this longitudinal retrospective study, Len/Eve showed real-world effectiveness in clinical practice in a heavily pretreated a/mRCC patient population.

Outcomes of patients with solid tumour malignancies treated with first-line immuno-oncology agents who do not meet eligibility criteria for clinical trials

BACKGROUND

Immuno-oncology (IO)-based therapies have been approved based on randomised clinical trials, yet a significant proportion of real-world patients are not represented in these trials. We sought to compare the outcomes of trial-ineligible vs. -eligible patients with advanced solid tumours treated with first-line (1L) IO therapy.

PATIENTS AND METHODS

Using the International Metastatic Renal Cell Carcinoma (RCC) Database Consortium and the Alberta Immunotherapy Database, patients with advanced RCC, non-small-cell lung cancer (NSCLC) or melanoma treated with 1L PD-(L)1 inhibition-based therapy were included. Trial eligibility was retrospectively determined as per commonly used exclusion criteria. The outcomes of interest were overall survival (OS), overall response rate (ORR), treatment duration (TD) and time to next treatment (TTNT).

RESULTS

A total of 395 of 1241 (32%) patients were deemed trial-ineligible. The main reasons for ineligibility based on preselected exclusion criteria were Karnofsky performance status <70%/Eastern Cooperative Oncology Group performance status >1 (40%, 158 of 395), brain metastases (32%, 126 of 395), haemoglobin < 9 g/dL (16%, 63 of 395) and estimated glomerular filtration rate <40 mL/min (15%, 61 of 395). Between the ineligible vs. eligible groups, the median OS, ORR, median TD and median TTNT were 10.2 vs. 39.7 months (p < 0.01), 36% vs. 47% (p < 0.01), 2.7 vs. 6.9 months (p < 0.01) and 6.0 vs. 16.8 months (p < 0.01), respectively. Subgroup analyses showed statistically significant inferior OS, TD and TTNT for trial-ineligible vs. -eligible patients across all tumour types. Adjusted hazard ratios for death in RCC, NSCLC and melanoma were 1.84 (95% confidence interval [CI] 1.22-2.77), 2.21 (95% CI 1.58-3.11) and 1.82 (95% CI 1.21-2.74), respectively..

CONCLUSIONS

Thirty-two percent of real-world patients treated with contemporary 1L IO-based therapies were ineligible for clinical trials. Although one-third of the trial-ineligible patients responded to treatment, the overall trial-ineligible population had inferior outcomes than trial-eligible patients. These data may guide patient counselling and temper expectations of benefit.

Understanding the immuno-biology of oesophageal adenocarcinoma: Towards improved therapeutic approaches

With an incidence that is constantly rising, oesophageal adenocarcinoma (OAC) is becoming an increasing health burden worldwide. Although significant advances in treatment regimens have improved patient outcomes, survival rates for this deadly cancer remain unsatisfactory. This highlights the need to improve current therapeutic approaches and develop novel therapeutic strategies for treating OAC patients. The advent of immunotherapy has revolutionised treatment across a range of malignancies, however outcomes in OAC show modest results. The inherent resistance of OAC to treatment reflects the complex genomic landscape of this cancer, which displays a lack of ubiquitous driver mutations and large-scale genomic alterations along with high tumour and immune heterogeneity. Research into the immune landscape of OAC is limited, and elucidation of the mechanisms surrounding the immune responses to this complex cancer will result in improved therapeutic approaches. This review explores what is known about the immuno-biology of OAC and explores promising therapeutic avenues that may improve responses to immunotherapeutic regimens.

The effect of adding immune checkpoint inhibitors on the risk of pneumonitis for solid tumours: a meta-analysis of phase III randomised controlled trials

BACKGROUND

Immune checkpoint inhibitors (ICIs) have become one of the standard treatment options for solid tumours; however, treatment-related adverse events, including pneumonitis, sometimes disrupt the ongoing treatment. To evaluate the impact of ICI addition on the risk of pneumonitis, a meta-analysis was conducted.

METHODS

Phase III randomised controlled trials comparing ICIs and conventional therapy with conventional therapy alone were selected by searching databases, including PubMed, Embase, Web of Science and Cochrane Library. The odds ratio (OR) of any grade and grade III-V pneumonitis was calculated. Meta-analysis was performed to compare the incidence of pneumonitis between the treatment arm with additional ICIs and the arm with conventional therapy.

RESULTS

A total of 25 randomised controlled trials (RCTs) representing 16,343 patients for grade I-V and 23 RCTs with 15,006 patients for grade III-V pneumonitis were analysed. Adding ICIs was associated with a significant increase in pneumonitis (grade I-V: OR, 2.67, 95% confidence interval [CI]: 2.12-3.37, grade III-V: OR, 1.83, 95% CI: 1.26-2.65). In subgroup analyses based on the mechanism of action of ICIs, cancer types (lung and non-lung cancer) and each ICI, no significant difference in heterogeneity was observed.

CONCLUSIONS

Adding ICIs to the conventional treatment for solid tumours significantly increased both grade I-V and grade III-V pneumonitis regardless of the mechanisms of ICIs and cancer type. These results would be helpful for oncologists to choose the appropriate treatment options using ICIs, particularly for patients with known risk factors of pneumonitis or interstitial lung disease.

The TIM3/Gal9 signaling pathway: An emerging target for cancer immunotherapy

Immune checkpoint blockade has shown unprecedented and durable clinical response in a wide range of cancers. T cell immunoglobulin and mucin domain 3 (TIM3) is an inhibitory checkpoint protein that is highly expressed in tumor-infiltrating lymphocytes. In various cancers, the interaction of TIM3 and Galectin 9 (Gal9) suppresses anti-tumor immunity mediated by innate as well as adaptive immune cells. Thus, the blockade of the TIM3/Gal9 interaction is a promising therapeutic approach for cancer therapy. In addition, co-blockade of the TIM3/Gal9 pathway along with the PD-1/PD-L1 pathway increases the therapeutic efficacy by overcoming non-redundant immune resistance induced by each checkpoint. Here, we summarize the physiological roles of the TIM3/Gal9 pathway in adaptive and innate immune systems. We highlight the recent clinical and preclinical studies showing the involvement of the TIM3/Gal9 pathway in various solid and blood cancers. In addition, we discuss the potential of using TIM3 and Gal9 as prognostic and predictive biomarkers in different cancers. An in-depth mechanistic understanding of the blockade of the TIM3/Gal9 signaling pathway in cancer could help in identifying patients who respond to this therapy as well as designing combination therapies.

A Phase I/II Study to Assess the Safety and Efficacy of Pazopanib and Pembrolizumab Combination Therapy in Patients with Advanced Renal Cell Carcinoma

BACKGROUND

This study assessed whether antiangiogenic treatment may potentiate immune checkpoint blockade in patients with advanced renal cell carcinoma.

PATIENTS AND METHODS

This was an open-label, two-part, multicenter study involving treatment-naïve patients with advanced renal cell carcinoma. Part 1 consisted of a phase I dose escalation and expansion of pazopanib plus pembrolizumab (combination therapy). Cohorts A and B received pazopanib in combination with pembrolizumab, whereas Cohort C received pazopanib monotherapy for 9 weeks before receiving the combination therapy. Part 2 was planned as a randomized three-arm study but was not conducted.

RESULTS

Overall, 42 patients were enrolled (10 each in Cohorts A and B, 22 in Cohort C). The maximum tolerated dose was not reached and the recommended phase II dose was not declared, as Cohort C was closed early because of safety concerns. The overall response rates were 60% and 20% in Cohorts A and B, respectively. In Cohort C, the overall response rates were 33%, 25%, and 0% in the combination therapy, pembrolizumab monotherapy, and pazopanib monotherapy groups, respectively. The median progression-free survival rates were 21.95 months and 41.40 months in Cohorts A and B, respectively. Grade 3 or 4 adverse events (AEs) were observed in 90% of patients in Cohorts A and B. In Cohort C, the frequencies of grade 3 or 4 AEs, serious adverse events, and AEs leading to dose reduction were typically high in the combination therapy group.

CONCLUSIONS

Despite preliminary signs of efficacy, significant hepatotoxicity was observed in Cohorts A and B. The sequential schedule of pazopanib followed by pazopanib plus pembrolizumab showed reduced hepatotoxicity; however, other safety issues emerged with this approach.

Time to Resolution of Axitinib-Related Adverse Events After Treatment Interruption in Patients With Advanced Renal Cell Carcinoma

INTRODUCTION

Combined axitinib and immuno-oncology (IO) therapy is approved for first-line advanced renal cell carcinoma. Overlapping toxicities represent a clinical challenge. Calculating the time to resolution (TTR) of common axitinib-related adverse events (AEs) after treatment interruption may help to identify AE etiology and determine appropriate management strategies.

MATERIALS AND METHODS

Data from 5 randomized or single-arm axitinib monotherapy or combination studies were analyzed. Patients with histologically confirmed clear cell advanced renal cell carcinoma were pooled into 3 cohorts based on treatment received: axitinib monotherapy, axitinib + IO, and other tyrosine kinase inhibitor (TKI). Any grade and grade ≥3 treatment-emergent diarrhea, fatigue, hypertension, nausea, and palmar-plantar erythrodysesthesia syndrome were assessed. TTR was defined as the time from treatment interruption/discontinuation to resolution.

RESULTS

The axitinib monotherapy cohort comprised 532 patients, the axitinib + IO cohort 541 patients, and the other TKI cohort 882 patients. Median TTR for all AEs (any grade) in the axitinib monotherapy cohort ranged from 1 to 3 days, except for fatigue (8 days). For diarrhea, hypertension, nausea, and palmar-plantar erythrodysesthesia syndrome, median TTRs were longer in the axitinib + IO (4-11 days) and other TKI (7-8 days) cohorts versus the monotherapy cohort. Results were similar when only AEs of grade ≥3 were considered.

CONCLUSIONS

The TTR of monotherapeutic axitinib-related AEs is ≤3 days, except for fatigue, and generally shorter than for other single-agent TKIs and axitinib + IO. This has important implications for identifying AE etiology with combined axitinib-IO therapy and implementation of appropriate management strategies. ClinicalTrials.org identifiers: NCT00678392, NCT00920816, NCT02493751, NCT02684006, NCT02853331.

Cancer research using organoid technology

Organoid technology has rapidly transformed basic biomedical research and contributed to significant discoveries in the last decade. With the application of protocols to generate organoids from cancer tissue, organoid technology has opened up new opportunities for cancer research and therapy. Using organoid cultures derived from healthy tissues, different aspects of tumour initiation and progression are widely studied including the role of pathogens or specific cancer genes. Cancer organoid cultures, on the other hand, are applied to generate biobanks, perform drug screens, and study mutational signatures. With the incorporation of cellular components of the tumour microenvironment such as immune cells into the organoid cultures, the technology is now also exploited in the rapidly advancing field of immuno-oncology. In this review, I discuss how organoid technology is currently being utilised in cancer research and what obstacles are still to be overcome for its broader use in anti-cancer therapy.

The role of the circadian clock in cancer hallmark acquisition and immune-based cancer therapeutics

The circadian system temporally regulates physiology to maintain homeostasis. Co-opting and disrupting circadian signals appear to be distinct attributes that are functionally important for the development of a tumor and can enable or give rise to the hallmarks that tumors use to facilitate their initiation, growth and progression. Because circadian signals are also strong regulators of immune cell proliferation, trafficking and exhaustion states, they play a role in how tumors respond to immune-based cancer therapeutics. While immuno-oncology has heralded a paradigm shift in cancer therapeutics, greater accuracy is needed to increase our capability of predicting who will respond favorably to, or who is likely to experience the troubling adverse effects of, immunotherapy. Insights into circadian signals may further refine our understanding of biological determinants of response and help answer the fundamental question of whether certain perturbations in circadian signals interfere with the activity of immune checkpoint inhibitors. Here we review the body of literature highlighting circadian disruption as a cancer promoter and synthesize the burgeoning evidence suggesting circadian signals play a role in how tumors respond to immune-based anti-cancer therapeutics. The goal is to develop a framework to advance our understanding of the relationships between circadian markers, cancer biology, and immunotherapeutics. Bolstered by this new understanding, these relationships may then be pursued in future clinical studies to improve our ability to predict which patients will respond favorably to, and avoid the adverse effects of, traditional and immune-based cancer therapeutics.

Metabolic regulation of T cells in the tumor microenvironment by nutrient availability and diet

Recent advances in immunotherapies such as immune checkpoint blockade (ICB) and chimeric antigen receptor T cells (CAR-T) for the treatment of cancer have generated excitement over their ability to yield durable, and potentially curative, responses in a multitude of cancers. These findings have established that the immune system is capable of eliminating tumors and led us to a better, albeit still incomplete, understanding of the mechanisms by which tumors interact with and evade destruction by the immune system. Given the central role of T cells in immunotherapy, elucidating the cell intrinsic and extrinsic factors that govern T cell function in tumors will facilitate the development of immunotherapies that establish durable responses in a greater number of patients. One such factor is metabolism, a set of fundamental cellular processes that not only sustains cell survival and proliferation, but also serves as a means for cells to interpret their local environment. Nutrient sensing is critical for T cells that must infiltrate into a metabolically challenging tumor microenvironment and expand under these harsh conditions to eliminate cancerous cells. Here we introduce T cell exhaustion with respect to cellular metabolism, followed by a discussion of nutrient availability at the tumor and organismal level in relation to T cell metabolism and function to provide rationale for the study and targeting of metabolism in anti-tumor immune responses.

Immuno-oncology: are TAM receptors in glioblastoma friends or foes?

Tyro3, Axl, and Mertk (TAM) receptors are a subfamily of receptor tyrosine kinases. TAM receptors have been implicated in mediating efferocytosis, regulation of immune cells, secretion of inflammatory factors, and epithelial-to-mesenchymal transition in the tumor microenvironment, thereby serving as a critical player in tumor development and progression. The pro-carcinogenic role of TAM receptors has been widely confirmed, overexpression of TAM receptors is tied to tumor cells growth, metastasis, invasion and treatment resistance. Nonetheless, it is surprising to detect that inhibiting TAM signaling is not all beneficial in the tumor immune microenvironment. The absence of TAM receptors also affects anti-tumor immunity under certain conditions by modulating different immune cells, as the functional diversification of TAM signaling is closely related to tumor immunotherapy. Glioblastoma is the most prevalent and lethal primary brain tumor in adults. Although research regarding the crosstalk between TAM receptors and glioblastoma remains scarce, it appears likely that TAM receptors possess potential anti-tumor effects rather than portraying a total cancer-driving role in the context of glioblastoma. Accordingly, we doubt whether TAM receptors play a double-sided role in glioblastoma, and propose the Janus-faced TAM Hypothesis as a conceptual framework for comprehending the precise underlying mechanisms of TAMs. In this study, we aim to cast a spotlight on the potential multidirectional effects of TAM receptors in glioblastoma and provide a better understanding for TAM receptor-related targeted intervention.

Refining Immuno-Oncology Approaches in Metastatic Prostate Cancer: Transcending Current Limitations

OPINION STATEMENT

Due to its immunosuppressive tumor microenvironment, prostate cancer has historically been difficult to treat with immuno-oncology approaches. Other than pembrolizumab, which is now regulatory-approved for all microsatellite instability (MSI)-high and tumor mutational burden (TMB)-high advanced solid tumors, sipuleucel-T is the only immunotherapeutic agent approved by the US Food and Drug Administration (FDA) for prostate cancer. However, sipuleucel-T efficacy is optimal for select patients with indolent metastatic castration-resistant prostate cancer. Although manipulation of immune regulation by blocking immune checkpoints has led to substantial benefit in many cancers, experience with single-agent CTLA-4 and PD-1 or PD-L1 antibodies has shown limited effect for the majority of patients with prostate cancer, especially when administered as monotherapy. Combination therapies are now being attempted, in addition to enrichment strategies employing patient clinicopathologic and biologic characteristics that may heighten responses to immuno-oncology treatment, such as PD-L1 expression, TMB, MSI status, and alterations in CDK12. More work is needed to overcome the immune-exclusive barriers in prostate cancer, such as relatively low TMB, increased activity of myeloid-derived suppressor cells (MDSCs) and regulatory T cells, and defects in major histocompatibility complex (MHC) class I expression and interferon (IFN)-1 signaling. A promising approach and the likely next step in immuno-oncology for prostate cancer involves forced direction to markers expressed by prostate cancer tumor cells, such as prostate-specific membrane antigen (PSMA), that bypass the typical requirements for MHC class I interaction. The future will incorporate bispecific antibodies and chimeric antigen receptor (CAR)-T cells, potentially targeted towards phenotypic markers identified by next-generation PET imaging as part of the next wave of "precision medicine" in prostate cancer. Ultimately, we believe that the immune-exclusive prostate cancer tumor microenvironment can be overcome, and that patient outcomes can be enhanced through these more refined immuno-oncology approaches.

Personalized Immuno-Oncology

Cancer immunotherapy, which aims to control the immune system to eradicate cancer cells and prevent their spread, needs to be personalized because anticancer immune responses can be inhibited in several ways that vary from patient to patient. Cancer immunotherapy includes pharmaceuticals such as immune checkpoint inhibitors and monoclonal antibodies (MAbs) as well as cell therapy, immunogene therapy, and vaccines. Combination of programmed cell death protein 1 (PD-1)/programmed cell death protein ligand 1 (PD-L1) drugs with other immunotherapy drugs, for example, antibody-drug conjugates, as well as combination of PD-1/PD-L1 drugs with other therapies, for example, chemotherapy and radiation therapy, are being explored. Biomarkers are important for predicting the response to immunotherapy. Molecular diagnostics and sequencing are important technologies for guiding treatment in immuno-oncology. Genomic profiling of tumor mutational burden may enhance the predictive utility of PD-L1 expression and facilitate personalized combination immunotherapy. Optimization of personalized immuno-oncology requires integration of several technologies and selection of those best suited for an individual patient. Advances in immuno-oncology are also attributed to technologies for targeted delivery of anticancer therapeutics such as antigen-capturing nanoparticles for precision targeting and selective delivery. A breakthrough in cell therapy of cancer is a chimeric antigen receptors-T cell, which combines the antigen-binding site of a MAb with the signal activating machinery of a T cell, freeing antigen recognition from major histocompatibility complex restriction. Gene-editing tools such as clustered regularly interspaced short palindromic repeats have a promising application for removing alloreactivity and decreasing immunogenicity of third-party T cells. In conclusion, personalized immuno-oncology is one of the most promising approaches to management of cancer.

Discovery of the RANKL/RANK/OPG system

Almost a quarter century has passed since discovery of receptor activator of NF-κB ligand (RANKL). This discovery had a major impact on identification of mechanisms regulating osteoclast differentiation and function, establishment of a research field bridging bone and the immune system (osteoimmunology), and development of a fully human anti-RANKL neutralizing antibody (denosumab). Denosumab is now clinically available for treatment of osteoporosis and cancer-induced bone diseases in the US, Europe and many other countries, including Japan. Denosumab is a so-called blockbuster drug, with sales of 5.0 billion US dollars in 2019. This is a real success story from bench to bedside. In this review, the pivotal roles of the RANKL/RANK/OPG system in osteoclast differentiation and function are shown. RANKL is a ligand required for osteoclast generation, RANK is the receptor for RANKL, and osteoprotegerin (OPG) is a decoy receptor for RANKL. The review covers recent results showing the importance of RANKL on osteoblasts in regulation of osteogenesis and the role of RANKL-RANK dual signaling in coupling of bone resorption and formation, including demonstration of RANKL reverse signaling that we had previously hypothesized. Possible applications of anti-RANKL antibody in treatment of cancer are also discussed.

Accelerating patient access to oncology medicines with multiple indications in Europe

Background: In recent years, innovation in oncology has created new challenges for pricing and reimbursement systems. Oncology medicines with multiple indications face a number of access challenges: (1) the number of assessments and administrative burden; (2) aligning price to different values of the same product; (3) managing clinical uncertainty at time of launch; and (4) managing budget uncertainty. These challenges impact a range of stakeholders and can result in delayed patient access to life-saving treatments. Consequently, countries have taken steps to facilitate patient access. Methods: Drawing on the experience across Europe we have reviewed different mechanisms countries have adopted that address these challenges. These include approaches aimed directly at the issue, multi-year-multi-indication (MYMI) agreements (BE, NL), and other approaches to manage access: flexible access agreements for new indications with clinical uncertainty (UK); development of a new agreement for each new indication (IT); and immediate access for new indications and bundled assessments (DE). Results: MYMI agreements are valuable where existing rules mean that every indication faces the same upfront evaluation process that delays patient access. They are also useful in managing budget impact and uncertainty. Other approaches that adopt an indication-specific approach helps manage clinical uncertainty at the time of launch and realise different values for the same product. They can help align price to value, even though indication-based pricing does not exist. Bundled assessments reduce the administrative burden for stakeholders, and the benefits of immediate reimbursement is that patient access is not delayed. Conclusion: The challenges for medicines with multiple indications impact a range of stakeholders and can result in delayed patient access to life-saving treatments. MYMI agreements have created a more pragmatic approach to HTA for medicines with multiple indications to ensure both fast and broad patient access. Continued innovation in oncology will require further innovative approaches in pricing and reimbursement. It is important that policymakers, payers and manufacturers engage in early discussions and are willing to find new solutions to help accelerate patient access to innovative therapies.

Peptides that immunoactivate the tumor microenvironment

Cancer immunotherapy has achieved positive clinical outcomes and is revolutionizing cancer treatment. However, cancer immunotherapy has thus far failed to improve outcomes for most "cold tumors", which are characterized by low infiltration of immune cells and immunosuppressive tumor microenvironment. Enhancing the responsiveness of cold tumors to cancer immunotherapy by stimulating the components of the tumor microenvironment is a strategy pursued in the last decade. Currently, most of the agents used to modify the tumor microenvironment are small molecules or antibodies. Small molecules exhibit low affinity and specificity towards the target and antibodies have shortcomings such as poor tissue penetration and high production cost. Peptides may overcome these drawbacks and therefore are promising materials for immunomodulating agents. Here we systematically summarize the currently developed immunoactivating peptides and discuss the potential of peptide therapeutics in cancer immunology.

4-Substituted-1,2,3-triazolo nucleotide analogues as CD73 inhibitors, their synthesis, in vitro screening, kinetic and in silico studies

Three series of nucleotide analogues were synthesized and evaluated as potential CD73 inhibitors. Nucleobase replacement consisted in connecting the appropriate aromatic or purine residues through a triazole moiety that is generated from 1,3-dipolar cycloaddition. The first series is related to 4-substituted-1,2,3-triazolo-β-hydroxyphosphonate ribonucleosides. Additional analogues were also obtained, in which the phosphonate group was replaced by a bisphosphonate pattern (P-C-P-C, series 2) or the ribose moiety was removed leading to acyclic derivatives (series 3). The β-hydroxyphosphonylphosphonate ribonucleosides (series 2) were found to be potent inhibitors of CD73 using both purified recombinant protein and cell-based assays. Two compounds (2a and 2b) that contained a bis(trifluoromethyl)phenyl or a naphthyl substituents proved to be the most potent inhibitors, with IC₅₀ values of 4.8 ± 0.8 µM and 0.86 ± 0.2 µM, compared to the standard AOPCP (IC₅₀ value of 3.8 ± 0.9 µM), and were able to reverse the adenosine-mediated immune suppression on human T cells. This series of compounds illustrates a new type of CD73 inhibitors.