Peripheral T cell expansion predicts tumour infiltration and clinical response.

Despite the resounding clinical success in cancer treatment of antibodies that block the interaction of PD1 with its ligand PDL11, the mechanisms involved remain unknown. A major limitation to understanding the origin and fate of T cells in tumour immunity is the lack of quantitative information on the distribution of individual clonotypes of T cells in patients with cancer. Here, by performing deep single-cell sequencing of RNA and T cell receptors in patients with different types of cancer, we survey the profiles of various populations of T cells and T cell receptors in tumours, normal adjacent tissue, and peripheral blood. We find clear evidence of clonotypic expansion of effector-like T cells not only within the tumour but also in normal adjacent tissue. Patients with gene signatures of such clonotypic expansion respond best to anti-PDL1 therapy. Notably, expanded clonotypes found in the tumour and normal adjacent tissue can also typically be detected in peripheral blood, which suggests a convenient approach to patient identification. Analyses of our data together with several external datasets suggest that intratumoural T cells, especially in responsive patients, are replenished with fresh, non-exhausted replacement cells from sites outside the tumour, suggesting continued activity of the cancer immunity cycle in these patients, the acceleration of which may be associated with clinical response.

Atezolizumab plus cabozantinib versus cabozantinib monotherapy for patients with renal cell carcinoma after progression with previous immune checkpoint inhibitor treatment (CONTACT-03): a multicentre, randomised, open-label, phase 3 trial.

BACKGROUND: Immune checkpoint inhibitors are the standard of care for first-line treatment of patients with metastatic renal cell carcinoma, yet optimised treatment of patients whose disease progresses after these therapies is unknown. The aim of this study was to determine whether adding atezolizumab to cabozantinib delayed disease progression and prolonged survival in patients with disease progression on or after previous immune checkpoint inhibitor treatment. METHODS: CONTACT-03 was a multicentre, randomised, open-label, phase 3 trial, done in 135 study sites in 15 countries in Asia, Europe, North America, and South America. Patients aged 18 years or older with locally advanced or metastatic renal cell carcinoma whose disease had progressed with immune checkpoint inhibitors were randomly assigned (1:1) to receive atezolizumab (1200 mg intravenously every 3 weeks) plus cabozantinib (60 mg orally once daily) or cabozantinib alone. Randomisation was done through an interactive voice-response or web-response system in permuted blocks (block size four) and stratified by International Metastatic Renal Cell Carcinoma Database Consortium risk group, line of previous immune checkpoint inhibitor therapy, and renal cell carcinoma histology. The two primary endpoints were progression-free survival per blinded independent central review and overall survival. The primary endpoints were assessed in the intention-to-treat population and safety was assessed in all patients who received at least one dose of study drug. The trial is registered with ClinicalTrials.gov, NCT04338269, and is closed to further accrual. FINDINGS: From July 28, 2020, to Dec 27, 2021, 692 patients were screened for eligibility, 522 of whom were assigned to receive atezolizumab-cabozantinib (263 patients) or cabozantinib (259 patients). 401 (77%) patients were male and 121 (23%) patients were female. At data cutoff (Jan 3, 2023), median follow-up was 15·2 months (IQR 10·7-19·3). 171 (65%) patients receiving atezolizumab-cabozantinib and 166 (64%) patients receiving cabozantinib had disease progression per central review or died. Median progression-free survival was 10·6 months (95% CI 9·8-12·3) with atezolizumab-cabozantinib and 10·8 months (10·0-12·5) with cabozantinib (hazard ratio [HR] for disease progression or death 1·03 [95% CI 0·83-1·28]; p=0·78). 89 (34%) patients in the atezolizumab-cabozantinib group and 87 (34%) in the cabozantinib group died. Median overall survival was 25·7 months (95% CI 21·5-not evaluable) with atezolizumab-cabozantinib and was not evaluable (21·1-not evaluable) with cabozantinib (HR for death 0·94 [95% CI 0·70-1·27]; p=0·69). Serious adverse events occurred in 126 (48%) of 262 patients treated with atezolizumab-cabozantinib and 84 (33%) of 256 patients treated with cabozantinib; adverse events leading to death occurred in 17 (6%) patients in the atezolizumab-cabozantinib group and nine (4%) in the cabozantinib group. INTERPRETATION: The addition of atezolizumab to cabozantinib did not improve clinical outcomes and led to increased toxicity. These results should discourage sequential use of immune checkpoint inhibitors in patients with renal cell carcinoma outside of clinical trials. FUNDING: F Hoffmann-La Roche and Exelixis.

Adjuvant atezolizumab versus placebo for patients with renal cell carcinoma at increased risk of recurrence following resection (IMmotion010): a multicentre, randomised, double-blind, phase 3 trial.

BACKGROUND: The standard of care for locoregional renal cell carcinoma is surgery, but many patients experience recurrence. The objective of the current study was to determine if adjuvant atezolizumab (vs placebo) delayed recurrence in patients with an increased risk of recurrence after resection. METHODS: IMmotion010 is a randomised, double-blind, multicentre, phase 3 trial conducted in 215 centres in 28 countries. Eligible patients were patients aged 18 years or older with renal cell carcinoma with a clear cell or sarcomatoid component and increased risk of recurrence. After nephrectomy with or without metastasectomy, patients were randomly assigned (1:1) to receive atezolizumab (1200 mg) or placebo (both intravenous) once every 3 weeks for 16 cycles or 1 year. Randomisation was done with an interactive voice-web response system. Stratification factors were disease stage (T2 or T3a vs T3b-c or T4 or N+ vs M1 no evidence of disease), geographical region (north America [excluding Mexico] vs rest of the world), and PD-L1 status on tumour-infiltrating immune cells (<1% vs ≥1% expression). The primary endpoint was investigator-assessed disease-free survival in the intention-to-treat population, defined as all patients who were randomised, regardless of whether study treatment was received. The safety-evaluable population included all patients randomly assigned to treatment who received any amount of study drug (ie, atezolizumab or placebo), regardless of whether a full or partial dose was received. This trial is registered with ClinicalTrials.gov, NCT03024996, and is closed to further accrual. FINDINGS: Between Jan 3, 2017, and Feb 15, 2019, 778 patients were enrolled; 390 (50%) were assigned to the atezolizumab group and 388 (50%) to the placebo group. At data cutoff (May 3, 2022), the median follow-up duration was 44·7 months (IQR 39·1-51·0). Median investigator-assessed disease-free survival was 57·2 months (95% CI 44·6 to not evaluable) with atezolizumab and 49·5 months (47·4 to not evaluable) with placebo (hazard ratio 0·93, 95% CI 0·75-1·15, p=0·50). The most common grade 3-4 adverse events were hypertension (seven [2%] patients who received atezolizumab vs 15 [4%] patients who received placebo), hyperglycaemia (ten [3%] vs six [2%]), and diarrhoea (two [1%] vs seven [2%]). 69 (18%) patients who received atezolizumab and 46 (12%) patients who received placebo had a serious adverse event. There were no treatment-related deaths. INTERPRETATION: Atezolizumab as adjuvant therapy after resection for patients with renal cell carcinoma with increased risk of recurrence showed no evidence of improved clinical outcomes versus placebo. These study results do not support adjuvant atezolizumab for treatment of renal cell carcinoma. FUNDING: F Hoffmann-La Roche and Genentech, a member of the Roche group.

Atezolizumab plus bevacizumab versus sunitinib in patients with previously untreated metastatic renal cell carcinoma (IMmotion151): a multicentre, open-label, phase 3, randomised controlled trial.

BACKGROUND: A phase 2 trial showed improved progression-free survival for atezolizumab plus bevacizumab versus sunitinib in patients with metastatic renal cell carcinoma who express programmed death-ligand 1 (PD-L1). Here, we report results of IMmotion151, a phase 3 trial comparing atezolizumab plus bevacizumab versus sunitinib in first-line metastatic renal cell carcinoma. METHODS: In this multicentre, open-label, phase 3, randomised controlled trial, patients with a component of clear cell or sarcomatoid histology and who were previously untreated, were recruited from 152 academic medical centres and community oncology practices in 21 countries, mainly in Europe, North America, and the Asia-Pacific region, and were randomly assigned 1:1 to either atezolizumab 1200 mg plus bevacizumab 15 mg/kg intravenously once every 3 weeks or sunitinib 50 mg orally once daily for 4 weeks on, 2 weeks off. A permuted-block randomisation (block size of 4) was applied to obtain a balanced assignment to each treatment group with respect to the stratification factors. Study investigators and participants were not masked to treatment allocation. Patients, investigators, independent radiology committee members, and the sponsor were masked to PD-L1 expression status. Co-primary endpoints were investigator-assessed progression-free survival in the PD-L1 positive population and overall survival in the intention-to-treat (ITT) population. This trial is registered with ClinicalTrials.gov, number NCT02420821. FINDINGS: Of 915 patients enrolled between May 20, 2015, and Oct 12, 2016, 454 were randomly assigned to the atezolizumab plus bevacizumab group and 461 to the sunitinib group. 362 (40%) of 915 patients had PD-L1 positive disease. Median follow-up was 15 months at the primary progression-free survival analysis and 24 months at the overall survival interim analysis. In the PD-L1 positive population, the median progression-free survival was 11·2 months in the atezolizumab plus bevacizumab group versus 7·7 months in the sunitinib group (hazard ratio [HR] 0·74 [95% CI 0·57-0·96]; p=0·0217). In the ITT population, median overall survival had an HR of 0·93 (0·76-1·14) and the results did not cross the significance boundary at the interim analysis. 182 (40%) of 451 patients in the atezolizumab plus bevacizumab group and 240 (54%) of 446 patients in the sunitinib group had treatment-related grade 3-4 adverse events: 24 (5%) in the atezolizumab plus bevacizumab group and 37 (8%) in the sunitinib group had treatment-related all-grade adverse events, which led to treatment-regimen discontinuation. INTERPRETATION: Atezolizumab plus bevacizumab prolonged progression-free survival versus sunitinib in patients with metastatic renal cell carcinoma and showed a favourable safety profile. Longer-term follow-up is necessary to establish whether a survival benefit will emerge. These study results support atezolizumab plus bevacizumab as a first-line treatment option for selected patients with advanced renal cell carcinoma. FUNDING: F Hoffmann-La Roche Ltd and Genentech Inc.

Adjuvant Atezolizumab in Patients with Sarcomatoid Renal Cell Carcinoma: A Prespecified Subgroup Analysis of IMmotion010.

Patients with sarcomatoid renal cell carcinoma (sRCC) have a poor prognosis. In the randomised, double-blind phase 3 IMmotion010 trial (NCT03024996), adjuvant atezolizumab did not demonstrate a disease-free survival (DFS) benefit versus placebo in the overall population of patients with locoregional renal cell carcinoma with an increased risk of recurrence following surgery. This prespecified subgroup analysis of efficacy and safety was completed in 104 patients with sRCC. Baseline characteristics were similar between treatment arms. At a median follow-up of 45 mo, the median DFS was not evaluable (NE; 95% confidence interval [CI], 12 mo-NE) in the atezolizumab arm (n = 37) and 23 mo (95% CI, 11-NE) in the placebo arm (n = 66; hazard ratio 0.77 [95% CI, 0.44-1.4]). In the sRCC subgroup, grade 3/4 treatment-related adverse events (TRAEs) occurred in one patient (2.7%) in the atezolizumab arm and two patients (3.0%) in the placebo arm. By comparison, 54 of 353 patients (15%) and 16 of 317 patients (5.0%) with non-sarcomatoid histology reported grade 3/4 TRAEs in the respective arms. In conclusion, the difference in DFS was not statistically significant between adjuvant atezolizumab and placebo in patients with sRCC. The safety profile was similar between patients with sRCC and non-sRCC. PATIENT SUMMARY: Patients with a specific type of locoregional kidney cancer (tumours with sarcomatoid features) were treated with atezolizumab or placebo after surgery. Slightly more patients treated with atezolizumab lived longer without the disease getting worse than those treated with placebo, although this finding was not statistically significant. The side effects were similar to those seen in patients with other types of kidney cancer treated with atezolizumab in the same study (IMmotion010). In patients with sarcomatoid kidney cancer, atezolizumab was tolerable and may be more effective than placebo, but this requires further study.

Histopathology Based AI Model Predicts Anti-Angiogenic Therapy Response in Renal Cancer Clinical Trial.

Background: Predictive biomarkers of treatment response are lacking for metastatic clearcell renal cell carcinoma (ccRCC), a tumor type that is treated with angiogenesis inhibitors, immune checkpoint inhibitors, mTOR inhibitors and a HIF2 inhibitor. The Angioscore, an RNA-based quantification of angiogenesis, is arguably the best candidate to predict anti-angiogenic (AA) response. However, the clinical adoption of transcriptomic assays faces several challenges including standardization, time delay, and high cost. Further, ccRCC tumors are highly heterogenous, and sampling multiple areas for sequencing is impractical. Approach: Here we present a novel deep learning (DL) approach to predict the Angioscore from ubiquitous histopathology slides. In order to overcome the lack of interpretability, one of the biggest limitations of typical DL models, our model produces a visual vascular network which is the basis of the model's prediction. To test its reliability, we applied this model to multiple cohorts including a clinical trial dataset. Results: Our model accurately predicts the RNA-based Angioscore on multiple independent cohorts (spearman correlations of 0.77 and 0.73). Further, the predictions help unravel meaningful biology such as association of angiogenesis with grade, stage, and driver mutation status. Finally, we find our model is able to predict response to AA therapy, in both a real-world cohort and the IMmotion150 clinical trial. The predictive power of our model vastly exceeds that of CD31, a marker of vasculature, and nearly rivals the performance (c-index 0.66 vs 0.67) of the ground truth RNA-based Angioscore at a fraction of the cost. Conclusion: By providing a robust yet interpretable prediction of the Angioscore from histopathology slides alone, our approach offers insights into angiogenesis biology and AA treatment response.

Preclinical and translational pharmacology of afucosylated anti-CCR8 antibody for depletion of tumour-infiltrating regulatory T cells.

BACKGROUND AND PURPOSE: RO7502175 is an afucosylated antibody designed to eliminate C-C motif chemokine receptor 8 (CCR8)+ Treg cells in the tumour microenvironment through enhanced antibody-dependent cellular cytotoxicity (ADCC). EXPERIMENTAL APPROACH: We report findings from preclinical studies characterizing pharmacology, pharmacokinetics (PK)/pharmacodynamics (PD) and safety profile of RO7502175 and discuss the translational PK/PD approach used to inform first-in-human (FiH) dosing strategy and clinical development in solid tumour indications. KEY RESULTS: RO7502175 demonstrated selective ADCC against human CCR8+ Treg cells from dissociated tumours in vitro. In cynomolgus monkeys, RO7502175 exhibited a biphasic concentration-time profile consistent with immunoglobulin G1 (IgG1) antibodies, reduced CCR8+ Treg cells in the blood, induced minimal and transient cytokine secretion, and was well tolerated with a no-observed-adverse-effect level (NOAEL) of 100 mg·kg-1. Moreover, RO7502175 caused minimal cytokine release from peripheral blood mononuclear cells (PBMCs) in vitro. A quantitative model was developed to capture surrogate anti-murine CCR8 antibody PK/PD and tumour dynamics in mice and RO7502175 PK/PD in cynomolgus monkeys. Subsequently, the model was used to project RO7502175 human PK and receptor occupancy (RO) in patients. Because traditional approaches resulted in a low FiH dose for this molecule, even with its superior preclinical safety profile, an integrated approach based on the totality of preclinical data and modelling insights was used for starting dose selection. CONCLUSION AND IMPLICATIONS: This work demonstrates a translational research strategy for collecting and utilizing relevant nonclinical data, developing a mechanistic PK/PD model and using a comprehensive approach to inform clinical study design for RO7502175.

CONTACT-01: A Randomized Phase III Trial of Atezolizumab + Cabozantinib Versus Docetaxel for Metastatic Non-Small Cell Lung Cancer After a Checkpoint Inhibitor and Chemotherapy.

PURPOSE: Although checkpoint inhibitors have improved first-line treatment for non-small cell lung cancer (NSCLC), a therapeutic need remains for patients whose disease does not respond or who experience disease progression after anti-PD-L1/PD-1 immunotherapy. CONTACT-01 (ClinicalTrials.gov identifier: NCT04471428) evaluated atezolizumab plus cabozantinib versus docetaxel in patients with metastatic NSCLC who developed disease progression after concurrent or sequential treatment with anti-PD-L1/PD-1 and platinum-containing chemotherapy. METHODS: This multicenter, open-label, phase III trial randomly assigned patients 1:1 to atezolizumab 1,200 mg intravenously once every 3 weeks (q3w) plus cabozantinib 40 mg orally once daily or docetaxel 75 mg/m2 intravenously once every 3 weeks. The primary end point was overall survival (OS). RESULTS: One hundred eighty-six patients were assigned atezolizumab plus cabozantinib, and 180 docetaxel. Minimum OS follow-up was 10.9 months. Median OS was 10.7 months (95% CI, 8.8 to 12.3) with atezolizumab plus cabozantinib and 10.5 months (95% CI, 8.6 to 13.0) with docetaxel (stratified hazard ratio [HR], 0.88 [95% CI, 0.68 to 1.16]; P = .3668). Median progression-free survival was 4.6 months (95% CI, 4.1 to 5.6) and 4.0 months (95% CI, 3.1 to 4.4), respectively (stratified HR, 0.74 [95% CI, 0.59 to 0.92]). Serious adverse events (AEs) occurred in 71 (38.4%) patients receiving atezolizumab plus cabozantinib and 58 (34.7%) receiving docetaxel. Grade 3/4 treatment-related AEs occurred in 73 (39.5%) patients receiving atezolizumab plus cabozantinib and 58 (34.7%) receiving docetaxel. Grade 5 AEs occurred in 14 (7.6%) and 10 (6.0%) patients in the atezolizumab plus cabozantinib and docetaxel arms, respectively (treatment-related in four [2.2%] and one [0.6%], respectively). CONCLUSION: Atezolizumab plus cabozantinib after disease progression following anti-PD-L1/PD-1 immunotherapy and platinum-containing chemotherapy for metastatic NSCLC did not improve OS compared with docetaxel. Safety was consistent with known profiles of these agents.

Development of a robust flow cytometry-based pharmacodynamic assay to detect phospho-protein signals for phosphatidylinositol 3-kinase inhibitors in multiple myeloma.

BACKGROUND: The phosphatidylinositol 3-kinase (PI3K) pathway plays an important role in multiple myeloma (MM), a blood cancer associated with uncontrolled proliferation of bone marrow plasma cells. This study aimed to develop a robust clinical pharmacodynamic (PD) assay to measure the on-target PD effects of the selective PI3K inhibitor GDC-0941 in MM patients. METHODS: We conducted an in vitro drug wash-out study to evaluate the feasibility of biochemical approaches in measuring the phosphorylation of S6 ribosomal protein (S6), one of the commonly used PD markers for PI3K pathway inhibition. We then developed a 7-color phospho-specific flow cytometry assay, or phospho flow assay, to measure the phosphorylation state of intracellular S6 in bone marrow aspirate (BMA) and peripheral blood (PB). Integrated mean fluorescence intensity (iMFI) was used to calculate fold changes of phosphorylation. Assay sensitivity was evaluated by comparing phospho flow with Meso Scale Discovery (MSD) and immunohistochemistry (IHC) assays. Finally, a sample handling method was developed to maintain the integrity of phospho signal during sample shipping and storage to ensure clinical application. RESULTS: The phospho flow assay provided single-cell PD monitoring of S6 phosphorylation in tumor and surrogate cells using fixed BMA and PB, assessing pathway modulation in response to GDC-0941 with sensitivity similar to that of MSD assay. The one-shot sample fixation and handling protocol herein demonstrated exceptional preservation of protein phosphorylation. In contrast, the IHC assay was less sensitive in terms of signal quantification while the biochemical approach (MSD) was less suitable to assess PD activities due to the undesirable impact associated with cell isolation on the protein phosphorylation in tumor cells. CONCLUSIONS: We developed a robust PD biomarker assay for the clinical evaluation of PI3K inhibitors in MM, allowing one to decipher the PD response in a relevant cell population. To our knowledge, this is the first report of an easily implemented clinical PD assay that incorporates an unbiased one-shot sample handling protocol, all (staining)-in-one (tube) phospho flow staining protocol, and an integrated modified data analysis for PD monitoring of kinase inhibitors in relevant cell populations in BMA and PB. The methods described here ensure a real-time, reliable and reproducible PD readout, which can provide information for dose selection as well as help to identify optimal combinations of targeted agents in early clinical trials.

CD8+ T cell-intrinsic IL-6 signaling promotes resistance to anti-PD-L1 immunotherapy.

Although immune checkpoint inhibitors (ICIs) are established as effective cancer therapies, overcoming therapeutic resistance remains a critical challenge. Here we identify interleukin 6 (IL-6) as a correlate of poor response to atezolizumab (anti-PD-L1) in large clinical trials of advanced kidney, breast, and bladder cancers. In pre-clinical models, combined blockade of PD-L1 and the IL-6 receptor (IL6R) causes synergistic regression of large established tumors and substantially improves anti-tumor CD8+ cytotoxic T lymphocyte (CTL) responses compared with anti-PD-L1 alone. Circulating CTLs from cancer patients with high plasma IL-6 display a repressed functional profile based on single-cell RNA sequencing, and IL-6-STAT3 signaling inhibits classical cytotoxic differentiation of CTLs in vitro. In tumor-bearing mice, CTL-specific IL6R deficiency is sufficient to improve anti-PD-L1 activity. Thus, based on both clinical and experimental evidence, agents targeting IL-6 signaling are plausible partners for combination with ICIs in cancer patients.

Final Overall Survival and Molecular Analysis in IMmotion151, a Phase 3 Trial Comparing Atezolizumab Plus Bevacizumab vs Sunitinib in Patients With Previously Untreated Metastatic Renal Cell Carcinoma.

IMPORTANCE: Interim analyses of the IMmotion151 trial (A Study of Atezolizumab in Combination With Bevacizumab Versus Sunitinib in Participants With Untreated Advanced Renal Cell Carcinoma) reported improved progression-free survival (PFS) for patients with programmed death ligand 1-positive (PD-L1+) metastatic renal cell carcinoma (mRCC) receiving the PD-L1 inhibitor atezolizumab plus the vascular endothelial growth factor (VEGF) inhibitor bevacizumab vs the receptor tyrosine kinase inhibitor sunitinib. Overall survival (OS) results were immature at interim analyses. OBJECTIVE: To report the final OS results, safety, and exploratory biomarker analyses of the association of transcriptomic subgroups with OS in the IMmotion151 trial. DESIGN, SETTING, AND PARTICIPANTS: IMmotion151 was a multicenter, open-label, phase 3 randomized clinical trial that compared the efficacy and safety of atezolizumab plus bevacizumab vs sunitinib in patients with untreated mRCC. IMmotion151 included patients from 152 academic medical centers and community oncology practices in 21 countries. Adult patients with mRCC with components of clear cell or sarcomatoid histologic features, measurable disease (according to Response Evaluation Criteria in Solid Tumors, version 1.1), adequate performance status, hematologic and end organ function, and tumor tissue available for PD-L1 testing were included. IMmotion151 was initiated on May 20, 2015, and the study is ongoing. This final analysis was performed from May 20, 2015, to February 14, 2020. INTERVENTIONS: Receipt of 1200 mg of intravenous (IV) atezolizumab every 3 weeks and 15 mg/kg of IV bevacizumab every 3 weeks or 50 mg orally once daily of sunitinib (4 weeks on and 2 weeks off). MAIN OUTCOMES AND MEASURES: The coprimary end points were PFS (previously reported) in patients with PD-L1+ disease and OS in the intention-to-treat population. Additional exploratory outcomes included OS in the PD-L1+ population, association with transcriptomic subgroups, and safety. RESULTS: The IMmotion151 trial assessed 915 patients with metastatic renal cell carcinoma. Mean (IQR) age was 62 (56-69) years for patients receiving atezolizumab plus bevacizumab and 60 (54-66) years for patients receiving sunitinib; 669 (73.1%) were male and 246 (26.9%) were female. The final analysis showed similar median OS in patients receiving atezolizumab plus bevacizumab vs sunitinib in the intention-to-treat (36.1 vs 35.3 months) and PD-L1+ (38.7 vs 31.6 months) populations. No new safety signals were reported. The additional exploratory outcome of atezolizumab plus bevacizumab vs sunitinib showed improved median OS trends in patients whose tumors were characterized by T-effector/proliferative, proliferative, or small nucleolar RNA transcriptomic profiles (35.4 vs 21.2 months; hazard ratio, 0.70; 95% CI, 0.50-0.98). CONCLUSIONS AND RELEVANCE: The primary end point of PFS was met at interim analyses, although no improvement in OS was observed with atezolizumab plus bevacizumab at the final analysis. Biomarker analyses provided insight into which patients with mRCC may benefit from combined anti-PD-L1 and anti-VEGF therapy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02420821.

First-In-Human Phase I Study of the OX40 Agonist MOXR0916 in Patients with Advanced Solid Tumors.

PURPOSE: OX40, a receptor transiently expressed by T cells upon antigen recognition, is associated with costimulation of effector T cells and impairment of regulatory T-cell function. This first-in-human study evaluated MOXR0916, a humanized effector-competent agonist IgG1 monoclonal anti-OX40 antibody. PATIENTS AND METHODS: Eligible patients with locally advanced or metastatic refractory solid tumors were treated with MOXR0916 intravenously once every 3 weeks (Q3W). A 3+3 dose-escalation stage (0.2-1,200 mg; n = 34) was followed by expansion cohorts at 300 mg (n = 138) for patients with melanoma, renal cell carcinoma, non-small cell lung carcinoma, urothelial carcinoma, and triple-negative breast cancer. RESULTS: MOXR0916 was well tolerated with no dose-limiting toxicities observed. An MTD was not reached. Most patients (95%) experienced at least one adverse event (AE); 56% of AEs, mostly grade 1-2, were related to MOXR0916. Most common treatment-related AEs included fatigue (17%), diarrhea (8%), myalgia (7%), nausea (6%), decreased appetite (6%), and infusion-related reaction (5%). Pharmacokinetic (PK) parameters were dose proportional between 80 and 1,200 mg and supported Q3W administration. The recommended expansion dose based on PK and OX40 receptor saturation was 300 mg Q3W. Immune activation and upregulation of PD-L1 was observed in a subset of paired tumor biopsies. One renal cell carcinoma patient experienced a confirmed partial response. Overall, 33% of patients achieved stable disease. CONCLUSIONS: Although objective responses were rarely observed with MOXR0916 monotherapy, the favorable safety profile and evidence of tumor immune activation in a subset of patients support further investigation in combination with complementary agents such as PD-1/PD-L1 antagonists.

Atezolizumab plus Bevacizumab Versus Sunitinib for Patients with Untreated Metastatic Renal Cell Carcinoma and Sarcomatoid Features: A Prespecified Subgroup Analysis of the IMmotion151 Clinical Trial.

Patients with metastatic renal cell carcinoma with sarcomatoid features (sRCC) have a poor prognosis and have shown limited responsiveness to inhibition of the VEGF pathway. We conducted a prespecified analysis of the randomised, phase 3 IMmotion151 trial in previously untreated patients with advanced or metastatic RCC to assess the effectiveness of atezolizumab + bevacizumab versus sunitinib in a subgroup of patients with sarcomatoid features. Patients whose tumour had any component of sarcomatoid features were included and received atezolizumab + bevacizumab (n = 68) or sunitinib (n = 74). Baseline characteristics were similar between the groups. Median progression-free survival was significantly longer in the group receiving atezolizumab + bevacizumab overall (8.3 vs 5.3 mo; hazard ratio [HR] 0.52 95% confidence interval [CI] 0.34-0.79) and in the subset of patients with PD-L1-positive tumours (8.6 vs 5.6 mo; HR 0.45, 95% CI 0.26-0.77). More patients receiving atezolizumab + bevacizumab achieved an objective response (49% vs 14%), including complete responses (10% vs 3%), and reported greater symptom improvements versus sunitinib. Safety was consistent with the known profiles of each drug and with that reported in the overall safety-evaluable population of IMmotion151. This analysis supports enhanced activity of atezolizumab + bevacizumab in patients with sRCC. PATIENT SUMMARY: In this report, we looked at patients with a specific type of kidney cancer (tumours with sarcomatoid features) that has been hard to treat. A treatment with two drugs (atezolizumab and bevacizumab) appeared to help patients live longer without the disease getting worse than another drug (sunitinib) that is often used. Patients who took the two drugs also said they were better able to carry out their everyday activities than patients who took sunitinib. The combination of these two drugs may work better in patients with this type of advanced kidney cancer.

Molecular determinants of response to PD-L1 blockade across tumor types.

Immune checkpoint inhibitors targeting the PD-1/PD-L1 axis lead to durable clinical responses in subsets of cancer patients across multiple indications, including non-small cell lung cancer (NSCLC), urothelial carcinoma (UC) and renal cell carcinoma (RCC). Herein, we complement PD-L1 immunohistochemistry (IHC) and tumor mutation burden (TMB) with RNA-seq in 366 patients to identify unifying and indication-specific molecular profiles that can predict response to checkpoint blockade across these tumor types. Multiple machine learning approaches failed to identify a baseline transcriptional signature highly predictive of response across these indications. Signatures described previously for immune checkpoint inhibitors also failed to validate. At the pathway level, significant heterogeneity is observed between indications, in particular within the PD-L1+ tumors. mUC and NSCLC are molecularly aligned, with cell cycle and DNA damage repair genes associated with response in PD-L1- tumors. At the gene level, the CDK4/6 inhibitor CDKN2A is identified as a significant transcriptional correlate of response, highlighting the association of non-immune pathways to the outcome of checkpoint blockade. This cross-indication analysis reveals molecular heterogeneity between mUC, NSCLC and RCC tumors, suggesting that indication-specific molecular approaches should be prioritized to formulate treatment strategies.

Efficacy and Safety of Atezolizumab Plus Bevacizumab Following Disease Progression on Atezolizumab or Sunitinib Monotherapy in Patients with Metastatic Renal Cell Carcinoma in IMmotion150: A Randomized Phase 2 Clinical Trial.

BACKGROUND: The use of immune checkpoint inhibitors combined with vascular endothelial growth factor (VEGF)-targeted therapy as second-line treatment for metastatic clear cell renal cancer (mRCC) has not been evaluated prospectively. OBJECTIVE: To evaluate the efficacy and safety of atezolizumab + bevacizumab following disease progression on atezolizumab or sunitinib monotherapy in patients with mRCC. DESIGN, SETTING, AND PARTICIPANTS: IMmotion150 was a multicenter, randomized, open-label, phase 2 study of patients with untreated mRCC. Patients randomized to the atezolizumab or sunitinib arm who had investigator-assessed progression as per RECIST 1.1 could be treated with second-line atezolizumab + bevacizumab. INTERVENTION: Patients received atezolizumab 1200 mg intravenously (IV) plus bevacizumab 15 mg/kg IV every 3 wk following disease progression on either atezolizumab or sunitinib monotherapy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The secondary endpoints analyzed during the second-line part of IMmotion150 included objective response rate (ORR), progression-free survival (PFS), and safety. PFS was examined using Kaplan-Meier methods. RESULTS AND LIMITATIONS: Fifty-nine patients in the atezolizumab arm and 78 in the sunitinib arm were eligible, and 103 initiated second-line atezolizumab + bevacizumab (atezolizumab arm, n = 44; sunitinib arm, n = 59). ORR (95% confidence interval [CI]) was 27% (19-37%). The median PFS (95% CI) from the start of second line was 8.7 (5.6-13.7) mo. The median event follow-up duration was 19.4 (12.9-21.9) mo among the 25 patients without a PFS event. Eighty-six (83%) patients had treatment-related adverse events; 31 of 103 (30%) had grade 3/4 events. Limitations were the small sample size and selection for progressors. CONCLUSIONS: The atezolizumab + bevacizumab combination had activity and was tolerable in patients with progression on atezolizumab or sunitinib. Further studies are needed to investigate sequencing strategies in mRCC. PATIENT SUMMARY: Patients with advanced kidney cancer whose disease had worsened during treatment with atezolizumab or sunitinib began second-line treatment with atezolizumab + bevacizumab. Tumors shrank in more than one-quarter of patients treated with this combination, and side effects were manageable.

Molecular Subsets in Renal Cancer Determine Outcome to Checkpoint and Angiogenesis Blockade.

Integrated multi-omics evaluation of 823 tumors from advanced renal cell carcinoma (RCC) patients identifies molecular subsets associated with differential clinical outcomes to angiogenesis blockade alone or with a checkpoint inhibitor. Unsupervised transcriptomic analysis reveals seven molecular subsets with distinct angiogenesis, immune, cell-cycle, metabolism, and stromal programs. While sunitinib and atezolizumab + bevacizumab are effective in subsets with high angiogenesis, atezolizumab + bevacizumab improves clinical benefit in tumors with high T-effector and/or cell-cycle transcription. Somatic mutations in PBRM1 and KDM5C associate with high angiogenesis and AMPK/fatty acid oxidation gene expression, while CDKN2A/B and TP53 alterations associate with increased cell-cycle and anabolic metabolism. Sarcomatoid tumors exhibit lower prevalence of PBRM1 mutations and angiogenesis markers, frequent CDKN2A/B alterations, and increased PD-L1 expression. These findings can be applied to molecularly stratify patients, explain improved outcomes of sarcomatoid tumors to checkpoint blockade versus antiangiogenics alone, and develop personalized therapies in RCC and other indications.

High systemic and tumor-associated IL-8 correlates with reduced clinical benefit of PD-L1 blockade.

Although elevated plasma interleukin-8 (pIL-8) has been associated with poor outcome to immune checkpoint blockade 1, this has not been comprehensively evaluated in large randomized studies. Here we analyzed circulating pIL-8 and IL8 gene expression in peripheral blood mononuclear cells and tumors of patients treated with atezolizumab (anti-PD-L1 monoclonal antibody) from multiple randomized trials representing 1,445 patients with metastatic urothelial carcinoma (mUC) and metastatic renal cell carcinoma. High levels of IL-8 in plasma, peripheral blood mononuclear cells and tumors were associated with decreased efficacy of atezolizumab in patients with mUC and metastatic renal cell carcinoma, even in tumors that were classically CD8+ T cell inflamed. Low baseline pIL-8 in patients with mUC was associated with increased response to atezolizumab and chemotherapy. Patients with mUC who experienced on-treatment decreases in pIL-8 exhibited improved overall survival when treated with atezolizumab but not with chemotherapy. Single-cell RNA sequencing of the immune compartment showed that IL8 is primarily expressed in circulating and intratumoral myeloid cells and that high IL8 expression is associated with downregulation of the antigen-presentation machinery. Therapies that can reverse the impacts of IL-8-mediated myeloid inflammation will be essential for improving outcomes of patients treated with immune checkpoint inhibitors.

CS1, a potential new therapeutic antibody target for the treatment of multiple myeloma.

PURPOSE: We generated a humanized antibody, HuLuc63, which specifically targets CS1 (CCND3 subset 1, CRACC, and SLAMF7), a cell surface glycoprotein not previously associated with multiple myeloma. To explore the therapeutic potential of HuLuc63 in multiple myeloma, we examined in detail the expression profile of CS1, the binding properties of HuLuc63 to normal and malignant cells, and the antimyeloma activity of HuLuc63 in preclinical models. EXPERIMENTAL DESIGN: CS1 was analyzed by gene expression profiling and immunohistochemistry of multiple myeloma samples and numerous normal tissues. HuLuc63-mediated antimyeloma activity was tested in vitro in antibody-dependent cellular cytotoxicity (ADCC) assays and in vivo using the human OPM2 xenograft model in mice. RESULTS: CS1 mRNA was expressed in >90% of 532 multiple myeloma cases, regardless of cytogenetic abnormalities. Anti-CS1 antibody staining of tissues showed strong staining of myeloma cells in all plasmacytomas and bone marrow biopsies. Flow cytometric analysis of patient samples using HuLuc63 showed specific staining of CD138+ myeloma cells, natural killer (NK), NK-like T cells, and CD8+ T cells, with no binding detected on hematopoietic CD34+ stem cells. HuLuc63 exhibited significant in vitro ADCC using primary myeloma cells as targets and both allogeneic and autologous NK cells as effectors. HuLuc63 exerted significant in vivo antitumor activity, which depended on efficient Fc-CD16 interaction as well as the presence of NK cells in the mice. CONCLUSIONS: These results suggest that HuLuc63 eliminates myeloma cells, at least in part, via NK-mediated ADCC and shows the therapeutic potential of targeting CS1 with HuLuc63 for the treatment of multiple myeloma.

CD8+ T cell infiltration in breast and colon cancer: A histologic and statistical analysis.

The prevalence of cytotoxic tumor infiltrating lymphocytes (TILs) has demonstrated prognostic value in multiple tumor types. In particular, CD8 counts (in combination with CD3 and CD45RO) have been shown to be superior to traditional UICC staging in colon cancer patients and higher total CD8 counts have been associated with better survival in breast cancer patients. However, immune infiltrate heterogeneity can lead to potentially significant misrepresentations of marker prevalence in routine histologic sections. We examined step sections of breast and colorectal cancer samples for CD8+ T cell prevalence by standard chromogenic immunohistochemistry to determine marker variability and inform practice of T cell biomarker assessment in formalin-fixed, paraffin-embedded (FFPE) tissue samples. Stained sections were digitally imaged and CD8+ lymphocytes within defined regions of interest (ROI) including the tumor and surrounding stroma were enumerated. Statistical analyses of CD8+ cell count variability using a linear model/ANOVA framework between patients as well as between levels within a patient sample were performed. Our results show that CD8+ T-cell distribution is highly homogeneous within a standard tissue sample in both colorectal and breast carcinomas. As such, cytotoxic T cell prevalence by immunohistochemistry on a single level or even from a subsample of biopsy fragments taken from that level can be considered representative of cytotoxic T cell infiltration for the entire tumor section within the block. These findings support the technical validity of biomarker strategies relying on CD8 immunohistochemistry.

Phase I study of the anti-α5ß1 monoclonal antibody MINT1526A with or without bevacizumab in patients with advanced solid tumors.

PURPOSE: MINT1526A is a monoclonal antibody that blocks the interaction of integrin alpha 5 beta 1 (α5ß1) with its extracellular matrix ligands. This phase I study evaluated the safety and pharmacokinetics of MINT1526A with or without bevacizumab in patients with advanced solid tumors. METHODS: MINT1526A was administered every 3 weeks (Q3W) as monotherapy (arm 1) or in combination with bevacizumab 15 mg/kg, Q3W (arm 2). Each arm included a 3 + 3 dose-escalation stage and a dose-expansion stage. RESULTS: Twenty-four patients were enrolled in arm 1 (dose range 2-30 mg/kg) and 30 patients were enrolled in arm 2 (dose range 3-15 mg/kg). Monocyte α5ß1 receptor occupancy was saturated at a dose of 15 mg/kg. No dose-limiting toxicities were observed, and the maximum tolerated dose was not reached in either arm. The most common adverse events, regardless of causality, included abdominal pain (25%), diarrhea (25%), nausea (21%), vomiting (21%), and fatigue (21%) in arm 1 and nausea (40%), fatigue (33%), vomiting (30%), dehydration (30%), headache (30%), and hypertension (30%) in arm 2. No grade ≥ 3 bleeding events were observed in either arm. No confirmed partial responses (PR) were observed in arm 1. In arm 2, one patient with thymic carcinoma experienced a confirmed PR and two patients with hepatocellular carcinoma (HCC) experienced durable minor radiographic responses. CONCLUSIONS: MINT1526A, with or without bevacizumab, was well-tolerated. Preliminary evidence of combination efficacy, including in patients with HCC, was observed, but cannot be distinguished from bevacizumab monotherapy in this phase I study.