Anti-TIGIT antibody improves PD-L1 blockade through myeloid and Treg cells.

Tiragolumab, an anti-TIGIT antibody with an active IgG1κ Fc, demonstrated improved outcomes in the phase 2 CITYSCAPE trial (ClinicalTrials.gov: NCT03563716 ) when combined with atezolizumab (anti-PD-L1) versus atezolizumab alone1. However, there remains little consensus on the mechanism(s) of response with this combination2. Here we find that a high baseline of intratumoural macrophages and regulatory T cells is associated with better outcomes in patients treated with atezolizumab plus tiragolumab but not with atezolizumab alone. Serum sample analysis revealed that macrophage activation is associated with a clinical benefit in patients who received the combination treatment. In mouse tumour models, tiragolumab surrogate antibodies inflamed tumour-associated macrophages, monocytes and dendritic cells through Fcγ receptors (FcγR), in turn driving anti-tumour CD8+ T cells from an exhausted effector-like state to a more memory-like state. These results reveal a mechanism of action through which TIGIT checkpoint inhibitors can remodel immunosuppressive tumour microenvironments, and suggest that FcγR engagement is an important consideration in anti-TIGIT antibody development.

Immunomodulatory effects and improved outcomes with cisplatin- versus carboplatin-based chemotherapy plus atezolizumab in urothelial cancer.

In metastatic urothelial cancer (mUC), cisplatin versus carboplatin leads to durable disease control in a subset of patients. The IMvigor130 trial reveals more favorable effects with atezolizumab combined with gemcitabine and cisplatin (GemCis) versus gemcitabine and carboplatin (GemCarbo). This study investigates the immunomodulatory effects of cisplatin as a potential explanation for these observations. Our findings indicate that improved outcomes with GemCis versus GemCarbo are primarily observed in patients with pretreatment tumors exhibiting features of restrained adaptive immunity. In addition, GemCis versus GemCarbo ± atezolizumab induces transcriptional changes in circulating immune cells, including upregulation of antigen presentation and T cell activation programs. In vitro experiments demonstrate that cisplatin, compared with carboplatin, exerts direct immunomodulatory effects on cancer cells, promoting dendritic cell activation and antigen-specific T cell killing. These results underscore the key role of immune modulation in cisplatin's efficacy in mUC and highlight the importance of specific chemotherapy backbones in immunotherapy combination regimens.

Updated Overall Survival by Circulating Tumor DNA Status from the Phase 3 IMvigor010 Trial: Adjuvant Atezolizumab Versus Observation in Muscle-invasive Urothelial Carcinoma.

BACKGROUND: Interim results from IMvigor010 showed an overall survival (OS) benefit for adjuvant atezolizumab (anti-PD-L1) versus observation in patients with circulating tumor DNA (ctDNA)-positive muscle-invasive urothelial carcinoma (MIUC). OBJECTIVE: To report updated OS and safety by ctDNA status. DESIGN, SETTING, AND PARTICIPANTS: This ad hoc analysis from a global, open-label, randomized, phase 3 trial (NCT02450331) included intention-to-treat (ITT) population with evaluable cycle 1 day 1 (C1D1) ctDNA samples. INTERVENTION: Atezolizumab (1200 mg every 3 wk) or observation for ≤1 yr. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: OS, relapse rates, and safety by ctDNA status were assessed. RESULTS AND LIMITATIONS: Among 581 of 809 ITT patients included, 214 (37%) were ctDNA positive. Atezolizumab did not improve OS versus observation in ITT patients (hazard ratio [HR] 0.91 [95% confidence interval {CI} 0.73-1.13]; median follow-up 46.8 mo [interquartile range, 36.1-53.6]). In the observation arm, ctDNA positivity versus negativity was associated with shorter OS (HR 6.3 [95% CI 4.3-9.3]). The ctDNA positivity identified patients with an OS benefit favoring atezolizumab versus observation (HR 0.59 [95% CI 0.42-0.83]). A greater reduction in ctDNA levels with atezolizumab (C3D1) was associated with longer OS (100% clearance, 60.0 mo [95% CI 35.5-not estimable]; 50-99% reduction, 34.3 mo [95% CI 15.2-not estimable]; <50% reduction, 19.9 mo [95% CI 16.4-32.2]). The ctDNA positivity at C1D1 + C3D1 was associated with relapse with greater sensitivity than C1D1 alone (68% vs 57%). Adverse events were more frequent with atezolizumab than with observation, regardless of ctDNA status. A study limitation was its exploratory design. CONCLUSIONS: Evidence suggests that ctDNA positivity in MIUC predicts a benefit with atezolizumab. An in-progress prospective study will further evaluate these findings. PATIENT SUMMARY: Among patients with urothelial cancer after surgery, survival was poorer if tumor-derived DNA was detected in their bloodstream; these patients' survival was longer with atezolizumab versus observation. Bloodstream tumor-derived DNA may identify patients who benefit from atezolizumab.

Atezolizumab plus chemotherapy versus placebo plus chemotherapy in untreated locally advanced or metastatic urothelial carcinoma (IMvigor130): final overall survival analysis results from a randomised, controlled, phase 3 study.

BACKGROUND: IMvigor130 demonstrated statistically significant investigator-assessed progression-free survival benefit with first-line atezolizumab plus platinum-based chemotherapy (group A) versus placebo plus platinum-based chemotherapy (group C) in patients with locally advanced or metastatic urothelial carcinoma. Overall survival was not improved in interim analyses. Here we report the final overall analysis for group A versus group C. METHODS: In this global, partially blinded, randomised, controlled, phase 3 study, patients (aged ≥18 years) with previously untreated locally advanced or metastatic urothelial cancer and who had an Eastern Cooperative Oncology Group performance status of 0-2 were enrolled at 221 hospitals and oncology centres in 35 countries. Patients were randomly assigned (1:1:1), with a permuted block method (block size of six) and an interactive voice and web response system, stratified by PD-L1 status, Bajorin risk factor score, and investigator's choice of platinum-based chemotherapy, to receive atezolizumab plus platinum-based chemotherapy (group A), atezolizumab monotherapy (group B), or placebo plus platinum-based chemotherapy (group C). Sponsors, investigators, and patients were masked to assignment to atezolizumab or placebo (ie, group A and group C) and atezolizumab monotherapy (group B) was open label. For groups A and C, all patients received gemcitabine (1000 mg/m2 intravenously; day 1 and day 8 of each 21-day cycle), plus investigator's choice of carboplatin (area under curve 4·5 mg/mL per min or 5 mg/mL per min; intravenously) or cisplatin (70 mg/m2 intravenously), plus either atezolizumab (1200 mg intravenously) or placebo on day 1 of each cycle. Co-primary endpoints of the study were investigator-assessed progression-free survival and overall survival for group A versus group C in the intention-to-treat (ITT) population (ie, all randomised patients), and overall survival for group B versus group C, tested hierarchically. Final overall survival and updated safety outcomes (safety population; all patients who received any amount of any study treatment component) for group A versus group C are reported here. The final prespecified boundary for significance of the overall survival analysis was one-sided p=0·021. The trial is registered with ClinicalTrials.gov, NCT02807636, and is active but no longer recruiting. FINDINGS: Between July 15, 2016, and July 20, 2018, 1213 patients were enrolled and randomly assigned to treatment, of whom 851 were assigned to group A (n=451) and group C (n=400). 338 (75%) patients in group A and 298 (75%) in group C were male, 113 (25%) in group A and 102 (25%) in group C were female, and 346 (77%) in group A and 304 (76%) in group C were White. At data cutoff (Aug 31, 2022), after a median follow up of 13·4 months (IQR 6·2-30·8), median overall survival was 16·1 months (95% CI 14·2-18·8; 336 deaths) in group A versus 13·4 months (12·0-15·3; 310 deaths) in group C (stratified hazard ratio 0·85 [95% CI 0·73-1·00]; one-sided p=0·023). The most common grade 3-4 treatment-related adverse events were anaemia (168 [37%] of 454 patients who received atezolizumab plus chemotherapy vs 133 [34%] of 389 who received placebo plus chemotherapy), neutropenia (167 [37%] vs 115 [30%]), decreased neutrophil count (98 [22%] vs 95 [24%]), thrombocytopenia (95 [21%] vs 70 [18%]), and decreased platelet count (92 [20%] vs 92 [24%]). Serious adverse events occurred in 243 (54%) patients who received atezolizumab plus chemotherapy and 196 (50%) patients who received placebo plus chemotherapy. Treatment-related deaths occurred in nine (2%; acute kidney injury, dyspnoea, hepatic failure, hepatitis, neutropenia, pneumonitis, respiratory failure, sepsis, and thrombocytopenia [n=1 each]) patients who received atezolizumab plus chemotherapy and four (1%; unexplained death, diarrhoea, febrile neutropenia, and toxic hepatitis [n=1 each]) who received placebo plus chemotherapy. INTERPRETATION: Progression-free survival benefit with first-line combination of atezolizumab plus platinum-based chemotherapy did not translate into a significant improvement in overall survival in the ITT population of IMvigor130. Further research is needed to understand which patients might benefit from first-line combination treatment. No new safety signals were observed. FUNDING: F Hoffmann-La Roche.

Atezolizumab monotherapy versus chemotherapy in untreated locally advanced or metastatic urothelial carcinoma (IMvigor130): final overall survival analysis from a randomised, controlled, phase 3 study.

BACKGROUND: The primary analysis of IMvigor130 showed a significant progression-free survival benefit with first-line atezolizumab plus platinum-based chemotherapy (group A) versus placebo plus platinum-based chemotherapy (group C) in patients with locally advanced or metastatic urothelial cancer. However, this finding did not translate into significant overall survival benefit for group A versus group C at the final analysis, precluding formal statistical testing of outcomes with atezolizumab monotherapy (group B) versus group C. Here we report the final overall survival results for group B versus group C; this report is descriptive and should be considered exploratory due to the study's statistical design. METHODS: In this global, partially blinded, randomised, controlled, phase 3 study, patients (aged ≥18 years) who had locally advanced or metastatic urothelial cancer previously untreated in the metastatic setting and Eastern Cooperative Oncology Group performance status of 0-2 were enrolled at 221 hospitals and oncology centres in 35 countries. Patients were randomly assigned (1:1:1), using a permuted block method (block size of six) and an interactive voice and web response system, stratified by PD-L1 status, Bajorin score, and investigator's choice of platinum-based chemotherapy, to receive either atezolizumab plus platinum-based chemotherapy (group A), atezolizumab alone (group B), or placebo plus platinum-based chemotherapy (group C). Sponsors, investigators, and patients were masked to assignment to atezolizumab or placebo in group A and group C; atezolizumab monotherapy in group B was open label. For groups B and C, atezolizumab (1200 mg) or placebo was administered intravenously every 3 weeks. Chemotherapy involved 21-day cycles of gemcitabine (1000 mg/m2 body surface area on day 1 and day 8 of each cycle) plus the investigator's choice of carboplatin (area under the curve 4·5 mg/mL per min or 5 mg/mL per min) or cisplatin (70 mg/m2 body surface area), administered intravenously. Co-primary endpoints were progression-free survival and overall survival in group A versus group C, and overall survival in group B versus group C, tested hierarchically, in the intention-to-treat (ITT) population, and then the populations with high PD-L1 tumour expression (immune cell [IC] expression score of IC2/3) if the results from group A versus group C were significant. Here, we report the co-primary endpoint of overall survival for group B versus group C in the ITT and IC2/3 populations. The ITT population for this analysis comprised concurrently enrolled patients in groups B and C who were randomly assigned to treatment. For the safety analysis, all patients enrolled in group B and group C who received any study treatment were included. The trial is registered with ClinicalTrials.gov, NCT02807636, and is active but no longer recruiting. FINDINGS: Between July 15, 2016, and July 20, 2018, 1213 patients were enrolled and randomly assigned to treatment, of whom 362 patients were assigned to group B and 400 to group C, of whom 360 and 359, respectively, were enrolled concurrently (ITT population). 543 (76%) of 719 patients were male, 176 (24%) were female, and 534 (74%) were White. As of data cutoff (Aug 31, 2022), after a median follow-up of 13·4 months (IQR 6·2-30·8), median overall survival was 15·2 months (95% CI 13·1-17·7; 271 deaths) in group B and 13·3 months (11·9-15·6; 275 deaths) in group C (stratified hazard ratio 0·98 [95% CI 0·82-1·16]). The most common grade 3-4 treatment-related adverse events were anaemia (two [1%] in patients who received atezolizumab monotherapy vs 133 [34%] in those who received placebo plus chemotherapy), neutropenia (one [<1%] vs 115 [30%]), decreased neutrophil count (0 vs 95 [24%]), and decreased platelet count (one [<1%] vs 92 [24%]). Serious adverse events occurred in 163 (46%) patients versus 196 (50%). Treatment-related deaths occurred in three (1%; n=1 each, pneumonia, interstitial lung disease, large intestinal obstruction) patients who received atezolizumab monotherapy and four (1%; n=1 each, diarrhoea, febrile neutropenia, unexplained death, toxic hepatitis) who received placebo plus chemotherapy. INTERPRETATION: The final analysis from IMvigor130 did not show a significant improvement in overall survival with first-line atezolizumab monotherapy compared with platinum-based chemotherapy in the intention-to-treat population. The safety profile of atezolizumab monotherapy remained acceptable after extended follow-up, with no new safety signals. FUNDING: F Hoffmann-La Roche.

Molecular residual disease detection in resected, muscle-invasive urothelial cancer with a tissue-based comprehensive genomic profiling-informed personalized monitoring assay.

Introduction: Circulating tumor DNA (ctDNA) detection postoperatively may identify patients with urothelial cancer at a high risk of relapse. Pragmatic tools building off clinical tumor next-generation sequencing (NGS) platforms could have the potential to increase assay accessibility. Methods: We evaluated the widely available Foundation Medicine comprehensive genomic profiling (CGP) platform as a source of variants for tracking of ctDNA when analyzing residual samples from IMvigor010 (ClinicalTrials.gov identifier NCT02450331), a randomized adjuvant study comparing atezolizumab with observation after bladder cancer surgery. Current methods often involve germline sampling, which is not always feasible or practical. Rather than performing white blood cell sequencing to filter germline and clonal hematopoiesis (CH) variants, we applied a bioinformatic approach to select tumor (non-germline/CH) variants for molecular residual disease detection. Tissue-informed personalized multiplex polymerase chain reaction-NGS assay was used to detect ctDNA postsurgically (Natera). Results: Across 396 analyzed patients, prevalence of potentially actionable alterations was comparable with the expected prevalence in advanced disease (13% FGFR2/3, 20% PIK3CA, 13% ERBB2, and 37% with elevated tumor mutational burden ≥10 mutations/megabase). In the observation arm, 66 of the 184 (36%) ctDNA-positive patients had shorter disease-free survival [DFS; hazard ratio (HR) = 5.77; 95% confidence interval (CI), 3.84-8.67; P < 0.0001] and overall survival (OS; HR = 5.81; 95% CI, 3.41-9.91; P < 0.0001) compared with ctDNA-negative patients. ctDNA-positive patients had improved DFS and OS with atezolizumab compared with those in observation (DFS HR = 0.56; 95% CI, 0.38-0.83; P = 0.003; OS HR = 0.66; 95% CI, 0.42-1.05). Clinical sensitivity and specificity for detection of postsurgical recurrence were 58% (60/103) and 93% (75/81), respectively. Conclusion: We present a personalized ctDNA monitoring assay utilizing tissue-based FoundationOne® CDx CGP, which is a pragmatic and potentially clinically scalable method that can detect low levels of residual ctDNA in patients with resected, muscle-invasive bladder cancer without germline sampling.

In situ tumour arrays reveal early environmental control of cancer immunity.

The immune phenotype of a tumour is a key predictor of its response to immunotherapy1-4. Patients who respond to checkpoint blockade generally present with immune-inflamed5-7 tumours that are highly infiltrated by T cells. However, not all inflamed tumours respond to therapy, and even lower response rates occur among tumours that lack T cells (immune desert) or that spatially exclude T cells to the periphery of the tumour lesion (immune excluded)8. Despite the importance of these tumour immune phenotypes in patients, little is known about their development, heterogeneity or dynamics owing to the technical difficulty of tracking these features in situ. Here we introduce skin tumour array by microporation (STAMP)-a preclinical approach that combines high-throughput time-lapse imaging with next-generation sequencing of tumour arrays. Using STAMP, we followed the development of thousands of arrayed tumours in vivo to show that tumour immune phenotypes and outcomes vary between adjacent tumours and are controlled by local factors within the tumour microenvironment. Particularly, the recruitment of T cells by fibroblasts and monocytes into the tumour core was supportive of T cell cytotoxic activity and tumour rejection. Tumour immune phenotypes were dynamic over time and an early conversion to an immune-inflamed phenotype was predictive of spontaneous or therapy-induced tumour rejection. Thus, STAMP captures the dynamic relationships of the spatial, cellular and molecular components of tumour rejection and has the potential to translate therapeutic concepts into successful clinical strategies.

A Phase 1b/2 Study of Atezolizumab with or Without Bacille Calmette-Guérin in Patients with High-risk Non-muscle-invasive Bladder Cancer.

BACKGROUND: Bacille Calmette-Guérin (BCG) is the standard therapy after transurethral resection of bladder tumour for high-risk non-muscle-invasive bladder cancer (NMIBC). However, post-BCG recurrence/progression occurs frequently, and noncystectomy options are limited. OBJECTIVE: To evaluate the safety and clinical activity of atezolizumab ± BCG in high-risk BCG-unresponsive NMIBC. DESIGN, SETTING, AND PARTICIPANTS: This phase 1b/2 GU-123 study (NCT02792192) treated patients with BCG-unresponsive NMIBC who had carcinoma in situ with atezolizumab ± BCG. INTERVENTION: Patients in cohorts 1A and 1B received atezolizumab 1200 mg IV q3w for ≤96 wk. Those in cohort 1B also received standard BCG induction (six weekly doses) and maintenance courses (three doses weekly starting at month 3) with optional maintenance at 6, 12, 18, 24, and 30 mo. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Coprimary endpoints were safety and 6-mo complete response (CR) rate. Secondary endpoints included 3-mo CR rate and duration of CR; 95% confidence intervals were calculated using the Clopper-Pearson method. RESULTS AND LIMITATIONS: At data cut-off (September 29, 2020), 24 patients were enrolled (cohort 1A, n = 12; cohort 1B, n = 12), and the recommended BCG dose was 50 mg in cohort 1B. Four patients (33%) had adverse events (AEs) leading to BCG dose modification/interruption. Three patients (25%) in cohort 1A reported atezolizumab-related grade 3 AEs; cohort 1B had no atezolizumab- or BCG-related grade ≥3 AEs. No grade 4/5 AEs were reported. The 6-mo CR rate was 33% in cohort 1A (median duration of CR, 6.8 mo) and 42% in cohort 1B (median duration of CR, not reached [≥12 mo]). These results are limited by the small sample size of GU-123. CONCLUSIONS: In this first report of the atezolizumab-BCG combination in NMIBC, atezolizumab ± BCG was well tolerated, with no new safety signals or treatment-related deaths. Preliminary results suggested clinically meaningful activity; the combination favoured a longer duration of response. PATIENT SUMMARY: We studied atezolizumab with and without bacille Calmette-Guérin (BCG) to determine whether this combination was safe and had clinical activity in patients with high-risk noninvasive bladder cancer (high-grade bladder tumours that affect the outermost lining of the bladder wall) that has previously been treated with BCG and is still present or occurred again. Our results suggest that atezolizumab with or without BCG was generally safe and could be used to treat patients unresponsive to BCG.

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.

NKG2A and HLA-E define an alternative immune checkpoint axis in bladder cancer.

Programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1)-blockade immunotherapies have limited efficacy in the treatment of bladder cancer. Here, we show that NKG2A associates with improved survival and responsiveness to PD-L1 blockade immunotherapy in bladder tumors that have high abundance of CD8+ T cells. In bladder tumors, NKG2A is acquired on CD8+ T cells later than PD-1 as well as other well-established immune checkpoints. NKG2A+ PD-1+ CD8+ T cells diverge from classically defined exhausted T cells through their ability to react to human leukocyte antigen (HLA) class I-deficient tumors using T cell receptor (TCR)-independent innate-like mechanisms. HLA-ABC expression by bladder tumors is progressively diminished as disease progresses, framing the importance of targeting TCR-independent anti-tumor functions. Notably, NKG2A+ CD8+ T cells are inhibited when HLA-E is expressed by tumors and partly restored upon NKG2A blockade in an HLA-E-dependent manner. Overall, our study provides a framework for subsequent clinical trials combining NKG2A blockade with other T cell-targeted immunotherapies, where tumors express higher levels of HLA-E.

LRRC15+ myofibroblasts dictate the stromal setpoint to suppress tumour immunity.

Recent single-cell studies of cancer in both mice and humans have identified the emergence of a myofibroblast population specifically marked by the highly restricted leucine-rich-repeat-containing protein 15 (LRRC15)1-3. However, the molecular signals that underlie the development of LRRC15+ cancer-associated fibroblasts (CAFs) and their direct impact on anti-tumour immunity are uncharacterized. Here in mouse models of pancreatic cancer, we provide in vivo genetic evidence that TGFß receptor type 2 signalling in healthy dermatopontin+ universal fibroblasts is essential for the development of cancer-associated LRRC15+ myofibroblasts. This axis also predominantly drives fibroblast lineage diversity in human cancers. Using newly developed Lrrc15-diphtheria toxin receptor knock-in mice to selectively deplete LRRC15+ CAFs, we show that depletion of this population markedly reduces the total tumour fibroblast content. Moreover, the CAF composition is recalibrated towards universal fibroblasts. This relieves direct suppression of tumour-infiltrating CD8+ T cells to enhance their effector function and augments tumour regression in response to anti-PDL1 immune checkpoint blockade. Collectively, these findings demonstrate that TGFß-dependent LRRC15+ CAFs dictate the tumour-fibroblast setpoint to promote tumour growth. These cells also directly suppress CD8+ T cell function and limit responsiveness to checkpoint blockade. Development of treatments that restore the homeostatic fibroblast setpoint by reducing the population of pro-disease LRRC15+ myofibroblasts may improve patient survival and response to immunotherapy.

Single-cell analysis reveals clonally expanded tumor-associated CD57+ CD8 T cells are enriched in the periphery of patients with metastatic urothelial cancer responding to PD-L1 blockade.

BACKGROUND: A growing body of evidence suggests that T-cell responses against neoantigens are critical regulators of response to immune checkpoint blockade. We previously showed that circulating neoantigen-specific CD8 T cells in patients with lung cancer responding to anti-Programmed death-ligand 1 (PD-L1) (atezolizumab) exhibit a unique phenotype with high expression of CD57, CD244, and KLRG1. Here, we extended our analysis on neoantigen-specific CD8 T cells to patients with metastatic urothelial cancer (mUC) and further profiled total CD8 T cells to identify blood-based predictive biomarkers of response to atezolizumab. METHODS: We identified tumor neoantigens from 20 patients with mUC and profiled their peripheral CD8 T cells using highly multiplexed combinatorial tetramer staining. Another set of patients with mUC treated with atezolizumab (n=30) or chemotherapy (n=40) were selected to profile peripheral CD8 T cells by mass cytometry. Using single-cell transcriptional analysis (single-cell RNA sequencing (scRNA-seq)), together with CITE-seq (cellular indexing of transcriptomes and epitopes by sequencing) and paired T-cell receptor (TCR) sequencing, we further characterized peripheral CD8 T cells in a subset of patients (n=16). RESULTS: High frequency of CD57 was observed in neoantigen-specific CD8 T cells in patients with mUC responding to atezolizumab. Extending these findings to bulk CD8 T cells, we found higher frequency of CD57 expressing CD8 T cells before treatment in patients responding to atezolizumab (n=20, p<0.01) but not to chemotherapy. These findings were corroborated in a validation cohort (n=30, p<0.01) and notably were independent of known biomarkers of response. scRNA-seq analysis identified a clonally expanded cluster enriched within CD57+ CD8 T cells in responding patients characterized by higher expression of genes associated with activation, cytotoxicity, and tissue-resident memory markers. Furthermore, compared with CD57- CD8 T cells, TCRs of CD57+ CD8 T cells showed increased overlap with the TCR repertoire of tumor-infiltrating T cells. CONCLUSIONS: Collectively, we show high frequencies of CD57 among neoantigen-specific and bulk CD8 T cells in patients responding to atezolizumab. The TCR repertoire overlap between peripheral CD57+ CD8 T cells and tumor-infiltrating lymphocytes suggest that accumulation of peripheral CD57+ CD8 T cells is reflective of an ongoing antitumor T-cell response. Our findings provide evidence and rationale for using circulating CD8 T cells expressing CD57 as a readily accessible blood-based biomarker for selecting patients with mUC for atezolizumab therapy.

Final Results of Neoadjuvant Atezolizumab in Cisplatin-ineligible Patients with Muscle-invasive Urothelial Cancer of the Bladder.

BACKGROUND: Neoadjuvant immunotherapies hold promise in muscle-invasive bladder cancer (MIBC). OBJECTIVE: To report on 2-yr disease-free (DFS) and overall (OS) survival including novel tissue-based biomarkers and circulating tumor DNA (ctDNA) in the ABACUS trial. DESIGN, SETTING, AND PARTICIPANTS: ABACUS was a multicenter, single-arm, neoadjuvant, phase 2 trial, including patients with MIBC (T2-4aN0M0) who were ineligible for or refused neoadjuvant cisplatin-based chemotherapy. INTERVENTION: Two cycles of atezolizumab were given prior to radical cystectomy. Serial tissue and blood samples were collected. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoints of pathological complete response (pCR) rate and dynamic changes to T-cell biomarkers were published previously. Secondary outcomes were 2-yr DFS and OS. A biomarker analysis correlated with relapse-free survival (RFS) was performed, which includes FOXP3, major histocompatibility complex class I, CD8/CD39, and sequential ctDNA measurements. RESULTS AND LIMITATIONS: The median follow-up time was 25 mo (95% confidence interval [CI] 25-26). Ninety-five patients received at least one cycle of atezolizumab. Eight patients did not undergo cystectomy (only one due to disease progression). The pCR rate was 31% (27/88; 95% CI 21-41). Two-year DFS and OS were 68% (95% CI 58-76) and 77% (95% CI 68-85), respectively. Two-year DFS in patients achieving a pCR was 85% (95% CI 65-94). Baseline PD-L1 and tumor mutational burden did not correlate with RFS (hazard ratio [HR] 0.60 [95% CI 0.24-1.5], p = 0.26, and 0.72 [95% CI 0.31-1.7], p = 0.46, respectively). RFS correlated with high baseline stromal CD8+ (HR 0.25 [95% CI 0.09-0.68], p = 0.007) and high post-treatment fibroblast activation protein (HR 4.1 [95% CI 1.3-13], p = 0.01). Circulating tumor DNA positivity values at baseline, after neoadjuvant therapy, and after surgery were 63% (25/40), 47% (14/30), and 14% (five/36), respectively. The ctDNA status was highly prognostic at all time points. No relapses were observed in ctDNA-negative patients at baseline and after neoadjuvant therapy. The lack of randomization and exploratory nature of the biomarker analysis are limitations of this work. CONCLUSIONS: Neoadjuvant atezolizumab in MIBC is associated with clinical responses and high DFS. CD8+ expression and serial ctDNA levels correlated with outcomes, and may contribute to personalized therapy in the future. PATIENT SUMMARY: We showed that bladder cancer patients receiving immunotherapy followed by cystectomy have good long-term outcomes. Furthermore, we found that certain biological features can predict patients who might have particular benefit from this therapy.

Molecular classification of hormone-sensitive and castration-resistant prostate cancer, using nonnegative matrix factorization molecular subtyping of primary and metastatic specimens.

BACKGROUND: Despite the rapidly evolving therapeutic landscape, immunotherapy has demonstrated limited activity in prostate cancer. A greater understanding of the molecular landscape, particularly the expression of immune-related pathways, will inform future immunotherapeutic strategies. Consensus nonnegative matrix factorization (cNMF) is a novel model of molecular classification analyzing gene expression data, focusing on biological interpretation of metagenes and selecting meaningful clusters. OBJECTIVE: We aimed to identify molecular subtypes of prostate cancer using cNMF and correlate these with existing biomarkers to inform future immunotherapeutic strategies. METHODS: A cohort of archival tumor specimens from hormone-sensitive and castration-resistant disease was studied. Whole transcriptomic profiles were generated using TruSeq RNA Access technology and subjected to cNMF. Comprehensive genomic profiling was performed with the FoundationOne assay. NMF subtypes were characterized by gene expression pathways, genomic alterations and correlated with clinical data, then applied to The Cancer Genome Atlas data set. RESULTS: We studied 164 specimens, including 52 castration-resistant and 13 paired primary/metastatic specimens. cNMF identified four distinct subtypes. NMF1 (19%) is enriched for immune-related and stromal-related pathways with transforming growth factor ß (TGFß) signature. NMF2 (36%) is associated with FOXO-mediated transcription signature and AKT signaling, NMF3 (26%) is enriched for ribosomal RNA processing, while NMF4 (19%) is enriched for cell cycle and DNA-repair pathways. The most common gene alterations included TMPRSS22 (42%), TP53 (23%), and DNA-repair genes (19%), occurring across all subtypes. NMF4 is significantly enriched for MYC and Wnt-signaling gene alterations. TMB, CD8 density, and PD-L1 expression were low overall. NMF1 and NMF4 were NMF2 was associated with superior overall survival. CONCLUSIONS: Using cNMF, we identified four molecularly distinct subtypes which may inform treatment selection. NMF1 demonstrates the most inflammatory signature with asuppressive TGFß signature, suggesting potential benefit with immunotherapy combination strategies targeting TGFß and PD-(L)1. Prospective studies are required to evaluate the use of this novel model to molecularly stratify patients for optimal treatment selection.

Atezolizumab with enzalutamide versus enzalutamide alone in metastatic castration-resistant prostate cancer: a randomized phase 3 trial.

Early clinical data indicate that some patients with castration-resistant prostate cancer may benefit from program death ligand-1 (PD-L1) inhibition, especially with enzalutamide. The IMbassador250 trial (no. NCT03016312) enrolled 759 men with metastatic castration-resistant prostate cancer whose disease progressed on abiraterone. The addition of atezolizumab to enzalutamide in an open-label randomized trial did not meet the primary endpoint of improved overall survival in unselected patients (stratified hazard ratio 1.12, 95% confidence interval (0.91, 1.37), P = 0.28), despite an acceptable safety profile. In archival tumor samples, prostate tumors showed comparatively low expression of key immune biomarkers. DNA damage-response alterations, phosphatase and tensin homolog status and PD-L1 expression levels were similar between hormone-sensitive and castration-resistant prostate cancers. In planned biomarker analysis, longer progression-free survival was seen with atezolizumab in patients with high PD-L1 IC2/3, CD8 expression and established immune gene signatures. Exploratory analysis linked progression-free survival in the atezolizumab arm with immune genes such as CXCL9 and TAP1, together with other potentially relevant biomarkers including phosphatase and tensin homolog alterations. Together these data indicate that the expected biology associated with response to immune checkpoint inhibitors is present in prostate cancer, albeit in fewer patients. Careful patient selection may be required for immune checkpoint inhibitors to identify subgroups of patients who may benefit from this treatment approach.

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.

ctDNA guiding adjuvant immunotherapy in urothelial carcinoma.

Minimally invasive approaches to detect residual disease after surgery are needed to identify patients with cancer who are at risk for metastatic relapse. Circulating tumour DNA (ctDNA) holds promise as a biomarker for molecular residual disease and relapse1. We evaluated outcomes in 581 patients who had undergone surgery and were evaluable for ctDNA from a randomized phase III trial of adjuvant atezolizumab versus observation in operable urothelial cancer. This trial did not reach its efficacy end point in the intention-to-treat population. Here we show that ctDNA testing at the start of therapy (cycle 1 day 1) identified 214 (37%) patients who were positive for ctDNA and who had poor prognosis (observation arm hazard ratio = 6.3 (95% confidence interval: 4.45-8.92); P < 0.0001). Notably, patients who were positive for ctDNA had improved disease-free survival and overall survival in the atezolizumab arm versus the observation arm (disease-free survival hazard ratio = 0.58 (95% confidence interval: 0.43-0.79); P = 0.0024, overall survival hazard ratio = 0.59 (95% confidence interval: 0.41-0.86)). No difference in disease-free survival or overall survival between treatment arms was noted for patients who were negative for ctDNA. The rate of ctDNA clearance at week 6 was higher in the atezolizumab arm (18%) than in the observation arm (4%) (P = 0.0204). Transcriptomic analysis of tumours from patients who were positive for ctDNA revealed higher expression levels of cell-cycle and keratin genes. For patients who were positive for ctDNA and who were treated with atezolizumab, non-relapse was associated with immune response signatures and basal-squamous gene features, whereas relapse was associated with angiogenesis and fibroblast TGFß signatures. These data suggest that adjuvant atezolizumab may be associated with improved outcomes compared with observation in patients who are positive for ctDNA and who are at a high risk of relapse. These findings, if validated in other settings, would shift approaches to postoperative cancer care.

Intratumoral CD103+ CD8+ T cells predict response to PD-L1 blockade.

BACKGROUND: CD8+ tissue-resident memory T (TRM) cells, marked by CD103 (ITGAE) expression, are thought to actively suppress cancer progression, leading to the hypothesis that their presence in tumors may predict response to immunotherapy. METHODS: Here, we test this by combining high-dimensional single-cell modalities with bulk tumor transcriptomics from 1868 patients enrolled in lung and bladder cancer clinical trials of atezolizumab (anti-programmed cell death ligand 1 (PD-L1)). RESULTS: ITGAE was identified as the most significantly upregulated gene in inflamed tumors. Tumor CD103+ CD8+ TRM cells exhibited a complex phenotype defined by the expression of checkpoint regulators, cytotoxic proteins, and increased clonal expansion. CONCLUSIONS: Our analyses indeed demonstrate that the presence of CD103+ CD8+ TRM cells, quantified by tracking intratumoral CD103 expression, can predict treatment outcome, suggesting that patients who respond to PD-1/PD-L1 blockade are those who exhibit an ongoing antitumor T-cell response.