The bladder cancer immune micro-environment in the context of response to immune checkpoint inhibition.

Treatment with neoadjuvant cisplatin-based chemotherapy followed by radical cystectomy is the default treatment for muscle-invasive bladder cancer (BC). However, with the encouraging results of immune checkpoint inhibitiors (ICI) directed against PD-1/PD-L1 and CTLA-4 in recent years, the treatment landscape of BC is rapidly changing. In addition, it is becoming clear that the effect of ICI is highly dependent on the interaction between tumor cells and the tumor immune micro-environment (TIME). Different immune cells are involved in an anti-tumor response in BC. Cytotoxic CD8+ T-cells are the main effector cells, aided by other immune cells including other T-cells, B-cells and pro-inflammatory macrophages. As part of the ongoing anti-tumor immune response, lymphocytes aggregate in clusters called tertiary lymphoid structures (TLS). Tumor mutational burden (TMB) and infiltration of immune cells into the tumor are both important factors for establishing an anti-tumor immune response. In contrast, transforming growth factor beta (TGF-ß) signaling in cancer-associated fibroblasts (CAFs) prevents infiltration of lymphocytes and potentially has an immunosuppressive effect. In conclusion, the effect of ICI seems to be reliant on a combination of tumor-intrinsic and TIME-related parameters. More research is needed to fully understand the underlying biological mechanisms to further improve patient care.

High- or low-dose preoperative ipilimumab plus nivolumab in stage III urothelial cancer: the phase 1B NABUCCO trial.

Cohort 1 of the phase 1B NABUCCO trial showed high pathological complete response (pCR) rates with preoperative ipilimumab plus nivolumab in stage III urothelial cancer (UC). In cohort 2, the aim was dose adjustment to optimize responses. Additionally, we report secondary endpoints, including efficacy and tolerability, in cohort 2 and the association of presurgical absence of circulating tumor DNA (ctDNA) in urine and plasma with clinical outcome in both cohorts. Thirty patients received two cycles of either ipilimumab 3 mg kg-1 plus nivolumab 1 mg kg-1 (cohort 2A) or ipilimumab 1 mg kg-1 plus nivolumab 3 mg kg-1 (cohort 2B), both followed by nivolumab 3 mg kg-1. We observed a pCR in six (43%) patients in cohort 2A and a pCR in one (7%) patient in cohort 2B. Absence of urinary ctDNA correlated with pCR in the bladder (ypT0Nx) but not with progression-free survival (PFS). Absence of plasma ctDNA correlated with pCR (odds ratio: 45.0; 95% confidence interval (CI): 4.9-416.5) and PFS (hazard ratio: 10.4; 95% CI: 2.9-37.5). Our data suggest that high-dose ipilimumab plus nivolumab is required in stage III UC and that absence of ctDNA in plasma can predict PFS. ClinicalTrials.gov registration: NCT03387761 .

Assessment of Predictive Genomic Biomarkers for Response to Cisplatin-based Neoadjuvant Chemotherapy in Bladder Cancer.

Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy is recommended for patients with muscle-invasive bladder cancer (MIBC). It has been shown that somatic deleterious mutations in ERCC2, gain-of-function mutations in ERBB2, and alterations in ATM, RB1, and FANCC are correlated with pathological response to NAC in MIBC. The objective of this study was to validate these genomic biomarkers in pretreatment transurethral resection material from an independent retrospective cohort of 165 patients with MIBC who subsequently underwent NAC and radical surgery. Patients with ypT0/Tis/Ta/T1N0 disease after surgery were defined as responders. Somatic deleterious mutations in ERCC2 were found in nine of 68 (13%) evaluable responders and two of 95 (2%) evaluable nonresponders (p = 0.009; FDR = 0.03). No correlation was observed between response and alterations in ERBB2 or in ATM, RB1, or FANCC alone or in combination. In an exploratory analysis, no additional genomic alterations discriminated between responders and nonresponders to NAC. No further associations were identified between the aforementioned biomarkers and pathological complete response (ypT0N0) after surgery. In conclusion, we observed a positive association between deleterious mutations in ERCC2 and pathological response to NAC, but not overall survival or recurrence-free survival. Other previously reported genomic biomarkers were not validated. PATIENT SUMMARY: It is currently unknown which patients will respond to chemotherapy before definitive surgery for bladder cancer. Previous studies described several gene mutations in bladder cancer that correlated with chemotherapy response. This study confirmed that patients with bladder cancer with a mutation in the ERCC2 gene often respond to chemotherapy.

Survival after neoadjuvant/induction combination immunotherapy vs combination platinum-based chemotherapy for locally advanced (Stage III) urothelial cancer.

Despite treatment with cisplatin-based chemotherapy and surgical resection, clinical outcomes of patients with locally advanced urothelial carcinoma (UC) remain poor. We compared neoadjuvant/induction platinum-based combination chemotherapy (NAIC) with combination immune checkpoint inhibition (cICI). We identified 602 patients who attended our outpatient bladder cancer clinic in 2018 to 2019. Patients were included if they received NAIC or cICI for cT3-4aN0M0 or cT1-4aN1-3M0 UC. NAIC consisted of cisplatin-based chemotherapy or gemcitabine-carboplatin in case of cisplatin-ineligibility. A subset of patients (cisplatin-ineligibility or refusal of NAIC) received ipilimumab plus nivolumab in the NABUCCO-trial (NCT03387761). Treatments were compared using the log-rank test and propensity score-weighted Cox regression models. We included 107 Stage III UC patients treated with NAIC (n = 83) or cICI (n = 24). NAIC was discontinued in 11 patients due to progression (n = 6; 7%) or toxicity (n = 5; 6%), while cICI was discontinued in 6 patients (25%) after 2 cycles due to toxicity (P = .205). After NAIC, patients had surgical resection (n = 50; 60%), chemoradiation (n = 26; 30%), or no consolidating treatment due to progression (n = 5; 6%) or toxicity (n = 2; 2%). After cICI, all patients underwent resection. After resection (n = 74), complete pathological response (ypT0N0) was achieved in 11 (22%) NAIC-patients and 11 (46%) cICI-patients (P = .056). Median (IQR) follow-up was 26 (20-32) months. cICI was associated with superior progression-free survival (P = .003) and overall survival (P = .003) compared to NAIC. Our study showed superior survival in Stage III UC patients pretreated with cICI if compared to NAIC. Our findings provide a strong rationale for validation of cICI for locally advanced UC in a comparative phase-3 trial.

A kinome-centered CRISPR-Cas9 screen identifies activated BRAF to modulate enzalutamide resistance with potential therapeutic implications in BRAF-mutated prostate cancer.

Resistance to drugs targeting the androgen receptor (AR) signaling axis remains an important challenge in the treatment of prostate cancer patients. Activation of alternative growth pathways is one mechanism used by cancer cells to proliferate despite treatment, conferring drug resistance. Through a kinome-centered CRISPR-Cas9 screen in CWR-R1 prostate cancer cells, we identified activated BRAF signaling as a determinant for enzalutamide resistance. Combined pharmaceutical targeting of AR and MAPK signaling resulted in strong synergistic inhibition of cell proliferation. The association between BRAF activation and enzalutamide resistance was confirmed in two metastatic prostate cancer patients harboring activating mutations in the BRAF gene, as both patients were unresponsive to enzalutamide. Our findings suggest that co-targeting of the MAPK and AR pathways may be effective in patients with an activated MAPK pathway, particularly in patients harboring oncogenic BRAF mutations. These results warrant further investigation of the response to AR inhibitors in BRAF-mutated prostate tumors in clinical settings.