Immune checkpoint inhibitors in advanced upper and lower tract urothelial carcinoma: a comparison of outcomes

Pembrolizumab in patients with advanced upper tract urothelial carcinoma: a real-world study from ARON-2 project

Upper tract urothelial carcinoma (UTUC) accounts for the 5-10% of all urothelial carcinomas (UCs). In this analysis, we reported the real-world data from the ARON-2 study (NCT05290038) on the efficacy of pembrolizumab in patients with UTUC who recurred or progressed after platinum-based chemotherapy. Medical records of patients with metastatic UTUC treated with pembrolizumab as second-line therapy were reviewed from 34 institutions in 14 countries. Patients were assessed for overall survival (OS), progression-free survival (PFS), and overall response rate (ORR). Univariate and multivariate analyses were used to explore the association of variables of interest with OS and PFS. 235 patients were included in our analysis. Median OS was 8.6 months (95% CI 6.6-12.1), the 1 year OS rate was 43% while the 2 years OS rate 29%. The median PFS was 5.1 months (95% CI 3.9-6.9); 46% of patients were alive at 6 months, 34% at 12 months and 25% at 24 months. According to RECIST 1.1, 18 patients (8%) experienced complete response (CR), 57 (24%) partial response (PR), 44 (19%) stable disease (SD), and 116 (49%) progressive disease (PD), with an ORR of 32%. Our study confirms the effectiveness of pembrolizumab in patients pretreated with a platinum-based combination, irrespective of their sensitivity to the first-line treatment and of their histology. In addition, we emphasized the limited benefit of the treatment with pembrolizumab in patients with hepatic metastases and poor ECOG performance status.

Safety and efficacy of radiotherapy combined with chemotherapy for recurrent metastatic renal pelvic and ureteral carcinoma

PURPOSE

To retrospectively investigate the safety and efficacy of radiotherapy combined with chemotherapy for recurrent metastatic renal pelvic and ureteral carcinoma.

METHODS

109 patients were enrolled in this study, including 44 patients in the radiochemotherapy group and 65 patients in the chemotherapy group. Propensity score matching (PSM) was used to balance the baseline characteristics of the two groups by 1:1 matching. Kaplan-Meier method was used to calculate PFS and OS. Cox regression model was used for multivariate analysis. The side effects were evaluated by CTCAE v5.0 RESULTS: The median follow-up time was 14.5 months. Multivariate analysis showed that radiotherapy was a good independent prognostic factor for OS (HR: 0.327, 95% CI 0.157-0.680, P = 0.003). After matching, there were 40 patients in both groups, and the median PFS and OS in the radiochemotherapy group were longer than those in the chemotherapy group (PFS: 10.4 vs. 6.7 months, P = 0.035; OS: 43.5 vs. 18.8 months, P < 0.001). In addition, in the radiochemotherapy group, patients treated with radiotherapy before first-line chemotherapy failure had a longer PFS than those treated with radiotherapy after chemotherapy failure (median PFS: 15.7 vs. 6 months, P = 0.003). There was no significant difference in the incidence of grade 3-4 toxicities between the two groups (52.3% vs. 50.8%, P = 0.878).

CONCLUSION

For patients with recurrent metastatic renal pelvic and ureteral carcinoma, radiotherapy combined with chemotherapy is well tolerable and expected to bring long-term survival benefits, and the benefits of early interventional radiotherapy may be more obvious.

Response and Outcomes of Maintenance Avelumab After Platinum-Based Chemotherapy (PBC) in Patients With Advanced Urothelial Carcinoma (aUC): "Real World" Experience

BACKGROUND

Platinum-based chemotherapy (PBC) followed by avelumab switch maintenance in nonprogressors is standard first line (1L) treatment for advanced urothelial carcinoma (aUC). We describe clinical features and outcomes in a "real-world' cohort treated with avelumab maintenance for aUC.

MATERIALS AND METHODS

This was a retrospective cohort study of patients (pts) who received 1L switch maintenance avelumab after no progression on PBC for aUC. We calculated progression-free survival (PFS) and overall survival (OS) from initiation of maintenance avelumab. We also described OS and PFS for specific subsets using Cox regression and observed response rate (ORR).

RESULTS

A total of 108 pts with aUC from 14 sites treated with maintenance avelumab were included. There was a median of 6 weeks1-30 from end of PBC to avelumab initiation; median follow-up time from avelumab initiation was 8.8 months (1-42.7). Median [m]PFS was 9.6 months (95%CI 7.5-12.1) and estimated 1-year OS was 72.5%. CR/PR (vs. SD) to 1L PBC (HR = 0.33, 95% CI 0.13-0.87) and ECOG PS 0 (vs. ≥1), (HR = 0.15, 95% CI 0.05-0.47) were associated with longer OS. The presence of liver metastases was associated with shorter PFS (HR = 2.32, 95% CI 1.17-4.59). ORR with avelumab maintenance was 28.7% (complete response 17.6%, partial response 11.1%), 29.6% stable disease, 26.9% progressive disease as best response (14.8% best response unknown).

CONCLUSIONS

Results seem relatively consistent with findings from JAVELIN Bladder100 trial and recent "real world" studies. Prior response to platinum-based chemotherapy, ECOG PS 0, and absence of liver metastases were favorable prognostic factors. Limitations include the retrospective design, lack of randomization and central scan review, and possible selection/confounding biases.

The poor antitumor effect of pembrolizumab in advanced upper urothelial carcinoma with renal parenchymal invasion

OBJECTIVES

We investigated poor prognosticators in advanced or unresectable urothelial carcinoma, focusing on renal parenchymal invasion (RPI).

METHODS

This study included 48 bladder cancer (BC) and 67 upper tract urothelial carcinoma (UTUC) patients treated with pembrolizumab from December 2017 to September 2022 at Kobe University Hospital. Medical records were retrospectively reviewed for clinical characteristics, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). Multivariate analyses were performed using the Cox proportional hazard regression model to identify parameters associated with either PFS or OS.

RESULTS

Of 67 UTUC patients, 23 had RPI and 41 patients did not, while 3 cases could not be evaluated. Patients with RPI were predominantly elderly and had liver metastases. ORR for patients with RPI was 8.7%, while it was 19.5% for those without RPI. PFS was significantly shorter for patients with RPI compared with those without RPI. Patients with RPI had significantly shorter OS than those without RPI. On multivariate analysis, performance status (PS) ≥ 2, neutrophil-lymphocyte ratio (NLR) ≥ 3, C-reactive protein ≥0.3 mg/dL and RPI were independent prognostic factors for PFS. PS ≥ 2, NLR ≥ 3, visceral metastasis and RPI were independent prognostic factors for OS. UTUC patient OS was significantly shorter than BC patient OS, while no significant difference in PFS or OS was observed between BC patients and UTUC patients without RPI.

CONCLUSIONS

RPI was a poor prognostic factor in advanced urothelial carcinoma treated with pembrolizumab, possibly resulting in a poorer prognosis for UTUC compared with BC.

Sustained complete response to first-line immunochemotherapy for highly aggressive TP53/MDM2-mutated upper tract urothelial carcinoma with ERBB2 mutations, luminal immune-infiltrated contexture, and non-mesenchymal state: a case report and literature review

Background

Upper tract urothelial carcinoma (UTUC) is a rare malignancy. The management of metastatic or unresectable UTUC is mainly based on evidence extrapolated from histologically homologous bladder cancer, including platinum-based chemotherapy and immune checkpoint inhibitor alone, whereas UTUC exhibits more invasiveness, worse prognosis, and comparatively inferior response to treatments. First-line immunochemotherapy regimens have been attempted in clinical trials for unselected naïve-treated cases, but their efficacies relative to standard chemo- or immuno-monotherapy still remain controversial. Here, we present a case of highly aggressive UTUC for whom comprehensive genetic and phenotypic signatures predicted sustained complete response to first-line immunochemotherapy.

Case presentation

A 50-year-old man received retroperitoneoscopic nephroureterectomy and regional lymphadenectomy for high-risk locally advanced UTUC. Postoperatively, he developed rapid progression of residual unresectable metastatic lymph nodes. Pathologic analysis and next-generation sequencing classified the tumor as highly aggressive TP53/MDM2-mutated subtype with features more than expression of programmed death ligand-1, including ERBB2 mutations, luminal immune-infiltrated contexture, and non-mesenchymal state. Immunochemotherapy combining gemcitabine, carboplatin, and off-label programmed death-1 inhibitor sintilimab was initiated, and sintilimab monotherapy was maintained up to 1 year. Retroperitoneal lymphatic metastases gradually regressed to complete response. Blood-based analyses were performed longitudinally for serum tumor markers, inflammatory parameters, peripheral immune cells, and circulating tumor DNA (ctDNA) profiling. The ctDNA kinetics of tumor mutation burden and mean variant allele frequency accurately predicted postoperative progression and sustained response to the following immunochemotherapy, which were mirrored by dynamic changes in abundances of ctDNA mutations from UTUC-typical variant genes. The patient remained free of recurrence or metastasis as of this publishing, over 2 years after the initial surgical treatment.

Conclusion

Immunochemotherapy may be a promising first-line option for advanced or metastatic UTUC selected with specific genomic or phenotypic signatures, and blood-based analyses incorporating ctDNA profiling provide precise longitudinal monitoring.

Immunotherapy with or without targeted therapy for metastatic upper tract urothelial carcinoma: case report and literature review

Background

Immune checkpoint inhibitors (ICIs) have been proved having a better safety profile compared to platinum-based chemotherapy and have demonstrated encouraging anti-tumor therapeutic effects for patients with metastatic urothelial carcinoma (mUC). However, few studies have evaluated the efficacy of ICIs in patients with metastatic upper tract urothelial carcinoma (mUTUC).

Case reports

Case 1 was a 71-year-old male patient diagnosed with left renal pelvic carcinoma, accompanied by a metastasis to the second lumbar spine. As the patient became refractory to chemotherapy, four cycles of camrelizumab, one of the ICIs, were administered, which helped to control the metastases and extend the patient's progression-free survival to five months. Case 2 was an 88-year-old female with middle and lower right ureter carcinoma with right iliac arteriovenous invasion. The patient received five cycles of camrelizumab plus vascular endothelial growth factor receptor 2 (VEGFR2) inhibitors and achieved stable disease.

Conclusion

For patients who are ineligible for chemotherapy, immunotherapy might be a feasible treatment, regardless of whether or not they are given VEGFR2 inhibitors.

Treatment Rechallenge With Immune Checkpoint Inhibitors in Advanced Urothelial Carcinoma

OBJECTIVES

To examine patient and disease characteristics, toxicity, and clinical outcomes for patients with advanced urothelial carcinoma (aUC) who are rechallenged with immune checkpoint inhibitor (ICI)-based therapy.

PATIENTS AND METHODS

In this retrospective cohort, we included patients treated with ICI for aUC after having prior ICI treatment. Endpoints included the evaluation of radiographic response and disease control rates with first and second ICI courses, outcomes based on whether there was a change in ICI class (anti-PD-1 vs. anti-PD-L1), and assessment of the reasons for ICI discontinuation.

RESULTS

We identified 25 patients with aUC from 9 institutions who received 2 separate ICI courses. ORR with first ICI and second ICI were 39% and 13%, respectively. Most patients discontinued first ICI due to progression (n = 19) or treatment-related toxicity (n = 4). Thirteen patients received non-ICI treatment between the first and second ICI, and 12 patients changed ICI class (anti-PD-1 vs. anti-PD-L1) at rechallenge. Among 10 patients who changed ICI class, 8 (80%) had progressive disease as best response with second ICI, while among 12 patients re-treated with the same ICI class, only 3 (25%) had progressive disease as best response at the time of rechallenge. With second ICI, most patients discontinued treatment due to progression (n = 18) or patient preference (n = 2).

CONCLUSIONS

A proportion of patients with aUC rechallenged with ICI-based regimens may achieve disease control, supporting clinical trials in that setting, especially with ICI-based combinations. Future studies are needed to validate our results and should also focus on identifying biomarkers predictive of benefit with ICI rechallenge.

Variant histology in upper tract carcinomas: Analysis of the National Cancer Database

INTRODUCTION

Upper urinary tract malignancies are relatively uncommon, with the majority representing urothelial carcinoma (UC). Variant histology (VH) is rare but has been increasingly shown to confer worse prognoses, and standardized approaches to treatment for upper tract cancers with VH have not been established. Our study aimed to analyze outcomes amongst various treatment modalities for upper tract malignancies based on VH subtype. Additionally, we stratified mortality outcomes associated with the upper tract tumors based on their primary location in the renal pelvis (RP) versus ureter.

METHODS

The National Cancer Database was queried for patients who were diagnosed with upper tract malignancy of the RP or ureter from 2005 to 2016. Populations were grouped based on tumor location (RP vs. ureter) and substratified based on tumor histology (UC vs. VH). Cox regression (CR) was used for multivariable survival analysis.

RESULTS

A total of 63,826 patients with upper tract malignancies met inclusion criteria: 36,692 (57.5%) cases involving the RP and 27,134 (42.5%) cases involving the ureter. VH was noted in 2.5% of all tumors with the squamous cell variant being the most common subtype (62.5%). VH presented with higher stage, increased mortality, and higher proportion of metastatic disease relative to UC.  Patients with VH were less likely to undergo surgical intervention and more likely to receive radiation or adjuvant chemotherapy. Neoadjuvant chemotherapy was not associated with tumor downstaging for VH. On multivariable CR, receiving definitive surgical excision improved survival for patients with any VH, and chemotherapy improved survival for patients with renal VH. On subanalysis of CR by VH subtype, survival benefits for surgery were significant for adenocarcinoma, neuroendocrine, and squamous in a renal location and adenocarcinoma, neuroendocrine, sarcoma, and squamous in a ureteral location. Additionally, benefits of chemotherapy were significant for adenocarcinoma in a renal location and neuroendocrine in a ureteral location.

CONCLUSION

Patients with upper tract VH are more likely to present at advanced stages and experience higher mortality rates when compared to pure UC. Generally, survival benefits are seen with either surgical excision or chemotherapy for renal VH and with surgical excision for ureteral VH, but mortality rates for these treatment modalities differ amongst specific subtypes.

Effectiveness and safety of immune checkpoint inhibitor monotherapy in advanced upper tract urothelial carcinoma: A multicenter, retrospective, real-world study

INTRODUCTION

The effectiveness and safety of immune checkpoint inhibitor (ICI) monotherapy in advanced upper tract urothelial carcinoma (UTUC) is less reported.

METHODS

In total, 106 consecutive advanced UTUC patients receiving ICI monotherapy were collected from nine high volume centers. Clinical outcomes were analyzed according to multiple parameters (e.g., treatment line, metastatic sites). Objective response rate (ORR), overall survival (OS) and progression-free survival (PFS) were captured after ICI initiation.

RESULTS

With a median follow-up of 12.0 months, 25 patients in the first-line group and 15 patients in the second-line group died of UTUC. We reported a median OS of 18.0 months, a median PFS of 5.0 months, and an ORR of 38.6% for patients in the first-line group; a median OS of 10.0 months, a median OS of 4.0 months, and an ORR of 27.8% for patients in the second-line group. Complete response was observed in two patients in the first-line group and one patient in the second-line group with a total complete response rate of 2.8%. In the univariate and multivariate analysis, visceral metastasis with a hazard ratio of 2.4 was associate with poor OS. The most common treatment-related adverse events included fatigue (11.3%), pruritus (10.4%), and diarrhea (6.6%).

CONCLUSIONS

This real-world study suggests that ICI monotherapy is active and has acceptable toxic effects for unresectable or metastatic UTUC as first-line therapy in cisplatin-ineligible patients or second-line therapy in platinum-refractory patients.

Association of prior local therapy and outcomes with programmed-death ligand-1 inhibitors in advanced urothelial cancer

OBJECTIVES

To compare clinical outcomes with programmed-death ligand-1 immune checkpoint inhibitors (ICIs) in patients with advanced urothelial carcinoma (aUC) who have vs have not undergone radical surgery (RS) or radiation therapy (RT) prior to developing metastatic disease.

PATIENTS AND METHODS

We performed a retrospective cohort study collecting clinicopathological, treatment and outcomes data for patients with aUC receiving ICIs across 25 institutions. We compared outcomes (observed response rate [ORR], progression-free survival [PFS], overall survival [OS]) between patients with vs without prior RS, and by type of prior locoregional treatment (RS vs RT vs no locoregional treatment). Patients with de novo advanced disease were excluded. Analysis was stratified by treatment line (first-line and second-line or greater [second-plus line]). Logistic regression was used to compare ORR, while Kaplan-Meier analysis and Cox regression were used for PFS and OS. Multivariable models were adjusted for known prognostic factors.

RESULTS

We included 562 patients (first-line: 342 and second-plus line: 220). There was no difference in outcomes based on prior locoregional treatment among those treated with first-line ICIs. In the second-plus-line setting, prior RS was associated with higher ORR (adjusted odds ratio 2.61, 95% confidence interval [CI]1.19-5.74]), longer OS (adjusted hazard ratio [aHR] 0.61, 95% CI 0.42-0.88) and PFS (aHR 0.63, 95% CI 0.45-0.89) vs no prior RS. This association remained significant when type of prior locoregional treatment (RS and RT) was modelled separately.

CONCLUSION

Prior RS before developing advanced disease was associated with better outcomes in patients with aUC treated with ICIs in the second-plus-line but not in the first-line setting. While further validation is needed, our findings could have implications for prognostic estimates in clinical discussions and benchmarking for clinical trials. Limitations include the study's retrospective nature, lack of randomization, and possible selection and confounding biases.

Radical nephroureterectomy for UTUC conferred survival benefits irrespective of age and comorbidities

PURPOSE

We investigated the effects of age, American Society of Anesthesiologists Physical Status Classification (ASA) grading and Charlson Comorbidity Index (CCI) on the survival outcomes of upper tract urothelial carcinoma (UTUC).

METHODS

The CROES-UTUC registry was an international, multicenter study on patients with UTUC. Primary outcomes were overall survival (OS) and disease-free survival (DFS). Kaplan-Meier and multivariate Cox regression analyses were performed by stratifying patients according to their age (≤ 70 and > 70 years old) and ASA grade (I-II and III-V)/CCI (0-1 and ≥ 2).

RESULTS

A total of 2352 patients were included in this study. Patients aged ≤ 70 years with ASA grading of I-II (p = 0.002), and patients aged ≤ 70 years with a CCI of 0-1 (p = 0.002) had the best OS. Upon multivariate analysis, both in patients aged ≤ 70 and > 70 years, ASA grading and CCI were not significantly associated with OS. Patients aged ≤ 70 years with ASA grading of III-IV (p = 0.024) had the best DFS. When stratified according to age and CCI, no significant difference in DFS was noted. Upon multivariate analysis, radical nephroureterectomy (RNU) was significantly associated with better DFS in patients aged ≤ 70 and > 70 years; CCI of ≥ 3 was significantly associated with worse DFS in patients ≤ 70 years; ASA grading was not associated with DFS in patients aged ≤ 70 and > 70 years.

CONCLUSIONS

A high ASA grading and CCI should not be considered contraindications for RNU. RNU should be considered even in elderly patients when it is deemed feasible and achievable after a geriatric assessment.

Immunotherapy for Urothelial Carcinoma: Focus on Clinical Utility of Nivolumab

Over the past decade, the emergence of immune checkpoint inhibitors has brought about significant change to the treatment landscape of bladder cancer. Nivolumab is an immune checkpoint inhibitor that has shown favorable results resulting in FDA approval for treatment of platinum-refractory locally advanced or metastatic urothelial carcinoma. More recently, it was the first (and only) immune checkpoint inhibitor to receive FDA approval for the treatment of urothelial carcinoma in the adjuvant setting after radical surgery. Multiple trials are now actively underway to further understand the nuances in which immune checkpoint inhibitors such as nivolumab can be beneficial. In this review, we explore the development of nivolumab in terms of its mechanism of action, its growing indications in the treatment of urothelial carcinoma, and potential future directions for clinical trials. Immune checkpoint inhibitors are a promising treatment for bladder cancer, but further work is needed to continue to improve outcomes for patients.

Association Between Sites of Metastasis and Outcomes With Immune Checkpoint Inhibitors in Advanced Urothelial Carcinoma

BACKGROUND

Sites of metastasis have prognostic significance in advanced urothelial carcinoma (aUC), but more information is needed regarding outcomes based on metastatic sites in patients treated with immune checkpoint inhibitors (ICI). We hypothesized that presence of liver/bone metastases would be associated with worse outcomes with ICI.

METHODS

We identified a retrospective cohort of patients with aUC across 26 institutions, collecting demographics, clinicopathological, treatment, and outcomes information. Outcomes were compared with logistic (observed response rate; ORR) and Cox (progression-free survival; PFS, overall survival; OS) regression between patients with/without metastasis beyond lymph nodes (LN) and those with/without bone/liver/lung metastasis. Analysis was stratified by 1st or 2nd+ line.

RESULTS

We identified 917 ICI-treated patients: in the 1st line, bone/liver metastases were associated with shorter PFS (Hazard ratio; HR: 1.65 and 2.54), OS (HR: 1.60 and 2.35, respectively) and lower ORR (OR: 0.48 and 0.31). In the 2nd+ line, bone/liver metastases were associated with shorter PFS (HR: 1.71 and 1.62), OS (HR: 1.76 and 1.56) and, for bone-only metastases, lower ORR (OR: 0.29). In the 1st line, LN-confined metastasis was associated with longer PFS (HR: 0.53), OS (HR:0.49) and higher ORR (OR: 2.97). In the 2nd+ line, LN-confined metastasis was associated with longer PFS (HR: 0.47), OS (HR: 0.54), and higher ORR (OR: 2.79); all associations were significant.

CONCLUSION

Bone and/or liver metastases were associated with worse, while LN-confined metastases were associated with better outcomes in patients with aUC receiving ICI. These findings in a large population treated outside clinical trials corroborate data from trial subset analyses.

Molecular intricacies of upper tract urothelial carcinoma and their relevance for therapy considerations

PURPOSE OF REVIEW

The aim of this study was to give an overview of molecular alterations in upper tract urothelial carcinomas (UTUCs) and to discuss them in the context of current and prospective systemic therapies.

RECENT FINDINGS

UTUCs not only share a similar molecular landscape with urothelial carcinoma of the bladder (UCB), but also have distinct molecular features that can have an impact on therapy selection. FGFR3 alterations occur with a significant higher frequency in UTUC, with up to 40% of tumours harbouring FGFR3 driver mutations compared with 20% in UCB. In addition, a substantial number of high-grade UTUC show an immune-depleted phenotype and a luminal papillary expression subtype, thus predisposing them for FGFR inhibitor treatment. Approximately 20% of UTUC tumours have acquired mutations in TP53 and demonstrate a significant degree of genomic instability, which makes them candidates for systemic chemotherapy or immunotherapy. Whereas microsatellite instability (MSI) is rare in sporadic UTUC, 5-10% of UTUC patients have germline mutations in DNA mismatch repair genes, which leads to high MSI with enriched neoantigen load and presumably better response rates to immunotherapy.

SUMMARY

Treatment decisions in UTUC should take molecular tumour characteristics into account. The currently most therapy-relevant molecular alterations in UTUC comprise FGFR3 mutational status and mutations in DNA mismatch repair genes with concomitant microsatellite instability.

Immunotherapy and Sonpavde score validation in advanced upper tract urothelial carcinoma: a retrospective study by the Italian Network for Research in Urologic-Oncology

Background: Few data are available regarding the effectiveness of immune checkpoint inhibitors in advanced upper tract urothelial carcinoma (UTUC) patients. Methods: To provide a real-world experience with anti-PD-1/PD-L1-based therapy in UTUC patients, we involved an Italian network in a multicenter retrospective analysis. Results: A total of 78 UTUC patients were enrolled. The median follow-up was 25.1 months. The median progression-free survival (mPFS) was 2.2 months (95% CI 1.8-2.6), and the median OS (mOS) was 6.0 months (95% CI 3.6-8.4). The Sonpavde score (including performance status > 0, hemoglobin < 10 g/dl, liver metastases, time from prior chemotherapy ≥ 3 months) split the patients into three groups (0 vs 1 vs 2-4 factors), efficiently predicting the OS and PFS outcome at the multivariate analyses (p < 0.0001). Conclusion: The prognosis of unselected UTUC patients is still unsatisfactory. The Sonpavde score was validated for the first time in an UTUC population, as a useful tool for the treatment decision-making process.

Safety, Efficacy and Biomarker Analysis of Toripalimab in Patients with Previously Treated Advanced Urothelial Carcinoma: Results from a Multicenter Phase II Trial POLARIS-03

PURPOSE

Immunotherapy offers a second-line option for patients with metastatic urothelial carcinoma (mUC) who failed standard therapy, but the biomarkers for predicting response remain to be explored. This study aims to evaluate the safety, efficacy, and correlative biomarker of toripalimab in patients with previously treated mUC.

EXPERIMENTAL DESIGN

Patients with mUC received toripalimab 3 mg/kg Q2W. Clinical response was assessed every 8 weeks by an independent review committee per RECIST v1.1. Tumor PD-L1 expression, tumor mutational burden (TMB), and other biomarkers were evaluated.

RESULTS

Among the intention-to-treat population (n = 151), 85% of the patients experienced treatment-related adverse event (TRAE) and 20% experienced grade 3 and above TRAE. The objective response rate (ORR) was 26% with a disease control rate (DCR) of 45%. The median duration of response, progression-free survival (PFS) and overall survival (OS) were 19.7 months (95% CI: 13.9 to NE), 2.3 months (95% CI: 1.8 to 3.6) and 14.4 months (95% CI: 9.3 to 23.1), respectively. Both PD-L1+ and TMB-high (10 mutations/Mb as the cut off) patients had better ORR than PD-L1- patients (42% versus 17%, p = 0.002) and TMB low patients (48% versus 22%, p = 0.014), respectively. The TMB-high group also showed better PFS (12.9 versus 1.8 months, p < 0.001) and OS (not reached versus 10.0 months, p = 0.018) than the TMB-low group.

CONCLUSIONS

Toripalimab has demonstrated encouraging clinical activity in the second-line treatment of mUC with a manageable safety profile. PD-L1 expression and TMB were two independent biomarkers in the study.