Difference of oncological efficacy between two immune checkpoint inhibitors following first-line platinum-based chemotherapy in patients with unresectable, metastatic, advanced urothelial carcinoma: a multicenter real-world Japanese cohort.

BACKGROUND: Maintenance avelumab is currently recommended for patients with unresectable and/or metastatic (mUC) achieving at least stable disease (SD) on first-line platinum-based chemotherapy (1L-CT). Pembrolizumab is an alternative therapeutic avenue for this patient cohort in clinical practice. We investigated real-world data, focusing on the correlation between response to 1L-CT and oncological efficacy of subsequent immune checkpoint inhibitor (ICI) therapy with avelumab or pembrolizumab. METHODS: A multicenter database registered 626 patients with mUC diagnosed from 2008-2023; among these, 175 receiving 2-6 cycles of 1L-CT followed by ICI therapy. Patients were categorized based on response to 1L-CT using the Response Evaluation Criteria in Solid Tumors (v1.1). Objective response rate on ICI, progression to ICI-free survival (ICI-PFS), and overall survival from start of 1L-CT were compared between avelumab-treated and pembrolizumab-treated patients in each response subgroup. RESULTS: ICI-PFS was significantly longer in patients achieving partial response on 1L-CT and subsequently receiving pembrolizumab compared to those receiving avelumab. Notably, patients achieving SD on 1L-CT and subsequently receiving pembrolizumab manifested significantly higher objective response rate (14% and 41%, respectively) and prolonged ICI-PFS relative to those receiving avelumab. In contrast, overall survival did not delineate difference between patients treated with avelumab versus pembrolizumab. Similar findings were discerned in the subanalysis of patients having favorable SD (tumor shrinkage, from - 29 to 0%) and unfavorable SD (tumor enlargement, from + 1 to + 19%) on 1L-CT. CONCLUSIONS: Our study provides real-world evidence regarding difference of oncological efficacy between maintenance avelumab and subsequent pembrolizumab in patients with mUC who achieved partial response or SD on 1L-CT.

[A Case of Refractory Intermittent Hematuria that Occurred during Paclitaxel/Ramucirumab Combination Therapy for Metastatic Gastric Cancer].

A 76-year-old male patient developed right hydronephrosis due to peritoneal and retroperitoneal dissemination after surgery for gastric cancer. A ureteral stent was inserted, and systemic chemotherapy was introduced for metastatic gastric cancer. Disease progression was observed, and paclitaxel/ramucirumab combination therapy was started as the second-line treatment. After seven courses, severe gross hematuria appeared intermittently, and refractory epistaxis was observed concurrently. No hemorrhagic lesion was found in the imaging test and urethrocystoscopy. The patient received conservative treatment, such as blood transfusion, and further examination was planned. However, hematuria and epistaxis resolved spontaneously during the course of treatment. From the clinical course, it was thought to be a hemorrhagic adverse event due to ramucirumab, and the patient's treatment was therefore changed to another drug. The patient recovered without recurrence of gross hematuria.

Response to Pembrolizumab After Dose-Reduced Cisplatin Plus Gemcitabine Chemotherapy Is Inferior to That After Carboplatin Plus Gemcitabine Chemotherapy in Cisplatin-Unfit Patients With Advanced Urothelial Carcinoma.

INTRODUCTION: Response to pembrolizumab after first-line chemotherapy is vital to prolonged survival in advanced, unresectable, and/or metastatic urothelial carcinoma (aUC). However, there are sparse clinical data on host-tumor immune modification by first-line platinum-based chemotherapy. This study investigated the association between response to first-line gemcitabine plus cisplatin (GC) or carboplatin (GCarbo) chemotherapy and response to subsequent pembrolizumab treatment. PATIENTS AND METHODS: A multicenter-derived database registered 454 patients diagnosed with aUC between 2008 and 2020. Of these, 108 patients who received first-line GC or GCarbo followed by second-line or later pembrolizumab were eligible for investigation and were classified into 3 groups: 48 receiving full-dose GC, 21 receiving dose-reduced GC, and 39 receiving GCarbo. Overall survival (OS) was calculated using the Kaplan-Meier method and compared using the log-rank test. Possible factors associated with the response to pembrolizumab were evaluated using binary logistic regression methods. RESULTS: The rate of patients undergoing surgical removal of the primary organ was higher and creatinine clearance was lower in the dose-reduced GC and GCarbo groups than in the full-dose GC groups. Pembrolizumab responders had significantly better survival benefits than nonresponders. The rate of pembrolizumab responders was much higher in first-line chemotherapy responders than in first-line chemotherapy nonresponders. In contrast to the full-dose GC and GCarbo groups, the pembrolizumab responder rate was lower, and no association was observed between response to first-line chemotherapy and response to pembrolizumab in the dose-reduced GC group. CONCLUSION: Cisplatin and carboplatin may play an important role in the antitumor immune response, which could impact the outcome of subsequent pembrolizumab treatment. Given that the rate of response to pembrolizumab after dose-reduced GC chemotherapy was relatively low, this regimen is not recommended for cis-unfit patients with aUC. Further studies are required to understand the mechanisms responsible for the cross-reactivity of platinum and immune checkpoint inhibitors.