Organ-Specific Therapeutic Effect of Paclitaxel and Carboplatin Chemotherapy After Platinum-Based Chemotherapy and Pembrolizumab for Metastatic Urothelial Carcinoma

Prognostic and Predictive Factors in Advanced Urothelial Carcinoma Treated with Immune Checkpoint Inhibitors: A Review of the Current Evidence

In recent years, the treatment landscape of urothelial carcinoma has significantly changed due to the introduction of immune checkpoint inhibitors (ICIs), which are the standard of care for second-line treatment and first-line platinum-ineligible patients with advanced disease. Despite the overall survival improvement, only a minority of patients benefit from this immunotherapy. Therefore, there is an unmet need to identify prognostic and predictive biomarkers or models to select patients who will benefit from ICIs, especially in view of novel therapeutic agents. This review describes the prognostic and predictive role, and clinical readiness, of clinical and tumour factors, including new molecular classes, tumour mutational burden, mutational signatures, circulating tumour DNA, programmed death-ligand 1, inflammatory indices and clinical characteristics for patients with urothelial cancer treated with ICIs. A classification of these factors according to the levels of evidence and grades of recommendation currently indicates both a prognostic and predictive value for ctDNA and a prognostic relevance only for concomitant medications and patients' characteristics.

Clinical Outcomes of Mixed Response to Pembrolizumab in Advanced Urothelial Carcinoma After Platinum-based Chemotherapy

BACKGROUND/AIM

Despite the presence of a mixed response (MR) in patients with urothelial carcinoma (UC) who receive immune checkpoint inhibitors, the clinical outcome of these patient has not been reported. We evaluated the clinical outcome of MR to pembrolizumab for advanced UC.

PATIENTS AND METHODS

Advanced UC patients who received pembrolizumab after platinum-based chemotherapy failure with measurable disease in multiple organs were retrospectively analyzed.

RESULTS

Among 31 patients, MR [including progressive disease (PD)+complete response (CR) or partial response (PR)] was confirmed in 4 (12.9%). The median overall survival (OS) of the CR+PR (including CR+SD±PR), stable disease (SD), PD (including PD±SD) and MR groups was 16.0, 5.1, 5.4 and 4.3 months, respectively. There was no significant difference in the OS between the MR and CR+PR response groups (log-rank test, p=0.069).

CONCLUSION

A mixed response to pembrolizumab in advanced UC was not uncommon. Despite the non-significant difference in the OS between the mixed and CR+PR response groups, the OS of the MR group tended to be similar to that of the SD and PD response groups.

Organ-Specific Tumor Response to Pembrolizumab in Advanced Urothelial Carcinoma After Platinum-Based Chemotherapy

Background

To evaluate the organ-specific therapeutic effect of pembrolizumab after the failure of platinum-based chemotherapy for advanced urothelial carcinoma (UC).

Materials and Methods

Patients with advanced UC who received pembrolizumab after the failure of platinum-based chemotherapy and who had measurable disease were retrospectively analyzed. The objective response rate (ORR) and organ-specific response rate (OSRR) were evaluated according to Response Evaluation Criteria in Solid Tumors, version 1.1.

Results

We analyzed 69 patients (male, n=51; median age, 71 years) with 226 metastases. The ORR was 23.2%. In total, 32, 31, 16, 14, 13 and 7 patients had measurable lung (OSSR 31.3%), lymph node (OSSR 29.0%), local recurrence (OSSR 12.5%), primary tumor organ (OSSR 7.1%), liver (OSSR 23.1%) and bone (OSSR 28.6%) disease, respectively. The median overall survival (OS) for pembrolizumab was 10.9 months (95% confidence interval, 5.9‑13.7 months). Regarding organ-specific OS, a Log rank test significant differences in OS were confirmed between patients with and without primary tumor organ disease (p=0.046) and liver metastasis (p<0.001).

Conclusion

Metastases and primary tumor organ disease showed different tumor responses to pembrolizumab. The most prominent tumor response was found in lung metastasis and the least response was found in primary organ sites. The mechanisms of these different responses were unclear and there does not appear to be a constant trend between tumor shrinkage and OS in tumor sites. Further studies are needed.