Paclitaxel and carboplatin chemotherapy after platinum-based chemotherapy and pembrolizumab for metastatic urothelial carcinoma

Durable Response to Enfortumab Vedotin Compared to Re-challenging Chemotherapy in Metastatic Urothelial Carcinoma After Checkpoint Inhibitors

BACKGROUND

Enfortumab vedotin (EV), an antibody-drug conjugate targeting Nectin-4, has been used for patients with metastatic urothelial carcinoma (mUC) after progressing on checkpoint inhibitors (CPIs). Re-challenging chemotherapy with platinum agents and continuing CPIs beyond progressive disease (PD) have often been chosen following PD on CPIs, and several studies indicate favorable treatment effects of re-challenging chemotherapy. There is little evidence for comparing EV and re-challenging chemotherapy in real-world clinical practice.

OBJECTIVE

The aim was to reveal the real-world treatment outcomes of EV, re-challenging chemotherapy, and continuing CPIs beyond PD in mUC patients.

PATIENTS AND METHODS

A multi-institutional dataset of 350 mUC patients treated with CPIs was utilized. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and duration of response (DOR) were evaluated to compare the treatment arms.

RESULTS

One hundred and nine mUC patients were treated with EV with a median follow-up of 6.4 months. The ORR and disease control rate (DCR) were 48% and 70%, respectively. The OS from PD on pembrolizumab exhibited significant differences among the three groups, with a median OS of 8, 14, and 29 months in continuing pembrolizumab beyond PD, re-challenging chemotherapy, and EV, respectively. When comparing the survival outcomes from the initiation of the treatment, there is neither a difference in OS (p = 0.124), PFS (p = 0.936), nor ORR (p = 0.816) between EV and re-challenging chemotherapy. Notably, the DOR in patients who achieved an objective response was significantly longer in the EV group than the re-challenging chemotherapy group (a median of 11 and 5 months, p = 0.049). For OS, the difference was not statistically significant (27 and 11 months in EV and re-challenging chemotherapy, respectively: p = 0.05).

CONCLUSIONS

A superior effect of EV on patient survival compared to re-challenging chemotherapy and continuing pembrolizumab beyond PD was observed in our real-world analysis, which is attributed to the durable DOR in EV treatment despite the similar ORR to re-challenging chemotherapy.

Re-challenging chemotherapy after pembrolizumab in platinum-refractory urothelial carcinoma

OBJECTIVES

To assess the real-world clinical benefit of re-challenging chemotherapy after pembrolizumab in patients with metastatic urothelial carcinoma (mUC), as there have been several reports suggesting that programmed cell death protein-1/programmed death-ligand 1inhibitors can restore platinum sensitivity.

PATIENTS AND METHODS

Of 236 patients treated with pembrolizumab, we excluded 45 patients who did not experience progressive disease (PD) for pembrolizumab during the follow-up and 86 patients who discontinued pembrolizumab by the diagnosis of PD followed by the best supportive care. A total of 105 patients were identified for a logistic regression propensity score model to compare the survival outcomes between patients treated with continuing pembrolizumab (80) and re-challenging chemotherapy (25) after the diagnosis of PD for pembrolizumab.

RESULTS

A median overall survival (OS) from PD for pembrolizumab was 11 months in 105 patients. Of 25 patients treated with re-challenging chemotherapy, platinum-including chemotherapy (gemcitabine and cisplatin; gemcitabine/cisplatin/paclitaxel [GCP]; methotrexate and vinblastine and adriamycin and cisplatin; and methotrexate and carboplatin and vinblastine MCAVI) was offered in 20 patients (80%). The objective response rate (ORR) for the first-line chemotherapy in the 105 patients was 30%, with a comparable ORR in 25 patients treated with re-challenging chemotherapy of 28%. GCP as a re-challenging regimen was offered in 12 of 25 (48%) patients. The ORR for the GCP regimen was 50%. Propensity score matching was performed using putative clinical factors, from which 34 patients were identified as pair-matched groups. The OS for patients treated with re-challenging chemotherapy was significantly longer than continuing pembrolizumab (a median of 13.9 and 5.8 months, respectively: P = 0.048).

CONCLUSION

Re-challenging chemotherapy including platinum agents after PD with pembrolizumab offers clinical benefits in patients with mUC.

Elucidation of Novel Molecular Targets for Therapeutic Strategies in Urothelial Carcinoma: A Literature Review

Urothelial carcinoma therapy is a rapidly evolving and expanding field. Traditional cytotoxic chemotherapy regimens have not produced optimal long-term outcomes, and many urothelial cancer patients have comorbidities that disqualify them as chemotherapy candidates. In recent years, a plethora of novel therapeutic agents that target diverse molecular pathways has emerged as alternative treatment modalities for not only metastatic urothelial carcinoma, but also for muscle-invasive bladder cancer and non-muscle invasive bladder cancer in adjuvant and definitive settings. This review paper aims to discuss the various categories of therapeutic agents for these different types of urothelial cancer, discussing immunotherapy, antibody-drug conjugates, kinase inhibitors, CAR-T cell therapy, peptide vaccination, and other drugs targeting pathways such as angiogenesis, DNA synthesis, mTOR/PI3K/AKT, and EGFR/HER-2.