Combined treatment with pemetrexed and vinflunine in patients with metastatic urothelial cell carcinoma after prior platinum-containing chemotherapy - results of an exploratory phase I study

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.

Safety and Activity of Sorafenib in Addition to Vinflunine in Post-Platinum Metastatic Urothelial Carcinoma (Vinsor): Phase I Trial

Lessons Learned.

First trial to report safety and activity of the microtubule inhibitor vinflunine plus the tyrosine kinase inhibitor sorafenib in post‐platinum metastatic urothelial cancer (mUC) patients.

A recommended phase II dose was identified for the treatment combination of vinflunine plus sorafenib, with main adverse events including fatigue, febrile neutropenia, neutropenia, hypertension, and hyponatremia.

An overall response rate of 41% to second‐line vinflunine plus sorafenib treatment in patients with platinum‐resistant mUC was confirmed.

Background.

Platinum‐progressive metastatic urothelial carcinoma (mUC) is a clinical challenge. The tyrosine kinase inhibitor sorafenib has demonstrated varied activity in mUC. This trial was designed to examine safety and activity of vinflunine plus sorafenib in mUC.

Methods.

In addition to standard dose of vinflunine (320 or 280 mg/m²), patients received sorafenib (400, 600, or 800 mg/day), in a 3 + 3 dose‐escalation phase I design.

Results.

Twenty‐two patients (median age 62.5 years) were included. Five patients received vinflunine 320 mg/m² and 17 received 280 mg/m². The maximum tolerated dose (MTD) of sorafenib with vinflunine 280 mg/m² was 600 mg, and with vinflunine 320 mg/m² it was not determined, owing to toxicity. Adverse events (AEs) grades 3 + 4 consisted of neutropenia (6 patients), febrile neutropenia (5), and hyponatremia (5). The overall response rate (ORR) in the efficacy‐evaluable patients was 41% (7 of 17), all partial responses evaluated by RECIST version 1.1. Median overall survival (OS) was 7.0 months (1.8–41.7).

Conclusion.

The defined recommended phase II dose (RPTD) was vinflunine 280 mg/m² plus sorafenib 400 mg. Sorafenib was too toxic in combination with vinflunine 320 mg/m². The ORR of 41% to this second‐line combination treatment of mUC is noteworthy and supports further trials.

Safety of Vinflunine in Patients with Advanced Urothelial Carcinoma Refractory to Platinum-based Chemotherapy: A Prospective Pilot Study

BACKGROUND

Several single chemotherapeutic agents have been evaluated as the second-line treatment of advanced urothelial carcinoma. Despite encouraging efficacy outcomes, toxicity has often led to dose modifications or discontinuation. We aimed to assess the safety of vinflunine in a particular population of advanced transitional cell carcinoma of urothelium (TCCU), that were exposed to the previous toxicity of chemotherapy.

METHODS

This is an open-label, prospective, single-center pilot study to evaluate the response rate and safety profile of vinflunine in patients with advanced TCCU. It was planned to enroll 25 evaluable patients. Eligible patients are those with progressive disease after first-line platinum-based regimen for advanced or metastatic disease.

RESULTS

The study was prematurely closed due to two sudden deaths that were judged by the review board as treatment-related. Only ten patients were evaluated and received at least one cycle of vinflunine. All but one were male and seven underwent radical surgery. Eight had a distant metastasis (mainly lung and/or liver). Disease control rate was 40%, four patients had a partial response with median duration of response of 3.5 months. The median overall survival was 3.2 months (95% CI:1.67- 4.73). There were three serious adverse events namely two sudden deaths and one grade 4 thrombocytopenia. Nine grade 3/4 adverse events occurred. The most common all-grade adverse events were fatigue (50%), constipation (40%) and vomiting (40%). Moreover, grade 3 fatigue occurred in 30% of patients. Only one patient, who achieved PR for 5 months, was fit to receive further cytotoxic chemotherapy.

CONCLUSION

The activity of vinflunine in advanced urothelial carcinoma came at the expense of its safety. The use of vinflunine has to be limited to the selected group of patients. However, this is a single institute experience in a limited number of patients.