Current Status of Targeted Therapy in Metastatic Transitional Cell Carcinoma of the Bladder

Everolimus and pazopanib (E/P) benefit genomically selected patients with metastatic urothelial carcinoma

BACKGROUND

Metastatic urothelial carcinoma (mUC) is a genomically diverse disease with known alterations in the mTOR pathway and tyrosine kinases including FGFR. We investigated the efficacy and safety of combination treatment with everolimus and pazopanib (E/P) in genomically profiled patients with mUC.

METHODS

mUC patients enrolled on a Phase I dose escalation study and an expansion cohort treated with E/P were included. The primary end point was objective response rate (ORR); secondary end points were safety, duration of response (DOR), progression-free survival (PFS) and overall survival (OS). Patients were assessed for mutations and copy number alterations in 300 relevant cancer-associated genes using next-generation sequencing and findings were correlated with outcomes. Time-to-event data were estimated with Kaplan-Meier methods.

RESULTS

Of the 23 patients enrolled overall, 19 had mUC. ORR was 21% (one complete response (CR), three partial responses (PR), eight with stable disease (SD). DOR, PFS and OS were 6.5, 3.6, and 9.1 months, respectively. Four patients with clinical benefit (one CR, two PR, one SD) had mutations in TSC1/TSC2 or mTOR and a 5th patient with PR had a FGFR3-TACC3 fusion.

CONCLUSIONS

Combination therapy with E/P is safe in mUC and select patients with alterations in mTOR or FGFR pathways derive significant clinical benefit.

Neoadjuvant and adjuvant chemotherapy approaches for invasive bladder cancer

Deeply invasive bladder cancer, representing approximately 20% of incident cases, is cured by radical cystectomy or radiotherapy in less than 50% of cases. In an effort to improve cure rates, based on objective response rates in metastatic disease of 40%-70% from combination chemotherapy regimens, systemic chemotherapy has been incorporated into programs of definitive treatment for this disease. Several randomized trials and a meta-analysis have confirmed a survival benefit from neoadjuvant chemotherapy followed by definitive local treatment, reflecting both median survival figures and cure rates. Despite several promising phase II trials, no randomized trial of classical adjuvant chemotherapy for bladder cancer has demonstrated an overall survival benefit, despite increments in disease-free survival. Molecular prognostication has been studied in an effort to improve the utility of systemic therapy for invasive non-metastatic bladder cancer, but randomized trials have not shown associated survival benefit. Despite level 1 evidence of a survival benefit from neoadjuvant MVAC (methotrexate, vinblastine, doxorubicin [Adriamycin], cisplatin) or cisplatin, methotrexate, and vinblastine (CMV) chemotherapy, more than 50% of incident cases do not receive such treatment.