Novel agents for muscle-invasive and advanced urothelial cancer

A single-arm, multicenter, open-label phase 2 study of lapatinib as the second-line treatment of patients with locally advanced or metastatic transitional cell carcinoma

BACKGROUND

The treatment of recurrent transitional cell carcinoma (TCC) remains an unmet clinical need. This study assessed lapatinib, a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and HER-2, as second-line therapy in patients with locally advanced or metastatic TCC.

METHODS

This was a single-arm, multicenter, open-label, prospective phase 2 study. Patients with TCC whose disease progressed on prior platinum-based chemotherapy received lapatinib until disease progression or unacceptable toxicity, with evaluations for response by Response Evaluation Criteria In Solid Tumors criteria performed every 8 weeks. The primary endpoint of the current study was objective tumor response rate. Secondary endpoints included safety, time to disease progression, and overall survival.

RESULTS

Fifty-nine patients were enrolled in the study, 25 of whom (42%) could not be evaluated for response. The primary endpoint of an objective response rate (ORR) >10% was observed in 1.7% (95% confidence interval [95% CI], 0.0%-9.1%) of patients; however, 18 (31%; 95% CI, 19%-44%) patients achieved stable disease (SD). The median time to disease progression and overall survival (OS) were 8.6 weeks (95% CI, 8.0 weeks-11.3 weeks) and 17.9 weeks (95% CI, 13.1 weeks-30.3 weeks), respectively. Clinical benefit (ORR and SD) was found to be correlated with EGFR overexpression (P = .029), and, to some extent, HER-2 overexpression. The median OS was significantly prolonged in patients with tumors that overexpressed EGFR and/or HER-2 (P = .0001). Lapatinib was well tolerated.

CONCLUSIONS

The study was considered to be negative because it did not meet its primary endpoint; however, further analysis demonstrated an improvement in OS in a subset of patients with tumors overexpressing EGFR and/or HER-2, which is encouraging and warrants further investigation.

Bladder cancer

PURPOSE OF REVIEW

To review the diagnosis and management of all stages of bladder cancer with an emphasis on studies and developments within the last year.

RECENT FINDINGS

Cystoscopy remains the mainstay in the detection and surveillance of bladder cancer, though fluorescent light may enhance detection as well as prolong recurrence-free survival. Urine cytology remains the gold standard for diagnosis and surveillance of bladder cancer; however, there are continued efforts in the development of urinary bladder cancer markers. Transurethral resection and instillation of perioperative chemotherapy remains the treatment of choice for superficial bladder cancer in most patients. Data supports the use of intravesical Bacillus Calmette-Guerin (including a maintenance regimen) for those at high risk for disease progression. Radical cystectomy with thorough pelvic lymphadenectomy remains the gold standard for management of muscle invasive disease. Research on the use of laparoscopy, robot-assisted laparoscopy, the effect on patient's health-related quality of life, and the potential role for bladder preservation strategies is ongoing. The value of neoadjuvant versus adjuvant chemotherapy around the time of cystectomy is still debated, though the best level-one evidence supports the use of neoadjuvant methotrexate, vinblastine, doxorubicin, and cisplatin followed by cystectomy. Platinum-based chemotherapeutic agents are most commonly used in the community setting. Work is ongoing to develop new regimens, especially in patients who cannot take cisplatin. Research in the development of targeted therapies alone or in combination with chemotherapeutic regimens continues and will hopefully broaden our treatment strategy for patients with advanced/metastatic disease.

SUMMARY

We are encouraged by the progress in bladder cancer diagnosis and management; however, continued research is needed in order to improve the lives of our patients with this disease.

Inactivation of p53 and Pten promotes invasive bladder cancer

Although bladder cancer represents a serious health problem worldwide, relevant mouse models for investigating disease progression or therapeutic targets have been lacking. We show that combined deletion of p53 and Pten in bladder epithelium leads to invasive cancer in a novel mouse model. Inactivation of p53 and PTEN promotes tumorigenesis in human bladder cells and is correlated with poor survival in human tumors. Furthermore, the synergistic effects of p53 and Pten deletion are mediated by deregulation of mammalian target of rapamycin (mTOR) signaling, consistent with the ability of rapamycin to block bladder tumorigenesis in preclinical studies. Our integrated analyses of mouse and human bladder cancer provide a rationale for investigating mTOR inhibition for treatment of patients with invasive disease.

Novel therapeutics in metastatic bladder cancer

BACKGROUND

Albeit transitional cell carcinoma of the urinary bladder is a chemosensitive neoplasm, metastatic disease is related with poor prognosis and short-term survival data.

OBJECTIVE

Cisplatin-based combination chemotherapy is recognised as the golden standard therapy for patients with inoperable locally advanced or metastatic bladder cancer. However, owing to treatment-related toxicities and short-response durations, novel treatment options or agents, with both enhanced efficacy and tolerability, have been sought.

METHODS

Reviewing the current status and addressing the future of novel anticancer therapeutics in metastatic urinary bladder cancer.

RESULTS/CONCLUSION

Non-platinum, single agents, such as gemcitabine and taxanes, as well as multidrug regimens in doublet or triplet chemotherapeutic combinations are regarded as promising alternatives. Dose intensification of conventional regimens, dose-dense sequential administration of new agents, the use of molecular markers for predicting chemosensitivity and the integration of biologically targeted agents to enhance chemotherapeutic efficacy are promising approaches.

Systemic therapy for unresectable and metastatic transitional cell carcinoma of the urothelium: first-line and beyond

PURPOSE OF REVIEW

The review aims to provide an overview of recent advances and future research direction in the management of patients with advanced transitional cell carcinoma.

RECENT FINDINGS

Early data of the randomized phase III study comparing paclitaxel, cisplatin, and gemcitabine with gemcitabine plus cisplatin for advanced urothelial cancer detected no survival difference. A phase II study investigated the safety and efficacy of trastuzumab, carboplatin, gemcitabine, and paclitaxel in human epidermal growth factor receptor-2/neu-positive advanced urothelial carcinoma and reported promising results. Renal-sparing regimens are under active development. A nonrandomized comparison of the 3-week with the 4-week schedule for gemcitabine and cisplatin showed that the 3-week schedule had less hematological toxicity and better dose intensity. Potential molecular markers such as excision repair cross-complementation group 1, emmprin, and survivin for survival and/or platinum resistance in patients with transitional cell carcinoma showed promise.

SUMMARY

Recent data do not support change in the current standard of care for advanced transitional cell carcinoma. Clinical testing of emerging anticancer therapies using new agents, new combinations, and new approaches is under active investigation. Rational combination and new strategy in clinical trial design are critical for new drug development for transitional cell carcinoma.