Clinical Activity of Vinflunine in Transitional Cell Carcinoma of the Urothelium and Other Solid Tumors

Ceric ammonium nitrate-promoted oxidative coupling reaction for the synthesis and evaluation of a series of anti-tumor amide anhydrovinblastine analogs

A new, practical and efficient method for the synthesis of anhydrovinblastine AVBL (1f) by oxidative coupling of vindoline and catharanthine in the presence of ceric ammonium nitrate (CAN) was developed. Under the optimized reaction conditions, we synthesized a new series of amide anhydrovinblastine analogs substituted at the vindoline moiety of C-23 site and, evaluated for their proliferation inhibition against HeLa cell. The aryl-substituted derivatives showed loss of potency, while alkyl-substituted derivatives retained some of its cytotoxic potency. The iso-butylamide compound 10b and 2-furancorboxamide compound 18b displayed a similar cytotoxic potency compared to the positive control AVBL.

Vinflunine in the treatment of advanced bladder cancer

Accounting for 14,000 deaths in the USA last year, research informs us that advanced bladder cancer is a lethal disease with a median survival that has remained a little over 1 year for the past two decades. For the majority of patients with metastatic disease, chemotherapy with cisplatin-based combinations is the standard first-line treatment. Although initial response rates are high, disease progression is common, creating a growing number of patients in need of effective second-line chemotherapy. For this population, no standard of care currently exists. Salvage chemotherapy is associated with low response rates and studies exploring potential clinical benefit over supportive care alone are limited to nonrandomized Phase II trials. Vinflunine, a novel anti-mitotic drug from the Vinca alkaloid class, is the first and only agent that has been compared with supportive care in the second-line setting. In Europe, vinflunine is approved as a treatment option for patients with advanced urothelial cancer who have failed a prior platinum-containing regimen. To date, in the USA, there is no FDA-approved second-line chemotherapy for patients with metastatic bladder cancer and treatment continues to emphasize patient enrollment into a clinical trial.

[Systemic chemotherapy for bladder cancer: news in 2009]

This review summarizes the results of first-line and second-line systemic chemotherapy for advanced urothelial carcinoma as well as data from adjuvant and neoadjuvant trials for locally advanced bladder cancer. Whereas conventional systemic chemotherapy prevailed for over two decades, targeted therapeutics have been introduced to treat urothelial cancer during recent years. As in other tumor entities, molecular profiling will presumably emerge in the future as a means to tailor individual therapy.

Ready for a comeback of natural products in oncology

Since the late 1990s and the rapid expansion of monoclonal antibodies and synthetic protein kinase inhibitors in oncology, anticancer natural products fell out of fashion with the pharmaceutical industry. But in 2007 with the approval of three new drugs derived from natural products, the emergence of promising antitumor compounds from microorganisms (e.g. alvespimycin, salinosporamide) and the growing importance of new formulations of known natural product-derived drugs (nanoparticle formulations, oral forms), we are witnessing a new wave for natural products in oncology. The recent approval of the microtubule-targeted epothilone derivative ixabepilone (Ixempra), the DNA-alkylating marine alkaloid trabectedin (Yondelis) and the inhibitor of mTOR protein kinase temsirolimus (Torisel) is emblematic of the evolution of the field which combines the long established finding of conventional cytotoxic agents and the emergence of molecularly targeted therapeutics. These three examples also illustrate the increasing importance of microbial sources for the discovery of medically useful natural products. The contribution of innovative biological targets is also highlighted here, with references to proteasome inhibitors and novel approaches such as manipulation of mRNA splicing. Altogether, these observations plead for the return of natural products in oncology.

Synthesis and SAR of vinca alkaloid analogues

Versatile intermediates 12'-iodovinblastine, 12'-iodovincristine and 11'-iodovinorelbine were utilized as substrates for transition metal based chemistry which led to the preparation of novel analogues of the vinca alkaloids. The synthesis of key iodo intermediates, their transformation into final products, and the SAR based upon HeLa and MCF-7 cell toxicity assays is presented. Selected analogues 27 and 36 show promising anticancer activity in the P388 murine leukemia model.

Vinflunine in the treatment of bladder cancer

Vinflunine (VFL) is a third-generation bifluorinated semi-synthetic vinca alkaloid obtained by superacidic chemistry from its parent compound, vinorelbine. As with the other vinca alkaloids, the main antineoplastic effects of VFL arise from its interaction with tubulin, the major component of microtubules in mitotic spindles. In contrast to other vinca alkaloids, VFL shows some distinctive properties in terms of tubulin binding, possibly explaining its superior antitumor activity in vitro and in vivo compared with vinorelbine as well as its excellent safety profile. In transitional cell carcinoma (TCC), two single-agent phase II trials were performed testing VFL in platinum-pretreated patients, showing moderate response rates and promising disease control rates. Therefore, the first phase III trial in modern times for second-line TCC of the urothelium was designed in order to further investigate the activity of VFL. First results were presented at the 2008 ASCO conference. VFL appears to be a possible treatment option for patients with TCC progressing after first-line platinum-containing chemotherapy.