Vinflunine maintenance shows promise in advanced urothelial carcinoma
medwireNews: Maintenance therapy with vinflunine plus best supportive care significantly delays disease progression over best supportive care alone in patients with transitional cell carcinoma of the urothelial tract, study data show.
The 87 Spanish patients included in the study had all achieved disease control with first-line cisplatin and gemcitabine chemotherapy and were randomly assigned to receive vinflunine 320 mg/m2 or 280 mg/m2 (based on Eastern Cooperative Oncology Group performance status, age, previous pelvic radiotherapy, creatinine clearance, and liver metastases) every 21 days plus best supportive care, or best supportive care alone.
After a median follow-up period of 15.6 months, 66% of 44 patients in the vinflunine group and 84% of 43 patients in the best supportive care group had disease progression, and 55% and 74% had died, respectively.
Joaquim Bellmunt (Harvard Medical School, Boston, Massachusetts, USA) and colleagues report that median progression-free survival was 6.5 months in the vinflunine group, which exceeded the predefined acceptable threshold of 5.3 months, and was significantly greater than the 4.2 months achieved in the best supportive care group (hazard ratio=0.59).
In addition, 21% of patients in the vinflunine group and 7% in the best supportive care group achieved objective responses, but the researchers note that the response seen in the latter group was likely due to late effects of cisplatin and gemcitabine. Disease control was achieved in 80% and 55%, respectively.
Writing in The Lancet Oncology, Bellmunt and co-authors also report that “[v]influnine maintenance had an acceptable safety profile.”
They found that the only grade 3 or 4 adverse events occurring in more than 5% of patients were neutropenia, asthenia or fatigue, and constipation, all of which “were manageable.” But there was one treatment-related death from pneumonia in a patient in the vinflunine group.
Overall, the researchers conclude: “Vinflunine maintenance therapy for patients with advanced transitional-cell carcinoma of the urothelial tract seems to improve progression-free survival compared with that in patients who receive best supportive care alone and might have a safety profile superior to that of second-line treatment with vinflunine.”
However, editorialist Robert Dreicer (University of Virginia, Charlottesville, USA) points out that in addition to the treatment-related death, 11 patients in the vinflunine group discontinued therapy because of adverse events or the patient’s preference. “These findings raise the question of whether a 2.3 month improvement in progression-free survival is clinically meaningful when data are unavailable to inform fully the question of early versus late use of vinflunine,” he writes.
Dreicer continues: “Thus, although [the researchers] must be congratulated on completing this well designed trial, the usefulness of the data for a management framework that is undergoing explosive change due to the rapid emergence of immune-checkpoint inhibitors remains unclear.”
Indeed, Bellmunt et al agree that further studies are needed “to better establish the role of vinflunine as maintenance therapy,” and they say that these should include combinations with emerging immunotherapeutics.
By Laura Cowen
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