As a natural expansion of their interest in using Navelbine® (vinorelbine) as a novel treatment for mesothelioma, researchers at the Department of Medical Oncology at St. Bartholomew's Hospital in London recently investigated the use of this chemotherapy drug in a clinical trial to determine its efficacy as a second-line treatment for mesothelioma patients who have relapsed after initial treatments.
Previously researchers from the same institute had examined vinorelbine as a first-line defense against malignant pleural mesothelioma (MPM) both singularly and combined with oxaliplatin. While single drug therapy showed promising results and low toxicity, the trial involving oxaliplatin showed similar results yet much higher incidences of side effects.
The study investigating the use of vinorelbine as a relapse treatment involved weekly administered doses of vinorelbine (30 mg/m(2)) over a period of six weeks. All of the 63 patients who took part in this clinical trial had previously been diagnosed with pleural mesothelioma, had been treated with conventional methods, and had experienced some success but had relapsed. The important factor was that none of the patients had previously been treated with vinorelbine.
First-line treatment of pleural mesothelioma had been shown to express success rates of up to 25%, either with progression-free survival or retardation of tumor growth. The majority of patients in previous clinical trials were males suffering from epithelioid mesothelioma.
In the current study, population percentages were similar but the results were quite different. Instead of nearly a quarter of patients responding positively, researchers observed that only 16% of the 62 patients actually responded at all. However, second-line treatment with vinorelbine was deemed a success in spite of the low response rate because survival averaged out at over 9 months. Keep in mind, these were patients who had already survived an initial bout with mesothelioma but had relapsed.
In addition, toxicity incidents remained low with relapsed patients as it had in previous trials with first-line patients. Indeed, the most prevalent side effect of second-line vinorelbine treatment was neutropenia (abnormally low white blood cell count.)
The researchers concluded that vinorelbine definitely deserves more attention when it comes to treatment of mesothelioma, both as a frontline and second-line therapy.
Source: The efficacy and safety of weekly vinorelbine in relapsed malignant pleural mesothelioma.