Phase II trial of temozolomide for leptomeningeal metastases in patients with solid tumors

There is a current unmet medical need for treatment of leptomeningeal metastases (LMD). To analyze the efficacy and safety of systemic temozolomide (TMZ) for first-line treatment of patients with LMD associated with solid tumors, a phase II, non-randomized, multicenter, prospective study was conducted. The planned duration of treatment was a maximum of six cycles (24 weeks) or until unacceptable toxicity was reported. One cycle of oral TMZ (100 mg/m² daily) consisted of one week on treatment/one week off treatment for four weeks. The study was stopped early because of poor accrual. Nineteen patients (median age 51(33–72); 32 % male) were enrolled. The LMD source was breast cancer (53 %) and non-small-cell lung cancer (37 %). Previous treatment was chemotherapy (100 %), surgery 74 %, radiotherapy 79 %, and hormone therapy 42 %. The average last dose of TMZ received by patients was 171 mg and only one patient required dose reduction. Three of 19 patients (15.8 %) had clinical benefit and 16 of 19 patients (84.2 %) progressed. Of the two patients completing the study (six cycles, 24 weeks), one had a partial response and the other stable disease. Median survival was 43 days (95 % CI 28.7–57.3); there were 18 deaths. Median TTP was 28 days (95 % CI 14–42). The most common adverse event was vomiting (52.6 %); nine patients (47.4 %) reported at least one serious adverse event but only one episode of thrombocytopenia was drug related. Median Karnofsky score remained at or above 70 % throughout the study, and was 75 % at the end of the study. First-line TMZ was well tolerated, and did not adversely affect the quality of life of patients with LMD. Future studies are needed to verify the efficacy results of this pilot trial.