German Cancer Society Neuro-Oncology Working Group NOA-03 multicenter trial of single-agent high-dose methotrexate for primary central nervous system lymphoma.

The prospective multicenter NOA-03 trial, conducted by the Neuro-Oncology Working Group (NOA) of the German Cancer Society, was initiated to define the feasibility and efficacy of single-agent high-dose methotrexate therapy without concomitant radiotherapy in immunocompetent patients with primary central nervous system lymphoma. Thirty-seven patients (median age, 60 years) received 179 biweekly courses of 8 g/m2 methotrexate. Response was assessed after 3 and 6 courses. We had planned to enter 105 patients into the trial. Since fewer than the projected 18 of 37 patients achieved a complete response after an intermediate analysis, the trial was closed. In intention-to-treat analysis, 11 of 37 patients (29.7%) achieved complete response, whereas 14 of 37 patients (37.8%) were found to have progressive disease. The median relapse-free survival among complete response patients was 13.7 months. Multivariate logistic regression analysis revealed that corticosteroid application during the first methotrexate course was associated with complete response. The regimen was well tolerated, but, unlike previously reported results, the activity of high-dose methotrexate was only moderate.