Low Grade Non-Hodgkin's Lymphomas: Disease Control with Mitoxanthrone Monotherapy in Patients Refractory to Conventional Therapy

Abstract

Salvage treatment modalities for refractory low grade non-Hodgkin's lymphomas (LGNHL) are limited. In the present analysis we investigate the effectiveness of mitoxanthrone monotherapy in resistant LGNHL. Fourteen patients from our Unit were studied. Eligibility criteria were as follows: histologic type of LGNHL, performance status 0, 1 or 2, clinical stage II, III or IV, A or B and refractoriness to conventional chemotherapy. The treatment protocol provided intravenous infusion of mitoxanthrone 6 mg/m² daily for 3 days every three to four weeks. The median number of treatment cycles until now was 4 (1-8). A minimum of 3 cycles was necessary for documentation of response. For the staging and response of our patients well known criteria were used. The term minor response (MR) was introduced for those patients who had less than 50% disease regression. Of the 14 patients one could not be evaluated. Among the remaining 13, one achieved complete remission (CR) (7.7%), six partial remissions (PR) (46.2%), three MR (23%), two remained stable (SD) (15.4%) and one had disease progression (DP) (7.7%). Overall response rate (CR + PR) was 53.9%. Response to treatment was better in patients with less pretreatment (one-two prior treatments) than in heavily pretreated ones (more than three) and this relation was found to be statistically significant (p < 0.05). In addition it seems that follicular small cleaved or mixed lymphoma and patients with less bulky disease responded better, although these differences could not be documented as statistically significant. The follow up of our patients is too short for any meaningful conclusions about the duration of response to be drawn. Median survival after mitoxanthrone administration was 7 months (1-15 mo), with 6 patients still alive and 8 dead. Patients tolerated treatment without major toxicity. We conclude from our study that mitoxanthrone is effective as a single agent in multipretreated patients with refractory LGNHL. Even patients with MR or ST had some benefit from the treatment, considering the poor therapeutic alternatives available.

Key Words:

• low grade lymphoma
• mitoxanthrone
• refractory