Current status and future perspectives in the treatment of low-grade non-Hodgkin's lymphomas

Randomized phase II study of concurrent and sequential rituximab and CHOP chemotherapy in untreated indolent B-cell lymphoma

CHOP combined with rituximab (R-CHOP) is regarded as one of the most effective treatments for indolent B-cell non-Hodgkin lymphoma (B-NHL), however, its optimal combination schedule remains unknown. We performed a randomized phase II study to explore a more promising schedule in untreated, advanced indolent B-NHL. Patients were randomized to receive either six courses of CHOP concurrently with rituximab (Arm C), or six courses of CHOP followed by six courses of weekly rituximab (Arm S). A total of 69 patients received the concurrent (n=34) or sequential (n=35) regimen. Overall response rate (ORR) in Arm C was 94% (95% confidence interval [CI], 79 to 99), including a 66% complete response (CR) compared with 97% (95% CI, 85-100), including a 68% CR in Arm S. Patients in Arm C experienced more grade 4 neutropenia (85%versus 70%) and experienced more grade 3 or greater non-hematological toxicities (21%versus 12%). Both arms were tolerated well. With a median follow-up of 28.2 months, the median progression-free survival (PFS) time was 34.2 months in Arm C, and was not reached in Arm S. R-CHOP is highly effective in untreated indolent B-NHL, either concurrent or in a sequential combination. Both combination schedules deserve further investigation.

High-dose therapy improves progression-free survival and survival in relapsed follicular non-Hodgkin's lymphoma: results from the randomized European CUP trial

PURPOSE

To determine, in a randomized clinical trial, whether high-dose therapy (HDT) followed by autologous stem-cell transplantation is more effective than standard treatment with regard to progression-free survival (PFS) and overall survival (OS) in patients with relapsed follicular non-Hodgkin's lymphoma; and to assess the additional value of B-cell purging of the stem-cell graft with regards to PFS and OS.

PATIENTS AND METHODS

Patients received three cycles of chemotherapy. Responding patients with limited bone marrow infiltration were eligible for random assignment to three further cycles of chemotherapy (C), unpurged HDT (U), or purged HDT (P).

RESULTS

Between August 1993 and April 1997, 140 patients were registered from 36 centers internationally, and 89 were randomly assigned. Reasons for not randomizing included patient refusal, early progression, or death on induction therapy. With a 69-month median follow-up, the log-rank P value for PFS and OS were.0037 and.079, respectively. For PFS, the hazard ratios (95% CIs) for U versus C, P versus C, and P versus U were 0.33 (0.16 to 0.70), 0.38 (0.19 to 0.79), and 1.02 (0.51 to 2.05), respectively. The hazard ratio (95% CI) for C versus U + P was 0.30 (0.15 to 0.61). Hazard ratios (95% CIs) for OS were 0.43 (0.18 to 1.06), 0.43 (0.18 to 1.02), and 0.72 (0.32 to 1.63). For C versus U + P, the hazard ratio (95% CI) was 0.40 (0.18 to 0.89). Kaplan-Meier estimates (95% CIs) of 2-year PFS for C, U, and P were 26% (8% to 44%), 58% (37% to 79%), and 55% (34% to 75%), respectively. OS at 4 years for C, U, and P are 46% (25% to 67%), 71% (52% to 91%), and 77% (60% to 95%) respectively.

CONCLUSION

HDT significantly improves PFS and OS. There is no clear evidence of benefit through purging.

Progress and promise in the treatment of indolent lymphomas

In the era of conventional alkylating agent-based chemotherapy, advanced stage indolent lymphoma has been considered incurable. The failure of our traditional therapies to cure these patients, coupled with the indolent course of the disease and the elderly population affected, has fostered a nihilistic attitude about the treatment of these diseases. Twenty years ago, in the absence of interesting alternatives to alkylating agents, judicious use and reuse of alkylators was perhaps the best we could do. There are now many reasons for optimism and excitement in the treatment of these diseases, including the availability of promising agents such as interferon-alpha, the nucleoside analogues, and rituximab. Radioimmunotherapy will also likely play a role in future therapy programs. Allogeneic stem cell transplantation is a high-risk approach that is not an option for all patients, but it has the potential to cure patients, even in the setting of relapse. Mini-allogeneic transplantation may permit an approach to allogeneic transplantation that is better tolerated than standard transplant strategies. In addition to these therapy options, biological insights have provided new options for monitoring patients. Molecular monitoring (polymerase chain reaction for bcl-2) is a stringent measure of short-term treatment efficacy, and one that correlates with durability of remission, i.e., it is a surrogate marker by which to judge treatment efficacy. There used to be a limited number of conventional treatment approaches, which consistently failed. The pendulum has swung. There are now many promising new options. It is time to plan and conduct trials that are geared for success.

Efficacy and toxicity of bendamustine in patients with relapsed low-grade non-Hodgkin's lymphomas

Low-grade non-Hodgkin's lymphomas (NHL) are very sensitive to a broad range of chemotherapeutic and biological agents. Relapses, however, occur even after aggressive cytostatic combinations in first-line therapy. Therefore, effective and well-tolerated salvage therapies are very important. In this single-institution trial, the efficacy and toxicity of bendamustine in the treatment of relapsed low-grade NHL was investigated. Fifty-eight patients with low-grade NHL pretreated with different cytostatic regimens were included. All patients received bendamustine at 120 mg/m(2) as a 1-h infusion on 2 consecutive days. The treatment was repeated every 3 weeks until complete remission (CR), partial remission (PR) or stable disease (SD) was confirmed on two consecutive cycles. Efficacy and toxicity were evaluated in 52 patients: CR was induced in 11%, PR in 62% and SD in another 10% of the patients. No response to treatment was seen in 17%. The median duration of remission was 16 months and the median survival time was 36 months. Side effects were generally mild, and restricted to myelosuppression, gastrointestinal toxicity and allergic reactions. Bendamustine proved to be very effective and was well tolerated in pretreated patients with relapsed or primary resistant low-grade NHL.

Low dose palliative radiotherapy in low grade non-Hodgkin's lymphoma

The clinical picture of disseminated (stage 3 and 4) low grade non-Hodgkin's lymphoma (NHL) is one of continuing relapse. Management options include observation only in asymptomatic patients, single agent chlorambucil or localised radiotherapy in patients with symptomatic nodal disease. Radiation doses of 25-40 Gray in 10-20 fractions have been the standard approach in low grade NHL, but in 1994 Ganem et al. [Hematol. Oncol. 8: 225-233, 1994] reported the use of low dose radiotherapy (LDRT)--4 Gray in 2 fractions over 3 days--for the palliation of symptomatic disease in patients with disseminated, chemoresistant low grade NHL. We describe here our early experience with this schedule.

MIB-1 and S-phase cell fraction predict survival in non-Hodgkin's lymphomas

The monoclonal antibody anti-Ki67 is used to detect proliferating cells, but its main limitation is the requirement of fresh-frozen material. On a series of patients with non-Hodgkin's lymphoma, we used a Ki67 equivalent monoclonal antibody, the recently proposed MIB-1, on formalin-fixed histopathological material using microwave antigen retrieval. MIB-1 expression was analysed in relation to other proliferation indices, such as autoradiographic H-thymidine labelling index (HTL1) and flow cytometric S-phase cell fraction (FCM-S) and to pathological status. Moreover, the prognostic relevance of the cell kinetic indices was defined in uni- and multivariate analyses including histology and tumour stage. The relationship between MIB-1 index and the other proliferation indices was statistically significant even though the correlation coefficient was around 0.6. The MIB-1 index was also related to the REAL (Revised European American Lymphoma) classification, but not to the Ann Arbor stage classification. Univariate analysis showed that the MIB-1 index was a significant predictor of 6-year survival in the overall series and in distinctly analysed low-grade and high-grade lymphoma subgroups. With regard to S-phase indices, HTLI was a powerful prognosticator in patients with high-grade histologies and FCM-S in patients with low-grade histologies. Multivariate analyses revealed that MIB-1 index, HTLI and FCM-S retained their prognostic significance independent of histology. In conclusion, the MIB-1 antibody provides prognostic information in non-Hodgkin's lymphomas and has the main advantage that it can be used in formalin-fixed, paraffin-embedded specimens.

Non-Hodgkin's lymphomas--current status of therapy and future perspectives

Non-Hodgkin's lymphomas (NHL) are a heterogeneous group of disorders which can either be classified according to their biology, represented by corresponding counterparts of normal lymphocyte development as in the Kiel classification, or according to their clinical course, used in the Working Formulation. The recently proposed Revised European-American Lymphoma (R.E.A.L.) classification may unify both aspects and facilitate the comparability of international studies. Besides histology, the extent of disease still comprises the major determinant of therapy. In high-grade lymphomas combination chemotherapy with cyclophosphamide, hydroxydaunorubin, vincristine and prednisone (CHOP) represents the treatment of first choice, and may be restricted to 3-4 cycles in patients with limited stages of the disease when followed by involved field radiotherapy. In more extended, bulky stage II to IV disease, treatment must be extended to six courses of CHOP and, potentially, additional irradiation. Even in advanced states of the disease, long-term remission and potential cure are achieved in 30-50% of cases. In low-grade lymphomas, most patients present with advanced stages III and IV for which chemotherapy can be applied with palliative intention only. Hence, a watch-and-wait approach still seems appropriate outside clinical investigations until the disease requires a therapeutic intervention. This consists preferentially of chemotherapy of moderate intensity such as cyclophosphamide, vincristine and prednisone (COP) or prednimustine and mitoxantrone (PmM). In responding patients, maintenance therapy with interferon-alpha is currently being explored and may result in prolongation of disease-free and, possibly also, overall survival. In both high- and low-grade lymphomas, intensification of therapy by myeloablative chemotherapy or combined chemoradiotherapy followed by autologous bone marrow transplantation (ABMT) or peripheral stem cell transplantation provides a promising and potentially curative prospective. In addition, new cytostatic agents such as the purine analogues--fludarabine, chlorodeoxyadenosine and deoxycoformycin--enlarge the therapeutic spectrum. More experimental approaches consist of the application of immunotoxins or radioisotypes, coupled to monoclonal antibodies directed against lymphoma-specific antigens. Overall, the substantial advances that have been achieved in the understanding of the biology and pathogenesis of malignant lymphomas, as well as the current achievements of therapy and the new promising perspectives, justify the hope that curative therapy can soon be offered to an increasing proportion of patients with NHL.