Phase I study of fludarabine and paclitaxel for the treatment of low-grade non-Hodgkin's lymphoma

Combinations of mTORC1 inhibitor RAD001 with gemcitabine and paclitaxel for treating non-Hodgkin lymphoma

Single-agent mammalian target of rapamycin complex 1 (mTORC1) inhibitors have recently been reported as effective salvage treatment in non-Hodgkin lymphoma (NHL). The combined effect of mTORC1 inhibitor, RAD001, with chemotherapeutic agents used for relapsed or refractory NHL was examined. Synergistic interactions were observed for RAD001 plus gemcitabine or paclitaxel in six NHL cell lines; enhanced gemcitabine- and paclitaxel-induced caspase-dependent apoptosis associated with down-regulation of mTOR signaling was detected. Synergistic interactions were also observed with RAD001 plus gemcitabine and paclitaxel. In conclusion, synergistic cytotoxicity was observed with RAD001 plus gemcitabine and paclitaxel in NHL cells. Combination therapy with these three drugs should be examined in patients with refractory or relapsed NHL.

Follicular lymphomas--a review of treatment modalities

Follicular lymphoma is the most common low-grade non Hodgkin's lymphoma and represent an homogeneous entity as defined by pathological, molecular and clinical data. This indolent disease is characterised by a slow growth pattern with possible spontaneous regression, is often disseminated but remains incurable with available treatments when disseminated. For localised stages, involved field radiotherapy remains the standard choice but other approaches remain to be investigated. In advanced disease, chemotherapy has been demonstrated to produce high response rates but recent trials with new treatment strategies including interferon and monoclonal antibodies may improve the current situation. In this article, we will review treatment of follicular lymphomas, specially emphasising published phase III trials.

In vitro cytotoxic effects of fludarabine (2-F-ara-A) in combination with commonly used antileukemic agents by isobologram analysis

Fludarabine phosphate (2-F-ara-AMP) is an adenine nucleoside analogue that shows significant activity against chronic lymphocytic leukemia and indolent lymphoma. We assessed the cytotoxic interaction produced by the combination of the active metabolite of fludarabine phosphate, fludarabine (9-beta-D-arabinofuranosyl-2-fluoroadenine, 2-F-ara-A), and some commonly used antileukemic agents against human hairy cell leukemia cell line JOK-1, human chronic lymphocytic leukemia cell line SKW-3, and adult T cell leukemia cell lines ED-40810 (-) and SALT-3. The leukemia cells were exposed simultaneously to 2-F-ara-A and to the other agents for 4 days. Cell growth inhibition was determined using MTT reduction assay. The isobologram method of Steel and Peckham was used to evaluate the cytotoxic interaction. 2-F-ara-A and cytarabine showed synergistic effects in SKW-3 cells, additive and synergistic effects in JOK-1 and SALT-3 cells, and additive effects in ED-40810(-) cells. 2-F-ara-A and doxorubicin showed additive effects in SKW-3, ED-40810(-) and SALT-3 cell lines, and additive and synergistic effects in JOK-1 cells. 2-F-ara-A showed additive effects with etoposide, 4-hydroperoxy-cyclophosphamide, and hydroxyurea in all four cell lines. 2-F-ara-A showed antagonistic effects with methotrexate and vincristine in all four cell lines. Our findings suggest that the simultaneous administration of fludarabine phosphate with cytarabine, doxorubicin, etoposide, cyclophosphamide, or hydroxyurea would be advantageous for cytotoxic effects. Among these agents, cytarabine may be the best agent for the combination with fludarabine phosphate. The simultaneous administration of fludarabine phosphate with methotrexate or vincristine would have little cytotoxic effect, and this combination may be inappropriate. These findings may be useful in clinical trials of combination chemotherapy with fludarabine phosphate and these agents.

Fludarabine, cyclophosphamide, and dexamethasone (FluCyD) combination is effective in pretreated low-grade non-Hodgkin's lymphoma

PURPOSE

Fludarabine phosphate is effective as a single agent in low-grade non-Hodgkin's lymphoma (NHL). Combined with other antineoplastic agents it enhances the antitumor effect. Our aim was to define the therapeutic efficacy and toxicity of a combination of fludarabine, cyclophosphamide and dexamethasone (FluCyD) in patients with advanced low-grade lymphoma.

PATIENTS AND METHODS

Twenty-five adults with pretreated advanced-stage low-grade NHL were treated with three-day courses of fludarabine 25 mg/m2/day, cyclophosphamide 350 mg/m2/day, and dexamethasone 20 mg/day, every four weeks for a maximum of six courses.

RESULTS

Of the 25 patients, 18 (72%) responded, 8 (32%) achieving CR and 10 (40%) PR. Seven were failures. The median follow-up was 21 months (5-26). Eight CR patients remain in CR after 5-21 months. Of 10 PR patients, 3 are in continuous PR without further treatment after 12, 17 and 18 months. Myelosuppression was the most prevalent toxic effect. Although severe granulocytopenia (granulocyte count nadir < 500/microliter) and thrombocytopenia (platelet count nadir < 50,000/microliter) occurred in only 10% and 16% of courses, respectively, slow granulocyte or platelet count recovery caused delay of 40% of the courses. Nine patients (36%) required discontinuation of therapy because of persistent granulocytopenia and/or thrombocytopenia: three after one course, three after 2-4 courses, and three after five courses. Thirteen infectious episodes in 11 patients complicated 11% of courses. Two of 10 patients monitored for the circulating EBV load showed increased viral load. One of these developed aggressive lymphoma. CD4+ lymphocytes declined from a pre-therapy median value of 425/microliter to 141/microliter post-treatment (P = 0.001). Non-hematologic toxicities were rare and mild.

CONCLUSIONS

The combination of fludarabine with cyclophosphamide and dexamethasone is effective in pretreated advanced-stage low-grade NHL. It may broaden the range of therapeutic options in the salvage treatment of these patients. The main toxicity of this combination is prolonged myelosuppression that may cause treatment delay or withdrawal. The benefit of adding granulocyte colony-stimulating factor, particularly in patients with poor marrow reserve, needs to be investigated.

Divergent effect of taxol on proliferation, apoptosis and nitric oxide production in MHH225 CD34 positive and U937 CD34 negative human leukaemia cells

Paclitaxel (Taxol) has been shown to be clinically effective in treatment of patients with breast and ovarian cancer. It has also shown promising results in various other solid tumours. Paclitaxel has induced apoptosis in the G2/M phase of the cell cycle in both HL-60 and U937 human leukaemia cells. A recent study has shown a dose-dependent cytotoxicity for both taxanes: paclitaxel (taxol) and docetaxel (Taxotere) on fresh leukaemia cells in primary culture from 16 ALL and four AML patients and proposed their use in treatment of acute leukaemia patients. AML is a heterogeneous disease in which malignant transformation and disease progression occur at the level of CD34 positive cells. Also, the multi-drug resistance gene product, P-glycoprotein is expressed only in CD34 positive AML cells. Therefore, an in vitro evaluation of the efficacy of paclitaxel, a P-glycoprotein substrate, in CD34 positive AML cells is warranted before considering its clinical use in acute leukaemia patients. Since all in vitro studies of paclitaxel reported so far have involved only CD34 negative (HL-60, U937, K562) human AML cells, the aim of the present study was to evaluate paclitaxel efficacy against CD34 positive AML cells. The IC50 of paclitaxel for apoptosis was significantly higher in MHH225 CD34 positive cells (12 +/- 2 microM) than in U937 CD34 negative cells (1.7 +/- 0.2 microM), P < 0.001. Paclitaxel has a significantly weaker cytotoxic effect on CD34 positive AML cells. One log higher concentration of paclitaxel was required in MHH225 CD34 positive AML cells to achieve the same apoptosis level achieved in U937 CD34 negative leukaemia cells. Also, at the high concentration achievable in vivo: 10 microM paclitaxel, only half the MHH225 CD34 positive AML cells were apoptotic versus 72% of U937 CD34 negative leukaemia cells. Clearly, paclitaxel has only weak or modest in vitro efficacy compared with several conventional anti-leukaemia drugs used in AML treatment. The present results support the poor level of in vivo induction of apoptosis achieved during a phase I clinical study with paclitaxel therapy in 26 leukaemia patients. Also, the present results have shown a significant increase in nitric oxide production during paclitaxel-induced apoptosis in U937 monocytic leukaemia cells, confirming the vital role of nitric oxide in mediating paclitaxel-induced apoptosis by monocytic cells. In conclusion, the present study has demonstrated a clear difference between the effect of paclitaxel on CD34 negative and CD34 positive AML cells. Given its poor performance in the phase I clinical study of 26 acute leukaemia patients and the present weak in vitro cytotoxic effect, it is unlikely that paclitaxel will have a role in the treatment of acute leukaemia. Also, the present study emphasises the need to use CD34 positive AML cells such as MHH225 rather than the unsuitable lineage-specific CD34 negative cells such as HL-60 or U937 for in vitro pre-clinical screening of potential novel effective anti-leukaemia agents.

Use of cellular and cytokine adjuvants in the immunotherapy of cancer

Cellular and cytokine adjuvants, often immune effector cells and soluble factors, respectively, are supplemental and/or follow-up treatments of human origin for cancer patients who have unsatisfactory clinical responses to conventional chemotherapy, radiotherapy, and surgery. Since many human studies with these reagents are in their infancy, extensive data collection is only now being performed to determine which strategy provides the greatest therapeutic benefit. Research published in the literature since the genesis of this approach to cancer treatment is summarized in this report. Methodologies attempting to generate anticancer responses by provoking or enhancing the patient's own immune system are new compared with the other standard types of cancer treatment. Although a few encouraging human studies can be discussed, many of the most promising techniques are only now being transferred from the laboratory to the clinic. The administration of immune effector cells in combination with immunomodulators, such as interferons or interleukins, often enhances clinical outcome. The literature cited in this report indicate that immune-cell- and cytokine-based therapies hold promise in our attempts to improve the quality and duration of life in those with cancer. With each report reaching the literature, more effective clinical trials are being designed and implemented.