Prolymphocytic leukemia

Phase I/II study of bortezomib-BEAM and autologous hematopoietic stem cell transplantation for relapsed indolent non-Hodgkin lymphoma, transformed, or mantle cell lymphoma

A phase I/II trial was designed to evaluate the safety and efficacy of adding bortezomib to standard BEAM (BCNU, etoposide, cytarabine, melphalan) and autologous hematopoietic stem cell transplantation (ASCT). Eligible patients had relapsed/refractory indolent or transformed non-Hodgkin lymphoma or mantle cell lymphoma (MCL) that was relapsed/refractory or in first partial (PR) or complete remission (CR). Patients received bortezomib on days -11, -8, -5, and -2 before ASCT. Phase I had 4 dose cohorts (.8, 1, 1.3, and 1.5 mg/m(2)) and 3 patients were accrued to each. Any nonhematological ASCT-related toxicity >2 on the Bearman scale occurring between day -11 and engraftment defined the maximum tolerated dose (MTD). After the MTD has been reached, another 20 patients were enrolled at this dose to determine a preliminary overall response rate (ORR). Patients who were in CR or PR at day +100 were considered responders. The study enrolled 42 patients through August 14, 2009. The median age was 58 (range, 34 to 73) years, with 33 males and 9 females. The most common diagnoses were MCL (23 patients) and follicular lymphoma (7 patients). The median number of prior therapies was 1 (range, 0 to 6). The median follow-up was 4.88 (range, 1.07 to 6.98) years. Thirteen patients were treated in phase I and 29 patients were treated in phase II. The MTD was initially determined to be 1.5 mg/m(2) but it was later decreased to 1 mg/m(2) because of excessive gastrointestinal toxicity and peripheral neuropathy. The ORR was 95% at 100 days and 87% at 1 year. For all 38 evaluable patients at 1 year, responses were CR 84%, PR 1%, and progressive disease 13%. Progression-free survival (PFS) was 83% (95% CI, 68% to 92%) at 1 year, and 32% (15% to 51%) at 5 years. Overall survival (OS) was 91% (95% CI, 79% to 96%) at 1 year and 67% (50% to 79%) at 5 years. The most common National Cancer Institute grade 3 toxicities were neutropenic fever (59%), anorexia (21%), peripheral neuropathy (19%), orthostatic hypotension/vasovagal syncope (16%), and 1 patient failed to engraft. Compared with 26 MCL in CR1 historic controls treated with BEAM and ASCT, PFS was 85% and 43% for the BEAM group versus 87% and 57% for those who received bortezomib in addition to standard BEAM (V-BEAM) at 1 and 5 years, respectively (log-rank P = .37). OS was 88% and 50% for the BEAM group versus 96% and 72% for V-BEAM at 1 and 5 years, respectively (log-rank P = .78). In conclusion, V-BEAM and ASCT is feasible. The toxicities were manageable and we did not observe any treatment-related mortalities; however, we did observe an excess of autonomic dysfunction and ileus, which is concerning for overlapping toxicity with BEAM conditioning. Determining relative efficacy of V-BEAM compared to BEAM would require a randomized trial.

Allogeneic hematopoietic cell transplant for prolymphocytic leukemia

The poor prognosis of patients with prolymphocytic leukemia (PLL) has led some clinicians to recommend allogeneic hematopoietic cell transplant (HCT). However, the data to support this approach is limited to case-reports and small case series. We reviewed the database of the Center for International Blood and Marrow Transplant Research (CIBMTR) to determine outcomes after allotransplant for patients with PLL. We identified 47 patients with a median age of 54 years (range: 30-75 years). With a median follow-up of 13 months, progression-free survival (PFS) was 33% (95% confidence interval [CI] 20%-47%) at 1 year. The most common cause of death was relapse or progression in 49%. The cumulative incidence of treatment-related mortality (TRM) at 1-year posttransplant was 28%. The small patient population prohibited prognostic factor analysis, but these data support consideration of allotransplant for PLL. Further study of a larger population of patients is needed to determine which patients are more likely to benefit.

Current status of older and new purine nucleoside analogues in the treatment of lymphoproliferative diseases

For the past few years more and more new cytotoxic agents active in the treatment of hematological malignancies have been synthesized and become available for either in vitro studies or clinical trials. Among them the class of antineoplastic drugs belonging to the purine nucleoside analogues group (PNAs) plays an important role. Three of them: pentostatin (DCF), cladribine (2-CdA) and fludarabine (FA) were approved by Food and Drug Administration (FDA) for the treatment of hematological malignancies. Recently three novel PNAs: clofarabine (CAFdA), nelarabine (ara-G) and forodesine (immucillin H, BCX-1777) have been synthesized and introduced into preclinical studies and clinical trials. These agents seem to be useful mainly for the treatment of human T-cell proliferative disorders and they are currently undergoing clinical trials in lymphoid malignancies. However, there are also several studies suggesting the role of these drugs in B-cell malignancies. This review will summarize current knowledge concerning the mechanism of action, pharmacologic properties, clinical activity and toxicity of PNAs accepted for use in clinical practice, as well as new agents available for clinical trials.

Emerging drugs for rarer chronic lymphoid leukemias

BACKGROUND

Rarer indolent lymphoid leukemias include well defined mature B-cell and T-cell neoplasm with widely varying natural history and specific morphological, immunophenotypic and molecular characteristics. Among these are prolymphocytic leukemia (PLL), hairy cell leukemia (HCL) and its variants, large granular lymphocyte leukemia (LGLL) and adult T-cell leukemia/lymphoma (ATLL).

OBJECTIVE

To present current therapies and emerging drugs potentially useful in the treatment of rarer chronic lymphoid leukemias.

METHODS

After searching MEDLINE, PubMed and the Current Contents database, and conference proceedings from the previous 3 years of the American Society of Hematology (ASH), the European Society of Hematology (EHA) and the American Society of Clinical Oncology (ASCO) were searched manually; articles written in English and additional relevant publications were then selected.

RESULTS/CONCLUSION

New drugs including monoclonal antibodies (mAbs), new purine analogs, small molecules targeting specific molecular targets and other agents are included. Future research should focus on the novel therapeutic strategies based on the molecular pathogenic mechanisms and the development of new targeted therapies for each distinct chronic lymphoid leukemia.

The Role of Alemtuzumab in the Management of T-Cell Malignancies

T-cell malignancies are rare, making up 10% to 15% of all lymphoid neoplasms in adults. They include many different types of disorders such as T-cell prolymphocytic leukemia, T-cell large granular lymphocytic leukemia, adult T-cell leukemia/lymphoma, cutaneous T-cell lymphoma, and peripheral T-cell lymphoma, which are themselves divided into multiple subcategories. Most T-cell malignancies arise as a result of chromosomal abnormalities, including T-cell receptor rearrangement anomalies. Viral infections are implicated in the development of adult T-cell leukemia/lymphoma and some cases of peripheral T-cell lymphoma have been linked to Epstein-Barr virus or human immunodeficiency virus infection. With the possible exception of T-cell large granular lymphocytic leukemia, which often has an indolent course, T-cell malignancies have not responded well to conventional chemotherapeutic treatment. The introduction of monoclonal antibodies for the treatment of cancer has changed the outlook for patients with T-cell malignancies. Recent studies with single-agent alemtuzumab, an anti-CD52 monoclonal antibody, have shown improved response rates and survival in patients with T-cell prolymphocytic leukemia and cutaneous T-cell lymphoma. Preliminary data also suggest that alemtuzumab may have activity in patients with heavily pretreated peripheral T-cell lymphoma who are refractory to conventional chemotherapy. Preclinical studies with mice bearing human adult T-cell leukemia/lymphoma cells suggest that alemtuzumab may have a potential therapeutic role in this setting. Treatment of T-cell hematologic malignancies with alemtuzumab appears promising. Earlier treatment and combination with chemotherapeutic agents may improve treatment outcome for patients with these malignancies and allow for consolidation with stem cell transplant strategies in selected patients.