Strategies in the management of alemtuzumab-related side effects

B-cell chronic lymphocytic leukemia has traditionally been treated with alkylating agents and purine analogues. The introduction of alemtuzumab, a CD52 monoclonal antibody with significant clinical activity in chemotherapy refractory B-cell chronic lymphocytic leukemia, is accompanied by a side effect profile different from that resulting from chemotherapy. The intravenous administration of alemtuzumab is usually accompanied by transient infusion-related side effects manifesting primarily as flu-like symptoms. These reactions can be reduced by use of corticosteroid prophylaxis, and will subside gradually during continued treatment. Alternatively, administration of alemtuzumab subcutaneously may markedly reduce the occurrence of general side effects but results in limited transient local skin reactions in most patients. Neutropenia (grade 4) may occur in approximately 20% of patients, but is usually transient and/or responds promptly to colony stimulating factor therapy; episodes of febrile neutropenia are infrequent. The major side effect of alemtuzumab is T-cell depletion, leading to an increased risk of infection, in particular reactivation of cytomegalovirus. This event typically occurs 3 to 8 weeks after initiation of therapy, coinciding with the T-cell nadir. With vigilance and early detection, these infections are usually manageable and do not cause organ failure. Preliminary data indicate that other infections following alemtuzumab therapy do not seem to occur at a frequency that is higher than expected, probably because of the general prophylactic use of cotrimoxazole (trimethoprim and sulfamethoxazole) and valacyclovir in combination with clinical tumor regressions. The overall safety profile of alemtuzumab appears to be beneficial in relation to disease severity and prognosis in patients with fludarabine-refractory B-cell chronic lymphocytic leukemia.

CHOP-like chemotherapy plus rituximab versus CHOP-like chemotherapy alone in young patients with good-prognosis diffuse large-B-cell lymphoma: a randomised controlled trial by the MabThera International Trial (MInT) Group

BACKGROUND

The role of rituximab in combination with different CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like chemotherapy regimens in young patients with good-prognosis diffuse large-B-cell lymphoma remains to be defined. We aimed to compare CHOP-like chemotherapy and rituximab with CHOP-like chemotherapy alone in these patients.

METHODS

824 patients who were from 18 countries; aged 18-60 years; and who had no risk factors or one risk factor according to age-adjusted International Prognostic Index (IPI), stage II-IV disease, or stage I disease with bulk were enrolled. These patients were randomly assigned to six cycles of CHOP-like chemotherapy and rituximab (n=413) or to six cycles of CHOP-like chemotherapy alone (n=411). Bulky and extranodal sites received additional radiotherapy. The primary endpoint was event-free survival; secondary endpoints were response, progression under therapy, progression-free survival, overall survival, and frequency of toxic effects. Analyses were done by intention to treat and per protocol. This trial is registered at http://www.clinicaltrials.gov, NCT 00064116.

FINDINGS

After a median follow-up of 34 months (range 0.03-61), patients assigned chemotherapy and rituximab had increased 3-year event-free survival compared with those assigned chemotherapy alone (79% [95% CI 75-83] vs 59% [54-64]; difference between groups 20% [13-27], log-rank p<0.0001), and had increased 3-year overall survival (93% [90-95] vs 84% [80-88]; difference between groups 9% [3-13], log-rank p=0.0001). Event-free survival was affected by treatment group, presence of bulky disease, and age-adjusted IPI: after chemotherapy and rituximab, a favourable subgroup (ie, IPI=0, no bulk) could be defined from a less-favourable subgroup (ie, IPI=1 or bulk, or both). Groups did not differ in the frequency of adverse events.

INTERPRETATION

Rituximab added to six cycles of CHOP is an effective treatment for young patients with good-prognosis diffuse large-B-cell lymphoma. The definition of two prognostic subgroups allows for a more refined therapeutic approach for these patients.

Generation of DC-based vaccine for therapy of B-CLL patients. Comparison of two methods for enriching monocytic precursors

BACKGROUND

The generation of Ag-loaded DC under good manufacturing practice (GMP) conditions is logistically challenging and further compounded when the starting precursors need to be purified from B-CLL patients who have overwhelming numbers of circulating B-CLL cells and decreased numbers of monocytes.

METHODS

We have previously demonstrated that DC with endocytosed B-CLL apoptotic bodies are powerful stimulators of anti-leukemic T cells. In this study we compared counterflow elutriation and immunomagnetic separation for enriching monocyte precursors, and evaluated the feasibility of generating DC from B-CLL patients and the effects of cryopreservation.

RESULTS

Monocyte yield from a single leukapheresis product of a B-CLL patient varied from 1 x 108 to 10 x 108 total cells, from which 40-200 x 106 mature DC could be produced. Adequate numbers of monocytes could not be enriched from one patient with 0.2% monocytes in the leukapheresis product, and the target of 50 x 106 DC was barely achieved in another patient with 0.9% monocytes in the pheresed cells. These results suggested that successful production of DC is dependent on a minimum frequency of 1% CD14(+) monocytes in the leukapheresis product. Cryopreservation of tumor cell-loaded DC yielded a recovery rate of 86+/-4.4% upon thawing, with a total viability of 90+/-2.8%. Most importantly, cryopreserved Ag-loaded DC retained their morphology, phenotype and function.

DISCUSSION

The results demonstrate that adequate numbers of functional DC required for clinical therapy can be generated from patients who have >1% of CD14(+) monocytes in the leukapheresis product. Moreover, Ag-loaded DC can be cryopreserved and recovered without significant change in phenotype or function.

IGF-1 receptor tyrosine kinase inhibition by the cyclolignan PPP induces G2/M-phase accumulation and apoptosis in multiple myeloma cells

Emerging evidence suggests the insulin-like growth factor-1 receptor (IGF-1R) to be an important mediator of tumor-cell survival and resistance to cytotoxic therapy in multiple myeloma (MM). Recently, members of the cyclolignan family have been shown to selectively inhibit the receptor tyrosine kinase (RTK) activity of the IGF-1R beta-chain. The effects of the cyclolignan picropodophyllin (PPP) were studied in vitro using a panel of 13 MM cell lines and freshly purified tumor cells from 10 patients with MM. PPP clearly inhibited growth in all MM cell lines and primary MM samples cultured in the presence or absence of bone marrow stromal cells. PPP induced a profound accumulation of cells in the G(2)/M-phase and an increased apoptosis. Importantly, IGF-1, IGF-2, insulin, or IL-6 did not reduce the inhibitory effects of PPP. As demonstrated by in vitro kinase assays, PPP down-regulated the IGF-1 RTK activity without inhibiting the insulin RTK activity. This conferred decreased phosphorylation of Erk1/2 and reduced cyclin dependent kinase (CDK1) activity. In addition, the expression of mcl-1 and survivin was reduced. Taken together, we suggest that interfering with the IGF-1 RTK by using the cyclolignan PPP offers a novel and selective therapeutic strategy for MM.

Fibromodulin, an extracellular matrix protein: characterization of its unique gene and protein expression in B-cell chronic lymphocytic leukemia and mantle cell lymphoma

Fibromodulin is an extracellular matrix protein normally produced by collagen-rich tissues; the fibromodulin gene has been found to be the most overexpressed gene in B-cell chronic lymphocytic leukemia. In this study, fibromodulin was expressed at the gene level (reverse transcription-polymerase chain reaction [RT-PCR]) in all patients with B-CLL (n = 75) and in most (5 of 7) patients with mantle cell lymphoma (MCL). No mutations in the fibromodulin gene were detected. Fibromodulin was also detected at the protein level in the cytoplasm of the B-CLL cells and in the supernatant after in vitro cultivation, but not at the cell surface. Fibromodulin was not found in patients with T-cell chronic lymphocytic leukemia (T-CLL), B-cell prolymphocytic leukemia (B-PLL), T-cell prolymphocytic leukemia (T-PLL), hairy cell leukemia, follicular lymphoma, lymphoplasmacytic lymphoma, multiple myeloma, acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), or chronic myelogenous leukemia (CML) or in 36 hematologic cell lines. Normal blood mononuclear cells (T and B lymphocytes, monocytes), tonsil B cells, and granulocytes did not express fibromodulin. Activation (phorbol 12-myristate 13-acetate [PMA]/ionomycin) of normal T and B lymphocytes induced weak fibromodulin gene expression, but not to the extent seen in freshly isolated B-CLL cells. The reason for the exclusive ectopic expression of fibromodulin in B-CLL and MCL is unknown. However, its unique protein expression makes it likely that fibromodulin is involved in the pathobiology of B-CLL and MCL. (Blood. 2005;105:4828-4835)

Ectopic and IFN-induced expression of Fas overcomes resistance to Fas-mediated apoptosis in multiple myeloma cells

Multiple myeloma (MM) is an as-yet incurable B-cell malignancy. Increased survival in vitro is a hallmark of MM cells, implying that a therapeutic potential may lie in circumventing antiapoptotic signals. We have previously reported that interferons (IFNs) sensitize MM cells to Fas/CD95-mediated apoptosis. In the present study, we explore the mechanism underlying this effect. In a wide screening of apoptosis-related genes, Apo2L/TRAIL (tumor necrosis factor [TNF]-related apoptosis inducing ligand) and Fas were identified as IFN targets. Sensitization to Fas-mediated apoptosis by IFNs was not affected by blocking Apo2L/TRAIL, suggesting that Apo2L/TRAIL is not a key mediator in this process. In contrast, we found that an elevated Fas expression was functionally linked to increased susceptibility to Fas-mediated apoptosis. This was further supported by the finding that IFN treatment enhanced Fas-mediated caspase-8 activation, one of the earliest signaling events downstream receptor activation. In addition, IFN treatment attenuated the interleukin 6 (IL-6)-dependent activation of signal transducer and activator of transcription 3 (Stat3), interfering with a known survival pathway in MM that has previously been linked with resistance to Fas-mediated apoptosis. Taken together, our results show that IFN-induced up-regulation of Fas sensitizes MM cells to Fas-mediated apoptosis and suggest that attenuation of Stat3 activation may be a potentially important event in this process.

Impact of epoetin-beta on survival of patients with lymphoproliferative malignancies: long-term follow up of a large randomized study*

Recent studies have suggested that epoetin treatment of anaemia may influence the survival of patients with cancer. We conducted an analysis of long-term survival in patients with lymphoproliferative malignancies treated with epoetin-beta or placebo in a large-scale study. This was a randomized, double-blind trial in which patients with transfusion-dependent anaemia and lymphoproliferative malignancy received epoetin-beta 150 IU/kg or placebo three times weekly for 16 weeks. Long-term survival data were analysed by standard Kaplan-Meier methods and differences between groups were assessed using a log-rank test. The intention-to-treat population consisted of 343 patients (epoetin-beta, n = 170; placebo, n = 173). There were no major differences between the two treatment groups in demographic or clinical characteristics/prognostic factors. A total of 110 (65%) patients died in the epoetin-beta group (censored, n = 60) and 109 (63%) died in the placebo group (censored, n = 64) up to the end of long-term follow up. Kaplan-Meier curves for survival were similar in both groups. Median survival was 17 months with epoetin-beta and 18 months with placebo. A log-rank test indicated no significant difference in survival (P = 0.76). This long-term follow up indicated that epoetin-beta has no significant effect on survival compared to placebo in anaemic patients with lymphoproliferative malignancies.

High expression of bfl-1 contributes to the apoptosis resistant phenotype in B-cell chronic lymphocytic leukemia

In order to identify regulatory genes involved in the development of an apoptosis-resistant phenotype in patients with chemotherapy refractory B-cell chronic lymphocytic leukemia (B-CLL) expression of apoptosis-regulating genes in B-CLL cells was quantified using cDNA arrays and RT-PCR. Data were obtained from and compared between 2 groups of B-CLL patients with either nonprogressive, indolent, previously untreated disease and with leukemic cells sensitive to in vitro fludarabine-induced apoptosis, referred to as sensitive B-CLL (sB-CLL) or with progressive, chemotherapy refractory disease and with leukemic cells resistant to in vitro fludarabine-induced apoptosis, referred to as resistant B-CLL (rB-CLL). By performing a supervised clustering of genes that most strongly discriminated between rB-CLL vs. sB-CLL a small group of genes was identified, where bfl-1 was the strongest discriminating gene (p < 0.05), with higher expression in rB-CLL. A group of apoptosis-regulating genes were modulated during induction of apoptosis by serum deprivation in vitro in a similar manner in all cases studied. However, bfl-1 was preferentially downregulated in sB-CLL as compared to rB-CLL (p < 0.05). We conclude that bfl-1 may be an important regulator of B-CLL apoptosis, which could contribute to disease progression and resistance to chemotherapy, and as such represent a future potential therapeutic target.

Signaling Molecules and Cytokine Production in T Cells of Patients with B-Cell Chronic Lymphocytic Leukemia (B-CLL): Comparison of Indolent and Progressive Disease

T-cell dysfunction in B-CLL patients might be attributed to altered expression of components of the TCR/CD3 complex and associated intracellular tyrosine kinases. Four-color flow cytometry was applied to the expression of these molecules as well as the T-cell regulatory cytokines (IFN-gamma and IL-4) in B-CLL patients with indolent and progressive disease. Intracellular levels [mean fluorescent intensity (MFI)] of IFN-gamma and IL-4 in both CD4 and CD8 T cells of both patient groups were significantly higher than in healthy donors. Absolute number of IL-4 producing CD4 T cells in patients with indolent was significantly higher than in healthy donors. The expression level (MFI) of the CD3-zeta chain was higher in patients than in normal donors as well as ZAP-70 in patients with indolent disease as compared to healthy donors and progressive patients. No significant difference was noted in the expression of p56lck, p59fyn, and PI3-kinase between healthy donors and patients or between the patient subgroups. The results indicate multiple T-cell abnormalities especially in indolent-stage B-CLL suggesting a state of chronic and aberrant activation. This information might be of significance when studying the immunobiology of B-CLL as well as developing new therapeutic approaches.

EORTC guidelines for the use of erythropoietic proteins in anaemic patients with cancer

Anaemia is frequently diagnosed in patients with cancer, yet it is difficult to identify a single cause due to its multifactorial aetiology. We conducted a systematic literature review (1996-2003) to produce evidence-based guidelines on the use of erythropoietic proteins in anaemic patients with cancer (see ). Level I evidence exists for a positive impact of erythropoietic proteins on haemoglobin (Hb) levels when administered to patients with chemotherapy-induced anaemia or anaemia of chronic disease, when used to prevent cancer anaemia, in patients undergoing cancer surgery and following allogeneic bone marrow transplantation. The Hb level at which erythropoietic protein therapy should be initiated is difficult to determine as it varied between studies; a large number of Level I studies in patients with chemotherapy-induced anaemia or anaemia of chronic disease enrolled patients with a Hb concentration </=105 g/L, but none compared the effect of different baseline Hb levels on the response to treatment. Similarly, several studies defined the target Hb concentration as 120-130 g/L following treatment with erythropoietic proteins, but none specifically addressed the correlation between target Hb level and clinical benefit in a randomised fashion. Level I evidence shows that red blood cell (RBC) transfusion requirements are significantly reduced with erythropoietic protein therapy in patients with chemotherapy-induced anaemia or when used to prevent cancer anaemia (approximately 20% reduction compared with controls). We found indirect Level I and III evidence that patients with chemotherapy-induced anaemia or anaemia of chronic disease initially classified as non-responders to standard doses proceed to respond to treatment following a dose increase (absolute increases in response rate ranged from 8% to 18%). However, none of these studies examined the effect on response rates of a longer treatment period at the lower dose, or performed a randomised comparison of a dose increase versus an unchanged dose. There is Level I evidence to show that quality-of-life (QOL) is significantly improved in patients with chemotherapy-induced anaemia and in those with anaemia of chronic disease, particularly in patients achieving a Hb response to erythropoietic protein therapy. There are insufficient data to determine the effect on survival following treatment with erythropoietic proteins in conjunction with chemotherapy or radiotherapy. There is Level I evidence that dosing of erythropoietic proteins less frequently than three times per week (TIW) is efficacious when used to treat chemotherapy-induced anaemia or prevent cancer anaemia. There is Level III evidence that initial doses of erythropoietic proteins considered to be higher than current standard practice produce higher haematological responses in patients with chemotherapy-induced anaemia or anaemia of chronic disease. Level I evidence demonstrates that several baseline patient parameters (e.g., low endogenous erythropoietin [EPO] concentration, age <60 years, Hb concentration >/=90 g/L) impact upon the response to erythropoietic proteins when used to treat chemotherapy-induced anaemia or prevent cancer anaemia. Evidence indicates that endogenous EPO concentration impacts on response in patients with lymphoproliferative malignancies, but is not a valid parameter in patients with solid tumours. There is Level I evidence that fixed doses of erythropoietic proteins can be used at the start of therapy to treat patients with chemotherapy-induced anaemia, but maintenance doses should be titrated individually. There is no evidence that pure red cell aplasia (PRCA) occurs following treatment with erythropoietic proteins in patients with chemotherapy-induced anaemia or when used prophylactically in patients with cancer. There is Level I evidence that the risk of thromboembolic events and hypertension are slightly elevated in patients with chemotherapy-induced anaemia receiving erythropoietic proteins. Level I evidence supports the effectiveness of erythropoietic proteins to prevenroteins to prevent anaemia in non-anaemic cancer patients receiving chemotherapy or radiotherapy or in those undergoing cancer surgery. However, these are non-licensed indications and we do not currently recommend the prophylactic use of erythropoietic proteins to prevent anaemia in patients who have normal Hb values at the start of treatment. Additional trials are warranted, especially on the issues of iron replacement and cost-effectiveness of erythropoietic protein therapy, as well as on tumour response/progression and survival.

Apoptotic tumor cells are superior to tumor cell lysate, and tumor cell RNA in induction of autologous T cell response in B-CLL

B cell chronic lymphocytic leukemia (B-CLL) is a chronic leukemia manifested by increased numbers of B cells in circulation. The slow, smouldering nature of the disease in a significant proportion of the cases makes it an ideal target for immunotherapy. Dendritic cell (DC)-based immunotherapy is emerging as an exciting modality with significant clinical potential. In this study, three strategies for delivering antigens to DC, namely apoptotic bodies (Apo-DC), tumor lysates, and tumor RNA were studied in an autologous setting. In all six CLL patients, Apo-DC induced higher HLA-restricted, T cell responses than DC pulsed with tumor lysate or RNA. Real-time PCR confirmed higher expression of genes for IL-2 and IFN-gamma in T cells stimulated with Apo-DC. Concurrently, no IL-10 and low IL-4 responses indicated that the immune response was primarily of the Th1 type. Enzyme-linked immunospot assay revealed high IFN-gamma secretion by T cells when Apo-DC was used to stimulate autologous T cells in all patients. Our data suggest that cellular vaccines with DC loaded with apoptotic bodies may be a suitable approach for immunotherapy of B-CLL.

Therapy for mycosis fungoides

Treatment of mycosis fungoides (MF) is indicated to reduce symptoms, improve clinical appearance, prevent secondary complications, and prevent progression of disease, all of which may have an impact on survival. Treatment of MF includes topical and systemic therapies, which can be administered alone or in combination. Psoralen and ultraviolet A radiation is effective in early-stage MF, inducing complete remissions in most patients. Psoralen and ultraviolet A radiation may also be combined with low doses of interferon (IFN)-alpha to treat stage I/II disease. However, early aggressive therapy with radiation and chemotherapy does not improve the prognosis. Local radiotherapy or total skin electron beam irradiation has been used with success to control advanced skin disease. Extracorporeal photopheresis may also be used successfully, but it is not generally available. Once the disease becomes refractory to topical therapy, IFN-alpha single-agent or combination chemotherapy may be administered, but the duration of response is often less than 1 year and ultimately all patients will relapse and become refractory. Among chemotherapeutic agents, pentostatin, gemcitabine, and liposomal doxorubicin seem to be particularly effective. Response rates after combined modality therapy with total skin electron beam irradiation and chemotherapy/IFN-alpha appear similar to response rates of chemotherapy alone. Therefore, there is a great need for the further development of novel emerging treatment modalities, such as retinoids (ie, bexarotene) and immunotherapeutic agents (ie, cytokines, tumor vaccines, and monoclonal antibodies), all of which appear to have significant therapeutic potential in patients with MF. Biologically based therapies may reduce the need for genotoxic therapies, such as cytostatics and radiotherapy.

Advances in the use of monoclonal antibodies in the therapy of chronic lymphocytic leukemia

Monoclonal antibody (moAb)-based therapies are evolving as an integrated component in the treatment of chronic lymphocytic leukemia (CLL). Advantages such as different mechanisms of action (compared with those of chemotherapy), no or minimal stem cell toxicity, as well as the absence of hair loss and delayed nausea may result in a rapidly increasing usage of these agents in different phases of the disease. The combination of moAbs with chemotheraputic agents has shown promising results in early studies as well as their role in the eradication of minimal residual disease (MRD). The availability of an increasing number of new moAbs together with a better understanding of their effector function will hopefully lead to improved therapeutic outcomes for patients with CLL and related disorders.

New erythropoietic proteins: rationale and clinical data

Anemia is a common condition in patients with cancer. Patients who develop severe anemia are frequently treated with red blood cell transfusions. However, the benefits are transient and associated with a number of risks (such as infection and immunosuppression). An alternative treatment option, recombinant human erythropoietin (rHuEPO) was introduced into the clinical setting more than a decade ago. Today, rHuEPO is increasingly being used to treat anemic patients with cancer. However, despite the well-documented clinical benefits of rHuEPO therapy, it has not been universally adopted as a routine treatment in the oncology setting and there remains an unmet need for an effective and convenient anemia treatment for cancer patients. Longer-acting versions of rHuEPO would avoid the need for frequent injections, increase biological activity and, potentially, the clinical efficacy of rHuEPO. One agent, darbepoetin alfa, is now available for the treatment of anemia in patients with cancer who are receiving chemotherapy, another agent, pegylated-epoetin beta, is in phase II trials, and additional compounds are in early stages of preclinical and clinical development. This review focuses on the available clinical experience with such agents and discusses how dose- and schedule-finding studies are optimizing their clinical use to maximize patient benefits.

Phase II study of cyclophosphamide, interferon-alpha and betamethasone (CIB) as induction therapy for patients 60-75 years of age with multiple myeloma stages II and III

Cyclophosphamide, interferon-alpha and betamethasone are all effective agents for the treatment of multiple myeloma (MM) with different mechanisms of action. The clinical effect of a combination of cyclophosphamide 725 mg/m(2) i.v. days 1 and 3, interferon-alpha 7 x 10(6) IE/m(2) s.c./day, days 1-4 and betamethasone 30 mg orally days 1-4 (CIB) was studied in patients aged 60-75 years with previously untreated MM stages II and III. Granulocyte-macrophage colony-stimulating factor (GM-CSF) 5 microg/kg/day s.c. was administered to all patients from day 5 until the day the granulocyte count exceeded 1.0 x 10(9)/l. CIB was repeated every fourth week. Interferon-alpha 3 x 10(6) IE s.c. t.i.w. was given as maintenance therapy in responding patients.A total of 28 patients (median age: 67 years) entered the study. In all, 12 patients had stage II and 16 had stage III MM. A total of 22 patients (79%) showed an objective response, including five complete remissions (CR) and 17 partial remissions (PR). All seven patients with Bence-Jones MM responded (five CR and two PR). The median response duration time was 14 months (range 5-38+). CIB was relatively well tolerated although febrile neutropenia or septicaemia occurred in 5% of the cycles and a dose-reduction of cyclophosphamide due to grade IV neutropenia was performed in 11% of the patients.CIB seems to be an effective regimen for remission induction in MM patients aged up to 75 years as an alternative to VAD (vincristine, doxorubicin, dexamethasone) if a regimen with intensity higher than that of oral melphalan/prednisone is warranted.

Blood concentrations of alemtuzumab and antiglobulin responses in patients with chronic lymphocytic leukemia following intravenous or subcutaneous routes of administration

Alemtuzumab is a humanized anti-CD52 antibody licensed for refractory B-cell chronic lymphocytic leukemia (B-CLL), when given intravenously at 30 mg thrice weekly. However, the intravenous route is associated with infusion-related reactions and is inconvenient. We measured blood concentrations in 30 relapsed patients treated with intravenous alemtuzumab and in 20 patients from a previously untreated group who received similar doses subcutaneously. Highest trough samples in the intravenous group were less than 0.5 microg/mL to 18.3 microg/mL (mean 5.4 microg/mL). The cumulative dose required to reach 1.0 microg/mL was 13 mg to 316 mg (mean 90 mg). Higher blood concentrations correlated with the achievement of better clinical responses and minimal residual disease. The highest measured concentrations in the subcutaneous group were similar (0.6 microg/mL to 24.8 microg/mL, mean 5.4 microg/mL). However, the cumulative dose to reach 1.0 microg/mL was higher: 146 mg to 1106 mg (mean 551 mg). No antiglobulin responses were detected in 30 patients given intravenous alemtuzumab whereas 2 of 32 patients given subcutaneous alemtuzumab made substantial anti-idiotype responses. Thus, subcutaneous alemtuzumab achieved concentrations similar to those for intravenous alemtuzumab, although with slightly higher cumulative doses. Subcutaneous alemtuzumab is more convenient and better tolerated but may be associated with some patients forming anti-alemtuzumab antibodies, particularly those patients who were previously untreated.

Rapamycin sensitizes multiple myeloma cells to apoptosis induced by dexamethasone

Circumvention of chemoresistance in the B-cell neoplasm multiple myeloma (MM) might be achieved by targeting certain intracellular signaling pathways crucial for survival of the malignant clone. The use of the macrolide rapamycin, selectively inhibiting the phosphoprotein mammalian target of rapamycin (mTOR) downstream of, for example, insulin-like growth factor-I receptor (IGF-IR), possibly represents such a molecular mode of therapy. By using a panel of MM cell lines we showed that rapamycin induced G0/G1 arrest, an effect being associated with an increase of the cyclin-dependent kinase inhibitor p27 and a decrease of cyclins D2 and D3. Interestingly, in primary, mainly noncycling MM cells, rapamycin, at clinically achievable concentrations, induced apoptosis. More important, rapamycin sensitized both MM cell lines and primary MM cells to dexamethasone-induced apoptosis. This effect was associated with a decreased expression of cyclin D2 and survivin. The phosphorylation of the serine/threonine kinase p70S6K at Thr389 and Thr421/Ser424 was down-regulated by rapamycin and/or dexamethasone. Strikingly, the combinatorial treatment with rapamycin and dexamethasone suppressed the antiapoptotic effects of exogenously added IGF-I and interleukin 6 (IL-6) as well as their stimulation of p70S6K phosphorylation. The induction of apoptosis by rapamycin and dexamethasone despite the presence of survival factors was also demonstrated in primary MM cells, thus suggesting this drug combination to be active also in vivo. (Blood. 2004;103:3138-3147)

A pilot study of alemtuzumab (anti-CD52 monoclonal antibody) therapy for patients with relapsed or chemotherapy-refractory peripheral T-cell lymphomas

Patients with peripheral T-cell lymphomas (PTLs) have an extremely poor prognosis when relapsed or refractory to conventional chemotherapy. We have studied alemtuzumab, a humanized anti-CD52 monoclonal antibody, as therapy for patients with heavily pretreated and refractory PTL. Fourteen patients entered the study. All had clinical stage III or IV disease. Patients received a rapidly escalating dosage of alemtuzumab during the first week and, thereafter, 30 mg intravenously 3 times per week for a maximum of 12 weeks. Trimethoprim/sulphamethoxazole and valaciclovir prophylaxis was given to all patients. The overall response rate was 36% (5 of 14). Three patients achieved a complete remission (CR) and 2 patients a partial remission. The durations of the CRs were 2, 6, and 12 months, respectively. Toxicity included cytomegalovirus reactivation in 6 patients, which was successfully treated with ganciclovir or foscarnet; pulmonary aspergillosis in 2 patients; and pancytopenia in 4 patients. Epstein-Barr virus–related hemophagocytosis was observed in 2 patients. Five patients died of causes related to the treatment, in combination with advanced disease. We conclude that alemtuzumab is active when used in patients with advanced, heavily pretreated PTL, although it is associated with significant hematologic toxicity and infectious complications. Further studies are warranted in younger patients and patients with less advanced disease. (Blood. 2004;103: 2920-2924)

Anemia in multiple myeloma

Anemia is a common complication in patients with multiple myeloma (MM) and occurs in more than two thirds of all patients. The most frequent underlying pathophysiological mechanism is anemia of chronic disease (ACD), relative erythropoietin (EPO) deficiency (due partly to renal impairment) and myelosuppressive effects of chemotherapy, but many other factors may account for or contribute to anemia in myeloma. In patients who achieve complete remission after chemotherapy, anemia usually normalizes. Nonresponders and relapsing myeloma patients often continue to suffer from anemia. Treatment options for anemic myeloma patients include red blood cell (RBC) transfusions and recombinant human erythropoietin (rHuEPO). Red blood cell transfusions convey an immediate effect and rapidly increase the patient's hemoglobin level. Unfortunately, effects of RBC transfusions are only transient and can be associated with several risks, including infections and mild to even life-threatening immunologic reactions. rHuEPO is biologically equivalent to the human endogenous hormone EPO, and its application leads to an increase of hemoglobin levels over an extended time without the risks of blood transfusions. Several studies reported a significant improvement of erythropoiesis, reduction in transfusion need, and improved quality of life by using rHuEPO as long-term treatment of myeloma-associated anemia. Recently, an international expert panel recommended the use of rHuEPO for anemic myeloma patients where other possible causes of anemia have been eliminated.

Cellular immune reconstitution after subcutaneous alemtuzumab (anti-CD52 monoclonal antibody, CAMPATH-1H) treatment as first-line therapy for B-cell chronic lymphocytic leukaemia

Little information is available on long-term immune reconstitution after therapy with alemtuzumab in B-CLL patients. We present long-term follow-up data for blood lymphocyte subsets analysed by flow cytometry in previously untreated B-CLL patients who received alemtuzumab subcutaneously as first-line therapy. All lymphoid subsets were significantly (P<0.001) and profoundly reduced; the median end-of-treatment counts for CD4(+), CD8(+), CD3(-)56(+) (natural killer (NK)), CD3(+)56(+) (NK-T) and CD19(+)5(-) (normal B) cells were 43, 20, 4, 1 and 8 cells/microl, respectively. The median cell count of all subsets remained at <25% of the baseline values for >9 months post-treatment. CD4(+) and CD8(+) levels in blood had reached >100 cells/microl in >50% of the patients at 4 months after the end of treatment. One patient had a cytomegalovirus reactivation and one patient developed Pneumocystis carinii pneumonia during therapy. No opportunistic or other major infections were recorded during unmaintained, long-term follow-up. There was no correlation between the cumulative dose of alemtuzumab and the severity or length of immunosuppression. CD52(-) T-cell subsets occurred during the treatment and comprised >80% of all CD4(+) and CD8(+) cells in the blood at the end of therapy. These subpopulations declined gradually during unmaintained follow-up. The relationship between these observations and the safety/antitumour effects of alemtuzumab is discussed.

Management Guidelines for Use of Alemtuzumab in B-Cell Chronic Lymphocytic Leukemia

An expert opinion roundtable held August 8-9, 2002, brought together clinicians with the most extensive experience with the use of alemtuzumab to pool knowledge and develop treatment goals and guidelines for optimal therapy. By sharing our collective experience, we have been able to formulate recommendations for current clinical practice, which are included in this report, and have emphasized results that have implications for future practice. Guidelines for the management of acute "first-dose" events, prophylaxis for infection, detection and treatment of cytomegalovirus reactivation, and hematologic support are presented, with emphasis on allowing patients to proceed smoothly through therapy while maximizing therapeutic benefit. Management of adverse events is facilitated by the predictable timing of their appearance. In general, hematologic adverse events are transient, manageable, and reversible. Clinicians should be cautious of prematurely terminating treatment at 4-6 weeks in patients whose disease responds to treatment. Although resolution of peripheral blood lymphocytosis occurs early in most patients, bone marrow is unlikely to be clear of disease. In particular, grade 4 neutropenia at this time is common and, because it is manageable, it is not an indication to discontinue treatment. The eradication of minimal residual disease from blood and bone marrow observed with alemtuzumab therapy is a major step forward in the treatment of B-cell chronic lymphocytic leukemia. Combination therapies such as alemtuzumab/fludarabine with the potential to maximize eradication at all disease sites should be systematically investigated. Because high response rates and few complications are observed in previously untreated patients, the use of alemtuzumab earlier in therapy may provide optimum benefit to patients.

Expression and transcriptional regulation of functionally distinct Bmf isoforms in B-chronic lymphocytic leukemia cells

Bmf is a BH3-only Bcl-2 family member that is normally sequestered to myosin V motors by binding to the dynein light chain 2 (DLC2). Certain damage signals release Bmf, which then binds prosurvival Bcl-2 proteins and triggers apoptosis. Here, two novel isoforms of human Bmf, Bmf-II and Bmf-III, were identified and cloned from cDNA derived from B-chronic lymphocytic leukemia (B-CLL) cells. Bmf-II and Bmf-III were characterized as two splice variants, lacking the BH3 domain but retaining the DLC2 binding domain. Bmf (here called Bmf-I) expression in HeLa cells induced apoptosis and reduced colony formation in contrast to Bmf-II and Bmf-III, which had no effect on apoptosis and instead increased colony formation. While bmf-I mRNA was expressed in many cell types, expression was higher in B lymphoid cells and bmf-II and bmf-III were mainly detected in B-CLL and normal B cells. bmf-I mRNA was upregulated in normal and leukemic B cells, while bmf-III mRNA was downregulated only in B-CLL cells by serum deprivation. We show that Bmf is regulated by transcriptional activation and alternative splicing and conclude that the relative levels of Bmf isoforms may have a role in regulating growth and survival in B cells and leukemic B-CLL cells.

Signalling molecules and cytokine production in T cells of multiple myeloma-increased abnormalities with advancing stage

T-cell immune dysfunction in patients with malignant tumours has been attributed to the altered expression of components of the T-cell receptor (TCR)/CD3 complex and their associated intracellular protein tyrosine kinases. In this study, four-colour flow cytometry was applied to study the surface bound molecules TCRalphabeta, CD28, CD152 and CD154 involved in T-cell signalling and the signal transduction molecules CD3zeta, p56lck, p59fyn, ZAP-70 and phosphatidyl-inositol-3 kinase (PI3-k) as well as the intracellular cytokines interferon-gamma (IFN-gamma), interleukin (IL)-4 and IL-2 as a functional read-out of non-stimulated and superantigen (staphylococcus enterotoxin B)-stimulated blood T cells of multiple myeloma (MM) patients at different stages of the disease. Multiple abnormalities were demonstrated in the CD4 and CD8 populations, both under non-stimulated and superantigen-stimulated conditions. There was a marked reduction, particular in advanced stage MM, in the proportion of CD4 and CD8 cells expressing CD28, CD152, CD3zeta, p56lck, ZAP-70 and PI3-k. The level of intracellular T-cell cytokines (IFN-gamma, IL-2 and IL-4) was normal or increased in non-stimulated cells but activation-induced cytokine production was impaired. These results illustrated profound and multiple T-cell signalling defects, from the surface and down-stream, consistent with involvement of a master T-cell function, especially in advanced stage MM. These data should be taken into consideration when developing immune-based therapeutic approaches and when applying new emerging technologies that aim to restore T-cell functions.

Kinetics of cytokine gene expression in human CD4+ and CD8+ T-lymphocyte subsets using quantitative real-time PCR

The time kinetics of five cytokines [interleukin-2 (IL-2), IL-5, interferon-gamma (IFN-gamma), granulocyte macrophage-colony stimulating factor (GM-CSF) and tumour necrosis factor-alpha (TNF-alpha)] and one cytotoxic effector protein (granzyme B) was analysed by real-time quantitative polymerase chain reaction (PCR) following in vitro stimulation of human CD4 and CD8 T lymphocytes. Two stimuli were used, a mitogen [phytohemagglutinin (PHA)] and a recall antigen [purified protein derivative (PPD)]. The pattern of cytokine mRNA expression was found to be dependent on the T-cell subset and stimulus used. A wide interindividual variability in the cytokine gene expression pattern was demonstrated. Two expression patterns were observed. A bell-shaped expression profile was seen for most cytokines upon PHA activation in both subsets and PPD-activated CD4 T cells, whereas a biphasic/multiphasic expression pattern was noted in CD8 T cells upon PPD stimulation. For most cytokines, the time to induction was within 30 min of activation, and maximum accumulation seemed to be obtained after 4-8 h of activation. A sustained high level could, however, be noticed for up to 24 h. Granzyme B gene expression was also induced within 30 min of activation but showed a continuous gradual increase and late maximal accumulation (48-72 h). The findings of the present study are of importance when designing studies using the cytokine gene expression profile as a marker for antigen-specific T lymphocytes. It might be recommended that cytokine gene expression (IL-2, IL-5 and IFN-gamma) should be measured after 4-8 h of specific activation but also up to 24 h of stimulation is acceptable. Granzyme B should preferentially be measured after 48-72 h of activation.