OBJECTIVE: Despite high rates of long-lasting remissions in patients with chronic lymphocytic leukaemia (CLL) treated with chemoimmunotherapy, none of the current therapeutic approaches is curative with the exception of allogeneic transplantation. One strategy to extend progression-free survival and long-term survival might be the establishment of consolidation therapies.
METHODS: In this trial, patients with complete or partial second remission after fludarabine-based treatment received consolidation therapy with alemtuzumab. The aim of this phase I/II trial was to determine the maximal tolerable dose (MTD) of alemtuzumab consolidation and to evaluate safety and efficacy in patients who responded to second-line fludarabine-based treatment. Thirteen patients in complete (CR) or partial remission (PR) received alemtuzumab dose escalation starting with 10 mg intravenously (iv) once weekly for 8 wk and increasing in 10-mg intervals per dose level.
RESULTS: The main dose-limiting toxicities (DLTs) were infectious complications, and the MTD was determined at 10 mg. After alemtuzumab consolidation, seven of 13 patients (53%) were in CR, and four of these patients (30.7%) achieved minimal residual disease (MRD) negativity (<1 × 10E-4). At a median follow-up of 71.5 months, four patients were progression-free, with a median progression-free survival (PFS) of 28.5 months after the end of second-line treatment.
CONCLUSION: The results provide a safe and efficient schedule with weekly intravenous application of 10 mg of alemtuzumab as a consolidation regime in patients with CLL.

Alemtuzumab is FDA-approved for the treatment of chronic lymphocytic leukemia (CLL). Nonetheless, its use for this indication has fallen out of favor due to serious concerns for infectious complications and increased risks of second malignancies from the profound and lasting immunosuppression. We report here in a patient with a rapidly progressive metastatic Merkel cell carcinoma (MCC) who was previously treated with alemtuzumab and fludarabine for CLL. He developed profound lymphopenia and hypogammaglobulinemia. While the risk of MCC is increased in CLL, its rapid dissemination has not been previously reported with fludarabine alone. In light of the rapidly fatal outcome in our patient due to MCC, we advise caution with the use of alemtuzumab. In patients treated with alemtuzumab for nononcologic indications, aggressive surveillance for cutaneous malignancies should be implemented until its safety profile can be further characterized.

Leukemia cutis describes the infiltration and dissemination of neoplastic leukemic cells into the epidermis, dermis, or subcutis, resulting in clinically identifiable cutaneous lesions. Depending on the type of leukemia, a wide range of clinical and histopathological findings may be encountered. This report describes a patient with a rosacea-like eruption as a unique clinical presentation of T-cell prolymphocytic leukemia.

The development of non-chemotherapeutic agents, including monoclonal antibodies (mAbs) and other targeted drugs, makes chemotherapy-free treatment an attractive option for chronic lymphocytic leukemia (CLL). The classical mAb, rituximab, has been authorized for use in both first-line and second-line therapy for CLL. New mAbs directed against CD20, ofatumumab, and obinutuzumab (GA-101) have also been approved for the treatment of this disease. Recently, several new mAbs with potential benefits over the approved anti-CD20 antibodies have been developed for use in CLL. Anti-CD37, anti-CD19, and anti-CD40 mAbs are in early clinical trials and show promise in treating CLL. In addition, the combination of mAbs with B-cell receptor signaling pathway inhibitors and immunomodulatory drugs makes the chemotherapy-free option a reality today. Combinations of antibodies with targeted drugs like ibrutinib, idelalisib, or lenalidomide are expected to replace chemotherapy-based combinations for treating CLL in the near future. However, phase III trials should confirm the benefit of these new treatment strategies and establish their exact place in the therapeutic armamentarium for CLL.

PURPOSE: Treatment of refractory Hodgkin disease deserves specific considerations. Recently, alemtuzumab-BEAM has been introduced in allogeneic hematopoietic stem cell transplantation (HSCT) in these patients.
METHODS: We retrospectively analyzed the outcome of 20 patients with relapsed/refractory Hodgkin's lymphoma (HL) who received allogeneic HSCT following conditioning therapy with alemtuzumab-BEAM.
RESULTS: Treatment-related toxicity was tolerable. Half of the patients (50 %) had infections. Of these, 50 % were found to have pneumonia or catheter-related infections. In 20 %, an oral mucositis was observed. Acute graft-versus-host disease (GvHD) (≥grade 2) was seen in three patients. Complete remission (CR) could be achieved in 17 patients (85 %), 2 patients had persistent Hodgkin disease, and 1 patient died from infection prior to CR evaluation. Median progression-free survival and overall survival were 17.9 and 67.5 months, respectively. From the 17 CR patients, 8 had a relapse after a median of 10 months. Notably, of the eight patients relapsing after HSCT, all patients received another salvage treatment and four patients are still alive, whereas the other four patients died due to further progress. Six out of the remaining nine patients are still in CR, whereas the other three died from chronic GvHD and multi-organ failure. Overall, seven patients experienced chronic GvHD.
CONCLUSION: In summary, alemtuzumab-BEAM is a well-tolerated conditioning therapy for allogeneic HSCT with high response rates in refractory HL.

PURPOSE: In patients undergoing allogeneic stem cell transplantation, conditioning regimens containing alemtuzumab instead of anti-thymocyte globulin (ATG) may result in an earlier platelet engraftment and a reduced number of platelet transfusions.
METHODS: We performed a retrospective, single-center, case-control study analyzing time to engraftment and transfusion needs using alemtuzumab in comparison with ATG as part of conditioning protocol.
RESULTS: Median values for time to platelet engraftment, number of transfused platelet concentrates and number of transfused red cell concentrates were 12 versus 19.5 days (p < 0.001), 2 versus 14 (p < 0.001) and 6 versus 14.5 (p = 0.003) in the alemtuzumab and ATG group. Time to leukocyte engraftment did not differ with median 15 days in both groups. Patients in the ATG group showed a significant higher decrease in platelet count during conditioning (68 vs. 29 %, p = 0.001), leading to significant lower median platelet counts at the day of stem cell infusion (38 vs. 95.5 Gpt/l, p = 0.008), and higher values for median C-reactive protein after first antibody infusion (69.0 vs. 43.6 mg/l, p = 0.001) compared with alemtuzumab group. Test for significance was done by using Wilcoxon rank-sum test. Subgroup analysis considering the type of ATG used (Thymoglobulin vs. ATG Fresenius) revealed that differences between alemtuzumab and ATG group were more due to effects of ATG Fresenius than Thymoglobulin.
CONCLUSIONS: The use of alemtuzumab in comparison with ATG as part of the conditioning regimen may be an approach to reduce the number of transfused platelet and red cell concentrates after allogeneic stem cell transplantation.

Mediastinal nonseminomatous germ cell tumor (MNSGCT)-associated histiocytic proliferations are rare and rapidly fatal disorders. Standard treatment modalities have yet to be established.We report a case of MNSGCT-associated hemophagocytic syndrome that evolved into malignant histiocytosis/disseminated histiocytic sarcoma (MH/HS), which was initially treated with intravenous immunoglobulin, corticosteroids, and cyclosporine. Then, thalidomide plus cyclophosphamide, adriamycin, oncovin, prednisolone chemotherapy followed by alemtuzumab-containing reduced-intensity allogeneic peripheral blood stem cell transplantation (PBSCT) was used as salvage therapy.The severe constitutional symptoms and pancytopenia resolved shortly after thalidomide with cyclophosphamide, adriamycin, oncovin, prednisolone. After PBSCT, the patient developed steroid-dependent skin graft-versus-host disease, but maintained a functional life for 1.5 years. Rapid resolution of chronic graft-versus-host disease preceded the fulminant recurrence of hemophagocytic syndrome and MH/HS.Thalidomide plus chemotherapy followed by alemtuzumab-containing reduced intensity allogeneic PBSCT is effective in allaying MNSGCT-associated histiocytic disorders, but does not prevent eventual relapse. However, further posttransplant immune modulation should be developed to completely eradicate the residual MH/HS cells.

The biology of engraftment syndrome is poorly understood, and the degree of overlap with acute graft-versus-host disease (GVHD) is unclear. To understand engraftment syndrome better, plasma cytokine profiles were evaluated in 56 pediatric allogeneic bone marrow transplant recipients before transplant, on the day of stem cell infusion, and weekly until day +100. Patients were divided into 4 groups: those with isolated engraftment syndrome (n = 8), acute GVHD (n = 12), both engraftment syndrome and acute GVHD (n = 4), and neither engraftment syndrome nor acute GVHD (n = 32). Engraftment syndrome was observed a median of 13.5 days (range, 10 to 28) after transplant, whereas acute GVHD was diagnosed a median of 55 days (range, 19 to 95) after transplant. Four patients developed both engraftment syndrome at a median of 10.5 days (range, 10 to 11) and acute GVHD at a median of 35 days (range, 23 to 56) after stem cell infusion. Median plasma levels of IL-1β, IL-6, IL-12, IL-4, and IL-13 were significantly elevated in patients with isolated engraftment syndrome when compared with isolated acute GVHD. A rise of proinflammatory cytokines (IL-1β, IL-6, and IL-12) was followed by surge in anti-inflammatory cytokines (IL-4 and IL-13) in patients with isolated engraftment syndrome. The observation of elevated IL-1β suggests that engraftment syndrome could be an inflammasome mediated phenomenon.

BACKGROUND: Alemtuzumab has single-agent activity in relapsed peripheral T cell lymphoma (PTL), but the optimal dose and/or schedule in combination with chemotherapy for first-line use is unknown. The primary objectives were to establish the maximally tolerated dose and pharmacokinetics (PK) of alemtuzumab combined in this way.
PATIENTS AND METHODS: Adult patients with untreated CD52-positive (CD52(+)) PTL were enrolled in a phase I trial. Alemtuzumab was given subcutaneously in escalating doses and/or schedules in combination with CHOP (cyclophosphamide, adriamycin, vincristine and prednisone) using a 3+3 design. Trough PK of alemtuzumab were measured on day 1 of each 21-day cycle and B and T cell subsets were serially measured.
RESULTS: Twenty patients were enrolled across 4 dose levels. Dose-limiting toxicities necessitated expansion at 10 mg weekly (fatal tuberculosis reactivation) and 60 mg every 3 weeks (grade 4 thrombocytopenia) dose levels. Maximally tolerated dose was not reached. Ten patients developed asymptomatic cytomegalovirus reactivations at a median of 39 days (range, 4-99 days). Two patients developed fungal pneumonias. The overall and complete response rates were 68% and 37%, respectively. Highest day 1 alemtuzumab trough levels were achieved at 60 mg (1973 ng/mL), but with significant inter- and intradose variability. Lymphopenia at baseline was common and T cell recovery was significantly delayed.
CONCLUSION: With monitoring and prophylaxis, alemtuzumab 60 mg combined with CHOP showed activity in CD52(+) PTL and achieved the highest drug levels.

Reactivation of hepatitis B virus (HBV) is a known complication that occurs in patients receiving chemotherapy especially for malignant lymphoma. The increased risk in lymphoma patients parallels the potency of the immunosuppressive treatment regimens that are provided. B-cell-depleting therapy such as anti-CD20 monoclonal antibodies, especially when combined with conventional chemotherapy, significantly increases the risk of HBV reactivation, even in patients with resolved HBV infection. The first reports of HBV reactivation with anti-CD20 therapy emerged only 4 years after its US Food and Drug Administration approval. Today, these drugs carry alert warnings on the risk of hepatic dysfunction and reactivation of HBV infection. Many other new/novel agents active against lymphoma have emerged since then, targeting the different pathways involved in lymphoma pathogenesis, including histone deacetylase inhibitors, antibody-drug conjugates, and proteasome inhibitors. These various drugs have differing depths and mechanisms of immunosuppression, necessitating due diligence when administrating these compounds to prevent infective complications such as HBV reactivation, which can lead to liver failure and death. This review focuses on HBV reactivation with non-Hodgkin lymphoma treatment, in particular with the various approved novel agents. We also discuss the current recommendations for screening non-Hodgkin lymphoma patients for HBV and the role of prophylactic antiviral therapy during and after immunosuppressive treatment.

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients requiring initial therapy are often older and frailer and unsuitable candidates for standard chemoimmunotherapy regimens. Shorter duration combination monoclonal antibody (mAb) therapy using alemtuzumab and rituximab has been shown to be effective and tolerable treatment for CLL. Standard dose anti-CD20 mAb therapy causes loss of CD20 expression by surviving CLL cells, which can be minimized by decreasing the mAb dose. We report a randomized phase II clinical trial enrolling older (≥ 65 years) patients (median age 76 years, n = 31) with treatment naïve progressive CLL. Patients received 8-12 weeks of standard subcutaneous alemtuzumab with either intravenous standard (375 mg/m(2) weekly)(n = 16) or low dose (20 mg/m(2) 3x week)(n = 15) rituximab. This study was closed before full accrual because the manufacturer withdrew alemtuzumab for treatment of CLL. The overall response rate was 90% with an 45% complete response rate, median progression-free survival of 17.9 months and no significant differences in outcome between the low and standard dose rituximab arms. The major toxicities were cytopenia and infection with one treatment fatality caused by progressive multifocal leukoencephalopathy but no other opportunistic infections. Combination mAb therapy was effective and tolerable treatment for older and frailer patients with progressive CLL, achieving a high rate of complete remissions. These data support the role of mAb in therapy for less fit CLL patients and the further study of low dose higher frequency anti-CD20 mAb therapy as a potentially more effective use of anti-CD20 mAb in the treatment of CLL.

B-cell (B-PLL) and T-cell (T-PLL) prolymphocytic leukemias are rare, poor-prognosis lymphoid neoplasms with similar presentation characterized by symptomatic splenomegaly and lymphocytosis. They can be distinguished from each other and from other T- and B-cell leukemias by careful evaluation of morphology, immunophenotyping, and molecular genetics. The clinical behavior is typically aggressive, although a subset of patients may have an indolent phase of variable length. First-line therapy for T-PLL is with intravenous alemtuzumab and for B-PLL is with combination purine analog-based chemo-immunotherapy. New B-cell receptor inhibitors, such as ibrutinib and idelalisib, may have a role in the management of B-PLL, especially for the patients harboring abnormalities of TP53. Allogenic stem cell transplantation should still be considered for eligible patients and may be the only current therapy capable of delivering a cure. In the past few years, many of the molecular mechanisms underlying disease pathogenesis and progression have been revealed and are likely to lead to the development of novel targeted approaches.

Mycosis fungoides (MF) and its leukemic variant, Sézary syndrome (SS), are malignancies of skin-homing T cells that comprise the majority of cutaneous T cell lymphomas (CTCL). Treatment of CTCL is limited and can be approached by skin-directed therapy or systemic therapy. Recent investigations into the pathogenesis of MF and SS have broadened the therapeutic targets; here, we review emerging concepts in the pathogenesis of MF and SS as well as novel and traditional systemic therapies for MF and SS. These include histone deacetylase inhibitors (vorinostat, romidepsin, panobinostat, and belinostat), monoclonal antibodies (alemtuzumab, brentuximab vedotin, and mogamulizumab) and single-agent cytotoxic chemotherapeutic agents (e.g., pralatrexate, doxorubicin, bendamustine, and forodesine), as well as multi-agent chemotherapy regimens.

Waldenström's macroglobulinemia (WM) is a rare, low-grade malignancy with no established standard of care. Rituximab regimens are most commonly used, supported by their efficacy in hematologic malignancies, including WM. A growing number of investigational regimens for WM have been evaluated in phase II clinical trials, including single-agent and combination strategies that include newer-generation monoclonal antibodies (ofatumumab and alemtuzumab), proteasome inhibitors (bortezomib and carfilzomib), immunomodulatory agents (thalidomide and lenalidomide), phosphoinositide 3-kinase/protein kinase B (Akt)/mammalian target of rapamycin pathway inhibitors (everolimus and perifosene), a Bruton's tyrosine kinase inhibitor (ibrutinib), and a histone deacetylase inhibitor (panobinostat). Other novel agents are in early-stage development for WM. International treatment guidelines for WM suggest suitable regimens in the newly diagnosed and relapsed/refractory settings, in accordance with patient age, disease presentation, and efficacy and safety profiles of particular drugs. These factors must be considered when choosing appropriate therapy for individual patients with WM, to maximize response and prolong survival, while minimizing the risk of adverse events. This review article provides a clinical perspective of the modern management of patients with WM, in the context of available trial data for novel regimens and recently updated treatment guidelines.

Use of monoclonal antibodies (mAbs) has revolutionized cancer therapy. Approaches targeting specific cellular targets on the malignant cells and in tumor microenvironment have been proved to be successful in hematologic malignancies, including cutaneous lymphomas. mAb-based therapy for cutaneous T-cell lymphoma has demonstrated high response rates and a favorable toxicity profile in clinical trials. Several antibodies and antibody-based conjugates are approved for use in clinical practice, and many more are in ongoing and planned clinical trials. In addition, these safe and effective drugs can be used as pillars for sequential therapies in a rational stepwise manner.

OBJECTIVE: We conducted a single-center retrospective analysis to determine the impact of the anti-CD52 monoclonal antibody alemtuzumab including route of administration compared to non-alemtuzumab-containing regimens in T-prolymphocytic leukemia (T-PLL).
PATIENTS AND METHODS: The study was a retrospective analysis of a consecutive cohort of adult patients diagnosed with T-PLL at Mayo Clinic Rochester from January 1, 1997, through September 30, 2014.
RESULTS: A total of 41 patients were diagnosed with T-PLL per the World Health Organization 2008 classification. The median age was 66 years, and 23 (56%) were male. After a median follow-up of 18 months (range, 0.4-66.1 months), 32 patients (78%) had died, with a median overall survival of 16.9 months. Approximately half the cohort was treated with alemtuzumab, almost exclusively after 2004. Median survival for patients receiving intravenous alemtuzumab-based therapy was 40.5 versus 10.3 months for all other therapies (P = .0004). A significant survival difference between intravenous versus subcutaneous alemtuzumab administration of 40.5 versus 13.7 months was noted (P = .0014). Only 4 (14%) of 28 patients aged < 70 years underwent hematopoietic stem cell transplantation, with a median survival after transplantation of 4 months.
CONCLUSION: In this large series of T-PLL patients treated at a single tertiary-care center, we confirmed the prior observation of the superiority of intravenous alemtuzumab over other therapies. Hematopoietic stem cell transplantation was feasible in a minority of potentially eligible patients. Early transplant referral should be considered for all eligible patients.

World Health Organization-defined myeloproliferative neoplasms share a common pathobiologic theme of constitutive activation of tyrosine kinases (TKs). While myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRA or PDGFRB exhibit exquisite responsiveness to imatinib, other eosinophilic disorders such as chronic eosinophilic leukemia--not otherwise specified (CEL-NOS) and idiopathic hypereosinophilic syndrome (HES) lack recurrent gene mutations or known druggable targets. In systemic mastocytosis (SM), KIT D816V is identified in ∼ 90% of patients, but demonstrates imatinib resistance. Recently, the multikinase/KIT inhibitor midostaurin (PKC412) has demonstrated encouraging activity in patients with advanced SM, and selective KIT D816V inhibitors are entering clinical development. Pre-clinical rationale also exists for use of small molecule inhibitors of TK-linked pathways (e.g., BTK, JAK-STAT, PI3K/AKT, and FGFR1) that are implicated in normal or dysregulated signaling in eosinophils or mast cells. A complementary therapeutic approach is the use of naked antibody (e.g., mepolizumab and alemtuzumab) or antibody-based drug immunoconjugates (brentuximab vedotin) against targets expressed on the surface of eosinophils or mastocytes that can block proliferation and/or induce apoptosis of these cells. Ultimately, biologic and molecular characterization of eosinophilia and SM cases will help to optimize selection of TK inhibitors or therapeutic antibodies for individual patients.

BACKGROUND: Alemtuzumab is effective in fludarabine-refractory patients with chronic lymphocytic leukemia. We performed a phase 2 study of alemtuzumab in combination with fludarabine in patients with relapsed disease.
PATIENTS AND METHODS: Patients received alemtuzumab and fludarabine daily on days 1 to 5 of a 28-day cycle for up to 6 cycles with the primary objective of determining the rate of complete response. Of 60 enrolled patients, 51 had previously received fludarabine, and 60% had received 3 or more prior therapies.
RESULTS: Five patients experienced complete response (8.3%) and 12 experienced partial response, yielding an overall response rate of 28.3% for the intention-to-treat population. Among the 41 patients who completed at least 4 cycles of therapy, the complete response rate was 20%. Median progression-free survival was 211 days. Forty-seven percent of patients experienced cytomegalovirus viremia, including 4 patients with symptomatic cytomegalovirus disease. All patients responded to antiviral therapy.
CONCLUSION: Despite some evidence of efficacy in this setting, the primary end point for the study was not met. In the era of targeted agents that are well tolerated, the combination of fludarabine and alemtuzumab should be used rarely for a select group of fit patients who are refractory to standard therapies.

INTRODUCTION: Sézary syndrome (SS) is characterized by rapidly progressive disease and poor survival. Although there is no standard treatment for SS, allogeneic stem cell transplantation (alloSCT) is the only treatment available that may offer a long survival. Alemtuzumab, a humanized monoclonal antibody that targets CD52, has reported some efficacy in this disease.
AIMS: To describe the experience with alemtuzumab treatment in patients with SS in our center.
MATERIALS AND METHODS: A total of six patients received alemtuzumab subcutaneously at different dosing regimens.
RESULTS: The median time of follow-up after alemtuzumab was 6 months (range 3-29 months). The overall response rate was 83.3% (5/6) with 66.7% complete responses. The disease-free survival (DFS) at 6 months was 33.3%. Increased DFS was observed in patients undergoing an alloSCT after alemtuzumab treatment. The overall survival at 6 months was 60%.
CONCLUSIONS: Alemtuzumab is an effective treatment in advanced mycosis fungoides/SS for palliation of symptoms and may be useful as a bridge therapy before alloSCT in relapsed/refractory patients.

Monoclonal antibodies (moAb) represent a novel way of delivering therapy through specific target antigens expressed on lymphoma cells and minimizes the collateral damage that is common with conventional chemotherapy. The paradigm of this approach is the targeting of CD20 by rituximab. Since its FDA approval in 1997, rituximab has become the standard of care in almost every line of therapy in most B-cell lymphomas. This review will briefly highlight some of the key rituximab trials while looking more closely at the evidence that is bringing other antibodies, including next generation anti-CD20 moAbs, and anti-CD30 moAbs, among others to the forefront of lymphoma therapy.

To evaluate the effect of first-line and subsequent therapies, the outcome of 1,558 patients with chronic lymphocytic leukemia from five prospective phase II/III trials conducted between 1999 and 2010 was analyzed. The 3-year overall survival rate was higher after first-line treatment with chemoimmunotherapies such as fludarabine/cyclophosphamide/rituximab (87.9%) or bendamustine/rituximab (90.7%) compared to chemotherapies without an antibody (fludarabine/cyclophosphamide: 84.6%; fludarabine: 77.5%; chlorambucil: 77.4%). Furthermore, the median overall survival was longer in patients receiving at least one antibody-containing regimen in any treatment line (94.4 months) compared to the survival in patients who never received an antibody (84.3 months, P<0.0001). Univariate Cox regression analysis demonstrated that patients who did receive antibody treatment had a 1.42-fold higher risk of death (hazard ratio, 1.42; 95% confidence interval: 1.185-1.694). Therapies administered at relapse were very heterogeneous. Only 55 of 368 patients (14.9%) who started second-line treatment >24 months after first-line therapy repeated the first-line regimen. Among 315 patients requiring treatment ≤24 months after first-line therapy, cyclophosphamide/doxorubicin/vincristine/prednisone with or without rituximab as well as alemtuzumab were the most commonly used therapies. In these early relapsing patients, the median overall survival was shorter following therapies containing an anthracycline and/or three or more cytotoxic agents (e.g. cyclophosphamide/doxorubicin/vincristine/prednisone or fludarabine/cyclophosphamide/mitoxantrone, 30.0 months) compared to single agent chemotherapy (e.g. fludarabine; 39.6 months) and standard chemoimmunotherapy (e.g. fludarabine/cyclophosphamide/rituximab: 61.6 months). In conclusion, the analysis confirms the superior efficacy of chemoimmunotherapies in patients with chronic lymphocytic leukemia. Moreover, the use of aggressive chemo(immuno)therapy combinations in patients with an early relapse does not offer any benefit when compared to less intensive therapies. Trial identifier: NCT00281918, ISRCTN75653261, ISRCTN36294212, NCT00274989 and NCT00147901.

Unconjugated monoclonal antibodies (mAbs) are an important component of effective combination therapies for chronic lymphocytic leukaemia (CLL). Antibody-dependent phagocytosis (ADP) is a major mediator of mAb cytotoxicity, but there is limited knowledge of the determinants of ADP efficacy. We used macrophages derived in vitro from autologous circulating monocytes to test the effects of mAb structure and concentration, target : effector cell ratio, duration of co-incubation and CLL cell CD20 expression on ADP. Next-generation anti-CD20 mAbs (ofatumumab, ublituximab, obinutuzumab, ocaratuzumab) were significantly more effective at inducing ADP compared to rituximab, but none were as effective as the anti-CD52 mAb alemtuzumab. Ofatumumab (10 μg/ml) used as a representative next-generation anti-CD20 mAb achieved an ADP plateau at 3 h co-incubation with a target : effector ratio of 10 : 1 (mean = 2.1 CLL cells/macrophage, range = 1.5-3.5). At 0.156 μg/ml (the lowest concentration tested) ofatumumab ADP was significantly higher than alemtuzumab. However, ofatumumab-induced ADP did not increase significantly at higher mAb concentrations. We show that anti-CD20 mAb ADP efficacy is determined by the mAb characteristics, target : effector ratio and incubation time. We suggest that preclinical evaluation of anti-CD20 mAbs to understand the determinants of ADP could be useful in designing future combination therapies for CLL.

Relapsed/refractory chronic lymphocytic leukemia (CLL) represents a clinical challenge, in particular when high risk gene mutations occur. In this setting, alemtuzumab was recognized to be effective. This retrospective study evaluates long-term efficacy and tolerability of low-dose alemtuzumab in relapsed/refractory CLL and correlates clinical outcome with biological feature. Sixty-two consecutive patients (median age 68 years) were evaluated; alemtuzumab was administered 30 mg weekly for up to 18 weeks. Among the patients included in the analysis, 37% were fludarabine-refractory, 33.3% carried a TP53 disruption, 14.8% a NOTCH1 mutation and 9% a SF3B1 mutation. Overall response rate (ORR) was 61.3% (complete remission 25.8%). After a median follow-up of 43 months, overall survival (OS) and progression free survival (PFS) were 43.1 and 15 months, respectively; while ORR was 77.8% for patients carrying TP53 disruptions (OS 33.8 months) and 43.5% for fludarabine-refractory patients (OS 30 months). Noteworthy, long-term survivors (OS ≥ 36 months) were 54.8%. None of the biological poor risk factors negatively impacted on ORR, PFS and OS. Grade ≥3 cytopenia occurred in 24.2% patients, 6.5% experienced a grade ≥3 non-CMV infection and no grade ≥3 CMV-event occurred. In conclusion, low dose-alemtuzumab is safe and effective in relapsed/refractory CLL, also in a long-term follow-up and high-risk genetic subgroups.

Reactivation of viral infections is common in patients with solid tumour or haematological malignancy. Incidence and severity depend on the extent of cellular immunosuppression. Antiviral prophylaxis may be effective to prevent viral reactivation. In 2006, the Infectious Diseases Working Party of German Society for Hematology and Medical Oncology (DGHO) published guidelines for antiviral prophylaxis in these patient populations. Here, we present an update of these guidelines for patients with solid and haematological malignancies undergoing antineoplastic treatment but not allogeneic stem cell transplantation. Relevant literature for reactivation of different viruses (herpes simplex virus (HSV), varicella zoster virus (VZV), hepatitis B virus (HBV) and respiratory viruses) is discussed to provide evidence-based recommendations for clinicians taking care of this patient population. We recommend a risk-adapted approach with (val)acyclovir against HSV and VZV in patients treated with alemtuzumab, bortezomib or purine analogues. Seasonal vaccination against influenza is recommended for all patients with solid or haematological malignancies regardless of antineoplastic therapy. Hepatitis B screening is recommended in lymphoproliferative disorders, acute leukaemia, and breast cancer, and during treatment with monoclonal anti-B-cell antibodies, anthracyclines, steroids and in autologous stem cell transplantation. In those with a history of hepatitis B prophylactic lamivudine, entecavir or nucleotide analogues as adefovir are recommended to prevent reactivation.

INTRODUCTION: Over the last few years, several new immunological drugs, particularly monoclonal antibodies (mAbs), immunomodulatory drugs and B-cell receptor (BCR) pathway inhibitors have been developed and investigated in chronic lymphocytic leukemia (CLL). This article summarizes recent discoveries regarding their mechanism of action, pharmacological properties, clinical activity and toxicity, as well as the emerging role of these agents in CLL.
AREAS COVERED: A literature review of mAbs, BCR pathway inhibitors and immunomodulating drugs was conducted of the MEDLINE database via PubMed for articles in English. Publications from 2000 through February 2015 were scrutinized. The search terms used were alemtuzumab, BI 836826, duvelisib ibrutinib, idelalisib, lenalidomide, monoclonal antibodies, MEDI-551, MOR208, obinutuzumab, ocaratuzumab, ofatumumab, ONO-4059, otlertuzumab, spebrutinib, veltuzumab and XmAb5574 in conjunction with CLL. Conference proceedings from the previous 5 years of the American Society of Hematology, European Hematology Association, American Society of Clinical Oncology, and ACR/ARHP Annual Scientific Meetings were searched manually. Additional relevant publications were obtained by reviewing the references from the chosen articles.
EXPERT OPINION: The use of mAbs, BCR inhibitors and immunomodulating drugs is a promising new strategy for chemotherapy-free treatment of CLL. However, definitive data from ongoing and future clinical trials will aid in better defining the status of immunological drugs in the treatment of this disease.

Relapsed and refractory (rel/ref) mantle cell lymphoma (MCL) portend a dismal prognosis. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) represents the only potentially curative therapy in this setting. We analyzed the survival outcomes of 29 recipients of non-myeloablative allo-HSCT for rel/ref MCL, and studied possible prognostic factors in this setting. The cumulative incidences of disease progression and non-relapse mortality at 3 years were 28% (95% confidence interval (CI): 13-46%) and 29% (95% CI: 13-47%), respectively. The cumulative incidence of grade II-IV acute GvHD at days +100 and +180 was 34% (95% CI: 18-52%) and 45% (95% CI: 26-62%), respectively. With a median follow-up in survivors of 53 (range 24-83) months, the 3-year overall survival (OS) and PFS were 54% (95% CI: 38-76%) and 41% (95% CI: 26-64%), respectively. In vivo T-cell depletion with alemtuzumab (n=6) was associated with inferior 3-year PFS (0% vs 51%, P=0.007) and OS (17% vs 64%, P=0.014). Conversely, a second-line international prognostic index (sIPI) at transplantation equal to 0 (no risk factors) was associated with an improved 3-year PFS (52% vs 22%, P=0.020) and OS (71% vs 22%, P=0.006) compared with sIPI ⩾1. Performing an allo-HSCT before 2007 was associated with a decreased 3-year OS (25% vs 76%, P=0.015) but not with a significantly inferior PFS (17% vs 59%, P=0.058). In this single-center series, we report encouraging results with allo-HSCT for patients with rel/ref MCL. High alemtuzumab doses should probably be avoided in this context.

T cell prolymphocytic leukemia (T-PLL) is a rare, mature T cell neoplasm with distinct features and an aggressive clinical course. Early relapse and short overall survival are commonplace. Use of the monoclonal anti-CD52 antibody alemtuzumab has improved the rate of complete remission and duration of response to more than 50% and between 6 and 12 months, respectively. Despite this advance, without an allogeneic transplant, resistant relapse is inevitable. We report seven complete and one partial remission in eight patients receiving alemtuzumab and cladribine with or without a histone deacetylase inhibitor. These data show that administration of epigenetic agents can overcome alemtuzumab resistance. We also report epigenetically induced expression of the surface receptor protein CD30 in T-PLL. Subsequent treatment with the anti-CD30 antibody-drug conjugate brentuximab vedotin overcame organ-specific (skin) resistance to alemtuzumab. Our findings demonstrate activity of combination epigenetic and immunotherapy in the incurable illness T-PLL, particularly in the setting of previous alemtuzumab therapy.

Anaplastic lymphoma kinase (ALK) expression is uncommon in primary cutaneous T-cell-lymphomas (CTCL). We report the case of a patient who was initially diagnosed with small plaque parapsoriasis, and eventually developed an unusual manifestation of CTCL 6 years later. The disease was characterized by aggressively ulcerating plaques and tumors of the entire skin. Histopathology revealed monoclonal proliferation of atypical T-lymphocytes and CD30-positive blasts with expression of ALK and identification of an ATIC-ALK fusion protein. Extensive staging confirmed the primary cutaneous origin of the lymphoma. After failure of several conventional treatments including polychemotherapy, the patient finally achieved remission after receiving brentuximab-vedotin, alemtuzumab and subsequent allogeneic stem cell transplantation. In the following, the patient developed inflammatory cutaneous lesions that pathologically showed no evidence for lymphoma relapse or classical cutaneous graft-versus-host disease. The patient responded to immunosuppression, but finally died from multi-organ failure due to sepsis 8 months after stem cell transplantation. This is a rare instance of ALK positivity in a CTCL, most likely resembling CD30+ transformed mycosis fungoides, because it was not typical for cutaneous anaplastic large cell lymphoma (ALCL). In contrast to its role in systemic ALCL as favorable prognostic marker, ALK expression here was associated with an aggressive course.

The combination of reduced-intensity conditioning, (188)rhenium anti-CD66 radioimmunotherapy, and in vivo T cell depletion was successfully applied in elderly patients with acute myeloid leukemia or myelodysplastic syndrome. Within a prospective phase II protocol, we investigated whether a dose reduction of alemtuzumab (from 75 mg to 50 mg MabCampath) would improve leukemia-free survival by reducing the incidence of relapse. Fifty-eight patients (median age, 67 years; range, 54 to 76) received radioimmunotherapy followed by fludarabine 150 mg/m(2) and busulfan 8 mg/kg combined with either 75 mg (n = 26) or 50 mg (n = 32) alemtuzumab. Although we observed a trend towards a shorter duration of neutropenia in the 50 mg group (median, 19 versus 21 days; P = .07), the time from transplantation to neutrophil and platelet engraftment as well as the overall incidence of engraftment did not differ. The incidence of severe acute graft-versus-host disease tended to be higher after the lower alemtuzumab dose (17% versus 4%; P = .15). No significant differences in the cumulative incidences of relapse (38% versus 35%; P = .81) or nonrelapse mortality (46% versus 27%; P = .31) were observed. Accordingly, disease-free and overall survival were not significantly different between groups. Although the feasibility of radioimmunotherapy plus reduced-intensity conditioning could be demonstrated in elderly patients, the dose reduction of alemtuzumab had no positive impact on overall outcome.

Central nervous system (CNS) relapse in non-Hodgkin lymphoma (NHL) carries a very poor prognosis. Risk factors and outcome have been studied in aggressive B-cell lymphomas, but very little is known about the risk in peripheral T-cell lymphoma (PTCL). We aimed at analyzing risk factors for CNS involvement at first relapse or progression, as well as the outcome of these patients, in a large population-based cohort of patients with PTCL. Twenty-eight out of 625 patients (4.5%) developed CNS disease over time. In multivariable analysis, disease characteristics at diagnosis independently associated with an increased risk for later CNS involvement were involvement of more than 1 extranodal site (hazard ratio [HR], 2.60; 95% confidence interval [CI], 1.07-6.29; P = .035) and skin (HR, 3.51; 95% CI, 1.26-9.74; P = .016) and gastrointestinal involvement (HR, 3.06; 95% CI, 1.30-7.18; P = .010). The outcome of relapsed/refractory patients was very poor, and CNS involvement was not associated with a significantly worse outcome compared with relapsed/refractory patients without CNS involvement in multivariable analysis (HR, 1.6; 95% CI, 0.96-2.6; P = .074). The results from the present study indicate that CNS relapse in PTCL occurs at a frequency similar to what is seen in aggressive B-cell lymphomas, but the poor outcomes in relapse are largely driven by systemic rather than CNS disease.