Administration Of Alemtuzumab Research Articles

Low Transplant Related Mortality Following Matched Unrelated Donor Allogeneic Transplantation in High Risk Patients Utilizing Low Dose Subcutaneous Campath.

The administration of alemtuzumab (Campath 1H) as part of the conditioning regimen prior to allogeneic stem cell transplantation (ASCT) results in a low incidence of acute and chronic GVHD. However, intravenous Campath administration is also associated with significant infusional toxicities and a higher risk of infectious complications post-transplant. We evaluated the role of low-dose subcutaneous Campath prior to unrelated donor ASCT in 13 patients deemed to be at high risk for mortality (age>40years, significant comorbidity, or prior autologous transplant). Median age of transplant recipients was 54 (37–61) years and three patients had a prior autograft. Diseases included secondary/poor risk AML-5, CML-1, MPS-2, relapsed HD-1, NHL-3, and CLL-1. The preparative regimen consisted of fludarabine and targeted oral busulfan (myeloid malignancies) or cytoxan±rituximab (lymphoid malignancies). Campath was administered subcutaneously from d-5 to d-3 at a total dose of 43mg. Low dose Campath was well tolerated with no untoward toxicity. Early mixed T cell chimerism generally occurred (median day +100 donor CD3 60% (8–100) and CD33 100% (67–100)), requiring door lymphocyte infusion (DLI) in 10 of 13 patients. Ten of 11 evaluable patients achieved complete donor chimerism at a median of 112 days (32–260), and no graft failures have occurred. Acute graft-versus-host disease (GVHD) occurred in 5/13 patients (38%) at median day +58 (23–152) (grade I[1] and II[4]). Chronic GVHD occurred in 6/12 evaluable patients (3 limited, 3 extensive) and no GVHD mortality has occurred. CMV reactivation occurred in 5 of 9 at-risk patients (55%) with a median day to reactivation of day +25 (9–38), median number of reactivations of 2 (1–4), but no CMV disease or mortality. After a median follow-up of 340 (84–631) days, eleven of thirteen patients survive for a one year actuarial survival of 83%. No patient has died from treatment-related mortality. Relapse occurred in 5/13 patients resulting in the death of two patients. Low dose subcutaneous campath administered during conditioning results in low TRM and promising survival in older high risk patients undergoing unrelated donor ASCT. [Display omitted]

A novel regimen incorporating the concomitant administration of fludarabine and alemtuzumab for the treatment of refractory adult acute lymphoblastic leukaemia: a report of three cases

A novel regimen incorporating the concomitant administration of fludarabine and alemtuzumab for the treatment of refractory adult acute lymphoblastic leukaemia: a report of three cases

Alemtuzumab in chronic lymphocytic leukemia.

With respect to outcomes such as survival, response rate, response duration, time to progression, and quality of life, is alemtuzumab a beneficial treatment option for patients with B-cell chronic lymphocytic leukemia (cll)?What toxicities are associated with the use of alemtuzumab?Which patients are more likely-or less likely-to benefit from treatment with alemtuzumab? Evidence was selected and reviewed by one member of the Hematology Disease Site Group (dsg) of Cancer Care Ontario's Program in Evidence-Based Care (pebc) and by methodologists. The practice guideline report was reviewed and approved by the Hema-tology dsg, which comprises hematologists, medical and radiation oncologists, and a patient representative. As part of an external review process, the report was disseminated to obtain feedback from practitioners in Ontario. Outcomes of interest were overall survival, quality of life, response rates and duration, and adverse event rates. A systematic review of the medline, embase, HealthStar, cinahl, and Cochrane Library databases was conducted to search for primary articles and practice guidelines. The evidence informed the development of clinical practice recommendations. The evidence review and recommendations were appraised by a sample of practitioners from Ontario, Canada, and were modified in response to the feedback received. The systematic review and modified recommendations were approved by a review body within the pebc. The literature review found no published randomized controlled trials (rcts) that evaluated alem-tuzumab alone or in combination with other chemotherapeutic agents for the treatment of relapsed or refractory cll. One rct evaluated alemtuzumab administered to consolidate a complete or partial response to first-line fludarabine-containing chemotherapy. That study was stopped early because of excessive grades 3 and 4 infection-related toxicity in the alemtuzumab arm. Patients receiving alemtuzumab experienced significantly improved progression-free survival as compared with patients undergoing observation. Six single-arm studies evaluated disease response with administration of alemtuzumab as a single agent in the treatment of patients with relapsed or refractory cll post-fludarabine. The pooled overall response rate was 38% (complete response: 6%; partial response: 32%). Adverse events associated with the use of alemtuzumab were commonly reported and included serious infusion-related, hematologic, and infection-related toxicities. This evidence-based recommendation applies to adult patients with B-cell cll. Treatment with alemtuzumab is a reasonable option for patients with progressive and symptomatic cll that is refractory to both alkylator-based and fludarabine-based regimens. The evidence supporting treatment with alemtuzumab comes principally from case series that evaluated disease response as the primary outcome measure. Patients should be informed that any possible beneficial effect of alemtuzumab on other outcome measures such as duration of response, quality of life, and overall survival are not supported in evidence and currently remain speculative. Treatment with alemtuzumab is associated with significant and potentially serious treatment-related toxicities. Patients must be carefully informed of the uncertain balance between potential risks of harm and the chance for benefit reported in studies. Given the current substantial uncertainty in this balance, patient preferences will likely play a large role in determining the appropriate treatment choice. Given the potential toxicities associated with alemtuzumab, and given the limited nature of the agent's testing in clinical trials in broad populations of patients with cll, the use of alemtuzumab in patients with important comorbidities may be associated with excessive risks.

Alemtuzumab (Campath-1H) in the treatment of chronic lymphocytic leukemia

Alemtuzumab (Campath-1H) is a humanized IgG1 monoclonal antibody that targets the human CD52 antigen. CD52 is expressed by a variety of lymphoid neoplasms and most human mononuclear cell subsets. In 2001, alemtuzumab was approved for marketing in the United States and Europe for use in patients with fludarabine-refractory chronic lymphocytic leukemia (CLL). In heavily pretreated patients with CLL, the overall response rate (ORR) is approximately 35%, and in previously untreated patients the ORR is greater than 80%, with a recent randomized study suggesting it is superior to alkylator-based therapy. Importantly, alemtuzumab is effective in patients with high-risk del(17p13.1) and del(11q22.3) CLL. Alemtuzumab combination studies with fludarabine and/or monoclonal antibodies such as rituximab have demonstrated promising results. Alemtuzumab is also being studied in CLL patients as consolidation therapy for treatment of minimal residual disease, in preparation for stem cell transplantation and to prevent acute and chronic graft versus host disease. Alemtuzumab is frequently associated with acute 'first-dose' reactions when administered intravenously, but is much better tolerated when administered subcutaneously without loss of therapeutic efficacy. Additional potential adverse events associated with alemtuzumab administration include myelosuppression as well as profound cellular immune dysfunction with the associated risk of viral reactivation and other opportunistic infections. Additional studies detailing the mechanism of action of alemtuzumab as well as new strategies for prevention of opportunistic infections will aid in the future therapeutic development of this agent.

Alemtuzumab in Chronic Lymphocytic Leukemia

Alemtuzumab is a humanized monoclonal antibody specific for CD52, a glycosylphosphatidylinositol-anchored, lymphocyte-surface glycoprotein. Administration of alemtuzumab to patients with chronic lymphocytic leukemia depletes normal and neoplastic lymphocytes from the blood, spleen and marrow, but appears to be less effective in resolving lymphadenopathy. Owing to its activity in clearing leukemia cells of patients who are refractory to purine analogs, such as fludarabine, alemtuzumab became the first and only monoclonal antibody approved by the US FDA and other regulatory authorities for the treatment of chronic lymphocytic leukemia. Here we review the results of clinical studies evaluating the activity and safety of alemtuzumab when used alone or in combination with other antileukemia agents for the treatment of this disease.

Opportunistic Infections in 547 Organ Transplant Recipients Receiving Alemtuzumab, a Humanized Monoclonal CD-52 Antibody

Alemtuzumab is being increasingly used for the prevention and/or treatment of acute allograft rejection in organ transplant recipients. We assessed the risks of infection in, to our knowledge, the largest cohort and broadest range of organ transplant recipients yet reported to have received alemtuzumab. All patients who received alemtuzumab from September 2002 through March 2004, either as induction therapy at the time of transplantation or for the treatment of rejection, were evaluated for the development of an opportunistic infection (OI) until death or for 12 months after receipt of the last dose of alemtuzumab. A total of 547 recipients were included, 65% of whom received alemtuzumab for induction therapy only. Overall, 56 recipients (10%) developed 62 OIs, including cytomegalovirus disease (n = 16), BK virus infection (n=12), posttransplantation lymphoproliferative disease (n=5), human herpesvirus 6 infection (n=1), parvovirus infection (n=1), esophageal candidiasis (n=12), cryptococcosis (n=2), invasive mold infection (n=4), Nocardia infection (n=4), mycobacterial infection (n=3), Balamuthia mandrillaris infection (n=1), and toxoplasmosis (n=1). Patients who received alemtuzumab for induction therapy were significantly less likely to develop an OI, compared with patients who received alemtuzumab for rejection therapy (4.5% vs. 21%; P<.001). Independent predictors of the development of an OI were administration of alemtuzumab for rejection therapy (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.8-6.8; P<.001), allograft failure (OR, 2.1; 95% CI, 1.1-4.4; P=.04), and receipt of a lung transplant (OR, 3.7; 95% CI, 1.7-8.0; P=.001) or an intestinal transplant (OR, 8.3; 95% CI, 3.5-19.5; P<.001). Patients who received alemtuzumab for the treatment of allograft rejection were significantly more likely to develop an OI, compared with patients who received alemtuzumab for induction therapy only. Such data have implications for new antimicrobial prophylactic strategies.

Self-Administered, Subcutaneous (SQ) Alemtuzumab To Eliminate Residual Disease in Patients (pts) with CLL.

Alemtuzumab is highly effective at eliminating chronic lymphocytic leukemia (CLL) from bone marrow, the usual site of residual disease following treatment with a fludarabine-based regimen. Eradication of residual disease has been associated with longer time to progression and overall survival. A clinical trial was conducted to evaluate the activity of alemtuzumab 30mg SQ thrice weekly for 4 weeks each course (up to 2) to eliminate residual disease. Eligible pts were recently treated and achieved NCI-WG partial remission (PR) with measurable disease or complete remission (CR) with residual disease present in the bone marrow by 2-color flow cytometry. Responders on this trial were pts with NCI-WG PR that converted to CR or nodular PR, pts with nPR converted to CR, or pts in CR that had no evidence of disease by 2-color flow cytometry following treatment. To date, 29 pts have been enrolled and treated, 3 CR, 7 nPR, and 19 PR. The median number of prior treatments was 1 (range, 1–6); 2 PR pts were fludarabine-refractory. The median age=65(49–82) yrs; WBC=4.9(2.5–18.3)K/μ L; HGB=13.7(10.8–16.6)g/dL; PLT=186(93–418)K/μ L; ANC 2.4(.2–7.1)K/μ L; β 2M=1.7(1.3–3.5)mg/L. There were 12 / 23 ZAP70+; 13 / 23 with unmutated IgVH; all had PS 0–1. Twenty-three pts completed 1 and 6 completed 2 courses. There was 1 death (PR) due to uncontrolled hemolytic anemia and 1 pt was not assessable (CR) for response. Of the 27 assessable pts, there were 21 (78%) responders: 2 / 2 CR, 8 / 9 nPR, and 11 / 16 PR. The median follow-up time is 10 mo; 11 / 22 continue with their response, the median time to loss of response is 10 mo. Grade (G)3 and G4 neutropenia was experienced by 4 and 3 pts during treatment, respectively. Anemia, G3 was seen in 2 pts; only 1 pt experienced G4 thrombocytopenia. Therapy was well-tolerated; 25 / 29 pts developed G1–2 injection-site reactions. Twenty-five pts self-administered alemtuzumab without difficulties. No patients developed anti-alemtuzumab antibodies. Two pts received treatment for documented CMV reactivation, and 1 received empiric treatment for fever but was CMV negative by PCR. There were 4 pts with serious adverse events: 1 neutropenic gram positive bacteremia; 1 neutropenic fever without infection; 1 neutropenic pneumonia; 1 pt with pneumonia and fatal AIHA. On a previous trial with alemtuzumab IV for residual disease (O'Brien et al. Cancer 98:2657, 2003), the updated response rate for 58 pts is 53%; the median time to loss of response is 34 mo, 9 mo for pts who had minimal residual disease (MRD) at end of treatment by PCR for IgVH. Therefore the median time to loss of response is shorter in this trial, despite a higher response rate. Evaluation for MRD in bone marrow is ongoing to determine if the shorter time to loss of response can be attributed to more MRD, possibly suggesting that longer treatment time may be needed for more durable responses with SQ alemtuzumab administration.

The Combination of Alemtuzumab [Continuous Intravenous Infusion (civ) Followed by Subcutaneous Injection (sc)] Plus Rituximab Has Activity in Patients (pts) with Relapsed Chronic Lymphocytic Leukemia (CLL).

Available data suggest enhanced activity of monoclonal antibodies in combinations. In a previous study of iv bolus alemtuzumab plus rituximab in relapsed CLL, we have shown that the combination is safe and produces a response rate of 54% following a 4-week treatment period (Blood 101: 3413, 2003). As questions remain about the optimal dose, schedule and route of administration of alemtuzumab, we have been exploring alemtuzumab by civ followed by sc injections in combination with rituximab in pts with relapsed/refractory CLL who express both CD20 and CD52. Forty-five pts have been enrolled of whom 32 pts are evaluable (30 CLL, 1 CLL/SLL, 1 MZL). Six pts are too early and 7 are inevaluable [withdrawal of consent prior to treatment start (2), ineligible (2), removal from study and continuation of therapy with home physician (3)]. All pts received alemtuzumab 15mg by civ over 24 hours daily x 6 days on days 2–7 of the first course followed by 30mg sc twice weekly on days 3 and 5 of weeks 2 to 4 (one course). Rituximab was given at 375mg/m2 iv on day 1 followed by 500mg/m2 on days 8, 15, and 22. Maximum duration of therapy was 3 courses. Pts received standard premedication with acetaminophen and an antihistamine, and antiinfective prophylaxis with TMP/SMX and valacyclovir. CMV antigenemia was tested before and after completion of each course. The median age was 59 yrs (range 39–78), the median number of prior therapies was 3 (1–8), and the median b2M 3.8 mg/dL (1.7–13.6). Seventeen pts (53%) had Rai stage ≥ 3 disease. Eighteen pts (56%) were refractory to fludarabine and alkylators. All pts had prior rituximab; only 4 (13%) had received alemtuzumab. Sixteen pts (50%) responded [8 CR (25%), 1 PRn (3%), 7 PR (23%)] following one course. Response by site: peripheral blood 24/26 (92%), marrow 22/32 (69%), lymph nodes 13/26 (50%) and liver/spleen 8/9 pts (89). The combination was well tolerated with no unexpected toxicities. Most non-hematologic AEs were infusion-related and ≤ grade 2 by NCI toxicity criteria. Fevers and chills occurred in up to 56% of pts, fatigue in 34%, skin rashes in 19%, nausea in 16%, myalgias in 9%, and diarrhea in 6%. Although toxicites were more frequent with civ alemtuzumab than during the s.c. injections (with the exception of skin rashes), civ alemtuzumab was well tolerated. CMV reactivation occurred in 7 pts (22%) and was the most common infectious complication. In conclusion, the combination of civ/sc alemtuzumab plus rituximab has activity in patients with relapsed and refractory CLL. Most responses occurred after 4 weeks of therapy only. The combination is well tolerated. Side effects are predictable and manageable.

The Impact of Alemtuzumab as a Component of Conditioning Regimens on Transplantation Outcomes in a Setting of CMV-Seropositive Recipient and Donor.

Background: Graft-versus-host disease (GVHD) is one of the main issues for allogenic stem cell transplantation (SCT). Previous studies demostrated that in vivo administration of alemtuzumab (an anti-CD52 antibody) was effective to decrease the incidence of GVHD after allogenic SCT. However, due to delayed immune reconstruction, graft failure or infection is concerned. We investigated the impact of in vivo administration of alemtuzumab on the post-transplantation outcomes.Patients and methods: Thirty-five patients entered a pilot study employing allogenic SCT with alemtuzumab-containing conditioning regimen in two centers (KNUH, CNUH). We evaluated the clinical outcomes, complications and their relationship with dose of alemtuzumab.Results: The median dose of alemtuzumab was 50mg (range, 20–75) which was not adjusted on body weight and surface. All recipients (9 BM, 26 PB) and donors were CMV-seropositive before transplantion. The median survival was 14.03 months and 2 year survival rate was 47.0%. The probability of nonrelapse mortality at 90 days and 1 year was 11.4% and 22.8%, respectively. The cumulative incidence of grade II-IV acute GVHD at day 90 was 37.1%. The overall incidence of chronic GVHD was 20.8% and the incidence of extensive chronic GVHD was only 8.3%. The cumulative incidence of CMV antigenemia was 70.2%, which has been well controlled with preemptive ganciclovir treatment, and two patients with CMV antigenemia developed into CMV disease. The febrile episode was 37.1% but the duration was relatively short (median, 3 days). There were no differenecies in engraft (P = 0.573), acute and chronic GVHD (P = 0.359, P = 0.335, respectively), relapse (P = 0.849), mortality (P = 0.229), CMV antigenemia (P = 0.227) or overall survival (P = 0.51) between two groups (treated with ≥50mg of alemtuzumab vs. <50mg).Conclusion: Our study has shown that alemtuzumab is effective for GVHD prevention but correlated with high incidence of CMV antigenemia regardless of its dose. As CMV antigenemia was easily controllable with preemptive ganciclovir, the conditioning regimen containing alemtuzumab seems hopeful especially in a setting of CMV-seropositive recipient and donor with a high risk of GVHD.

CD52 Expression in Adult Acute Lymphoblastic Leukemia (ALL): Quantitative Flow Cytometry Provides New Insights.

We recently tested the feasibility of incorporating Alemtuzumab, a humanized anti-CD52 monoclonal antibody, into frontline therapy of adult ALL (CALGB 10102) in an attempt to eradicate minimal residual disease (MRD). We have previously reported that CD52 expression occurs in 68% of newly diagnosed ALL. This assessment was based upon the use of a qualitative flow cytometric assay performed on all pre-treatment cases in a central CALGB reference laboratory. Cases with > 10% CD52 expression on lymphoblasts relative to an isotype control were considered CD52 positive and eligible to receive Alemtuzumab during post-remission therapy. To better characterize the CD52 expression level on lymphoblasts and to obtain insights for the design of future subset specific therapies in adult ALL, we developed a quantitative assay to measure CD52 antigen density on lymphoblasts using custom PE conjugated clinical grade Alemtuzumab on 29 cases of precursor B-cell (pre-B) ALL and 9 cases of precursor T-cell (pre-T) ALL. In this assay, CD52 is expressed in arbitrary units of antibody bound per cell (ABC). We also measured CD52 levels on residual normal B and T lymphocytes in every specimen to calculate a normalized ratio (NR) of lymphoblast CD52ABC/ normal lymphocytes CD52 ABC. The results are tabulated below:CD52 ExpressionCell TypePrecursor B-Cell ALL (n=29) median (range)Precursor T Cell ALL (n=9) median (range)CD52 ABC unitsBlasts27658 (2042–206952)10222 (3784–35337)CD52 ABC unitsNormal B Lymphocytes125475 (59872–282245)146478 (68098–291878)CD52 ABC unitsNormal T Lymphocytes64142 (27406–141635)78720 (22412–144350)CD52 NRBlasts/Normal B Lymphocytes0.19 (0.02–0.88)0.06 (0.02–0.16)CD52 NRBlasts/Normal T Lymphocytes0.38 (0.04–2.16)0.12 (0.07–0.26)Pre-B lymphoblasts express significantly lower levels of CD52 antigen than normal B lymphocytes (p<0.0001). Similarly, Pre-T lymphoblasts express significantly lower levels of CD52 antigen than the normal T lymphocytes (p<0.0001). Moreover, lymphoblasts in pre-T ALL show a near-significant lower expression of CD52 than pre-B lymphoblasts (two-sided p=0.05). Calculation of the NR confirms these observations. We have also begun to investigate CD52 expression by cytogenetic subset. Of note, we have determined that Philadelphia chromosome positive (Ph+) lymphoblasts were CD52+ in 26/28 (93%) cases studied; quantification of CD52 expression in Ph+ cases and in other common cytogenetic subsets is in progress. Correlation of CD52 expression with Alemtuzumab plasma levels and with development of opportunistic infections is underway. In conclusion, these data are the first to demonstrate that lymphoblasts from patients with untreated ALL express lower levels of CD52 antigen than residual normal lymphocytes present at the time of diagnosis. These findings may lead to improved selection of patients most likely to benefit from administration of Alemtuzumab and may have important implications for optimizing dosing and scheduling of Alemtuzumab during ALL therapy.

Alemtuzumab (Campath-1H): A Systematic Review in Organ Transplantation

Alemtuzumab (Campath-1H) is a powerful antilymphocyte antibody that produces profound and long-lasting lymphopenia. It is being used with increasing frequency for induction in organ transplantation, with the aim of allowing steroid-free and/or calcineurin-free/sparing maintenance immunosuppressive protocols. Despite a considerable experience with this agent, mostly in kidney transplantation, there are only two relatively small randomized controlled trials available, and therefore the level of evidence for its role in transplantation is limited. Nevertheless, it does appear that the incidence of acute rejection is low after induction with alemtuzumab, perhaps if used with a calcineurin inhibitor, and that steroid-free and calcineurin-sparing protocols are possible. Although there is a profound and long-lasting T cell lymphopenia after administration of alemtuzumab, there is no apparent increase in infection, posttransplantation lymphoproliferative disease, or other side effects, other than perhaps autoimmune disease. Whether alemtuzumab is more effective than Thymoglobulin or anti-interleukin 2 receptor antibodies cannot be answered at this time. However from a cost aspect, the use of alemtuzumab for induction compares more than favorably with other lymphocyte-depleting agents. Alemtuzumab is an attractive agent for induction in organ transplantation, but there is a need for more and larger randomized trials with long-term follow-up before its true role can be established, particularly with respect to safety.

The anti-lymphoma effect of antibody-mediated immunotherapy is based on an increased degranulation of peripheral blood natural killer (NK) cells

In patients treated with rituximab and alemtuzumab for lymphomas or CLL, antibody-dependent cellular cytotoxicity (ADCC) is a major mechanism of action. Therefore, assessment of ADCC is mandatory to understand the complex mechanisms leading to the anti-lymphoma effects of monoclonal antibodies (mAb). Due to methodical difficulties, little is yet known about the relevant cell subpopulations and effector mechanisms leading to tumor lysis in ADCC. We used a novel flow cytometric assay that detects CD107a as a marker for NK-cell degranulation to characterize and quantify peripheral blood natural killer (NK) cells mediating ADCC in vitro and in vivo. We observed specific and dose-dependent NK-cell activation after administration of rituximab and alemtuzumab. The number of degranulating NK cells was closely related to the concentration of mAb and the effector:target ratio. We were able to quantify and characterize the peripheral blood NK cells mediating ADCC. The majority of degranulating NK cells had the phenotype: CD56(dim), CD69(+), NKG2D(+), NKp30(-), NKp46(-), and CD94(-). Furthermore, we found that the CD107a assay can also visualize ADCC under clinical conditions as we observed increased numbers of NK cells degranulating in response to CD20(+) lymphoma cell lines in patients with non-Hodgkin's lymphoma treated with rituximab. We were able to quantify and characterize NK cells mediating ADCC with a new and feasible method. The CD107a assay may be useful for predicting treatment responses of individual patients and may help find the optimal dosage and timing for treatment with mAb.

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.

High-Risk Fludarabine-Pretreated B-Cell Chronic Lymphocytic Leukemia's High Response Rate Following Sequential DHAP and Alemtuzumab Administration Though in Absence of Molecular Remission

B-CLL patients with resistant/relapsed disease or adverse prognostic factors at presentation are suitable for alternative treatments. In the present pilot study we investigated a novel intensive chemo-immunotherapy approach for high-risk, fludarabine pretreated patients. Ten patients with resistant/relapsed, advanced stage BCLL were included. Age was 37-60 yr (median 53). All but one had an unmutated IgVH status. The treatment schedule included debulking with two DHAP courses followed by alemtuzumab (30 mg, eight doses), followed by peripheral blood progenitor cell (PBPC) mobilization with intermediate/high-dose cyclophosphamide and by autografting after high-dose mitoxantrone+L-Pam. The DHAP-alemtuzumab combination was highly effective. Eight patients out of 10 responded to DHAP, with a single complete remission. Following alemtuzumab, the number of overall responses increased to nine, and the complete remissions to five. After alemtuzumab PB double-positive clonal CD5+/CD19+ lymphocytes dropped, with median purification rate 99.95%. Owing to poor PBPC mobilization, only five patients underwent autografting, and three of these experienced post-graft recurrence. The six patients entering complete remission were free of disease 3-23 mo after study entry, and three of them were still in remission at 3, 7, and 22 mo. However, molecular evaluation regularly revealed persistence of minimal residual disease, both in all PBPC collections tested and in post-treatment follow-up samples. The use of DHAP/alemtuzumab appears useful to re-induce disease remission in relapsed/refractory, high-risk B-CLL patients. However, the addition of autograft was not usually feasible and of questionable clinical use. Other strategies should thus be considered for remission maintenance.

Adefovir added to lamivudine for hepatitis B recurrent infection in refractory B-cell chronic lymphocytic leukemia on prolonged therapy with Campath-1H

We describe a case of severe reactivation of occult hepatitis B virus infection in a 49-year-old man, who was treated with high doses of chlorambucil for a Binet stage A B-cell chronic lymphocytic leukemia (B-CLL). The patient was initially treated with lamivudine and subsequently with lamivudine and adefovir dipivoxil combination therapy to control viral replication and allow for long-term anti-cancer chemotherapy with alemtuzumab (Campath-1H), which was introduced to rescue for a B-CLL relapse. During 20 months of anti-HBV therapy, ALT and HBV-DNA levels progressively declined and B-CLL was successfully kept under control by long-term alemtuzumab administration.

Low Dose Alemtuzumab (Campath 1H) Prior to Allogeneic Stem Cell Transplantation Is Associated with Low Incidence of Acute and Chronic GVHD but Protracted Immune Recovery.

Background: The administration of alemtuzumab (Campath 1H) as part of the conditioning regimen prior to allogeneic stem cell transplantation has been associated with a low incidence of acute and chronic GVHD. Initial studies employing doses of 100 mg have reported a high incidence of viral infections. Lower alemtuzumab doses combined with standard GVHD prophylaxis regimens (calcineurin inhibitor + MTX) have also resulted in a low incidence of acute GVHD in patients with CD52-positive malignancies. We investigated the effect of low-dose (40 mg) alemtuzumab on engraftment (VNTR chimerism studies), the incidence of acute and chronic GVHD, CMV reactivation, survival, and immune reconstitution (examined by TREC content at various time points after transplant).Patient and Transplant characteristics: Twenty-seven patients underwent a matched (n=24) or 1-antigen mismatched (n=3) related (n=13) or unrelated (n=14) allogeneic stem cell transplantation for various hematologic malignancies. Median age was 41 years (19–59). Disease stage at transplant was early for 48%, intermediate for 11% and late for 41%. Three patients received bone marrow and 24 received PBSC grafts. Conditioning regimen consisted of TBI 10 Gy with partial lung shielding, Thiotepa 500 mg/m2, and Alemtuzumab 20 mg IV on day -4 and day -1. GVHD prophylaxis was with cyclosporine (n=13) or tacrolimus (n=14) and full-dose MTX. High-dose viral prophylaxis with valacyclovir 2000 mg QID was given to all recipients from a CMV seropositive recipient/donor pair starting at patient #9, due to a high incidence of CMV reactivation amongst the first 8 patients. Three patients received DLI for disease relapse. Median follow-up for survivors is 13 months (6–26).Results: Of eighteen evaluable patients (3 relapsed, 5 expired, 1 not done) at day 100, 15 had ≥ 95% donor chimerism, and 3 had 90–94% donor chimerism. The cumulative incidence of acute GVHD grade II-IV at day 100 was 4% (95% CI 1–16%), and the cumulative incidence of chronic GVHD at 1 year was 31% (12–52%). Cumulative incidence of non-relapse mortality at day 100 was 18% (7–35%), and at 1 year 31% (14–49%). Cumulative incidence of relapse at 1 year was 28%, resulting in a projected 1-year disease-free survival of 41% (22–60%), and overall survival of 54% (33–71%). Amongst the first eight patients, all (5/5) at-risk recipients developed CMV reactivation. After initiation of prophylaxis with high-dose valacyclovir, 4/11 at-risk recipients developed CMV reactivation. No patient died from CMV disease. TREC analysis in a limited number of patients showed rapid increase in TREC between day 0 and day 180, but no further increment between day 180 and day 365.Conclusions: The use of low-dose alemtuzumab results in low incidences of acute and chronic GVHD. CMV reactivation is common, and can be partially prevented by use of high-dose valacyclovir. Immune reconstitution data on a small subset of patients show limited output of thymic emigrant T cells after 6 months.

Subcutaneous Administration of Alemtuzumab: A Single Institution Experience.

Alemtuzumab is an active drug in the treatment of a number of lymphoid malignancies and is currently indicated for intravenous administration to patients with B-cell chronic lymphocytic leukemia (CLL) who have failed therapy with fludarabine. Unfortunately, despite premedication, grade 3/4 infusion-related reactions (IRR) are common during alemtuzumab IV administration (fever = 19%, rigors = 16%, and hypotension = 5%, amongst others). If grades 1/2 IRR are included, these numbers increase to 86%, 85%, and 32%, respectively. Nausea also occurs in 54% of patients. In addition to complicating therapy, these reactions sometimes make it necessary to prematurely discontinue therapy. These toxicities may be avoided by administering alemtuzumab subcutaneously (SC); a promising modality, but one with limited supporting data. We report the results of our institutional experience with SC alemtuzumab administration. We performed a retrospective chart review examining data points related to demographics, safety, and efficacy. This IRB - approved review looked at 20 patients who were treated with SC alemtuzumab (13 = CLL, 1 = CLL/AML, 3 = CTCL, 3= PTCL); 2 of these were retreated subcutaneously after receiving IV therapy. Treatment was attempted with a dose-escalation scheme of 3mg-10mg-30mg; with the goal of a 12-week regimen. The average age of the patients was 61 (median 62, range 45–76). 13 were male and 7 were female. The average number of weeks of subcutaneous therapy received was 7 (median 7, range 1–12 weeks). The average number of prior treatment regimens was 3 (median 2, range 1–7). ORR to therapy with alemtuzumab= 60%. (CR = 4, PR = 8). 9 patients had refractory or progressive disease. Patients tolerated the therapy well. Toxicities were all grades 1/2 and usually resolved with supportive therapy and continued alemtuzumab administration; these included hemolytic anemia (n=1), mild pruritis (n=1), anemia (n=1), neutropenia (n=2), fever (n=3), rigors (n=2) mild skin reactions (n=2). Infectious complications included bacterial pneumonia (n=1), herpes zoster (3 months after the completion of therapy, n=1), CMV reactivation (antiviral therapy with alemtuzumab held for two weeks, n=1). No patients discontinued therapy due to grade 3/4 IRR. Of particular interest are the two patients retreated with SC alemtuzumab after previously receiving the drug IV. (1 = PR after first and second course, 1 = PR after first course and no response to second course.) These patients tolerated the drug well with minimal toxicity. One of the retreated patients who had experienced bronchospasm with IV therapy, had no respiratory issues with subcutaneous administration. Based on this data, we conclude that SC alemtuzumab is a safe, well-tolerated, and effective alternative to IV administration. Final data will be available at presentation.

Pharmacokinetic Analysis of Subcutaneous Alemtuzumab as Consolidation Therapy To Achieve MRD-Negative Responses.

Persistence of minimal residual disease (MRD) after therapy has been shown to be a powerful prognostic factor for relapse among patients with chronic lymphocytic leukemia (CLL). Treatment with the anti-CD52 monoclonal antibody alemtuzumab (Campath®), either as a single agent or in combination with fludarabine, has been shown to induce MRD-negative responses, even among patients who are not responsive to traditional therapeutic interventions. Dramatically improved responses and MRD negativity have also been achieved using alemtuzumab as consolidation therapy, to purge MRD after initial therapy with a fludarabine-based regimen. The pharmacokinetics (PK) of alemtuzumab administered subcutaneously to achieve MRD negativity after induction therapy with fludarabine are reported here. Of 41 patients (median age, 54 years) who received consolidation therapy with alemtuzumab, all 16 patients participating in the PK analysis were MRD-positive after receiving induction therapy as measured by PCR consensus primer. At least 8 weeks following the completion of induction therapy, dose escalated alemtuzumab 10 mg was administered for 6 weeks, 3 times a week. Plasma samples were collected from 16 patients on Days 1, 3, 5, 15, 17, 22 and 31, and ELISA was used to assess the PK of alemtuzumab. On Day 15, blood samples were drawn at 1, 2, 3, 4, 6, 8 and 12 hours after alemtuzumab administration. Alemtuzumab plasma concentrations gradually increased during the first 2 weeks, and reached concentrations 25.5-fold higher on Week 3. The median pre-dose concentrations (Cpre-dose) were: 0.01 μg/mL (range, 0–0.07 μg/mL) on Day 3, 0.58 μg/mL (range, 0–1.2 μg/mL) on Day 15, 0.51 μg/mL (range, 0–2.61 μg/mL) on Day 17, and 1.09 μg/mL (range, 0.19–3.08 μg/mL) on Day 31. The median Cmax plasma concentration was 1.05 μg/mL (range, 0.097–1.75 μg/mL) and the median Cpre-dose was 0.58 μg/mL (range, 0–1.2 μg/mL). An analysis was performed to correlate quantitative response as represented by polyclonal complete remission and AUC0–12 values. Preliminary data indicate that the systemic exposure associated with effective therapy corresponds with an AUC0–12 value higher than 5 μg•h/mL on Day 15 of the administration schedule. Therefore, complete response (CR) rates, expressed as percentage of patients with AUC0–12 values correlating with effective treatment, increased with higher levels of systemic exposure to alemtuzumab.

Reconstitution of the T Cell Repertoire Following Treatment with Alemtuzumab in Patients with B-Cell Chronic Lymphocytic Leukemia (B-CLL).

Background and Methods: B-cell chronic lymphocytic leukemia (B-CLL) occurs as a result of clonal accumulation of functionally abnormal B cells. Alemtuzumab is a humanized monoclonal antibody specific for the CD52 antigen, which is highly expressed on both B-CLL cells and normal lymphocytes, but not on hematopoietic (CD34) stem cells. Alemtuzumab has been shown to effectively deplete the blood and bone marrow of lymphocytes, including CD4 and CD8 T cells, which may lead to profound immunosuppression and make patients more susceptible to infections. We and others have previously shown that the CD4 T cells in B-CLL patients may be clonally distinct from the normal population in that they present a more clonal pattern of the T-cell receptor (TCR) repertoire (Rezvany et al, Blood 2003; 101:1063–1070). It is therefore of interest to study the T cell repertoire following alemtuzumab administration as well as factors affecting T cell reconstitution following CD52 targeted therapy. In this study, we evaluated in depth the T-cell receptor-beta-variable sequence (TCR BV) in CD4 and CD8 T cells by real-time PCR, before and repeatedly after/during long term follow-up, in 5 B-CLL patients who had received alemtuzumab as first-line therapy (Lundin et al, Blood 2002; 100:768–773). Also, an analysis was conducted of CDR3 length polymorphism to describe changes in the clonality pattern.Results: A decline in most of BV genes either in CD4 or CD8 T cells was observed shortly after alemtuzumab treatment, which was followed by a gradual increase in most of the BV genes during long-term follow up. CDR3 length polymorphism analysis shortly after treatment revealed an even more highly restricted pattern in CD4 T cells compared to baseline with a shift towards a monoclonal/oligoclonal pattern regardless of increased or decreased BV usage. Furthermore, in the analysis of the clonal spectrum that was expressed shortly after alemtuzumab therapy, the number of peaks was significantly reduced in CD4 (P <0.01) but not in CD8 T cells, which was followed by a gradual increase in diversity towards a polyclonal repertoire during long-term follow up.Conclusions: These results indicate that perturbations in the T cell repertoire following alemtuzumab are complex, and are not reflected by changes in CD4/CD8 T cell numbers only. The restricted CDR3 pattern present prior to therapy became even more restricted after end of treatment, followed by a normalization of CDR3 patterns in CD4 T-cells during long-term follow-up. These results further suggest a regulatory role for T cells in relation to the malignant B cell clone in patients with B-CLL.

Incorporation of Alemtuzumab into Front-Line Therapy of Adult Acute Lymphoblastic Leukemia (ALL) Is Feasible: A Phase I/II Study from the Cancer and Leukemia Group B (CALGB 10102).

Eradication of minimal residual disease (MRD) during the first months of treatment for patients (pts) with ALL is associated with improved disease-free survival (DFS). We hypothesized that Alemtuzumab, a humanized monoclonal antibody directed against CD52, might be an effective, novel agent for eradication of MRD in ALL based on data demonstrating strong CD52 expression in other lymphoid malignancies and in several ALL cell lines, and from case reports of clinical activity in advanced ALL. In CALGB 10102, to define the percentage of CD52+ cases and to demonstrate feasibility, we tested dose escalation of Alemtuzumab in sequential cohorts to a target dose of 30 mg administered sc 3X/week for 4 weeks (12 doses) during post-remission therapy. Pts are eligible to receive Alemtuzumab if lymphoblast CD52 expression at diagnosis is ≥ 10% as determined in a CALGB reference laboratory. The 10102 therapy is composed of monthly treatment modules outlined below:Treatment module sequence is: A,B,C, D, A, B, C followed by maintenance therapy for a total of 2 years. Antimicrobial prophylaxis for cytomegalovirus (CMV) (e.g. acyclovir 800 mg qid) and pneumocystis carinii is mandated. Weekly quantitative monitoring for CMV viremia is performed. 150 pts with untreated ALL have enrolled: Median age is 48 yrs. 124 (83%) pts have precursor-B; 19(13%) have precursor T-ALL and 7 (4%) have biphenotypic or bilineal ALL. Of 139 evaluable pts, 95 (68%) had CD52 ≥ 10%. By immunophenotype, 72% of precursor B and 61% of precursor T pts were eligible to receive Alemtuzumab. Phase I dose escalation was recently completed. Dose limiting toxicity (DLT) for Phase I was defined as the inability to proceed with protocol treatment within 6 weeks of the last dose of Alemtuzumab. Non-heme toxicities have been mild and sc Alemtuzumab administration was well tolerated. Hematologic and infectious toxicities are summarized below:Myelosuppression was transient and use of G-CSF was permitted during Module D. 2 pts were treated for CMV viremia due to rising CMV titers in 2 sequential assays. 6 other pts had transient CMV elevations during or immediately following completion of Alemtuzumab that did not require treatment. 22/24 phase I pts received all 12 doses of Alemtuzumab. There were 2 DLTs reported: 1 pt in cohort 2 due to CMV viremia requiring gancyclovir following completion of Alemtuzumab; and 1 pt in cohort 3 due to ANC < 1500 six weeks after Alemtuzumab (pt was not given G-CSF). Based on these Phase I data, the targeted dose of 30 mg Alemtuzumab was recommended for further study in the ongoing Phase II study. In summary, we report for the first time that CD52 is expressed in the majority of ALL cases and demonstrate the feasibility of employing Alemtuzumab in front-line therapy. Ongoing accrual to the phase II study will evaluate the efficacy of Alemtuzumab in eradication of MRD in adult ALL.Module AModule BModule CModule D (Alemtuzumab)MaintenanceCytoxanCytoxanMethotrexate (IV, PO, IT)10 mg* cohort 1VincristineDaunorubicinCytarabineVincristine20 mg* cohort 2DexamethasoneVincristineVincrisitne6-MP30 mg* cohort 36-MPDexamethasoneL-asparaginase*Phase I dose escalationMethotrexateL-asparaginaseIT-MethotrexateAlemtuzumab cohortsNMyelosuppression (grades 3 or 4)LymphopeniaCMV viremia10 mg621220 mg1011430 mg8102