Gary Calandra

Rapid mobilization of murine and human hematopoietic stem and progenitor cells with AMD3100, a CXCR4 antagonist

Improving approaches for hematopoietic stem cell (HSC) and hematopoietic progenitor cell (HPC) mobilization is clinically important because increased numbers of these cells are needed for enhanced transplantation. Chemokine stromal cell derived factor-1 (also known as CXCL12) is believed to be involved in retention of HSCs and HPCs in bone marrow. AMD3100, a selective antagonist of CXCL12 that binds to its receptor, CXCR4, was evaluated in murine and human systems for mobilizing capacity, alone and in combination with granulocyte colony-stimulating factor (G-CSF). AMD3100 induced rapid mobilization of mouse and human HPCs and synergistically augmented G-CSF–induced mobilization of HPCs. AMD3100 also mobilized murine long-term repopulating (LTR) cells that engrafted primary and secondary lethally-irradiated mice, and human CD34+ cells that can repopulate nonobese diabetic-severe combined immunodeficiency (SCID) mice. AMD3100 synergized with G-CSF to mobilize murine LTR cells and human SCID repopulating cells (SRCs). Human CD34+ cells isolated after treatment with G-CSF plus AMD3100 expressed a phenotype that was characteristic of highly engrafting mouse HSCs. Synergy of AMD3100 and G-CSF in mobilization was due to enhanced numbers and perhaps other characteristics of the mobilized cells. These results support the hypothesis that the CXCL12-CXCR4 axis is involved in marrow retention of HSCs and HPCs, and demonstrate the clinical potential of AMD3100 for HSC mobilization.

Plerixafor and G-CSF versus placebo and G-CSF to mobilize hematopoietic stem cells for autologous stem cell transplantation in patients with multiple myeloma.

This phase 3, multicenter, randomized (1:1), double-blind, placebo-controlled study evaluated the safety and efficacy of plerixafor with granulocyte colony-stimulating factor (G-CSF) in mobilizing hematopoietic stem cells in patients with multiple myeloma. Patients received G-CSF (10 microg/kg) subcutaneously daily for up to 8 days. Beginning on day 4 and continuing daily for up to 4 days, patients received either plerixafor (240 microg/kg) or placebo subcutaneously. Starting on day 5, patients began daily apheresis for up to 4 days or until more than or equal to 6 x 10(6) CD34(+) cells/kg were collected. The primary endpoint was the percentage of patients who collected more than or equal to 6 x 10(6) CD34(+) cells/kg in less than or equal to 2 aphereses. A total of 106 of 148 (71.6%) patients in the plerixafor group and 53 of 154 (34.4%) patients in the placebo group met the primary endpoint (P < .001). A total of 54% of plerixafor-treated patients reached target after one apheresis, whereas 56% of the placebo-treated patients required 4 aphereses to reach target. The most common adverse events related to plerixafor were gastrointestinal disorders and injection site reactions. Plerixafor and G-CSF were well tolerated, and significantly more patients collected the optimal CD34(+) cell/kg target for transplantation earlier compared with G-CSF alone. This study is registered at www.clinicaltrials.gov as #NCT00103662.

Phase III Prospective Randomized Double-Blind Placebo-Controlled Trial of Plerixafor Plus Granulocyte Colony-Stimulating Factor Compared With Placebo Plus Granulocyte Colony-Stimulating Factor for Autologous Stem-Cell Mobilization and Transplantation for Patients With Non-Hodgkin's Lymphoma

PURPOSE This study evaluates the safety and efficacy of plerixafor (AMD3100), a CXCR4 antagonist, in mobilizing hematopoietic stem cells for autologous stem-cell transplantation in non-Hodgkins lymphoma (NHL) patients. PATIENTS AND METHODS This is a phase III, multicenter, randomized (1:1), double-blind, placebo-controlled study. Patients with non-Hodgkins lymphoma requiring an autologous hematopoietic stem-cell transplantation in first or second complete or partial remission were eligible. Patients received granulocyte colony-stimulating factor (G-CSF; 10 microg/kg) subcutaneously daily for up to 8 days. Beginning on evening of day 4 and continuing daily for up to 4 days, patients received either plerixafor (240 microg/kg) or placebo subcutaneously. Starting on day 5, patients began daily apheresis for up to 4 days or until > or = 5 x 10(6) CD34+ cells/kg were collected. The primary end point was the percentage of patients who collected > or = 5 x 10(6) CD34+ cells/kg in 4 or fewer apheresis days. RESULTS This report presents all data for all patients (n = 298) through 12 months follow-up. Eighty-nine (59%) of 150 patients in the plerixafor group and 29 (20%) of 148 patients in the placebo group met the primary end point (P < .001). One hundred thirty-five patients (90%) in plerixafor group and 82 patients (55%) in placebo group underwent transplantation after initial mobilization. Median time to engraftment was similar in both groups. The most common plerixafor-associated adverse events were GI disorders and injection site reactions. CONCLUSION Plerixafor and G-CSF were well tolerated and resulted in a significantly higher proportion of patients with non-Hodgkins lymphoma achieving the optimal CD34+ cell target for transplantation in fewer apheresis days, compared with G-CSF alone.

Rapid Mobilization of CD34+ Cells Following Administration of the CXCR4 Antagonist AMD3100 to Patients With Multiple Myeloma and Non-Hodgkin's Lymphoma

PURPOSE Interactions between the chemokine receptor CXCR4 and its ligand stromal derived factor-1 regulate hematopoietic stem-cell trafficking. AMD3100 is a CXCR4 antagonist that induces rapid mobilization of CD34+ cells in healthy volunteers. We performed a phase I study assessing the safety and clinical effects of AMD3100 in patients with multiple myeloma (MM) and non-Hodgkins lymphoma (NHL). PATIENTS AND METHODS Thirteen patients (MM, n=7; NHL, n=6) received AMD3100 at a dose of either 160 microg/kg (n=6) or 240 microg/kg (n=7). WBC and peripheral blood (PB) CD34+ cell counts were analyzed at 4 and 6 hours following injection. RESULTS AMD3100 caused a rapid and statistically significant increase in the total WBC and PB CD34+ counts at both 4 and 6 hours following a single injection. The absolute CD34+ cell count increased from a baseline of 2.6 +/- 0.7/microL (mean +/- SE) to 15.6 +/- 3.9/microL and 16.2 +/- 4.3/microL at 4 hours (P=.002) and 6 hours after injection (P =.003), respectively. The absolute CD34+ cell counts observed at 4 and 6 hours following AMD3100 were higher in the 240 microg/kg group (19.3 +/- 6.9/microL and 20.4 +/- 7.6/microL, respectively) compared with the 160 microg/kg group (11.3 +/- 2.7/microL and 11.3 +/- 2.5/microL, respectively). The drug was well tolerated and only grade 1 toxicities were encountered. CONCLUSION AMD3100 appears to be a safe and effective agent for the rapid mobilization of CD34+ cells in patients who have received prior chemotherapy. Further studies in combination with granulocyte colony-stimulating factor in patients with lymphoid malignancies are warranted.

Safety, pharmacokinetics, and antiviral activity of AMD3100, a selective CXCR4 receptor inhibitor, in HIV-1 infection

AMD3100 is a CXCR4 receptor inhibitor with anti–HIV-1 activity in vitro. We tested the safety, pharmacokinetics, and antiviral effect of AMD3100 administered for 10 days by continuous intravenous infusion in an open-label dose escalation study from 2.5 to 160 μg/kg/h. Forty HIV-infected patients with an HIV RNA level >5000 copies/mL on stable antiretroviral (ARV) regimens or off therapy were enrolled. Syncytium-inducing (SI) phenotype in an MT-2 cell assay was required in higher dose cohorts. Most subjects were black (55%), male (98%), and off ARV therapy. HIV phenotype was SI (30%), non–SI (45%), or not tested (25%). One patient (5 μg/kg/h) had serious and possibly drug-related thrombocytopenia. Two patients (40 and 160 μg/kg/h) had unexpected, although not serious, premature ventricular contractions. Most patients in the 80- and 160-μg/kg/h cohorts had paresthesias. Steady-state blood concentration and area under the concentration-time curve were dose proportional across all dose levels; the median terminal elimination half-life was 8.6 hours (range: 8.1–11.1 hours). Leukocytosis was observed in all patients, with an estimated maximum effect of 3.4 times baseline (95% confidence interval: 2.9–3.9). Only 1 patient, the patient whose virus was confirmed to use purely CXCR4 and who also received the highest dose (160 μg/kg/h), had a significant 0.9-log10 copies/mL HIV RNA drop at day 11. Overall, however, the average change in viral load across all patients was +0.03 log10 HIV RNA. Given these results, AMD3100 is not being further developed for ARV therapy, but development continues for stem cell mobilization.

AMD3100 plus G-CSF can successfully mobilize CD34 + cells from non-Hodgkin's lymphoma, Hodgkin's disease and multiple myeloma patients previously failing mobilization with chemotherapy and/or cytokine treatment : compassionate use data

AMD3100 given with G-CSF has been shown to mobilize CD34+ cells in non-Hodgkins lymphoma (NHL), multiple myeloma (MM), and Hodgkins disease (HD) patients who could not collect sufficient cells for autologous transplant following other mobilization regimens. These poor mobilizers are usually excluded from company-sponsored trials, but have been included in an AMD3100 Single Patient Use protocol, referred to as a Compassionate Use Protocol (CUP). A cohort of 115 data-audited poor mobilizers in CUP was assessed, with the objective being to collect ⩾2 × 106 CD34+ cells per kg following AMD3100 plus G-CSF mobilization. The rates of successful CD34+ cell collection were similar for patients who previously failed chemotherapy mobilization or cytokine-only mobilization: NHL—60.3%, MM—71.4% and HD—76.5%. Following transplant, median times to neutrophil and PLT engraftment were 11 days and 18 days, respectively. Engraftment was durable. There were no drug-related serious adverse events. Of the adverse events considered related to AMD3100, two (1.6%) were severe (one patient—headache, one patient—nightmares). Other AMD3100-related adverse events were mild (84.8%) or moderate (13.6%). The most common AMD3100-related adverse events were gastrointestinal reactions, injection site reactions and paresthesias. AMD3100 plus G-CSF offers a new treatment to collect CD34+ cells for autologous transplant from poor mobilizers, with a high success rate.

Rapid mobilization of functional donor hematopoietic cells without G-CSF using AMD3100, an antagonist of the CXCR4/SDF-1 interaction

Allografts from HLA-matched sibling donors were mobilized and collected without granulocyte colony-stimulating factor (G-CSF) using AMD3100, a direct antagonist of CXCR4/stromal-derived factor 1 (SDF-1/CXCL12). Donors (N = 25) were treated with AMD3100 at a dose of 240 mug/kg by subcutaneous injection, and leukapheresis was then initiated just 4 hours later. Two-thirds of the donors collected an allograft with a CD34(+) cell dose sufficient for transplantation after just one dose of AMD3100. No donor experienced more than grade 1 toxicity. After a myeloablative regimen, 20 patients with hematologic malignancies received allografts collected after AMD3100 alone. All patients engrafted neutrophils (median day 10) and platelets (median day 12) promptly. Acute graft-versus-host disease (GVHD) grades 2 through 4 occurred in 35% of patients. One patient died due to complications related to acute GVHD. No unexpected adverse events were observed in any of the recipients. All 14 patients surviving in remission have robust trilineage hematopoiesis and are transfusion-free with a median follow-up of 277 days (range, 139-964 days). Direct antagonism of CXCR4 by AMD3100 may provide a more rapid and possibly less toxic and cumbersome alternative to traditional G-CSF-based mobilization in normal donors. This trial was registered as no. NCT00241358 at www.ClinicalTrials.gov.

Augmented mobilization and collection of CD34+ hematopoietic cells from normal human volunteers stimulated with granulocyte-colony-stimulating factor by single-dose administration of AMD3100, a CXCR4 antagonist.

BACKGROUND: AMD3100, a selective antagonist of CXCR4, rapidly mobilizes CD34+ hematopoietic progenitor cells (HPCs) from marrow to peripheral blood with minimal side effects.

Safety and preliminary efficacy of plerixafor (mozobil) in combination with chemotherapy and G-CSF: An open-label, multicenter, exploratory trial in patients with multiple myeloma and non-Hodgkin's lymphoma undergoing stem cell mobilization

Plerixafor, a novel CXCR4 inhibitor, is effective in mobilizing PBSCs particularly when used in conjunction with G-CSF. In four cohorts, this pilot study explored the safety of plerixafor mobilization when incorporated into a conventional stem cell mobilization regimen of chemotherapy and G-CSF. Forty (26 multiple myeloma and 14 non-Hodgkins lymphoma) patients were treated with plerixafor. Plerixafor was well tolerated and its addition to a chemo-mobilization regimen resulted in an increase in the peripheral blood CD34+ cells. The mean rate of increase in the peripheral blood CD34+ cells was 2.8 cells/μl/h pre- and 13.3 cells/μl/h post-plerixafor administration. Engraftment parameters were acceptable after myeloblative chemotherapy, with the median day for neutrophil and plt engraftment being day 11 (range 8–20 days) and day 13 (range 7–77 days), respectively. The data obtained from the analysis of the cohorts suggest that plerixafor can safely be added to chemotherapy-based mobilization regimens and may accelerate the rate of increase in CD34+ cells on the second day of apheresis. Further studies are warranted to evaluate the effect of plerixafor in combination with chemomobilization on stem cell mobilization and collection on the first and subsequent days of apheresis, and its impact on resource utilization.

A Phase II Study of Plerixafor (AMD3100) plus G-CSF for Autologous Hematopoietic Progenitor Cell Mobilization in Patients with Hodgkin Lymphoma

Collection of an adequate number of hematopoietic stem cells can be difficult in patients with relapsed or refractory Hodgkin lymphoma (HL) who are candidates for autologous stem cell transplantation (ASCT). Plerixafor (AMD3100), an inhibitor of the interaction between stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4, is an effective hematopoietic stem cell mobilization agent in patients with multiple myeloma and non-Hodgkin lymphoma (NHL). This study was undertaken to investigate the efficacy and safety of hematopoietic stem cell mobilization with plerixafor in patients with HL. Twenty-two patients with HL who were candidates for ASCT underwent hematopoietic stem cell mobilization with a combination of granulocyle-colony stimulating factor (G-CSF), 10 microg/kg daily, and plerixafor, 240 microg/kg subcutaneous, 10-11 hours prior to apheresis. The primary endpoint was the proportion of patients who collected>or=5x10(6) CD34+ cells/kg. Outcomes were compared to a historical control population of HL patients mobilized with G-CSF alone. Pharmacokinetic (PK) analysis of plerixafor was performed in a subset of patients. Fifteen patients (68%) collected>or=5x10(6) CD34+ cells/kg, and 21 patients (95%) achieved the minimum collection of >or=2x10(6) CD34+ cells/kg, in a median 2 apheresis procedures. Both the proportion of patients collecting>or=5x10(6) CD34+ cells/kg and the median CD34+ cells collected in days 1-2 of apheresis were significantly improved over historical controls. The PK of plerixafor in this patient population was similar to that previously seen in healthy volunteers. The regimen was generally safe and well tolerated.