Angell, Jennifer

Abstract Introduction: The impact of transplanted CD34+ cell dose on clinical outcomes remains controversial. The purpose of this study was to examine the relationship between CD34+ cell dose transplanted and platelet, neutrophil, and lymphocyte counts at 100 days, 6, and 12 months following autologous transplantation in patients with non-Hodgkin’s lymphoma (NHL) and multiple myeloma (MM). Methods: Data were obtained from two phase 3 clinical studies that compared the safety and efficacy of plerixafor and G-CSF with placebo and G-CSF in mobilization of hematopoietic blood stem cells for autologous transplantation in NHL patients and in MM patients. The details of the study designs and preliminary safety and efficacy outcomes have been reported (DiPersio, ASH 2007). The following data were obtained from the two clinical study databases: number of CD34+ cells transplanted (first transplant only) as determined by a central laboratory, absolute neutrophil, platelet, red blood cell, and lymphocyte counts at 100 days, 6, and 12 months post-transplant. The proportions of patients who had platelet ≥150 x 109/L or neutrophil ≥2.5 x 109/L or lymphocyte ≥0.5 x 109/L at 100 days, 6, and 12 months were compared among these transplanted CD34+ cell dose categories regardless of mobilization treatment: 2–4 x 106 cells/kg, >4–6 x 106 cells/ kg, and > 6 x 106 cells/kg. Two separate analyses were performed, one for NHL patients and one for MM patients. Results: For the NHL study, 135/150 (90.0%) patients in the plerixafor group underwent transplantation after initial mobilization compared with 82/148 (55.4%) patients in the placebo group, p<0.001. The mean number of CD34+ cells transplanted was 6.06 ± 2.98 x 106 (median 5.41, range 1.79–17.6) for the plerixafor-treated patients and 4.09 ± 1.56 x 106 (median 3.85, range 1.98–8.7) for the placebo-treated patients, p<0.001. For the MM study, 142/148 (95.9%) patients in the plerixafor group and 136/154 (88.3%) patients in the placebo group underwent transplantation. The mean number of CD34+ cells transplanted was 5.84 ± 2.64 x 106 (median 5.34, range 1.9 to 16.7) for the plerixafor-treated patients and 4.37 ± 2.01 x 106 (median 3.98, range 1.8 to 16.9) CD34+ cells/kg for the placebo- treated patients. A significant linear trend with increasing proportion of patients with platelet count ≥150 x 109/L with increasing transplanted cell dose categories was observed at 100 days, 6, and 12 months for NHL patients and at 100 days for MM patients (Table 1). There were no apparent significant relationships between transplanted cell dose categories and other hematopoietic parameters. Table 1: Analysis of percentage of patients reaching a platelet count of ≥ 150 x 109/L by transplanted cell dose categories Transplant Cell Dose (CD34+ cells/kg) 2–4 x 106 ≥ 4–6 x 106 ≥ 6 x 106 P value* NHL Patients N=76 N=75 N=66 100 days 28 (48.3%) 42 (66.7%) 45 (81.8%) <0.001 6 months 31 (56.4%) 36 (66.7%) 42 (76.4%) 0.026 12 months 18 (56.3%) 21 (80.8%) 24 (82.8%) 0.020 MM Patients N=75 N=82 N=64 100 days 41 (68.3%) 57 (90.5%) 47 (88.7%) 0.004 6 months 48 (78.7%) 61 (89.7%) 51 (87.9%) 0.147 12 months 25 (73.5%) 33 (82.5%) 26 (81.3%) 0.435 For all transplanted cell dose categories, the proportions of patients are based on the number of patients with available data at each time point.*p-value for testing linear trend using Mantel-Haenszel Chi-square test Conclusions: Results from these ad hoc analyses confirm previous reports that transplanted cell dose may be associated with better long-term platelet recovery. Due to the small sample size in each transplanted cell dose category and the nature of ad hoc analyses, further studies are warranted to determine if the introduction of plerixafor will allow the mobilization and transplantation of higher quantity of CD34+ cells, which may positively influence long-term hematopoietic recovery.

Abstract AMD3100, Plerixafor (A)+G-CSF (G) have safely and effectively allowed aHSC mobilization in Phase I and II studies. This Phase III, multicenter, randomized, double-blind, placebo controlled study compared the safety and efficacy of A+G versus Placebo (P)+G to mobilize and transplant patients with NHL. Methods: Adult NHL patients requiring an aHSC transplant, in first or second CR or PR were eligible to participate. Patients received G (10μg/kg/day) subcutaneously (SQ) for 4 days. On the evening of Day 4, patients received either A (240μg/kg SQ) or P. Patients underwent apheresis on Day 5 after an AM dose of G and 10–11 hours after administration of study treatment. Patients continued to receive the evening dose of study treatment, followed by AM dose of G and apheresis for up to a total of 4 aphereses or until ≥5 x 106 CD34+cells/kg were collected. Only study cells were used for transplant. Patients who failed to mobilize ≥2 x 106 CD34+cells/kg could enter into a rescue arm of A+G, without unblinding of randomized treatment. The primary endpoint was the percentage of patients who achieved ≥5 x 106 CD34+cells/kg in 4 or less aphereses days. All patients will be followed for ≥12 months post-transplant. Results: 298 patients were enrolled and randomized. All patients have completed 100 days follow-up and are included in this intent-to-treat analysis. Baseline characteristics were similar between groups. The primary endpoint was met in 89/150 (59%) patients in the A+G group and 29/148 (20%) patients in the P+G group, p<0.0001. 130/150 (87%) patients in the A+G group and 70/148 (47%) patients in the P+G group collected ≥2 x 106 CD34+cells/kg in 4 or less aphereses days, p<0.0001. Kaplan-Meir Estimates of Time to Trget Collection of ≥ × 106 CD34 + cells/kg Kaplan-Meir Estimates of Time to Trget Collection of ≥ × 106 CD34 + cells/kg The figure shows that more patients in the A+G group reached target after 1 day of apheresis than patients in the P+G group after 4 days of apheresis. A+G rescue was successful in 33/52 rescue patients in the P+G group and 4/10 rescue patients in the A+G group. 135 patients (90%) in A+G group and 82 patients (55%) in P+G group underwent transplantation. Median time to engraftment was Day 10 for PMN and Day 20 for platelets in both groups. Through 100 days, grafts were durable in all but 2 A+G (133/135) patients and in all P+G (82) patients. A+G patients experienced a higher incidence of GI effects (mild to moderate) and injection site erythema than P+G patients. There were 2 drug related serious adverse events in the A+G group and 1 in the P+G group. Conclusions: In this study, the addition of AMD3100 to G-CSF is generally safe and well tolerated and is superior to G-CSF alone for aHSC mobilization in NHL patients. A+G patients were statistically significantly more likely to achieve target cell collection quicker and to achieve sufficient cells for successful transplant than P+G patients.

Abstract AMD3100, Plerixafor (A)+G-CSF (G) have effectively allowed aHSC mobilization in Phase I and II studies. This Phase III, multicenter, randomized, double-blind, placebo controlled study compares the safety and efficacy of A+G Vs. placebo (P)+G to mobilize and transplant patients with MM. Methods: Adult MM patients requiring an aHSC transplant, in first or second CR or PR were eligible to participate. Patients were declared for single or tandem transplant with the second transplant occurring within 6 months from the first. Patients received G (10μg/kg/day) subcutaneously (SQ) for 4 days; on the evening of Day 4 they received either A (240μg/kg SQ) or P. Patients underwent apheresis on Day 5 after an AM dose of G and 10–11 hours after administration of study treatment. Patients continued to receive the evening dose of study treatment followed by AM dose of G and apheresis for up to a total of 4 apheresis or until ≥6 x 106 CD34+ cells/kg were collected. Patients who failed to collect ≥2 x 106 CD34+ cells/kg were eligible for rescue therapy with A+G, without unblinding of randomized treatment. Only study cells were used for transplant. The primary endpoint was the percentage of patients who achieved ≥6 x 106 CD34+ cells/kg in 2 or less apheresis days. All patients will be followed for ≥12 months post-transplant. Results: 302 patients were enrolled and randomized into the study. All have completed 100 days follow-up and are included in this intent-to-treat analysis. Baseline characteristics were similar between groups. The primary endpoint was met in 106/128 (72%) patients in the A+G group and 53/154 (34%) patients in the P+G group, p<0.0001. The figure shows that 54% of A+G patients reached target after 1 day of apheresis but 56% P+G patients required up to 4 days of apheresis to reach target. 7 patients in the P+G group required rescue therapy and all collected ≥2 x 106 CD34+ cells/kg after A+G rescue. 142 patients (96%) in A+G group and 136 patients (88%) in the P+G group underwent transplant. Tandem transplants were performed in 32 and 28 patients in A+G and P+G groups, respectively. Median time to engraftment was Day 11 for PMN and Day 18 for platelets in both groups. Grafts were durable in all patients in both group at ≥100 days post-transplant. Patients in the A+G group experienced more GI effects and injection site erythema than patients in the P+G group. These adverse events were generally mild. There were no drug related serious adverse events in either group. Conclusions: In this study, the addition of AMD3100 to G-CSF is generally safe and well tolerated and is superior to G-CSF alone for aHSC mobilization in MM patients. A+G patients were statistically significantly more likely to achieve target earlier than P+G patients and had successful transplant. Figure Figure

Abstract Background: AMD3100 (plerixafor)+G-CSF (A+G) was generally safe and more effective in mobilizing CD34+ hematopoietic stem cells compared to placebo+G-CSF (P+G) in a Phase III, multicenter, randomized, double-blind, placebo controlled study conducted in patients with non-Hodgkin’s lymphoma (NHL). In the intent-to-treat analysis, 78/148 (53%) patients in the P+G group and 20/150 (13%) patients in the A+G group failed to mobilize ≥ 2 x 106 CD34+ cells/kg, p<0.0001. Of these failure patients, 52 in the P+G group and 10 in the A+G group consented to enter into the rescue arm of the study. This abstract reports the outcomes of these rescue patients. Methods: Patients enrolled in the Phase III study who failed to mobilize ≥2 x 106 CD34+ cells/kg could enter into the rescue arm of the study and receive A+G. The patient’s treatment assignment in the study remained blinded. Following a rest period of ≥7 days, patients were given G (10 μg/kg/day) subcutaneously (SQ) for 4 days. In the evening around 10PM on Day 4, patients were given a dose of A (240 μg/kg SQ). On Day 5, all patients returned to clinic to receive a morning dose of G before apheresis. Patients continued to receive the evening dose of A followed by morning dose of G and apheresis the next day for up to a total of 4 aphereses or until ≥5 x 106 CD34+ cells/kg were collected. Pooled cells were allowed for transplantation. Results: After rescue therapy, 33/52 (63%) patients who previously failed P+G and 4/10 (40%) patients who previously failed A+G collected ≥2 x 106 CD34+ cells/kg. Seven of the 33 patients who previously failed with P+G collected ≥ 5 x 106 CD34+ cells/kg. Six of the ten A+G patients and 46/52 P+G patients were transplanted. Median time to PMN engraftment was Day 10 and Day 11 for the A+G and P+G groups, respectively. Median time to platelet engraftment was Day 22 and Day 20 for the A+G and P+G groups, respectively. One patient in the P+G group never had platelet counts > 50,000 and was counted as a failure to engraft, even though the patient was clinically stable through 6 months post-transplant. In the re-mobilized group, 9 patients died (2 patients were never transplanted and 7 patients had disease progression). Grafts were durable for ≥100 days in all 6 rescued A+G patients and all 41 rescued P+G patients who engrafted. The predominant adverse events were mild gastrointestinal effects (diarrhea, nausea, vomiting, and abdominal pain) and injection site reactions. There were no drug-related serious adverse events reported in these re-mobilized patients. Conclusions: The addition of AMD3100 to G-CSF successfully mobilized sufficient stem cells for transplant in 63% of NHL patients who previously failed mobilization with G-CSF alone. The high success rate is consistent with the Compassionate Use Protocol experience. AMD3100 was generally well tolerated. The 40% success rate in the patients who previously failed AMD3100+G-CSF suggests that re-mobilization with the same combination is a potentially useful strategy for similar patients.