ALBERT

Description: Abstract 1360 Introduction: The tyrosine kinase inhibitor (TKI) imatinib is used as the first-line therapy for newly diagnosed chronic myeloid leukemia (CML). However, some patients fail to respond or become intolerant to imatinib. Nilotinib is a second-generation TKI with higher selectivity and more potent inhibitory effects on BCR-ABL than imatinib. Several studies have shown hematologic and cytogenetic responses to nilotinib in patients with imatinib-resistant or intolerant CML. Purpose: To investigate the safety and efficacy of nilotinib for patients with imatinib-resistant or intolerant, chronic (CP)- or accelerated (AP)-phase CML from the East Japan CML Study Group (EJCML) trial by evaluating molecular responses in terms of the BCR-ABL1 mutational status and plasma trough concentration of nilotinib. Methods: In this multicenter phase II clinical trial, nilotinib (400 mg bid) was administered orally for one year and the molecular responses were monitored by means of the international scale of quantitative PCR (IS-PCR). BCR-ABL1 mutations were analyzed by direct sequencing at the baseline and 12 months or at the time of the event for discontinuation of the treatment (i.e., progressive disease, insufficient effects, or severe adverse events). The plasma trough concentration of nilotinib was measured by high-performance liquid chromatography 3 months after nilotinib administration. Results: From March 2009 through February 2011, 51 patients were registered in this study, and data of 49 patients whose molecular responses were evaluated by the IS-PCR were analyzed (imatinib-resistant CML = 33, imatinib-intolerant CML = 16; CP CML = 46, AP CML = 3). The median follow-up period was 12.0 months (range = 0.1–13.3 months). At 6 and 12 months, the major molecular response (MMR; ≤0.1% IS) rates were 52.5% and 67.6%, respectively, and the complete cytogenetic response (CCyR)-equivalent (≤1.0% IS) rates were 75.0% and 85.3%, respectively. Five types of BCR-ABL1 mutations (M244V, F317L, N358D, F359V, and E459K) were detected in 6 patients (12.2%) at the baseline, but the M244V, N358D, and E459K mutations disappeared after the nilotinib treatment. Acquired BCR-ABL1 mutations (Y253H, I418V, and exon 8/9 35bp insertion) were detected in 3 patients (8.6%) at 12 months or at the time of the event; these patients did not achieve a CCyR or an MMR. No patients showed an acquired mutation of T315I. Most patients except 11 subjects (22.4%) still received the treatment. The reasons for discontinuation were progressive disease in one patient with an F317L mutation, insufficient effects in one patient without any mutation, and adverse events in 9 patients (thrombocytopenia in 5 patients, hyperbilirubinemia in 2 patients, headache in one patient, and heart disease in one patient). Among 30 patients without BCR-ABL1 mutations, the plasma trough concentration of nilotinib was significantly higher in 21 patients with an MMR than in those without an MMR by 12 months (median = 1255.1 ng/mL vs. 372.8 ng/mL, P = 0.0012 by Mann–Whitney U-test; see the figure). The concentration of 761 ng/mL was significantly associated with an MMR by 12 months in a receiver-operating characteristic (ROC) curve analysis of the best sensitivity (76.2%) and specificity (77.8%). Conclusion: The patients with imatinib-resistant or intolerant, CP or AP CML, even those having BCR-ABL1 mutations M244V, N358D, and E459K, achieved an MMR by 12 months of nilotinib treatment. The plasma trough concentration of the drug was related to the MMR by 12 months, and the plasma threshold of nilotinib should be set above 761 ng/mL. These findings suggest that nilotinib shows good efficacy and tolerability in Japanese patients with imatinib-resistant or intolerant, CP or AP CML. (ClicalTrials.gov, UMIN ID 000002201) Disclosures: No relevant conflicts of interest to declare.

Description: Using the intra-bone marrow injection (IBMI) method, we have identified human cord blood (CB)-derived CD34-negative (CD34−) severe combined immunodeficiency (SCID)-repopulating cells (SRCs) with multi-lineage repopulating ability (Blood101:2924,2003). Functional studies revealed that these CD34− SRCs have different hematopoietic stem cell (HSC) characteristics from CD34+ SRCs. In order to further clarify the HSC characteristics of CD34− SRCs, here we investigate the proliferative potential and redistribution kinetics of human CB-derived CD34− SRCs, and compare them with those of CD34+CD38+/− SRCs using IBMI. First, we performed limiting dilution analyses and revealed that the incidence of CD34+CD38− SRCs in CB-derived Lin−CD34+CD38− cells was 1 out of 41 cells by IBMI. In contrast, the incidence of CD34− SRCs in Lin−CD34− cells was 1 out of 24,100, as we previously reported. Based on these data, we transplanted 200 to 5,000 Lin−CD34+CD38− cells (containing 5 to 120 SRCs), 15,000 to 50,000 Lin−CD34+CD38+ cells (containing 10 to 30 SRCs), or 60,000 to 70,000 Lin−CD34− cells (containing 3 SRCs) into primary recipient NOD/Shi-scid mice. After 5 weeks, all mice that received transplants of Lin−CD34+CD38+/− cells showed the human CD45+ cell repopulation in the other bones as well as the injected left tibiae. However, the human CD45+ cells were only detected in the injected left tibiae in mice that received transplants of Lin−CD34− cells 5 weeks after the transplantation. In the mice that received transplants of 200 Lin−CD34+CD38− cells (containing 5 SRCs), the CD45+CD34+ as well as CD45+CD34− cells were detected in both sites. In contrast, only CD45+CD34− cells were detected in the mice that received transplants of 70,000 Lin−CD34− cells (3 SRCs). These results suggested that CD34− SRCs might remain or slowly proliferate as CD34− cells at the site of injection for at least 5 weeks. Next, we serially investigated the human CD45+ cell repopulation in the injected site and the other bones, separately. Very interestingly, CD34+CD38+/− SRCs began to migrate 2 weeks after the transplantation. The human cell repopulation in these mice was observed in other bones by 3 weeks after transplantation. Moreover, these CD34+ SRCs actively proliferated at both sites and produced CD34+ progenies. In contrast, CD34− SRCs began to migrate 5 weeks after the transplantaion. Furthermore, these CD34− SRCs showed significantly higher proliferative potential 8 weeks after transplantation than CD34+ SRCs and produced more CD34+ progenies not only at the site of injection, but also in the other bones. These results indicated that CD34− SRC as well as CD34+CD38+/− SRCs could actively migrate from the injected site to the other bones. However, the time of initiation of migration was different between CD34+/− SRCs. All these findings indicate that CD34− SRCs show different proliferative potential and redistribution kinetics, and suggest that our identified CD34− SRCs are distinct class of primitive HSCs in comparison with CD34+CD38+/− SRCs. We are now in the progress of clarifying whether the CD34− SRCs migrate to other bones with the CD34− immunophenotype or after their conversion (differentiation) to the CD34+ cells.

Description: We have identified a specific dual Bcr-Abl/Lyn inhibitor, NS-187 (elsewhere described as CNS-9), which is 25–55 times more potent than imatinib against wild type Bcr-Abl in vitro. To evaluate the potential of NS-187 as a therapeutic agent, we assessed its in vivo activity. When Balb/c mice were given NS-187 orally at a dose of 30 mg/kg, the pharmacokinetic parameters were as follows: Tmax, 2 h; Cmax, 586 ng/ml; AUC0-∝, 2999 ng•h/ml; T1/2, 1.0 h; and bioavailability value (BA), 33%. The maximal tolerated dose (MTD) of NS-187 in Balb/c or Balb/c-nu/nu mice was 200 mg/kg/day (100 mg/kg, twice daily). To test the effect of NS-187 on in vivo tumor growth, Balb/c-nu/nu mice were injected subcutaneously with Bcr-Abl-positive KU812 cells on Day 0 and given NS-187 or imatinib orally twice a day from Day 7 to Day 17. At 20 mg/kg/day, imatinib inhibited tumor growth slightly, while at 200 mg/kg/day, it inhibited tumor growth almost completely. In contrast, at only 0.2 mg/kg/day NS-187 significantly inhibited tumor growth, while at 20 mg/kg/day it completely inhibited tumor growth without any adverse effects. The body weights of the treated tumor-bearing mice were not significantly different from those of untreated mice, even at a dosage of 200 mg/kg/day NS-187. Thus, NS-187 was at least 10-fold more potent than imatinib in vivo with complete inhibition of tumor growth as the end-point. We also tested the ability of NS-187 to suppress tumor growth in another murine tumor model, namely, Balb/c-nu/nu mice intravenously transplanted with BaF3 cells harboring wild type Bcr-Abl. The mice were treated orally with NS-187 or imatinib for 11 days starting on Day 1. All eight untreated mice and all eight mice treated with 400 mg/kg/day imatinib had died by Day 25 due to leukemic cell expansion, and NS-187 significantly prolonged the survival of the mice in a dose-dependent manner. We next examined the ability of NS-187 to block the in vivo growth of BaF3 cells harboring one of the Abl point-mutants M244V, G250E, Q252H, Y253F, T315I, M351T and H396P in Balb/c-nu/nu mice. These mice were treated with NS-187 or imatinib for 11 days starting on Day 1. NS-187 at 200 mg/kg/day significantly prolonged the survival of mice inoculated with BaF3 cells harboring any of these mutants except T315I compared with untreated or imatinib-treated mice (see Figure for an example). Thus, NS-187 was more potent than imatinib and could override the point-mutation-based imatinib-resistance mechanism in vivo. The efficacy and safety of NS-187 for Ph+ leukemias is expected to be verified by early-phase clinical trials. Figure Figure

Description: Recently, we have successfully identified human cord blood (CB)-derived CD34-negative (CD34−) severe combined immunodeficiency (SCID)-repopulating cells (SRCs) with extensive lymphoid and myeloid repopulating ability using the intra-bone marrow injection (IBMI) method (Blood101:2924,2003). These CD34− SRCs could home into the BM niche only by IBMI, because they expressed lower levels of homing receptors including CXCR4. These CD34− SRCs did not express CD38 as well as c-kit. It is well documented that the tyrosine kinase receptors c-kit and flt3 are expressed and function in early mouse and human hematopoiesis. In murine model, it was reported that Lin−CD34−Sca−1+c-kit+flt3− cells supported long-term multilineage hematopoietic reconstitution. In contrast, Lin−CD34−Sca-1+c-kit+flt3+ cells are progenitors for the common lymphoid progenitor. More recently, these Lin−CD34−Sca-1+c-kit+flt3+ hematopoietic stem cells (HSCs) have been revealed to lack erythro-megakaryocytic potential. In this study, we have investigated the function of flt3 in our identified human CB-derived CD34− SRCs. First, we studied the SRC activity of CB-derived Lin-CD34+Flt3+/− or CD34−Flt3+/− cells using IBMI. Both CD34+FLT3+/− cells repopulated all 13 recipient mice. The level of human CD45+ cells in murine BMs received transplants of CD34+Flt3+ cells (29.3~90.8%, median 62.8%) was higher than those received transplants of CD34+Flt3− cells (9.8~45.1%, median 17.7%). On the other hand, only CD34−Flt3− cells repopulated all 7 recipient mice and the level of human CD45+ cells in murine BMs was 11.7~63.3% (median 37.9%). To further evaluate the long-term repopulating potential of these three populations, including CD34+Flt3+/− and CD34−Flt3− cells, BM cells obtained from each primary recipient mice were accessed for their SRC activities by secondary transplantation by IBMI. While CD34+Flt3+ cells did not show secondary repopulating activity, CD34+Flt3− cells could repopulate 83% (5/6) of secondary recipients. Moreover, CD34−Flt3− cells did repopulate all 5 secondary recipient mice with higher repopulating rate. Next, we cocultured CD34−Flt3−cells with the murine stromal cell line, HESS-5 in the presence of SCF, TPO, IL-3, IL-6, and G-CSF. After one week, significant numbers of CD34+Flt3− and CD34+Flt3+ cells were generated. Then we sorted these two populations, CD34+Flt3+/− cells, and tested their SRC activities by IBMI. Seven out of 10 and 5 out of 10 mice received CD34+Flt3+/− cells were repopulated with human cells, respectively. These results indicated that human CB-derived Lin−CD34−Flt3− cells produced CD34+Flt3− as well as CD34+Flt3+ SRCs in vitro. Our present study has demonstrated that human CB-drived CD34− SRCs do not express Flt3 tyrosine kinase receptor as did murine CD34− KSL cells. Based on these data, we propose that the immunophenotype of very primitive long-term repopulating human HSC is Lin−CD34−CD38−c-kit-Flt3−.

Description: Abstract 4147 Whole-body diffusion-weighted magnetic resonance imaging (DWI-MRI) provides functional information and is able to highlight oncological lesions, but the usefulness has not been established in malignant lymphoma especially for monitoring therapeutic response. Positron emission tomography with fluorine-18 fluorodeoxyglucose (FDG-PET) is a useful imaging producer for tumor staging and therapy monitoring that can visualize active tumor tissue including malignant lymphoma. The spatial resolution of FDG-PET is limited, and low accuracy rates in diabetic patients and those with low grade lymphoma have been reported. We prospectively studied the utility of DWI-MRI with T2 imaging and apparent diffusion coefficient (ADC) for staging and monitoring therapeutic responses in patients with malignant lymphoma compared with FDG-PET/CT. Twenty-eight patients with malignant lymphoma (16 patients with diffuse large B cell lymphoma: DLBCL, 7 with follicular Lymphoma: FL, 3 with aggressive T cell lymphoma: TCL and 2 with Hodgkin lymphoma: HL, including one diabetic patient) received both MRI and FDG-PET examination before (n=28), after 2 courses of chemotherapy (n=25) and one month after the end of chemotherapy (n=9). MRI examination was performed with a 3-Tesla MR system (Signa Excite, Generel Electrics). Whole-body DWI-MRI was performed with echo planar imaging sequence with short T1 inversion recovery (STIR) fat suppression. ADC measurement was performed based on the region of interest (ROI) method. ROI was placed on the lesion showing the highest standardized uptake value (SUV) on FDG-PET/CT scanner (Discovery LS, General Electrics) in each patient, and crucial parameters of the ADC and SUV were compared. Based on staging by PET/CT, 4 patients were clinical stage I, 8 were stage II, 7 were stage III and 9 were stage IV. DWI-MRI findings alone matched PET/CT in 22 patients (79%), whereas these findings combined with T2 imaging increased match in 26 patients (93%). Regarding the early response to chemotherapy, 19 of 25 patients (76%) were considered to show CR on PET/CT and the DWI findings matched PET/CT 23 patients (92%). To evaluate the final response after chemotherapy, 7 of 9 patients (78%) were considered to show CR on PET/CT and the DWI findings matched PET/CT in 8 of 9 patients (89%). Of these nine, one patient with DLBCL who did not show a match was a false positive on PET/CT. In all patients with TCL and HL, the DWI-MRI findings combined with T2 imaging matched PET/CT findings for staging and therapeutic response. Interestingly, the ADC values on DWI-MRI did not differ between DLBCL and FL (0.77 +/− 0.23 and 0.70 +/− 0.08, p=0.99, mean +/− SD respectively), whereas the SUV values of DLBCL on PET/CT were higher than those of FL (14.5 +/− 6.97 and 6.09 +/− 2.54, p 〈 0.0005, mean +/− SD respectively), suggesting the DWI-MRI could detect the lymphoma lesion more accurately than PET/CT in patients with indolent lymphoma such as FL. We conclude that whole-body DWI-MRI combined with T2 imaging and ADC analysis could be promising sensitive method for staging and therapeutic response evaluation in patients with malignant lymphoma. Disclosures: No relevant conflicts of interest to declare.

Description: Background Invasive fungal infections (IFIs) are of great concern after allogeneic hematopoietic stem cell transplantation (HSCT), the risk of which is considered to be particularly prominent among cord blood transplantation (CBT) recipients. Patients and Methods We retrospectively analysed the records of 749 adult patients who underwent CBT or unrelated bone marrow transplantation (uBMT) for the first time at the Toranomon Hospital between 2002 and 2012, and who had neither prior history nor suspicious findings of IFIs. As prophylaxis for IFIs, fluconazole (FLCZ) or itraconazole (ITCZ) capsules were conventionally used until around 2006, which were then changed to newer mold-active agents including ITCZ oral solution, voriconazole or micafungin after their approval in Japan, the choice of which was subjected to physician's discretion. Results Engraftment achieved in 418 CBT patients and 198 uBMT patients with a significantly longer neutropenic period in CBT patients (median 20 days vs 18 days, P

Description: Objectives Fever during neutropenia occurs in 〉 90% and 80% of allogeneic and autologous hematopoietic stem cell transplantation (HSCT) recipients, respectively. Current guidelines recommend the prophylaxis with fluoroquinolones (FQs) in HSCT patients. Although there is evidence that antibiotic prophylaxis improve clinical outcome in patients with chemotherapy-induced neutropenia, prophylactic antibiotic therapy has not been thoroughly evaluated in HSCT recipients. Therefore, we performed a meta-analysis to evaluate the impact of systemic antibiotic prophylaxis in HSCT recipients on mortality, incidence of infection and related adverse events. Data sources We identified reports that were not restricted to those in English and not restricted to published trials through PubMed, the Cochrane Library, and references of identified studies. Review Methods We included prospective, randomized studies on systemic antibiotic prophylaxis in HSCT recipients. The outcome measures included the all-cause mortality, infection-related mortality, febrile episodes, incidence of clinically or microbiologically documented infection, bacteremia, or related adverse events. The summarized odds ratios (ORs) were calculated using the Mantel–Haenszel method and the DerSimonian–Laird method. Results Seventeen trials with 1453 patients (842 autologous and 407 allogeneic HSCT recipients) were included. The percentage of autologous and allogeneic HSCT recipients was not specified in 2 trials. Systemic antibiotic prophylaxis was compared with placebo or no prophylaxis in 10 trials and with non-absorbable antibiotic in 2 trials, respectively. Systemic antibiotics other than FQs were evaluated in five out of these 12 trials. Four trials evaluated the effect of addition of antibiotics for gram positive bacteria to FQs. Remaining 1 trial compared the two different systemic antibiotic regimens, FQs versus trimethoprim sulfamethoxazole. As a result, systemic antibiotic prophylaxis reduced the incidence of febrile episodes (OR 0.16; 95 percent confidence interval [CI], 0.09-0.30), clinically or microbiologically documented infection (OR 0.41; 95% CI 0.30-0.57) and bacteremia (OR 0.37; 95% CI 0.26-0.53) without the significant effect on all-cause mortality or infection-related mortality (OR 0.89; 95% CI 0.48-1.66, OR 1.37; 95% CI 0.50-3.76, respectively). Impact of prophylaxis with FQs on mortality was inconclusive because of small number of clinical trials evaluated. Adverse events increased in patients with systemic antibiotic prophylaxis compared to controls (OR 3.32; 95% CI 1.45-7.63). In meta-regression, percentage of allogeneic HSCT recipients was not associated with each outcome measure. With regard to the comparison between different prophylactic regimens, addition of antibiotics for gram positive bacteria to FQs decreased the incidence of bacteremia (OR 0.44; 0.24-0.80) without significant effects on all-cause mortality, infection related death and febrile episodes. There was not significant, but consistent decrease in clinically or microbiologically documented infection (OR 0.55; 95% CI 0.30-1.01). There was significant increase of adverse events in patients receiving addition of antibiotics for gram positive bacteria to FQs (OR 6.65; 95% CI 2.15-20.54). Conclusions Systemic antibiotic prophylaxis successfully reduced the incidence of infection in HSCT recipients. However, there was no significant impact on mortality. Impact of prophylaxis with FQs on mortality in HSCT recipients was inconclusive because of small number of trials evaluated. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 2007 Background: High-dose cyclophosphamide (HD-CY) + granulocyte-colony stimulating factor (G-CSF) and G-CSF alone have been used to mobilize hematopoietic stem cells (HSCs) for autologous SC transplantation (ASCT) in multiple myeloma (MM). However, which regimen is better is unknown; anti-myeloma effects of HD-CY + G-CSF have not been established. From January 1999 to June 2009, we administered HD-CY+G-CSF but changed to G-CSF alone during July 2009–December 2010. We retrospectively assessed HSC collection efficacy, complications, and anti-myeloma effects of these regimens. Patients and methods: We analyzed 147 MM patients from whom HSCs were to be collected at our institute. For mobilization, 115 patients were administered HD-CY (4 g/m2)+G-CSF (600 mg/body filgrastim or 500 mg/body lenograstim) and 32 were administered G-CSF alone (same dose as HD-CY). Here, 17 patients received therapeutic intervention between mobilization and transplantation without disease progression (PD). To avoid the patient outcome effect, we defined event- and progression-free survivals (EFS and PFS). EFS was defined as PD, death, or therapeutic intervention without PD. PFS was defined as PD or death, where therapeutic intervention without PD was used as a censor. Both were calculated from the start of mobilization. For analyzing response by mobilization, patients receiving therapeutic intervention without PD were excluded. Response was evaluated in those not receiving therapeutic intervention without PD or in whom response could not be evaluated before ASCT. Thalidomide was administered as maintenance therapy to 14 and 6 patients in the HD-CY+G-CSF and G-CSF groups after ASCT. Thalidomide administration was used as a censor. Results: Vincristine, doxorubicin, and dexamethasone (VAD) and HD dexamethasone (HDD) therapies were administered as induction therapy (VAD for 117, HDD for 2, and both for 11). New (bortezomib or thalidomide) and alkylating agents were administered to 7 and 13 patients, respectively. Before mobilization, 26 patients received radiotherapy; none were administered lenalidomide. No statistical difference was seen in baseline characteristics (Durie-Salmon stage, International staging system, interval from diagnosis to mobilization, disease control, and previous therapies) between both groups. However, patients mobilized by G-CSF alone were significantly older. Among 147 patients, 121 underwent planned ASCT. Of the 17 receiving therapeutic intervention without PD, 13 and 4 belonged to the HD-CY+G-CSF and G-CSF groups, respectively. More than 2 × 106 CD34-positive cells/kg were collected from 93% and 75% patients in the HD-CY+G-CSF and G-CSF (p = 0.0079) groups, respectively. More than 4 × 106 CD34-positive cells/kg were collected from 84% and 69% in the HD-CY+G-CSF and G-CSF (p = 0.07). Mean HSC count was 11.4 × 106/kg in the HD-CY+G-CSF group and 4.5 × 106/kg in the G-CSF group (p = 0.0007). Among patients receiving HD-CY+G-CSF, 66% were treated with intravenous antibiotics; 3 suffered cardiac shock and 2 septic shock. However, among those receiving G-CSF alone, no severe complications were seen. Median hospitalization days were 21 and 8 for the HD-CY+G-CSF and G-CSF groups, respectively (p 〈 0.0001). In the HD-CY+G-CSF group, 16% improved in disease control before ASCT, 71% showed no change, and 13% progressed. However, no patient improved, 63% showed no change, and 27% progressed in the G-CSF group (p = 0.015). Median EFS was 25 months in the HD-CY+G-CSF group and 13 in the G-CSF group (fig 1, p value of log-rank test = 0.012). Median PFS was 28 months in the HD-CY+G-CSF group and 15 in the G-CSF group (fig 2, p value of log-rank test = 0.011). Median overall survival did not differ significantly. Conclusion: Regarding the safety and duration of hospitalization, G-CSF alone may be safer and beneficial. However, HD-CY+G-CSF was more effective as a mobilization regimen and showed higher anti-myeloma effects than G-CSF alone. Disclosures: No relevant conflicts of interest to declare.

Description: Central nervous system (CNS) relapse accompanying prolonged administration of imatinib mesylate, an Abl-specific tyrosine kinase inhibitor, has recently become apparent as an impediment to the therapy of Philadelphia-chromosome-positive (Ph+) leukemia. CNS relapse may be explained by limited penetration of imatinib into the cerebrospinal fluid due to presence of P-glycoprotein (P-gp) at blood-brain barrier. To overcome imatinib-resistance mechanisms such as bcr-abl gene amplification, point mutations within ABL kinase domain, and activation of Lyn, we recently developed a specific dual BCR-ABL/Lyn inhibitor, INNO-406 (formerly NS-187), which is 25–55 times more potent than imatinib in vitro and at least 10 times more potent in vivo (Blood106: 3948–3954, 2005). The aim of this study was to investigate the efficacy of INNO-406 in treating CNS Ph+ leukemia. The intracellular accumulation of [14C]INNO-406 in P-gp overexpressing LLC-GA5-COL150 cells was much less than that in parental LLC-PK1 cells. The addition of 10 mM cyclosporin A (CsA) increased the intracellular accumulation of [14C]INNO-406 in both LLC-PK1 cells and LLC-GA5-COL150 cells. The peak concentration of INNO-406 in the brain when 30 mg/kg INNO-406 was administered p.o. was 50 ng/ g (87 nM), representing only 10% of plasma drug level. These findings suggested that INNO-406 is also a substrate of P-gp, as is imatinib. However, the residual concentration of INNO-406 in the CNS was enough to inhibit the growth of Ph+ leukemic cells according to the in vitro data. To increase the concentration of INNO-406 in CNS, we next examined the combined effects of CsA. In the brain, the concentration of INNO-406 was doubled following prior administration of 50 mg/kg CsA. Since pharmacokinetic studies suggested the possible effects of INNO-406 against CNS Ph+ leukemia, we investigated in vivo anti-CNS Ph+ leukemia effects of INNO-406 alone and combination of INNO-406 and CsA using immunodeficient mice (nude or NOD/SCID) which received Ph+ leukemic cells into the cerebral ventricle. INNO-406 alone inhibited growth of leukemic cells harboring either wild type or mutated BCR-ABL such as E255K and M351T in CNS. Furthermore, CsA significantly enhanced anti-CNS Ph+ leukemia effects of INNO-406 in vivo not only against cells harboring wild type BCR-ABL but also against cells harboring BCR-ABL/M351T (Figure). In conclusion, INNO-406 was found to inhibit Ph+ leukemic cell growth in CNS in spite of efflux of the compound by P-gp, and CsA augmented the anti-CNS Ph+ leukemia effects of INNO-406. Phase I clinical study on INNO-406 was initiated in the U.S.A. in July 2006. The efficacy and safety of INNO-406 in the treatment of leukemias is expected to be verified by early-phase clinical trials. Figure Figure

Description: Survivin, a member of the inhibitors of the apoptosis family, is overexpressed frequently in a variety of cancers and hematological malignancies, but not in normal tissues. Murine in vivo and human in vitro studies have suggested that immunotherapy of cancer patients using survivin peptide might be feasible. In the present study, we examined whether HLA-A24 restricted cytotoxic T lymphocytes (CTL) which recognize survivin peptide can be generated from peripheral blood of lymphoma patients. HLA-A24 positive four lymphoma patients and two healthy volunteers were enrolled. Three immunodominant 9-mer candidate peptides (2B, 3A, 3B) were selected on the basis of anchoring motif of peptide binding to HLA-A24 molecule. CD8 T cells from the patients and healthy volunteers were stimulated several times with autologous monocyte-derived dendritic cells pulsed with survivin or control HIV peptides and tested for peptide-specific cytotoxicity by an LDH-release assay. CTL generated with survivin 2B peptide lysed autologous monocytes pulsed with a relevant peptide. However, other survivin peptides did not elicit CTL response. Non-pulsed or HIV peptide-pulsed monocytes were not lysed. On the other hand, CTL generated with HIV peptide only lysed HIV peptide-pulsed monocytes. CTL did not lyse allogeneic monocytes regardless of the peptide pulse. Cytotoxic activity was inhibited by the pretreatment of target cells by anti-HLA class I, not by anti-HLA-DR monoclonal antibody, indicating that the lysis was HLA class I (A24) restricted. These cells did not lyse Daudi and K562, excluding the involvement of LAK or NK activity. Importantly, these survivin peptide-specific CTL showed cytotoxicity to the patient’s lymphoma cells and HLA-A24 positive lymphoma cells. Based on these preclinical data, we have just started a pilot clinical study to examine the safety and the efficacy of peptide vaccination to relapsed, chemotherapy-resistant malignant lymphoma patients who are HLA-A24 and survivin positive. A 46-year old male patient with diffuse large B-cell lymphoma has just completed two courses of four vaccinations at two-week intervals with survivin 2B peptide (1 μg subcutaneously) in an incomplete Freund’s adjuvant (Montanide ISA-51, SEPPIC Co. France). We observed a marked decrease in the size of extra-nodular surface and cervical lymphnodes following vaccinations without serious adverse events. Immunological evaluations using HLA-tetramer and T cell receptor clonality assays revealed an increase in survivin-specific CTL frequency after vaccinations. The in-vitro feasibility study and pilot clinical trial indicate that a vaccination with a survivin peptide is safe and might be a promising novel strategy for the treatment of lymphoma patients.