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Everolimus (RAD001) is an mTOR inhibitor that has been successfully used as an immunosuppressant in solid-organ transplantation. Data in allogeneic hematopoietic stem cell transplantation (HSCT) is limited. This study aimed to investigate pharmacokinetics, safety, and efficacy of RAD001 in a canine allogeneic HSCT model. First, pharmacokinetics of RAD001 were performed in healthy dogs in order to determine the appropriate dosing. Doses of 0.25 mg RAD001 twice daily in combination with 15 mg/kg cyclosporin A (CsA) twice daily were identified as appropriate starting doses to achieve the targeted range of RAD001 (3-8 μg/L) when orally administered. Subsequently, 10 dogs were transplanted using 2 Gy total body irradiation (TBI) for conditioning and 0.25 mg RAD001 twice daily plus 15 mg/kg CsA twice daily for pre- and posttransplantation immunosuppression. Seven of the 10 transplanted dogs were maintained at the starting RAD001 dose throughout the study. For the remaining 3 dogs, dose adjustments were necessary. RAD001 accumulation over time did not occur. All dogs initially engrafted. Five dogs eventually rejected the graft (weeks 10, 10, 13, 27, and 56). Two dogs died of pneumonia (weeks 8 and 72) but were chimeric until then. Total cholesterol rose from median 4.1 mmol/L (3.5-5.7 mmol/L) before HSCT to 6.0 mmol/l (5.0-8.5 mmol/l) at day 21 after HSCT, but remained always within normal range. Changes in creatinine and triglyceride values were not observed. Long-term engraftment rates were inferior to sirolimus/CsA and mycophenolate mofetil (MMF)/CsA regimen, respectively. RAD001/CsA caused a more pronounced reduction of platelet counts to median 2 × 109/L (range: 0-21 × 109/L) and longer time to platelet recovery of 21 days (range: 14-24 days) compared with MMF/CsA. CsA c2h levels were significantly enhanced in the RAD001/CsA regimen, but c0h and area under the curve from 0 to 12 hours (AUC0-12h) values did not differ compared with an MMF/CsA immunosuppression. In summary, immunosuppression consisting of RAD001 and CsA is well tolerated but not as efficient as with other established immunosuppressants in a canine nonmyeloablative HSCT regimen. Hence, our study does not support the application of RAD001/CsA as standard practice in this setting. [Copyright &y& Elsevier]

This trial investigates the addition of panitumumab to chemotherapy with fluorouracil/folinic acid and oxaliplatin (FOLFOX) in a 2:1 randomised, controlled, open-label, phase II trial in RAS wild-type colorectal cancer patients with R0/1-resected liver metastases. The primary endpoint was progression-free survival (PFS) two years after randomisation. The experimental arm (12 weeks of biweekly mFOLFOX6 plus panitumumab followed by 12 weeks of panitumumab alone) was considered active if the two-year PFS rate was ≥65%. Based on historical data, a two-year PFS rate of 50% was estimated in the control arm (12 weeks of biweekly FOLFOX). The trial was performed with a power of 80% and an alpha of 0.05. Secondary endpoints included overall survival (OS) and toxicity. The trial is registered with ClinicalTrials.gov , NCT01384994. The full analysis set consists of 70 patients (pts) in the experimental arm and 36 pts in the control arm. The primary endpoint was missed with a two-year PFS of 35.7% with FOLFOX plus panitumumab and 30.6% in the control arm. In comparative analyses, trends towards improved PFS (HR 0.83; 95%CI, 0.52–1.33; P = 0.44) and OS (HR 0.70; 95% CI, 0.34–1.46; P = 0.34) were observed in favour of the panitumumab-based study arm. No new or unexpected safety signals were observed with FOLFOX plus panitumumab following liver resection. The PARLIM trial failed to demonstrate a two-year PFS rate of 65% after resection of colorectal liver metastases. The positive trends in survival endpoints may support future trials evaluating treatment with anti-EGFR agents after resection of liver metastases. • FOLFOX plus panitumumab after the resection of liver metastases is safe and feasible. • The free-of-disease endpoint was missed with panitumumab and FOLFOX. • Survival trends may suggest panitumumab efficacy after the resection of metastases. [ABSTRACT FROM AUTHOR]

An intra–bone marrow (IBM) hematopoietic stem cell transplantation (HSCT) is assumed to optimize the homing process and therefore to improve engraftment as well as hematopoietic recovery compared with conventional i.v. HSCT. This study investigated the feasibility and efficacy of IBM HSCT after nonmyeloablative conditioning in an allogeneic canine HSCT model. Two study cohorts received IBM HSCT of either density gradient (IBM-I, n = 7) or buffy coat (IBM-II, n = 6) enriched bone marrow cells. An historical i.v. HSCT cohort served as control. Before allogeneic HSCT experiments were performed, we investigated the feasibility of IBM HSCT by using technetium-99m marked autologous grafts. Scintigraphic analyses confirmed that most IBM-injected autologous cells remained at the injection sites, independent of the applied volume. In addition, cell migration to other bones occurred. The enrichment process led to different allogeneic graft volumes (IBM-I, 2 × 5 mL; IBM-II, 2 × 25 mL) and significantly lower counts of total nucleated cells in IBM-I grafts compared with IBM-II grafts (1.6 × 10 8 /kg versus 3.8 × 10 8 /kg). After allogeneic HSCT, dogs of the IBM-I group showed a delayed engraftment with lower levels of donor chimerism when compared with IBM-II or to i.v. HSCT. Dogs of the IBM-II group tended to reveal slightly faster early leukocyte engraftment kinetics than intravenously transplanted animals. However, thrombocytopenia was significantly prolonged in both IBM groups when compared with i.v. HSCT. In conclusion, IBM HSCT is feasible in a nonmyeloablative HSCT setting but failed to significantly improve engraftment kinetics and hematopoietic recovery in comparison with conventional i.v. HSCT. [ABSTRACT FROM AUTHOR]

The canine hematopoietic stem cell transplantation (HSCT) model has become accepted in recent decades as a good preclinical model for the development of new transplantation strategies. Information on factors associated with outcome after allogeneic HSCT are a prerequisite for designing new risk-adapted transplantation protocols. Here we report a retrospective analysis aimed at identifying risk factors for allograft rejection in the canine HSCT model. A total of 75 dog leukocyte antigen–identical sibling HSCTs were performed since 2003 on 10 different protocols. Conditioning consisted of total body irradiation at 1.0 Gy (n = 20), 2.0 Gy (n = 40), or 4.5 Gy (n = 15). Bone marrow was infused either intravenously (n = 54) or intraosseously (n = 21). Cyclosporin A alone or different combinations of cyclosporine A, mycophenolate mofetil, and everolimus were used for immunosuppression. A median cell dose of 3.5 (range, 1.0 to 11.8) total nucleated cells (TNCs)/kg was infused. Cox analyses were used to assess the influence of age, weight, radiation dose, donor/recipient sex, type of immunosuppression, and cell dose (TNCs, CD34 + cells) on allograft rejection. Initial engraftment occurred in all dogs. Forty-two dogs (56%) experienced graft rejection at median of 11 weeks (range, 6 to 56 weeks) after HSCT. Univariate analyses revealed radiation dose, type of immunosuppression, TNC dose, recipient weight, and recipient age as factors influencing long-term engraftment. In multivariate analysis, low radiation dose ( P < .001) and low TNC cell count ( P = .044) were identified as significant independent risk factors for graft rejection. Peripheral blood mononuclear cell chimerism ≥30% ( P = .008) and granulocyte chimerism ≥70% ( P = .023) at 4 weeks after HSCT were independent predictors of stable engraftment. In summary, these data indicate that even in low-dose total body irradiation–based regimens, the irradiation dose is important for engraftment. The level of blood chimerism at 4 weeks post-HSCT was predictive of long-term engraftment in the canine HSCT model. [ABSTRACT FROM AUTHOR]

The mammalian target of rapamycin inhibitor everolimus (RAD001) is a successfully used immunosuppressant in solid-organ transplantation. Several studies have already used RAD001 in combination with calcineurin inhibitors after hematopoietic stem cell transplantation (HSCT). We investigated calcineurin inhibitor-free pre- and post-transplantation immunosuppression of RAD001 combined with mycophenolate mofetil (MMF) in a nonmyeloablative HSCT setting. After nonmyeloablative conditioning with 2 Gy total body irradiation, 8 dogs received HSCT from dog leukocyte antigen-identical siblings. Immunosuppressives were given at doses of 1.5 mg RAD001 twice daily from day -1 to +49, then tapered until day +56, and 20 mg/kg MMF from day 0 to +28, then tapered until day +42. An historical cyclosporin A (CsA)/MMF regimen was used in the control group. All dogs engrafted. Median platelet nadir amounted in all dogs to 0 × 109/L (median, day +10; duration <50 × 109/L, 22 days) and median leukocyte nadir was 1.0 × 109/L (range, .1 to 2.5 × 109/L; median, day +13). Eventually, 5 of 8 (63%) animals rejected their grafts. Two dogs died of infections on day +19 and +25. Pharmacokinetics of RAD001 and MMF showed median trough levels of 19.1 (range, 10.5 to 43.2) µg/L and .3 (.1 to 1.3) mg/L, respectively. The median area under the curve was 325 (range, 178 to 593) µg/L × hour for RAD001 and 29.6 (range, 7.9 to 40.5) ng/L × hour for MMF. All dogs developed clinically mucosal viral infections during the clinical course. Compared with the control group, the level of toxicities for RAD001/MMF increased in all qualities. Combined immunosuppression of RAD001 and MMF after nonmyeloablative HSCT is associated with significant toxicities, including a prolonged platelet recovery time as well as increased infections compared to the CsA/MMF regimen. [ABSTRACT FROM AUTHOR]

Abstract: Indolylmaleimides display a broad spectrum of biological activity and offer great opportunity to influence several aspects of cell fate, as proliferation and differentiation. In this study we describe the effect of PDA-66, a newly synthesised indolylmaleimide, showing a strong dose dependent anti-proliferative effect on immortalised human progenitor and cancer cells. We demonstrated a highly depolymerizing effect on in vitro tubulin assembly and conclude that PDA-66 acts as microtubule destabilising agent. In addition we found that PDA-66 induces mitotic arrest of cells in the G2/M phase of the cell cycle. Subsequently cells undergo apoptosis, indicating the major mechanism of the anti-proliferative effect. To prove a potential anti-cancer activity of PDA-66 we examined the effect of PDA-66 on human SH-SY5Y neuroblastoma and A-459 lung cancer cells, showing a significant reduction in cancer cell proliferation in a dose dependent manner. Thus PDA-66 is a new anti-mitotic compound with an indole-core with the potential to be used for cancer therapy. [Copyright &y& Elsevier]

Objective: Stable mixed hematopoietic chimerism can be established in a canine stem cell transplantation model using a conditioning consisting of total body irradiation (TBI; 2 Gy) and postgrafting immunosuppression with mycophenolate mofetil (MMF) and cyclosporin (CSA). Reduction of TBI had resulted previously in graft rejection in this model. We investigated whether postgrafting stimulation of donor T cells against recipient''s hematopoietic antigens or graft augmentation with donor monocyte-derived dendritic cells (MoDC) promote engraftment following 1 Gy TBI. Materials and Methods: All dogs received dog leukocyte-antigen−identical bone marrow transplantation. Dogs were conditioned with either 2 Gy TBI (group 1) or 1 Gy TBI, followed by repetitive recipient hematopoietic cell lysate vaccinations (group 2) or graft augmentation with MoDC (group 3). Immunosuppression consisted of CSA and MMF. Results: In group 1, four animals remained stable chimeras for >110 weeks, and three rejected their grafts (week 10, week 14, week 16). All dogs in groups 2 and 3 rejected their graft (median: week 10 and 11, respectively). Peak chimerism and engraftment duration was shorter in the 1-Gy groups (p < 0.05) compared to group 1. Conclusion: Neither postgrafting vaccination nor graft augmentation with MoDC were effective in supporting durable engraftment. Additional modifications are necessary to improve potential strategies aimed at establishment of early tissue specific graft-vs-host reactions. [Copyright &y& Elsevier]

Background Allogeneic hematopoietic stem cell transplantation (HCT) remains a challenge in elderly and comorbid AML and MDS patients. This patient population is at increased risk for non-relapse mortality (NRM) when treated with standard myeloablative conditioning and was selected to compare a newly developed treosulfan-based with a well-established reduced intensity busulfan-based preparative regimen in a prospective randomized clinical phase III trial. Methods Adult patients with AML in remission or MDS scheduled for HCT from matched related or unrelated donors, aged ≥50 years or with a comorbidity index (HCT-CI) of >2 were enrolled by a central stratified randomization procedure. Treatment arms consisted of intravenous (IV) treosulfan (10 g/m²/day [d-4 to d-2]) or IV busulfan (3.2 mg/kg/day [d-4 to d-3]), both combined with IV fludarabine (30 mg/m²/day [d-6 to d-2]). The primary objective was to compare event-free survival (EFS) at two years with relapse/progression of disease, graft failure, or death reported as events. Secondary endpoints were safety evaluation (according to CTCAE v4.03), engraftment, chimerism, overall survival (OS), relapse/progression incidence (RI), NRM and acute or chronic GvHD. After a previously conducted confirmatory interim analysis (based on 476 patients), which resulted in early termination of patient accrual due to significant non-inferiority of treosulfan treatment with improved EFS, NRM and OS (Beelen et al., ASH 2017), results of the final analysis of all 570 randomized patients including post surveillance data are provided here. Results Median age of the 551 patients (352 AML; 199 MDS) included in the full analysis set (268 treosulfan; 283 busulfan) was 60 years (range: 31, 70). Frequencies of early adverse events (d-6 to d+28) and incidences of acute and chronic GvHD were largely comparable between the two regimens, while extensive chronic GvHD was numerically in favor of treosulfan (19.7% vs. 26.7%; p=0.0750). Primary neutrophil recovery at day +28 was comparable, while the rate of complete donor-type chimerism (day +28) was higher after treosulfan (93.2% vs. 83.3%; p<0.0001). After a median follow-up of 29 months (range: 3.0, 54.3) the 2-year EFS was significantly higher in the treosulfan arm (65.7% vs. 51.2%; hazard ratio [HR] 0.64; p=0.0012) as was OS (72.7% vs. 60.2%; HR 0.64; p=0.0037) and NRM (12.0% vs. 20.4%; HR 0.63; p=0.0343). RI was comparable between both regimens (22.0% vs. 25.2%; HR 0.82; p=0.2631). Results were consistent within all pre-defined major prognostic subgroups of patients. Conclusions Final evaluation of this phase III trial substantiates the previous confirmatory analysis resulting in significantly improved survival after treosulfan-based conditioning. Due to the reduction of NRM a major clinical benefit of the new treosulfan conditioning regimen was demonstrated in the selected AML/MDS patient population. [ABSTRACT FROM AUTHOR]

Progress of age-related hematopoietic diseases such as myelodysplastic syndrome has previously been linked to enhanced levels of reactive oxygen species (ROS). Uncoupling protein 2 (UCP2) was found to reduce mitochondrial ROS production through uncoupling of the respiratory chain. The impact of UCP2 loss and elevated ROS on hematopoiesis during aging has not yet been investigated. In this study, UCP2 knockout mice were analyzed at aging stages of 3, 12, and 24 months with respect to oxidative and energy status of bone marrow cells. Further, the cellular bone marrow subpopulation composition was characterized, as were the differential blood counts at all time points. UCP2 knockout mice revealed enhanced levels of mitochondrial superoxide in elderly animals. Following oxidative stress, adenosine triphosphate (ATP) levels decreased more in the knockout mice than in the wild type. Investigation of bone marrow and blood counts of the knockout mice revealed an enhanced amount of monocytes and neutrophils, as well as a decreased amount of B cells and impaired erythropoiesis throughout aging. In summary, UCP2 induces protective effects on ROS and ATP levels during aging. Additionally, the results suggest an imbalance in hematopoiesis because of the lack of UCP2. [ABSTRACT FROM AUTHOR]