[Show abstract][Hide abstract] ABSTRACT: Treosulfan (TREO) is currently investigated as an alternative treatment for busulfan in conditioning prior to hematopoietic stem cell transplantation. The knowledge of the blood - brain barrier penetration of the drug is still scarce. In this paper penetration of TREO and its active monoepoxide (S,S-EBDM) and diepoxide (S,S-DEB) into CNS was studied in juvenile (JR) and young adult rats (YAR) for the first time. CD(®) rats of both sexes (n = 96) received an intravenous dose of TREO 500 mg/kg b.w.. Concentrations of TREO, S,S-EBDM and S,S-DEB in rat plasma, brain and cerebrospinal fluid (CSF, in YAR only) were determined by validated bioanalytical methods. Pharmacokinetic calculations were performed in WinNonlin using a noncompartmental analysis and statistical evaluation was done in Statistica software. In male JR, female JR, male YAR and female YAR, the brain/plasma area under the curve (AUC) ratio for unbound TREO amounted 0.14, 0.17, 0.10 and 0.07, and for unbound S,S-EBDM 0.52, 0.48, 0.28 and 0.22, respectively. The CSF/plasma AUC ratio in male and female YAR was 0.12 and 0.11 for TREO, and 0.66 and 0.64 for S,S-EBDM, respectively. Elimination rate constants of TREO and S,S-EBDM in all the matrices were sex-independent with a tendency to be lower in the JR. No quantifiable levels of S,S-DEB were found in the studied samples. TREO and S,S-EBDM demonstrated poor and sex-independent penetration into CNS. However, the brain exposure was greater in juvenile rats, so very young children might probably be more susceptible to high-dose TREO-related CNS exposure than young adults.
Preview · Article · Oct 2015 · Drug metabolism and disposition: the biological fate of chemicals
[Show abstract][Hide abstract] ABSTRACT: Purpose:
A new pegylated recombinant L-asparaginase (MC0609) was designed to improve pharmacokinetic characteristics and to further reduce immunogenicity in comparison with the currently marketed pegylated Escherichia coli L-asparaginase (pegaspargase, Oncaspar(®)).
Comparative pharmacokinetics (PK), bioavailability, pharmacodynamics and immunogenicity studies were performed in CD(®) rats and Beagle dogs after intravenous (i.v.) and intramuscular (i.m.) single-dose administration of MC0609 or Oncaspar(®). Bioanalytical data on enzymatic activity in serum of animals were used to develop a population pharmacokinetic (PopPK) model to simulate different dosages of MC0609 comparable to the activity time profile of Oncaspar(®).
In contrast to Oncaspar(®), which showed an accelerated elimination over time, a constant serum elimination of enzymatic activity over time was seen for MC0609. Linear PK of MC0609 resulted in a prolonged and dose-dependent duration of enzymatic activity and longer depletion of L-asparagine in peripheral blood. The different PK characteristics of MC0609 and Oncaspar(®) were confirmed by PopPK analysis and model development. The PK parameters of Oncaspar(®) in dog scaled to body surface area were in the same range than the parameters determined in paediatric acute lymphoblastic leukaemia patients. Therefore, the dog is considered a clinically relevant model for PK evaluation of Oncaspar(®). Distinct differences in immunogenic potential of both preparations were detected after single-dose administration of a therapeutic dose to dogs. An absolute bioavailability of 66 % was calculated for the intramuscular administration of MC0609.
The new pegylated recombinant L-asparaginase preparation MC0609 revealed striking differences in PK/PD properties compared with Oncaspar(®) in rat and dog.
No preview · Article · Jun 2014 · Cancer Chemotherapy and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Allogeneic hematopoietic cell transplantation (HCT) offers curative therapy for many patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). However, post-HCT relapse remains a major problem, particularly in patients with high-risk cytogenetics. In this prospective phase II trial we assessed the efficacy and toxicity of treosulfan, fludarabine and 2 Gy total body irradiation (TBI) as conditioning for allogeneic HCT in patients with MDS or AML. Ninety-six patients with MDS (n=36; 15 RCMD; 15 RAEB-1; 10 RAEB-2; 1 CMML-1) or AML (n=60; 35 CR1; 18 CR2; 3 advanced CR; 4 refractory relapse) were enrolled; median age was 51 (range: 1-60) years. Twelve patients had undergone a prior HCT with high intensity conditioning. Patients received intravenous (IV) treosulfan, 14 g/m(2)/day on days -6 to -4, IV fludarabine, 30 mg/m(2)/day on days -6 to -2, and 2 Gy TBI on day 0, followed by infusion of hematopoietic cells from related (n=27) or unrelated (n=69) donors. Graft-vs.-host disease prophylaxis consisted of tacrolimus and methotrexate. With a median follow-up of 30 months, the 2-year overall survival (OS), relapse incidence and non-relapse mortality were 73%, 27% and 8%, respectively. The incidences of grades II-IV (III-IV) acute and chronic graft-versus-host disease were 59% (10%) and 47%, respectively. Two-year OS was not significantly different between MDS patients with poor risk and good/intermediate risk cytogenetics (69% and 85%, respectively), or between AML patients with unfavorable and favorable/intermediate risk cytogenetics (64% and 76%, respectively). In AML patients, minimal residual disease (MRD; n=10) at the time of HCT predicted higher relapse incidence (70% vs. 18%) and lower OS (41% vs. 79%) at 2 years, when compared to patients without MRD. In conclusion, treosulfan, fludarabine and low-dose TBI provided effective conditioning for allogeneic HCT in patients with MDS or AML, and resulted in low relapse incidence, regardless of cytogenetic risk. In patients with AML, MRD at the time of HCT remained a risk factor for post-HCT relapse.
Preview · Article · Jan 2014 · Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation
[Show abstract][Hide abstract] ABSTRACT: Different RIC regimens were evaluated prior to allo-HSCT in different hematological malignancies. We conducted this prospective study in adult patients with various hematological malignancies in order to evaluate the toxicity and efficacy of treosulfan-based conditioning, followed by allo-HSCT from 10/10 HLA-identical unrelated donors. Conditioning included treosulfan 12 g/m(2)/day i.v. (day -6 to day -4), fludarabine 30 mg/m(2)/day i.v. (day -6 to day -2), and ATG 2.5 mg/kg/day (day -2 to day -1). PBSC were used as HSC source. We included 56 patients (29 AML, 9 MM, 8 MDS, 6 CLL, 3 ALL, and 1 CML) with a median age of 57 years (18-65.5). Fifty-four (96%) patients engrafted; the cumulative incidence of aGVHD grade ≥II at 3 months reached 31%. The cumulative incidence of cGVHD at 18 months was 34% limited and 8% extensive. The median overall survival (OS) was not reached with a 3-year probability of 52%. The cumulative incidence of relapse at 3 years was 25%, and the cumulative incidence of transplant-related mortality (TRM) at 12 and 24 months was 20% and 23%, respectively. Treosulfan appears to be a good alternative for conditioning of MUD transplant patients with promising results in terms of OS, relapse, and TRM.
No preview · Article · Feb 2012 · Annals of Hematology
[Show abstract][Hide abstract] ABSTRACT: An alternative reduced-toxicity conditioning regimen for allogeneic transplantation, based on treosulfan and fludarabine, has recently been identified. The safety and efficacy of this new conditioning regimen has been investigated prospectively in patients with AML. A total number of 75 patients with AML in CR were treated with 3 × 14 g/m(2) treosulfan and 5 × 30 mg/m(2) fludarabine, followed by matched sibling or unrelated SCT. Patients were evaluated for engraftment, adverse events, GVHD, and for non-relapse mortality, relapse incidence, overall and disease-free survival (DFS). All patients showed primary engraftment of neutrophils after a median of 20 days. Non-hematological adverse events grade III-IV in severity included mainly infections (59%) and gastrointestinal symptoms (7%). Acute GVHD grade II-IV occurred in 21% and extensive chronic GVHD occurred in 16% of the patients. After a median follow-up of 715 days, the 2-year overall and DFS estimates were 61% and 55%, respectively. The 2-year incidences of relapse and non-relapse mortality reached 34% and 11%, respectively. In summary, our data confirm promising safety and efficacy of the treosulfan-based conditioning therapy in AML patients, ClinicalTrials.gov Identifier: NCT01063660.
Full-text · Article · Dec 2011 · Bone marrow transplantation
[Show abstract][Hide abstract] ABSTRACT: An alternative reduced-toxicity conditioning regimen for allogeneic transplantation, based on treosulfan and fludarabine, has recently been identified. The rationale for this study was to investigate the efficacy and safety of this regimen prospectively in patients with a primary myelodysplastic syndrome.
A total of 45 patients with primary myelodysplastic syndromes were conditioned with 3×14 g/m(2) treosulfan and 5×30 mg/m(2) fludarabine followed by allogeneic hematopoietic stem cell transplantation. Subtypes of myelodysplastic syndromes were refractory anemia with excess blasts-2 (44%), refractory cytopenia with multilineage dysplasia (27%), refractory anemia (9%), refractory anemia with ringed sideroblasts (4%), refractory cytopenia with multilineage dysplasia and ringed sideroblasts (4%), refractory anemia with excess blasts-1 (2%), and myelodysplastic syndrome with isolated del (5q) (2%). The myelodysplastic syndrome was unclassified in 7% of the patients. Forty-seven percent of the patients had a favorable karyotype, 29% an unfavorable one, and 18% an intermediate karyotype. Patients were evaluated for engraftment, adverse events, graft-versus-host disease, non-relapse mortality, relapse incidence, overall survival and disease-free survival.
All but one patient showed primary engraftment of neutrophils after a median of 17 days. Non-hematologic adverse events of grade III-IV in severity included mainly infections and gastrointestinal symptoms (80% and 22% of the patients, respectively). Acute graft-versus-host disease grade II-IV developed in 24%, and extensive chronic graft-versus-host disease in 28% of the patients. After a median follow-up of 780 days, the 2-year overall and disease-free survival estimates were 71% and 67%, respectively. The 2-year cumulative incidences of non-relapse mortality and relapse were 17% and 16%, respectively.
Our safety and efficacy data suggest that treosulfan-based conditioning therapy is a promising treatment option for patients with myelodysplastic syndromes. clinicaltrials.gov identifier: NCT01062490.
[Show abstract][Hide abstract] ABSTRACT: Treosulfan was introduced recently as a conditioning agent for allogeneic blood stem-cell transplantation. The favorable nonhematologic toxicity profile at 3 x 10 g/m(2) was the basis for dose escalation in this prospective, multicenter trial.
Fifty-six patients with various hematologic malignancies who were not eligible for standard conditioning were treated with one of three doses: 10 g/m(2), 12 g/m(2), or 14 g/m(2) of intravenous treosulfan, which was administered on days -6 to -4 combined with fludarabine 30 mg/m(2) on days -6 to -2. Patients in complete remission (CR; 42%) or non-CR (58%) received grafts from matched related (47%) or matched unrelated (51%) donors; one patient had a mismatched related donor (2%).
No engraftment failure occurred. Overall, extramedullary toxicity and the nonrelapse mortality rate at 2 years (20%) were low and did not increase with dose. Cumulative incidence of relapse/progression reached 31%. The overall survival and progression-free survival rates were 64% and 49%, respectively, in the total study population. An inverse dose dependency of relapse incidence was indicated in the subgroup receiving transplantations from matched related donors (P = .0568).
Treosulfan-based conditioning was feasible at all three doses. The 3 x 14 g/m(2) dose was selected for additional studies, because it combines desired characteristics of low toxicity and a low relapse rate.
Full-text · Article · May 2010 · Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Treosulfan (Treo) and total body irradiation (TBI) demonstrate a high therapeutic activity in treatment of acute leukemia and lymphoma. We investigated the combination of Treo and TBI prior to bone marrow transplantation (BMT) in rats. Female Lewis rats were treated with Treo on 3 consecutive days followed by TBI with either 5 Gy (n = 28) or 7.5 Gy (n = 48). After conditioning animals received 4 x 10E7 bone marrow cells (BC) from female Lewis rats. Additional 16 rats were transplanted with 4 x 10E7 BC and 1.5 x 10E7 spleen T-cells from female Brown-Norway (BN) rats. Animals were examined daily for clinical signs and toxicity was investigated by necropsy and histology in all animals. Gastrointestinal toxicity was the dose-limiting factor of Treo in combination with TBI. The highest tolerable dose of Treo in combination with 7.5 Gy TBI was 3 x 0.5 g/kg and the highest tolerable dose of Treo in combination with 5 Gy TBI was 3 x 0.6 g/kg. Allogeneic BMT from BN donors resulted in engraftment and survival of 12 out of 16 animals. Gastrointestinal toxicity is the dose-limiting factor in the treatment with Treo and TBI. Furthermore, Treo possesses certain characteristics of a radiosensitizer.
No preview · Article · Dec 2009 · Immunopharmacology and Immunotoxicology
[Show abstract][Hide abstract] ABSTRACT: Allogeneic transplantation can not be offered to many patients due to potential side-effects of conventional conditioning. Dose-reduced conditioning approaches improve tolerability, however, treatment efficacy may be reduced as well. We have, therefore, developed a dose intense but toxicity reduced conditioning regimen based on treosulfan and fludarabine and report first results.
65 patients with a median age of 50 years were transplanted from related (n = 21) or unrelated donors (n = 44) after conditioning with treosulfan (3 x 10, 3 x 12 or 3 x 14 g/m(2) i. v.) and fludarabine (5 x 30 mg/m(2) i. v.). 21 patients were in complete remission (CR) and 44 patients had not reached a CR at the time of transplantation. 59 of 65 patients were considered unfit for a conventional conditioning regimen.
The actuarial overall survival after 3 years is 59.2 %, the event-free survival 40.1 %. Patients with a related donor or transplantation in CR had a better overall (85.4 resp. 74.2 %) and event-free survival (52.2 % resp. 61.9 %). The cumulative incidence of relapse at 3 years was 26.2 %. Non-relapse mortality at day 100 is 17.4 % (cumulative incidence). In stepwise Cox regression analyses for overall survival, event-free survival and non-relapse mortality the covariables transplantation in CR vs. not in CR and the donor status were shown to be influential.
These results with a conditioning therapy of treosulfan and fludarabine indicate that patients despite higher age, concomitant disease or after intensive pretreatment can be successfully transplanted without increased treatment-related mortality.
No preview · Article · Oct 2005 · DMW - Deutsche Medizinische Wochenschrift
[Show abstract][Hide abstract] ABSTRACT: Gemcitabine plus treosulfan (GeT) is under investigation in metastatic uveal melanoma. In this phase II trial, cisplatin was added to a GeT regimen to investigate the efficacy and toxicity of two alkylating agents in combination with gemcitabine. Patients received 30 or 40 mg/m of cisplatin, 1000 mg/m of gemcitabine and 3000 mg/m of treosulfan on days 1 and 8. Therapy was repeated on day 29. A maximum of six cycles was administered. Nineteen patients were included in the trial, of whom 17 were evaluable for response. No objective response was observed; seven patients (41%) had stable disease and 10 (59%) progressed. The median progression-free survival of all 19 patients was 3.0 months [95% confidence interval (CI), 1.8-3.1]; the median overall survival was 7.7 months (95% CI, 1.9-13.8). Grade 3 and 4 thrombopenia and leucopenia occurred in eight and nine of the 19 patients, respectively. The addition of cisplatin to the GeT regimen results in excessive haematological toxicity without improvement in efficacy.
No preview · Article · Jul 2005 · Melanoma Research
[Show abstract][Hide abstract] ABSTRACT: Treosulphan has recently demonstrated antileukaemic activity and potent haematopoietic stem cell toxicity. Dose-escalated treosulphan (3 x 12 or 3 x 14 g/m2) combined with cyclophosphamide (Cy) was chosen for a new preparative regimen before allogeneic haematopoietic stem cell transplantation in 18 patients (median age 44, range 19-64 years) with haematological malignancies, considered ineligible for other myeloablative preparative regimens. Pharmacokinetic studies demonstrated rapid treosulphan plasma clearance and a dose-dependent increase of its maximum plasma concentrations and area under the concentration-time curves. Rapid and sustained white blood cell and platelet recovery and full donor chimerism was attained in all evaluable patients. Nonhaematological regimen-related CTC grades 3-4 adverse events were transient and predominantly consisted of cardiac (28%), gastrointestinal (39%), and hepatic (39%) toxicities. The 1-year nonrelapse mortality was 22%. Principal causes of transplant-related lethal events were infections in three of four affected patients. Only one patient died from regimen-related cardiac toxicity. The 1-year relapse estimate is 22%, overall and progression-free survival estimates are 67 and 56%, respectively. In conclusion, this new treosulphan and Cy combination is an effective, comparatively well-tolerated myeloablative preparative regimen even in patients with an increased risk for regimen-related toxic complications.
Full-text · Article · Mar 2005 · Bone Marrow Transplantation
[Show abstract][Hide abstract] ABSTRACT: Treosulfan (L-threitol-1,4-bismethanesulfonate) is an alkylating agent with routine clinical application in the treatment of ovarian cancer. In this murine study we show that this drug also has the ability to deplete primitive hematopoietic stem cells in a dose-dependent manner as determined by the cobblestone area-forming cell assay and is similar to its parent compound busulfan. Because busulfan is frequently used as part of the conditioning regimen before stem cell transplantation, we investigated an alternative nonmyeloablative protocol in an allogeneic bone marrow transplantation model in which low-dose treosulfan was added to an immune-suppressive regimen consisting of T cell-depleting antibodies, fludarabine, and thymic irradiation. Although this treatment protocol produced minimal myelosuppression, the addition of treosulfan proved to be important for allowing stable multilineage and mixed chimerism in C57BL/6 recipients of major histocompatibility complex-mismatched B10.A bone marrow without evidence of graft-versus-host disease. Donor lymphocyte infusion performed at 10 weeks after bone marrow transplantation had the effect of transforming the state of mixed chimerism to full donor-type cells, again without evidence of graft-versus-host disease. Donor-specific immunologic tolerance in the mixed chimeric animals was indicated by the acceptance of donor-type and rejection of third-party skin grafts. Thus, low-dose treosulfan may be considered as a useful component of a truly nonmyeloablative conditioning protocol in providing for mixed hematopoietic chimerism and, consequently, in establishing a platform for adoptive immunotherapy.
Full-text · Article · May 2004 · Biology of Blood and Marrow Transplantation
[Show abstract][Hide abstract] ABSTRACT: Acute myeloid leukemia (AML) still is fatal in the majority of patients. Therefore, we evaluated the antileukemic effect of the alkylating agent treosulfan in AML.
Chemosensitivity tests were performed in AML cell lines and primary cells from patients. Because protein kinase C (PKC) is known to play an integral role in the regulation of diverse cellular functions such as apoptosis, several PKC modulators were evaluated in conjunction with treosulfan.
U937, THP-1, HL-60, TUR cells, and primary AML cells obtained from five consecutive patients displayed dose-dependent sensitivity to treosulfan. The LC(90) was approximately 100 microM, which is several fold below clinically achievable plasma levels. Cell death was associated with cellular events indicating apoptosis such as breakdown of the mitochondrial transmembrane potential, proteolytic activation of caspase-3, or appearance of a sub-G(1) DNA peak. Synergistic antileukemic effects were observed in all cell lines and patient samples tested using the PKC activators bryostatin-1 and 12-O-tetradecanoylphorbol-13-acetate (TPA), whereas the PKC inhibitor GF109203X substantially reduced apoptosis. Furthermore, long-term preincubation with bryostatin-1 or TPA, both of which are known to down-regulate PKC protein levels, likewise inhibited treosulfan-induced apoptosis. Immunoblots revealed membrane translocation of PKC-delta, indicating activation of this enzyme upon treosulfan exposure.
Our data provide evidence for a strong antileukemic effect of treosulfan in both cell lines and AML blasts from patients at concentrations below the plasma levels described at standard dose levels. Furthermore, the proapoptotic effect of treosulfan is mediated at least in part by activation of PKC isoforms and can be augmented by coincubation with bryostatin-1.
No preview · Article · Feb 2004 · Experimental Hematology
[Show abstract][Hide abstract] ABSTRACT: Multiple myeloma is a non-curable haematological disease involving transformed plasma cells. High rates of complete remission can be achieved with autologous peripheral blood stem cell transplantation. Treosulfan is an alkylating substance that has been used in the treatment of ovarian carcinomas for many years. It has a favourable side-effect profile even at high-dose protocols. Thus, the objective of this study was to evaluate the effect of treosulfan on myeloma cells. The treatment of the myeloma cell lines, NCI-H929 and U266, with treosulfan led to apoptosis in both cell lines in a dose- and time-dependent manner. The induction of apoptosis was accompanied by cleavage of caspases -3 and -9 as well as downregulation of the antiapoptotic protein Mcl-1 and upregulation of the inhibitor of cyclin-dependent kinases, p21WAF1/CIP1. Furthermore, 100 micro mol/l treosulfan was capable of inducing cell death in 63.6 +/- 23.9% of primary myeloma cells, whereas treatment with the same concentration of melphalan showed 59.7 +/- 26% cell death. These in vitro concentrations were at least 10-fold lower than achievable plasma levels, even at conventional doses of treosulfan. Our results suggest that treosulfan might be an appropriate candidate for novel treatment protocols for patients with multiple myeloma.
Preview · Article · Oct 2003 · British Journal of Haematology
[Show abstract][Hide abstract] ABSTRACT: Treosulfan (L-threitol-1,4-bis-methanesulphonate; Ovastat(R)) is a bifunctional alkylating drug indicated for the treatment of advanced ovarian carcinoma. Recent data revealed immunosuppressive characteristics and substantial haematopoietic stem cell toxicity after repeated dosing of mice. Therefore, treosulfan is considered to be an alternative conditioning agent to busulfan (for example) administered prior to allogeneic/autologous stem cell transplantation of patients with haematological malignancies. An antineoplastic activity for treosulfan has been previously shown in preclinical models of melanoma, breast, lung and renal-cell carcinomas. Here, in vivo antileukaemic activity of treosulfan is compared with the activity of equitoxic doses of cyclophosphamide or busulfan for the first time using human acute lymphoblastic leukaemia (ALL)-models of paediatric origin xenotransplanted into non-obese diabetic (NOD)/severe combined immunodeficient (SCID) mice. Treosulfan treatment achieved an optimum treated to control (T/C) value of 159% (survival time) against B-ALL-SCID 7 and a T/C value of 0% (tumour growth) against T-ALL-SCID 4 and proB-ALL-SCID 19, respectively. Complete regression of established subcutaneously (s.c.) growing nodules of ALL-SCID 4 and 19 was obvious and long-term survivors without tumour re-growth were observed. Equitoxic doses of busulfan (ALL-SCID 4, 7, 19) or cyclophosphamide (ALL-SCID 19) were less effective with regard to the numbers of complete regressions and the number of cured animals. Side-effects included myelotoxicity and a small reduction in body weight, but these were tolerable. Treosulfan can be considered a highly active antileukaemic drug whose corresponding clinical value is to be tested in appropriate protocols with leukaemic patients.
No preview · Article · May 2003 · European Journal of Cancer
[Show abstract][Hide abstract] ABSTRACT: The purpose of this multicentre phase II trial was to evaluate time to progression, survival time, rate of objective tumour response and toxicity of second-line intravenous treosulfan chemotherapy in stage IV melanoma patients. Thirty-one patients with measurable stage IV malignant melanoma and prior chemotherapy with a dacarbazine-containing regimen were included. Of this group, 26 patients were evaluable. All patients received treosulfan (8 g/m intravenously on day 1; cycle repeated every 28 days up to six courses). Patients were evaluated for tumour response, survival time and toxicity. No objective responses (complete or partial) were observed. Five patients (19%) showed no change and 21 had progressive disease after treosulfan treatment. Four patients experienced a minor or mixed response. The median time to progression was 1.8 months (95% confidence interval [CI] 1.6-2.1 months) and the median overall survival was 6.5 months (95% CI 3.1-10 months). The 1 year survival rate was 33.9% (95% CI 15.4-52.3%). Leukocytopenia and thrombocytopenia (Common Toxicity Criteria grades 3 and 4) occurred in 15% and 18% of cases, respectively. The non-haematological toxicity of this outpatient regimen was mild. In conclusion, intravenous treosulfan treatment does not induce objective response rates when used as a second-line treatment of metastatic malignant melanoma.
No preview · Article · Mar 2003 · Melanoma Research