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.
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.
To study the safety and efficacy of treosulfan, a cytotoxic alkylating agent, in patients with active secondary progressive multiple sclerosis.
Treosulfan (L-threitol-1,4-bis(methanesulfonate)) is a ...bifunctional alkylating agent with a favorable profile of side effects, approved for the treatment of ovarian cancer. Treosulfan has previously been shown to reduce the severity of experimental allergic encephalomyelitis under pre-therapeutic and therapeutic conditions. In human peripheral blood mononuclear cells, treosulfan reduces proliferative capacity and increases apoptosis.
This is a nonrandomized, open label study conducted in two centers. Eleven patients with active secondary progressive MS that failed to or did not qualify for approved disease modifying drugs were treated with treosulfan for 1 year. Patients received intravenous infusions of 7 g/m(2) every 4 weeks for 3 months (cycles 1-4, induction phase) with a predefined one-step dose escalation, thereafter every 3 months for the following 9 months (cyles 5-7, maintainance phase). Cranial MRI was performed every 3 months, EDSS and MSFC as well as physical examination were assessed at each clinical visit.
Treatment with treosulfan was safe and well tolerated. Nine of 11 patients remained on study drug over the complete treatment period and showed clinical stabilisation or improvement as determined by EDSS and MSFC. Two patients discontinued study drug because of leukocytopenia and withdrawal of consent, respectively. No clinical relapses were observed during the treatment period. Thus, the median number of relapses per year was reduced signifi- cantly by 1.5 (range -3 to 0), p < 0.016, compared to prestudy. Therapy with treosulfan lead to a clear reduction of MRI activity as revealed by a reduced number of Gd + enhancing lesions on T1 weighted images. The mean number and volume of T2 lesions remained unchanged over 1 year. Four out of 9 patients under treosulfan showed no detectable disease activity (no Gd enhancing lesions, no new or newly enlarging T2 lesions).
Application of treosulfan in MS was safe and well tolerated. Further studies are warranted to evaluate the efficacy of this treatment in secondary progressive MS.
Numerous effects of tumor necrosis factor are signaled by its 55-kDa receptors. Studying their expression we found that the level of receptor mRNA was decreased during the phorbol ester-induced ...differentiation of myelomonocytic cell lines. While only minor changes in transcription were noted, the half-life of receptor mRNA in the differentiated cells was markedly decreased, indicating the involvement of post-transcriptional regulation. In an electrophoretic mobility shift assay, formation of complexes between radiolabeled receptor mRNA and cellular proteins was observed. The decrease in receptor mRNA levels during phorbol ester-induced differentiation was paralleled by a change in the pattern of those complexes. Protein-RNA interaction was selective, as it was not competed by unrelated RNAs. Yet, certain mRNAs that contain AU-rich sequences, known to be involved in the control of their stability, did compete with the receptor mRNA, although the latter is devoid of such sequences. A region of 18 nucleotides within its coding region was found to contain an element essential for the formation of all complexes and sufficient for the formation of those with lower molecular mass. Adjacent bases were required in addition for the formation of the complexes with higher molecular mass. The results suggest that proteins interacting with this region of the 55-kDa tumor necrosis factor receptor mRNA contribute to the regulation of its expression.
Numerous effects of tumor necrosis factor are signaled by its 55-kDa receptors. Studying their expression we found that the level of receptor mRNA was decreased during the phorbol ester-induced ...differentiation of myelomonocytic cell lines. While only minor changes in transcription were noted, the half-life of receptor mRNA in the differentiated cells was markedly decreased, indicating the involvement of post-transcriptional regulation. In an electrophoretic mobility shift assay, formation of complexes between radiolabeled receptor mRNA and cellular proteins was observed. The decrease in receptor mRNA levels during phorbol ester-induced differentiation was paralleled by a change in the pattern of those complexes. Protein-RNA interaction was selective, as it was not competed by unrelated RNAs. Yet, certain mRNAs that contain AU-rich sequences, known to be involved in the control of their stability, did compete with the receptor mRNA, although the latter is devoid of such sequences. A region of 18 nucleotides within its coding region was found to contain an element essential for the formation of all complexes and sufficient for the formation of those with lower molecular mass. Adjacent bases were required in addition for the formation of the complexes with higher molecular mass. The results suggest that proteins interacting with this region of the 55-kDa tumor necrosis factor receptor mRNA contribute to the regulation of its expression.
The receptors for tumor necrosis factor (TNF) play an important role in the response to this cytokine, both as signal transducing molecules and, in their shed forms, as regulators of TNF ...availability. Expression of the receptors was studied in the human monocytic leukemia line THP-1. Within two days of incubation, the proinflammatory cytokines, interferon (IFN)-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF), each induced a slight increase in cell surface expression of the 75 kDa TNF receptors (TNF-R75), and a more pronounced increase in the generation of soluble TNF-R75. Similarly, receptor mRNA levels were increased in response to both cytokines. GM-CSF and IFN-gamma in combination induced a much stronger increase in cell surface and soluble receptors as well as in receptor mRNA. Expression of the 55 kDa TNF receptor and its mRNA was largely unaffected by the two cytokines. Experiments using TNF-neutralizing antibodies indicate that the changes in TNF-R75 expression occurred independently of endogenously-produced TNF. The half life of TNF-R75 mRNA in cells exposed to GM-CSF + IFN-gamma did not differ significantly from that in untreated cells. According to nuclear run-on assays the synthesis of TNF-R75 mRNA in cells treated with GM-CSF + IFN-gamma, as well as with the phorbol ester TPA, was markedly increased compared to untreated cells, indicating that the observed changes in receptor expression primarily involve altered transcription of the gene. The results suggest that in inflammatory processes, GM-CSF and IFN-gamma contribute to increased synthesis of TNF-R75 by monocytic cells, a prerequisite for the formation of large amounts of soluble receptors.
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