Biomedical subjects
Publications and source records attributed to N Basara.
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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.
A total of 155 patients with acute myeloid leukemia (AML) received hematopoietic stem cell transplants from unrelated donors after standard conditioning. Clinical outcome after the use of two different antithymocyte globulins for the prevention of graft-versus-host disease (GvHD) was analyzed in a retrospective study as follows: rabbit ATG (Thymoglobulin Sangstat/Genzyme, n=49, median age 42 years, 53% in CR, further ATG-S); rabbit ATG (ATG-Fresenius, n=38, median age 42 years, 58% in CR, further ATG-F) or no ATG (n=68, median age 36 years, 55% in CR). The groups were comparable regarding disease status at transplant, age, CMV status and cytogenetics. Grade III-IV acute GvHD was found in 15% in the ATG and 27% in the no ATG group (P=0.44). The most important independent risk factors for chronic GvHD (cGvHD) were the use of ATG, disease status at transplant and conditioning. cGvHD developed significantly more frequently in no ATG group. With the median follow-up of 34 months, the 5-year survival is 42% for those transplanted in CR. To conclude, these data demonstrate that the transplants performed in CR, with ATG, are associated with a good outcome, low incidence of cGvHD and no increase of relapse.
We describe successful treatment of a 38-year-old patient with composite lymphoma stage IV(A), who presented with multifocal enlarged lymph nodes. The lymph node histology showed classic morphologic features of Hodgkin's disease, mixed cellularity subtype and follicular B-cell lymphoma. Immunophenotypic analysis showed immunoreactivity for CD20, CD10 and Ki-67 in the malignant small cell population. The areas of Hodgkin's disease demonstrated positive immunoreactivity for CD30 and CD20 in the Hodgkin's cells. Both cell populations were bcl2-oncoprotein positive. Eight courses of dose-escalated BEACOPP were administered. Restaging after chemotherapy showed radiological partial remission, but biopsy confirmed persisting follicular B-cell lymphoma without bone marrow infiltration and no evidence of Hodgkin's disease. He was treated with monoclonal CD 20-antibody (Rituximab) 10 mg/kg weekly for eight consecutive weeks due to marked positivity of CD 20-antigen in follicular lymphoma cells. This treatment was well tolerated and final staging showed complete remission of the composite lymphoma. This patient continues to be in remission 28 months after the end of the treatment. In conclusion, in the very rare case of composite lymphoma a combination of chemotherapy and subsequent immunotherapy might be considered as a promising therapeutic option.
We report a 30-year-old patient with therapy-refractory T-ALL undergoing unrelated allogeneic PBSCT. He developed severe tumor lysis syndrome (TLS) with extreme biochemical changes, cardiac and neurological symptoms and dialysis-dependent acute renal failure after TBI (4 Gy) on the first day of reduced intensity conditioning (RIC) for unrelated allogeneic PBSCT. The patient's clinical condition was stabilized after beginning daily hemodialysis and treatment for disturbed electrolytes, metabolic acidosis and plasma coagulation, as well as reduction of uric acid by rasburicase. The conditioning therapy and the allogenic PBSCT were scheduled according to the preparative regimen. According to our knowledge, severe TLS induced by 4 Gy TBI has not been reported so far. Regimen-related toxicity using RIC regimen was mild, allowing 30-50% of the patients to have an entirely outpatient transplantation. However, we would like to point out that severe TLS could also complicate PBSCT using RIC regimens in patients with relatively radiation-sensitive malignancies and high tumor burden.
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According to recent reports, fast engraftment with minimal transplant-related toxicity and mortality (TRT, TRM) can be achieved by using reduced-intensity preparative regimens in allogeneic hematopoietic stem cell transplantation (HSCT). We report our experience with related (39%) and unrelated (61%) HSCT in 44 high risk patients (AML, ALL, CML, CLL) receiving either busulfan/fludarabine or busulfane/fludarabine/ATG or TBI/fludarabine as reduced-intensity preparative regimens. Organ toxicity was minimal with mild mucositis and no major bleeding. Acute GVHD was recorded in 64% of the patients. Twenty-three patients achieved complete remission after transplantation, and complete chimerism was obtained in all patients with stable engraftment (35 patients). Twenty-nine patients died: 15 due to relapse/progression, 14 due to TRM. Survival with median follow-up of 18.5 months was significantly better in patients with matched related transplants compared to patients with other transplants. However, there was no difference between related and unrelated transplants with regard to engraftment, TRM and GVHD. In conclusion, our results in high-risk patients transplanted in CR or with smoldering leukemia from a related donor are encouraging, although a longer follow-up and a larger group of patients is needed in order to evaluate the role of different reduced-intensity preparative regimens in unrelated and related HSCT.
Soft tissue sarcomas are mesenchymal tumors which respond poorly to systemic therapy. Recent studies suggest a higher response rate with an increased doxorubicin dosage. However, this was parallel with a profound hematotoxicity in 75% of patients. Transfer of the human multidrug resistance 1 (MDR1) gene to normal hematopoietic stem cells and transplantation may significantly reduce the hematotoxicity of anthracyclin-based chemotherapy. To test this concept of supportive gene therapy in advance of a clinical study, we transduced mobilized peripheral blood progenitor cells (PBPC) with the retroviral vector SF91m3 containing the human MDR1 gene, transplanted these cells to immune-deficient mice, allowed 6 weeks for engraftment to occur and treated the animals with MDR1-based chemotherapy. In the MDR1-transduced group the human leukocytes were significantly protected from the toxicity of chemotherapy (p < 0.05). While the gene transfer rate was in the range of 10% and thus comparable to recent clinical trials, the gene expression was 59% of transduced cells and thus significantly higher than previously reported for less-advanced vectors. On the other hand, ifosfamide, a drug which has been used successfully for stem cell mobilization, is active in soft tissue sarcoma. Due to these favorable characteristics sarcoma is an attractive target to test the efficacy of MDR1 gene therapy in a clinical setting. Gene therapeutic strategies may also be used to directly target sarcoma cells, e.g. by transfer of suicide genes. We found that adenoassociated virus 2 (AAV-2) vectors efficiently transduce human HS-1 and HT1080 sarcoma cells (>90%) while other tumor cell lines and primary human PBPC were less susceptible. The thymidine kinase (TK) suicide gene was cloned into an AAV-2 vector and a complete kill of TK-transduced HS-1 and HT1080 cells was observed following exposure to aciclovir or ganciclovir (GCV), while >90% of mock-transduced HS-1 cells survived at these dosages. Transplantation of those sarcoma cells to nonobese diabetic (NOD)/LtSz-severe-combined immunodeficient (scid)/scid (NOD/SCID) mice resulted in a survival of >5 months in the AAV-TK-transduced/GCV-treated group, while the mice in the mock-transduced/GCV-treated group had died after 3 weeks. These data show that soft tissue sarcomas are a particularly suitable model system for the development and clinical testing of new gene therapeutic concepts.
Biological and clinical significance of growth pattern of hematopoietic progenitors were investigated in 117 patients with primary myelodysplastic syndromes (MDSs) at referral. Abnormal (i.e., "leukemic" or absent) growth of GM colonies (CFU-GM) and GM clusters was found in 47% of patients with "advanced" MDS (RAEB, RAEB-t, and CMML) and in 15% of "low-risk" (RA/RARS) patients. In vitro erythropoiesis was decreased in most of the patients, with significantly lower number of BFU-E in "advanced" MDS than in RA/RARS patients. Megakaryocyte progenitors (CFU-MK) were very low or absent in almost all the patients, regardless of the FAB type. Significant correlation was demonstrated between the number of BFU-E and hemoglobin concentration and between number of CFU-MK and platelet count. Growth capacity of GM progenitors appears to be in proportion to "myeloproliferative" capacity of the malignant clone. T-cell depletion had no influence on growth capacity of hematopoietic progenitors, nor did colony growth respond in a dose-dependent manner to different concentrations of LCM. Growth capacity of MDS hematopoietic progenitors was independent of Bournemouth score, of the presence and type of cytogenetic abnormality, and of the expression of CD95 and caspase-3 antigens on bone marrow cells. However, in patients with "abnormal" growth of GM progenitors, CD34 antigen expression was significantly higher than in patients with "normal" growth. "Abnormal" GM growth was found to be independently predictive regarding the survival and the risk for AML development. In contrast, the prognostic value of erythroid and megakaryocyte cultures was found to be limited.
The clinical results in 107 patients receiving a peripheral blood stem cell (PBSC) graft mobilized by granulocyte colony-stimulating factor (G-CSF) from HLA-A, -B, and -DR-compatible unrelated donors were compared to 107 matched controls receiving unrelated bone marrow (BM) transplants. Engraftment was achieved in 94% of the patients in both groups. The PBSC graft contained significantly more nucleated cells, CD34(+), CD3(+), and CD56(+) cells (P <.001), and resulted in a significantly shorter time-to-neutrophil (15 versus 19 days) and platelet engraftment (20 versus 27 days), compared to the BM control group (P <.001). Probabilities of acute graft-versus-host disease (GVHD) grades II to IV were 35% and 32% (not significant [NS]) and of chronic GVHD 61% and 76% (NS) in the PBSC and BM groups, respectively. There was no difference between the 2 groups in bacteremia, cytomegalovirus reactivation or disease, and fungal infection. The 3-year transplant-related mortality (TRM) rates were 42% in the PBSC group and 31% in the BM controls (P =.7) and the survival rates were 46% and 51%, respectively. The probability of relapse was 25% and 31% in both groups (NS), resulting in disease-free survival rates of 43% in the PBSC group and 46% in the BM controls (NS). In the multivariate analysis, early disease, acute GVHD grade 0 to I, and presence of chronic GVHD were independent factors associated with a better disease-free survival in this study. PBSC from HLA-compatible unrelated donors can be used safely as an alternative to BM for stem cell transplantation.
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Acute and chronic GvHD are still a major concern in allogeneic hematopoietic stem cell transplantation, still contributing substantially to morbidity and mortality in this therapeutic procedure. Over the past decade, many advances have been made with regard to the prevention and treatment of GvHD using various drugs such as cyclosporine A, FK506, mycophenolate mofetil and/or monoclonal IL-2 receptor antagonists. Despite these measurements with regard to the prevention of acute GvHD, it is very difficult to treat these clinical conditions successfully. However, if patients do not experience any GvHD often the desired effect of graft versus leukemia (GvL) remains absent increasing the probability of a relapse, in particular, in patients transplanted, which are considered at higher risk for relapse. At the present time, new strategies in the prevention of acute GvHD are in progress in particular the use of genetic manipulated donor T cells expressing suicide genes. Further clinical and laboratory studies are required in order to improve the prevention and, in particular, the therapy of established GvHD.
We compared the outcomes in patients receiving unrelated peripheral blood stem cell transplants (PBSCT) with those receiving bone marrow transplants (BMT) in a matched pair analysis. Seventy-four patients with hematological malignancies with HLA-matched (77%) and mismatched (23%) donors were analyzed in this study. Thirty-four patients (45%) were considered as high risk patients. Sixty-eight patients received standard conditioning regimens with Bu/Cy or TBI/Cy. Six patients received an intensified conditioning regimen with the addition of etoposide, thiotepa or melphalan. GVHD prophylaxis consisted of prednisolone, cyclosporine and methotrexate. Groups were matched for patient, donor, transplant characteristics and HLA compatibility. Peripheral blood stem cell collection led to the collection of a higher number of CD34+ and CD3+ cells in comparison to bone marrow collection. Leukocyte engraftment in the PBSCT group occurred in 14 days (median; range 6-26 days) and in the BMT group in 19 days (range 9-29 days; P < 0.02). The time of platelet engraftment did not differ significantly. The incidence of grades II-lV acute GVHD in the group of HLA-identical patients was 35% in the PBSCT group and 25% in the BMT group (P < 0.33, log-rank). However, there was a significant difference (P < 0.05, log-rank) in incidence and time to onset of acute GVHD II-IV comparing all patients, including the 17 mismatched transplants. Disease-free survival was 51% (19 patients) with a median of 352 days and 59% (21 patients) with a median of 760 days for PBSC and BMT transplants, respectively. In conclusion, our results indicate that allogeneic PBSCT led to significantly faster leukocyte engraftment but is associated with a higher incidence and more rapid onset of severe acute GVHD comparing all patients, including the 17 mismatched transplants. However, the incidence of severe acute GVHD in HLA-identical patients was not different between the PBSCT and BMT groups.
Hematopoietic stem cell transplantation (HSCT) is a treatment option for autoimmune diseases but can also cause clinical features similar to those of autoimmune diseases. In some of these cases the autoimmune-like condition is associated with autoimmune cytopenia, a complication that can be unresponsive to established treatment strategies and which may be fatal. The majority of cases reported on immune hemolytic anemia have been of alloimmune origin due to ABO red blood cell antigen incompatibilities between donor and recipient. We now report a patient with a lupus-like syndrome, presenting with severe thrombocytopenia and hemolytic anemia 9 months after HLA-mismatch, ABO compatible-related PBSCT who experienced no response to high-dose steroids, but who had a sustained response to repeated IvIG therapy.
Competitive inhibition of interleukin 2-dependent lymphocytes by daclizumab demonstrates some beneficial effects in the treatment of graft-versus-host disease (GVHD). Sixteen patients with steroid refractory GVHD received daclizumab (1 mg/kg BW) on d 1, 2 (-5), 7, 14 and 21. Twelve patients suffered from grade III-IV acute GVHD and four patients from extensive chronic GVHD. Responses were observed in nine patients (six acute, three chronic GVHD). Fourteen out of 16 patients acquired infections during daclizumab treatment and three deaths were infection related. Daclizumab demonstrates limited activity and is associated with an increased incidence of infectious complications.
GenVec, in collaboration with Pfizer (formerly Parke-Davis), is developing AdGVVEGF121.10 (BioBypass), a gene therapy involving the 121-residue isoform of vascular endothelial growth factor (VEGF), licensed from Scios, for the potential treatment of coronary artery disease (CAD) and peripheral vascular disease (PVD) [262000]. By March 2000, phase II trials in CAD had commenced [359531], [359532], [359538]. By August 2000, phase II trials were also underway for PVD [386293]. The initial phase II trial will include approximately 70 patients with severe CAD who are not candidates for bypass surgery and will assess exercise capacity and patient well-being, before and after treatment, as well as safety and drug tolerance [364137]. Scios licensed the gene transfer applications of VEGF121 to GenVec in June 1996 [263381]. In September 1997, GenVec entered into an agreement with Parke-Davis, a subsidiary of Warner-Lambert (now Pfizer), to develop the therapy [262000]. In May 1999, Warner-Lambert signed an agreement with Bioscience for a device for the administration of AdGVVEGF121.10 1325443]. In May 2000, Merrill Lynch predicted a US filing in the first half of 2003 [375962]. In January 2001, AG Edwards predicted the product would generate $70 million in revenues to Pfizer and $12 million in royalties to GenVec in 2005. In February 1999, GenVec was awarded US-05846782, covering vectors for targeting the transfer of therapeutic genes to specific tissues in the human body [316038].