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Moshe Talpaz

Publications and source records attributed to Moshe Talpaz.

At least 55 records · Page 3Linked to original sources

High-dose imatinib mesylate therapy in newly diagnosed Philadelphia chromosome-positive chronic phase chronic myeloid leukemia.

Imatinib mesylate (STI571) is effective in chronic phase chronic myelogenous leukemia (CML). However, most patients treated with 400 mg imatinib daily have variable levels of residual molecular disease. We treated 114 patients with newly diagnosed chronic phase CML with 400 mg imatinib twice daily. Overall, 109 patients (96%) had a major cytogenetic response (Philadelphia chromosome [Ph] < 35%), and 103 (90%) had a complete response (Ph 0%). With a median follow-up of 15 months, no patient has progressed to accelerated or blastic phase. The estimated 2-year survival rate was 94%. By quantitative polymerase chain reaction (QPCR) studies, 71 (63%) of 112 patients showed BCR-ABL/ABL percentage ratios decrease to less than 0.05%, and 31 (28%) to undetectable levels. Compared with standard-dose imatinib, high-dose imatinib was associated with significantly better complete cytogenetic response (P =.0005), major molecular response (QPRC < 0.05%; P =.00001), and complete molecular response (undetectable BCR-ABL; P =.001). High-dose imatinib was well tolerated but resulted in more frequent myelosuppression; 82% of patients continue to receive 600 mg or more of imatinib daily. In conclusion, high-dose imatinib induced higher rates of complete cytogenetic response and of molecular response in patients with newly diagnosed chronic phase CML.

Adolescent↗

Nuclear factor-kappaB and STAT3 are constitutively active in CD138+ cells derived from multiple myeloma patients, and suppression of these transcription factors leads to apoptosis.

Chemoresistance is a major problem in the treatment of patients with multiple myeloma (MM). Because of the central role of the nuclear transcription factors nuclear factor-kappaB (NF-kappaB) and signal transducer and activator of transcription 3 (STAT3) in chemoresistance, cell survival, and proliferation, we investigated whether MM cells derived from patients express activated NF-kappaB and STAT3 and if their suppression induces apoptosis. We assayed CD138+ cells from the bone marrow of 22 MM patients and checked for the activated forms of NF-kappaB and STAT3 by immunocytochemistry. We found that MM cells from all the patients expressed the activated forms of NF-kappaB and STAT3 but to a variable degree (NF-kappaB: low, 3 of 22; moderate, 5 of 22; or high, 14 of 22; STAT3: none, 1 of 22; low, 3 of 22; moderate, 5 of 22; or high, 14 of 22). Constitutive activation of NF-kappaB was in some cases also independently confirmed by electrophoretic mobility gel shift assay. In contrast to MM patients, activated forms of NF-kappaB and STAT3 were absent in cells from healthy individuals. Suppression of NF-kappaB and STAT3 activation in MM cells by ex vivo treatment with curcumin (diferuloylmethane) resulted in a decrease in adhesion to bone marrow stromal cells, cytokine secretion, and in the viability of cells. When compared with curcumin, dexamethasone was less effective in suppression of NF-kappaB activation and induction of apoptosis in myeloma cells. Overall, our results indicate that fresh cells from MM patients express constitutively active NF-kappaB and STAT3, and suppression of these transcription factors inhibits the survival of the cells.

Adult↗

Imatinib mesylate therapy improves survival in patients with newly diagnosed Philadelphia chromosome-positive chronic myelogenous leukemia in the chronic phase: comparison with historic data.

BACKGROUND: The International Randomized study of Interferon-alpha plus cytarabine (IFN-alpha plus ara-C) versus STI571 (imatinib mesylate) [IRIS trial] in patients with newly diagnosed Philadelphia chromosome (Ph)-positive, chronic-phase chronic myelogenous leukemia (CML) has not shown (to date) a survival advantage for imatinib. This was most likely because approximately 90% of patients receiving IFN-alpha plus ara-C changed to imatinib therapy after a median of 8 months into therapy. METHODS: The authors analyzed the results with imatinib therapy in patients with newly diagnosed Ph-positive CML in chronic phase and compared their outcome with patients who received IFN-alpha regimens. A total of 187 patients with Ph-positive CML in early chronic phase treated with imatinib were compared with a historic group of 650 similar patients treated with IFN-alpha regimens from 1982 until 1997. RESULTS: Patients who received imatinib were significantly older and had significantly more bone marrow basophilia and less leukocytosis. The complete cytogenetic response (Ph 0%) rates were better with imatinib (81% vs. 32%; P < 0.001), as were the survival rates (30-month estimated survival rates 98% vs. 88%; P = 0.01). A multivariate analysis of the total study group of 837 patients identified imatinib therapy to be a significant independent favorable prognostic factor for survival (P = 0.01). CONCLUSIONS: The current study is the first to indicate the survival advantage of imatinib compared with IFN-alpha, the previous standard of care, in patients with early chronic-phase CML.

Administration, Oral↗

Sequential interleukin 3 and granulocyte-macrophage-colony stimulating factor therapy in patients with bone marrow failure with long-term follow-up of responses.

BACKGROUND: Interleukin-3 (IL-3) and granulocyte-macrophage-colony stimulating factor (GM-CSF) have synergistic, hematopoietic growth-promoting activity in preclinical studies. Because of the paucity of effective therapies for patients with chronic bone marrow failure states, the authors studied the biologic activity of sequential IL-3/GM-CSF in such patients. METHODS: IL-3 was given subcutaneously for 5 days (at escalating doses of 0.15 microg/kg, 0.3 microg/kg, 0.6 microg/kg, 1.2 microg/kg, 2.5 microg/kg, 5.0 microg/kg, 10.0 microg/kg, or 15.0 microg/kg per day), and GM-CSF for was given subcutaneously for 9 days (at a dose of 5 microg/kg per day; Phase I 3 + 3 design) followed by 14 days of rest (total, 2 courses), then maintenance therapy. RESULTS: The majority of 38 evaluable patients had aplastic anemia or myelodysplastic syndrome. Most patients (79%) had neutrophil responses. Ten patients (26%), all of whom were treated with IL-3 doses >/= 1.2 microg/kg per day, had platelet responses, with a median increase of 132 x 10(9)/L (range, 41-180 x 10(9)/L) over baseline in responders. Six patients (16%) had trilineage recovery, which could be durable (the longest ongoing at 6.5 years after therapy completion). The most common toxicities were low-grade fever, headache, and fatigue. The maximum tolerated doses were IL-3 at 10 microg/kg per day and GM-CSF at 5 microg/kg per day. CONCLUSIONS: Sequential IL-3/GM-CSF effectively raised blood counts in some patients with bone marrow failure at doses that were tolerated well. These results indicate that early-acting growth factors can induce durable, multilineage responses in a subset of individuals with bone marrow failure.

Adult↗

Imatinib mesylate causes hypopigmentation in the skin.

BACKGROUND: Imatinib mesylate is a tyrosine kinase inhibitor that targets the BCR-ABL protein in CML, c-kit (KIT) and platelet-derived growth factor receptors. In clinical trials with imatinib mesylate, common side effects of nausea, emesis, diarrhea, periorbital edema, fluid retention, and myelosuppression have been documented. METHODS: In this case series, the authors describe unique clinical findings of skin hypopigmentation in six patients with CML who were treated with imatinib mesylate. RESULTS: Most patients developed onset of skin hypopigmentation within the first month of treatment and all of the patients experienced additional drug toxicity. Despite patient susceptibility to toxicity, the presence of hypopigmentation did not appear to predict leukemic cell response or clinical outcome. All six patients established a hematologic response but only two patients had a complete cytogenetic response. Imatinib mesylate induced hypopigmentation also appeared to be reversible and potentially dose related. CONCLUSION: Skin hypopigmentation is a benign side effect from imatinib mesylate treatment that appears to be reversible upon discontinuation or dose reduction. Several lines of evidence have previously reported that KIT and its ligand stem cell factor (SCF) have a regulatory role in melanocyte development and survival, suggesting a rational mechanism of action for imatinib mesylate in the pathogenesis of hypopigmentation. The signal transduction mechanism currently is believed to involve SCF ligand binding of KIT and downstream activation of MAP kinase (Erk-2). Microphthalmia (Mi), a basic helix-loop-helix leucine zipper (bHLHZip) transcription factor, is phosphorylated by MAP kinase at a serine residue (S73). Once phosphorylated, Mi transactivates the tyrosine pigmentation gene promoter and affects pigment production.

Adult↗

Chromosomal abnormalities in Philadelphia chromosome-negative metaphases appearing during imatinib mesylate therapy in patients with Philadelphia chromosome-positive chronic myelogenous leukemia in chronic phase.

BACKGROUND: Anecdotal cases of chromosomal abnormalities in Philadelphia chromosome (Ph)-negative metaphases have been reported in patients with chronic myelogenous leukemia (CML) in the chronic phase during treatment with interferon and, more recently, with imatinib. This phenomenon is different from true clonal evolution in that the additional cytogenetic abnormality occurs in Ph-negative cells. METHODS: The authors analyzed their experience with 342 patients with CML in chronic phase treated with imatinib to investigate the frequency and significance of this event. RESULTS: After a median follow-up of 30 months (range, 16-35 months), 21 patients (6%; 95% confidence interval, 0.04, 0.09) developed 25 chromosomal abnormalities in Ph-negative cells. Thirteen (54%) of these abnormalities were seen in 2 or more metaphases. The median time from the start of treatment with imatinib to the appearance of the abnormalities was 6 months (range, 3-22 months). The most common cytogenetic abnormality detected was trisomy 8 (33%). Twenty of 21 patients (95%) achieved a major (Ph < 35%) cytogenetic response (complete cytogenetic response in 13-62%). After a median follow-up of 22 months (range, 4-33 months), all 21 patients were alive, 20 of them in chronic phase and in complete hematologic response. None of the patients showed features of myelodysplasia. CONCLUSIONS: Cytogenetic abnormalities occur in Ph-negative cells in a fraction of patients with CML in chronic phase treated with imatinib. With a short follow-up, no clear clinical consequences can be identified.

Adult↗

Treatment of Philadelphia chromosome-positive acute lymphocytic leukemia with hyper-CVAD and imatinib mesylate.

Imatinib mesylate, an inhibitor of the Bcr-Abl tyrosine kinase, has modest activity in refractory/relapsed Philadelphia chromosome (Ph)-positive acute lymphocytic leukemia (ALL). Use of concurrent chemotherapy and imatinib mesylate in newly diagnosed Ph-positive ALL was explored. There were 20 patients who received hyper-CVAD (cyclophosphamide, vincristine, Adriamycin, and dexamethasone) and imatinib mesylate followed by imatinib mesylate-based consolidation/maintenance therapy. Of these patients, 11 had de novo disease, 4 were primary failures after induction (without imatinib mesylate), and 5 were in complete remission (CR) after induction (without imatinib mesylate). All 15 patients treated for active disease achieved CR. Within a median of 3.5 months in first CR, 10 patients underwent allogeneic stem cell transplantation (SCT). One patient relapsed after matched related SCT. The other 9 patients remained alive in CR with median follow-up of 12 months after SCT (range, 1+ to 17+ months). Among 10 patients ineligible for (no donor or older age) or refusing allogeneic SCT, 1 patient relapsed after one year. There were 5 patients who remained alive in continuous CR for a median of 20 months (range, 4+ to 24+ months), with 2 older patients dying in CR at 15 and 16 months of comorbid conditions. Molecular CRs were achieved in both groups (SCT or no SCT). Outcome with hyper-CVAD and imatinib mesylate appears better than with prior regimens; continued accrual and longer follow-up of the current cohort is needed.

Adolescent↗

Analysis of the impact of imatinib mesylate therapy on the prognosis of patients with Philadelphia chromosome-positive chronic myelogenous leukemia treated with interferon-alpha regimens for early chronic phase.

BACKGROUND: The effect on prognosis of adding imatinib mesylate to the treatment of patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) has not been explored fully. The objective of the current study was to evaluate the benefit of adding imatinib to the treatment sequence of patients with early chronic phase Ph-positive CML who received interferon alpha (IFN)-based regimens as frontline therapy. METHODS: A total of 201 patients with early chronic phase Ph-positive CML who were treated on our 3 recent frontline IFN-based programs and were impacted early by the availability of sequential therapy with imatinib were analyzed. Their outcome was compared with that of a historical control group of 293 patients treated from 1982 until 1990 who were treated with IFN programs for early chronic phase CML and who did not have the opportunity of early access to imatinib (because it was not available during that period). Multivariate analysis was used to evaluate the independent effect of imatinib therapy on survival. RESULTS: Of 201 patients who were treated, 159 patients (79%) had their regimen changed sequentially to imatinib after a median duration of 14 months of IFN therapy. Of 139 patients who continued evaluation at our institution, 101 patients (73%; 64% of the total group) achieved a complete cytogenetic response, and 20 of 80 patients analyzed (25%; 10% of the total group) had no disease according to molecular studies (quantitative polymerase chain reaction studies). The estimated 5-year survival rate for the total study group of 201 patients was 86%. Survival of this group was significantly superior to the historic control group of IFN-treated patients who did not have the benefit of imatinib (P = 0.03). The trend also was observed within defined CML risk groups. Imatinib therapy was confirmed as an independent, significant, favorable prognostic factor for survival by multivariate analysis, after accounting for the independent prognostic effect of pretreatment prognostic factors (P = 0.005). CONCLUSIONS: The current analysis is the first to indicate the independent, favorable effect of imatinib on the survival of patients with Ph-positive CML.

Aged↗

Effects of age on prognosis with imatinib mesylate therapy for patients with Philadelphia chromosome-positive chronic myelogenous leukemia.

BACKGROUND: Older age is a consistent poor prognostic factor in patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML). Whether this is related to an intrinsic worse disease biology or to inadequate drug delivery or excessive treatment-associated toxicity is unknown. The availability of imatinib mesylate, a selective, Bcr-Abl-targeted therapy that is administered orally with minimal side effects, may clarify whether older age would remain an adverse factor (thus, implying a different age-related CML biology). METHODS: Seven hundred forty-seven patients in different phases of Ph-positive CML who were treated with imatinib from 1999 until the time of last follow-up were evaluated. Among them, 187 patients had newly diagnosed, early chronic phase CML; 351 patients had chronic phase CML after interferon alpha (IFN) failure; 133 patients had accelerated phase CML; and 76 patients had blastic phase CML. The imatinib daily dose varied from 400 mg to 800 mg orally, according to the protocol design. Patients were categorized into a group of older patients (age 60 years or older) or younger patients (age younger than 60 years). Their characteristics, responses to therapy, and survival were compared by univariate and multivariate analyses. RESULTS: One hundred eighty-seven patients had newly diagnosed CML, and 49 patients (26%) were in the older age group. Older patients had similar cytogenetic response rates and survival compared with younger patients. Among 351 patients with late chronic phase CML after IFN failure, 120 patients (34%) were in the older age group. Although the older patients had a lower incidence of achievement of complete cytogenetic response (Ph, 0%) by univariate analysis (56% vs. 44%; P = 0.05), age was not found to be an independent poor prognostic factor in the multivariate analysis. Similarly, older age was not an adverse poor prognostic factor for survival. Forty-two of 133 patients (32%) with accelerated phase CML were older. The incidence of any cytogenetic response was lower in older patients (53% vs. 33%; P = 0.04), but age was not significant in the multivariate analysis. Older patients also had a trend toward worse survival (P = 0.09) that was not significant in the multivariate analysis. Twenty-eight of 76 patients (37%) evaluated in blastic phase were older. Older age was not a significant prognostic factor either for achieving response or for survival. CONCLUSIONS: With imatinib therapy, older age appears to have lost much of its prognostic relevance. This suggests that the previous poor prognosis observed with older age was related to treatment-associated factors (e.g., toxicity with allogeneic transplantation or with IFN therapy) rather than to an intrinsic, different disease biology of CML in older patients.

Administration, Oral↗

Results of triple therapy with interferon-alpha, cytarabine, and homoharringtonine, and the impact of adding imatinib to the treatment sequence in patients with Philadelphia chromosome-positive chronic myelogenous leukemia in early chronic phase.

BACKGROUND: Before the discovery of imatinib mesylate, a Bcr-Abl selective tyrosine kinase inhibitor, three agents, interferon-alpha (IFN-alpha), cytarabine (ara-C), and homoharringtonine (HHT), had demonstrated activity against Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) as single agents and in couplet combinations. The goals of the current study were to evaluate the efficacy of the triple combination regimen with IFN-alpha, ara-C, and HHT in newly diagnosed Ph-positive CML and to assess the impact of the added sequential therapy with imatinib on overall prognosis. METHODS: Ninety patients with Ph-positive CML in early chronic phase received the triple regimen. Therapy consisted of 5 million units (MU)/m(2) IFN-alpha subcutaneously (s.c. daily, ara-C 10 mg s.c. daily, and HHT 2.5 mg/m(2) by continuous infusion over 24 hours daily x 5 every month. After a median duration of 16.5 months of therapy, 78 patients had their therapy changed to 400 mg orally administered imatinib daily. RESULTS: With the triple regimen, 85 patients (94%) achieved complete hematologic response and 67 patients (74%) had a cytogenetic response (Ph suppression to < or = 90%) which was complete (Ph 0%) in 20 patients (22%) and major in 42 patients (46%). Myelosuppression was significant, resulting in considerable reductions in the dose schedules. After 12 months of therapy, the median IFN-alpha dose was 1.6 MU/m(2) daily, the median ara-C dose was 1.85 mg daily, and the median number of HHT days was 2 every month. Only three patients developed blastic phase while receiving the triple regimen. With the change to imatinib therapy, currently 57 patients (63%) are in complete cytogenetic response and 69 patients (76%) in major cytogenetic response. With a median follow-up time of 46 months for the total study group, the estimated 5-year survival rate was 88%, and only 8 patients (9%) to date have developed blastic phase. CONCLUSIONS: The sequence of IFN-alpha, ara-C, and HHT followed by imatinib (imposed by the discovery of the latter drug) resulted in an estimated 5-year survival rate of 88%. This finding suggests that imatinib combination regimens may improve the prognosis in CML.

Adult↗

Impact of p210(Bcr-Abl) on ultraviolet C wavelength-induced DNA damage and repair.

Recently, it was shown that both Bcr and Bcr-Abl can interact with xeroderma pigmentosum group B (XPB/ERCC3), a protein implicated in DNA repair after UV-induced damage. To further analyze the effect of Bcr-Abl on the DNA damage response, we used cell lines stably transfected with the BCR-ABL gene and their parental counterparts (MBA-1 versus MO7E and Bcr-AblT1 versus 4A2(+)-pZAP) and several assays reflecting DNA repair: the comet assay, a radioimmunoassay for cyclobutane pyrimidine dimers, and clonogenic assays. After exposure to UVC (0.5-5.0 joules m(-2)), the Comet assay demonstrated greater efficiency of DNA repair in the BCR-ABL-positive cells (both MBA-1 and Bcr-AblT1) when compared with their parental counterparts. Furthermore, there was less production of the UV-induced DNA adduct-cyclobutane pyrimidine dimers-as well as a more rapid rate of disappearance of these adducts and greater UV survival (clonogenic assays) in MBA-1 cells as compared with MO7E cells. Apoptosis (annexin V-FITC/propidium iodide staining) was markedly reduced in the BCR-ABL-positive cells. These results indicate that BCR-ABL confers enhanced resistance to UV radiation-induced damage and increased efficiency of DNA repair and that these changes are associated with a protective antiapoptotic effect.

Annexin A5↗

Farnesyltransferase inhibitor R115777 in myelodysplastic syndrome: clinical and biologic activities in the phase 1 setting.

R115777 is a potent farnesyltransferase (FTase) inhibitor with substantial antitumor activity in preclinical models. We conducted a phase 1 study (3 + 3 design) of R115777 in patients with myelodysplastic syndrome (MDS). R115777 was administered twice daily (3-weeks-on/1-week-off schedule for 8 weeks) (starting dosage, 300 mg by mouth twice daily; total, 600 mg). Maintenance therapy at the dose/schedule tolerated during induction could be continued until toxicity or lack of benefit. Twenty-one patients with MDS were treated (median age, 66 years). Four (19%) patients had ras mutations (n-ras,3; k-ras, 1). Objective responses (hematologic improvement, 3; partial remission, 2; or complete remission, 1) were seen in 6 of 20 (30%) evaluable patients, only 2 of whom had ras mutations. Response sequences were unusual in some patients who had increases in platelet counts without intervening aplasia. Other responders demonstrated an initial, albeit modest, myelosuppressive effect. The maximum tolerated dose was 400 mg by mouth twice a day. The most frequent side effect was myelosuppression. Dose-limiting toxicities (fatigue and confusion) occurred at 900 mg by mouth total daily dose. R115777 inhibited HDJ-2 prenylation and suppressed the activity of FTase, but not of the related geranylgeranyltransferase I enzyme, in peripheral blood mononuclear cells. Modulation of Akt, Erk, and signal transducer and activator of transcription 3 (STAT3) phosphorylation was variable, and responses occurred even without their down-regulation. Reductions in serum tumor necrosis factor-alpha (TNF-alpha) levels by day 7 showed a trend toward correlation with response (P =.09). We conclude that, at doses that are well tolerated, R115777 markedly inhibits the FTase target and has antitumor activity in MDS.

Aged↗

Results of decitabine (5-aza-2'deoxycytidine) therapy in 130 patients with chronic myelogenous leukemia.

BACKGROUND: General and site-specific DNA methylation is associated with tumor progression and resistance in several cancers, including chronic myelogenous leukemia (CML). Decitabine is a hypomethylating agent that has shown encouraging preliminary anti-CML activity. This study evaluated the activity and toxicity of decitabine in different phases of CML. METHODS: One hundred and thirty patients with CML were treated: 123 with Philadelphia chromosome (Ph)-positive CML (64 blastic, 51 accelerated, 8 chronic) and 7 with Ph-negative CML. Decitabine was given at 100 mg/m(2) over 6 hours every 12 hours x 5 days (1000 mg/m(2) per course) in the first 13 patients, 75 mg/m(2) in the subsequent 33 patients, and 50 mg/m(2) in the remaining 84 patients. RESULTS: A total of 552 courses were given to the 130 patients. Only four patients (3%) died during the first course from myelosuppressive complications (three patients) or progressive disease (one patient). Of 64 patients in the CML blastic phase, 18 patients (28%) achieved objective responses. Of these 18 patients, 6 achieved complete hematologic responses (CHR), 2 achieved partial hematologic responses (PHR), 7 achieved hematologic improvements (HI), and 3 returned to the second chronic phase (second CP). Five patients (8%) had cytogenetic responses. Among 51 patients in the accelerated phase, 28 patients (55%) achieved objective responses (12 CHR, 10 PHR, 3 HI, and 3 second CP). Seven patients (14%) had cytogenetic responses. Among eight patients treated in the chronic phase, five (63%) had objective responses. Of seven patients treated for Ph-negative CML, four (57%) had objective responses. There was no evidence of a dose-response effect. The estimated 3-year survival rate was less than 5% in the blastic phase and 27% in the accelerated phase. The only significant toxicity reported was severe myelosuppression, which was delayed, prolonged, and dose dependent. With decitabine 50-75 mg/m(2), the median time to granulocyte recovery above 0.5 x 10(9)/L was about 4 weeks. Myelosuppression-associated complications included febrile episodes in 37% and documented infections in 34%. CONCLUSIONS: Decitabine appears to have significant anti-CML activity. Future studies should evaluate lower-dose, longer-exposure decitabine schedules alone in imatinib-resistant CML, as well as combinations of decitabine and imatinib in different CML phases.

Adolescent↗

Sudden onset of the blastic phase of chronic myelogenous leukemia: patterns and implications.

BACKGROUND: Therapeutic options in Philadelphia chromosome-positive chronic myelogenous leukemia (Ph-positive CML) in chronic phase include allogeneic stem cell transplantation (SCT) and treatments other than allogeneic SCT. The choice of therapy often depends on the mortality risk of allogeneic SCT. Delaying SCT until the disease demonstrates resistance to other strategies (e.g., imatinib mesylate or interferon-alpha) entails the risk of the development of a sudden blastic phase, which may not permit enough time to perform a SCT. METHODS: The current study was performed to define the incidence and patterns of sudden-onset blastic-phase CML in relation to the risk inherent in delaying allogeneic SCT. Of a study group of 1286 patients who were referred in early chronic-phase CML between 1981-2001 and who received therapies other than allogeneic SCT, 1093 patients had regular follow-up at the study institution. A sudden onset of blastic phase was defined as having its onset within 3 months from a previously documented complete hematologic response. RESULTS: Among the 1093 patients, 183 patients developed blastic-phase disease, which was of sudden onset in 46 patients (25%; 4% of the total). The incidence of sudden blastic phase was 0.4% in the first year, 1.8% in the second year, and 2.6% in the third year. Patients with sudden blastic-phase disease were found to have more often low-risk features at the time of presentation, including low incidences of blasts and thrombocytosis. Sudden blastic-phase CML was found to be associated with a higher incidence of lymphoid blastic morphology (67% vs. 22%; P < 0.0001), which resulted in a higher response rate to blastic-phase therapy (70% vs. 29%; P < 0.0001) and significantly longer survival from the onset of blastic-phase disease (median of 12 months vs. 6 months; P < 0.01). Twenty-four of the 42 patients with sudden blastic-phase disease who were treated at the M. D. Anderson Cancer Center were able to undergo allogeneic SCT in second chronic phrase (n = 13) or transformed phase (n = 11); at the time of last follow-up, 6 patients were alive without evidence of disease at a median of 18 months. CONCLUSIONS: The low rates of sudden blastic transformation in the first 3 years of the course of disease for CML and the salvage rate of these patients with allogeneic SCT should be considered in relation to the transplantation mortality in patients with early chronic-phase disease and the early promising results with imatinib mesylate therapy.

Adult↗

Treatment of Philadelphia chromosome-positive chronic myelogenous leukemia with weekly polyethylene glycol formulation of interferon-alpha-2b and low-dose cytosine arabinoside.

BACKGROUND: To evaluate the activity and toxicity of weekly Schering 54301, a polyethylene glycol formulation of interferon- alpha-2b (PEG-IFN-alpha-2b), with cytosine arabinoside (ara-C) in patients with chronic myelogenous leukemia (CML). METHODS: Seventy-six patients with Philadelphia chromosome (Ph)-positive early chronic-phase CML were treated with the combination of PEG-IFN-alpha-2b and ara-C (10 mg daily subcutaneously [s.c.]). The starting dose of PEG-IFN-alpha-2b was 6 microg/kg s.c. weekly in the first 24 patients but was reduced to 4.5 microg/kg in the next 52 patients. RESULTS: Overall, 73% of patients had a complete hematologic response, 35% of patients had a major cytogenetic response (Ph < 35%), and 21% of patients had a complete cytogenetic response (Ph = 0%). With a median follow-up of 19 months, the estimated 2-year survival rate was 89%. Therapy was discontinued in 24% of patients due to Grade III-IV toxicity. Frequent severe side effects that required dose reductions included neutropenia (49%), fatigue (43%), and neurologic toxicity (17%). The median PEG-IFN-alpha-2b and ara-C doses delivered were 3 microg/kg weekly and 7.5 mg daily, respectively, at 12 months of therapy. The activity and toxicity profiles of this combination was similar to those observed in historical patients treated with IFN-alpha and cytarabine. CONCLUSIONS: The combination of PEG-IFN-alpha-2b and ara-C is active but has significant toxicity in patients with chronic-phase CML at the dose schedule used. The recommended dose of PEG-IFN-alpha-2b in future combination studies is 3 microg/kg or less.

Adult↗

TWEAK mediates signal transduction and differentiation of RAW264.7 cells in the absence of Fn14/TweakR. Evidence for a second TWEAK receptor.

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is a member of the tumor necrosis factor family that is implicated in apoptosis, proliferation, migration, and inflammation. We describe our findings showing that TWEAK mediated the differentiation of RAW264.7 (RAW) monocyte/macrophage cells into multinuclear, functional osteoclasts. The effect of TWEAK was direct and not mediated by the receptor activator of nuclear factor-kappa B (NF-kappa B) ligand (RANKL) as shown by the use of TWEAK- or RANKL-neutralizing antibodies and by osteoprotegerin, a decoy receptor for RANKL. Recently, fibroblast growth factor-inducible 14 (Fn14) was suggested to be a receptor for TWEAK. We show that the Fn14/TWEAK receptor (TweakR) was not responsible for the osteoclastic effect of TWEAK on RAW cells. Flow cytometry analysis did not reveal the expression of Fn14/TweakR on RAW cells. Moreover, Fn14/TweakR-neutralizing antibodies did not block TWEAK-induced RAW cell differentiation into osteoclasts. This indicated that a second TweakR, TweakR2, exists on RAW cells and is responsible for mediating TWEAK-induced differentiation. We next compared the signaling pathways that are activated by the two receptors. TWEAK binding to TweakR2 activated the NF-kappa B, mitogen-activated protein kinase and c-Jun N-terminal kinase signaling cascades in RAW cells. In contrast, TWEAK binding to Fn14/TweakR activated the NF-kappa B and c-Jun N-terminal kinase pathways but induced only a weak activation of MAPK in HT-29 human colon adenocarcinoma cells expressing endogenous Fn14/TweakR. We propose that the biological effects of TWEAK are mediated by binding to one of at least two distinct receptors that induce differential activation of downstream signaling pathways.

Animals↗

Results of imatinib mesylate therapy in patients with refractory or recurrent acute myeloid leukemia, high-risk myelodysplastic syndrome, and myeloproliferative disorders.

BACKGROUND: Imatinib mesylate is a selective tyrosine kinase inhibitor of c-abl, bcr/abl, c-kit, and platelet-derived growth factor-receptor (PDGF-R). c-kit is expressed in most patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) and PDGF has been implicated in the pathogenesis of myeloproliferative disorders (MPD). METHODS: The authors investigated the efficacy of imatinib in patients with these disorders. Forty-eight patients with AML (n = 10), MDS (n = 8), myelofibrosis (n = 18), atypical chronic myeloid leukemia (CML; n = 7), chronic myelomonocytic leukemia (CMML; n = 3), or polycythemia vera (n = 2) were treated with imatinib 400 mg daily. RESULTS: None of the patients with AML or MDS responded. Among patients with myelofibrosis, 10 of 14 patients with splenomegaly (71%) had a 30% or greater reduction in spleen size, 1 patient had trilineage hematologic improvement, 2 had erythroid hematologic improvement, and 1 had improvement in platelet count. One patient with atypical CML had erythroid hematologic improvement. Both patients with polycythemia vera needed fewer phlebotomies (from 2-3 per year to none during the 8 months of therapy and from 3-6 per year to 1 during 9 months of therapy). None of the three patients with CMML responded. Treatment was well tolerated. The side effects were similar to those observed in patients with CML. CONCLUSIONS: Within these small subgroups of disease types, single-agent imatinib did not achieve a significant clinical response among patients with AML, MDS, atypical CML, or CMML without PDGF-R fusion genes. Preliminary data on polycythemia vera are promising and deserve further investigation. Responses among myelofibrosis patients were minor. Therefore, a combination treatment regimen including imatinib may be more effective.

Adult↗