Older-age AML: Disease biology and dose response

7058

Background: In 2602 pts entering two sequential trials the 47% pts of 60+y compared to the younger pts achieved 55 vs 71% CR, 19 vs 41% OS and 77 vs 54% RR (relapse risk) at 3 years. While the trials addressed various options for both de-novo and secondary AML understanding the age related biology of AML required restriction to pts comparable in history, therapy and availability of risk factors. Methods: We therefore selected from the two trials pts with de-novo AML and known karyotype assigned to one of two different intensity induction regimens, either TAD-HAM (HAM, high-dose araC 3(age <60) and 1(age 60+) g/m2x6), or HAM-HAM. All pts received TAD consolidation and monthly reduced TAD maintenance. Results: In the 1284 selected pts the CR rate is 60% in pts of 60+y and 70% in those of 16 −<60y (p<.001), the OS is 23 vs 41% (log rank p<0.001) and the RR is 73 vs 50% (p<.001). There are advantages for younger pts in favorable (16 vs 7%) and unfavorable (18 vs 24%) karyotypes (p<.001) whereas WBC (p=.002) and LDH (p=.002) are lower in the older pts. Among normal karyotypes (52%) the favorable NPM mutation in absence of Flt3 mutation account for 33% of NPM/Flt3 combinations in older and 37% in younger pts (n.s.). The inferior CR, OS and RR in the older vs younger pts is seen in all prognostic subgroups. Thus, the OS at 3 years is 36 vs 62% in favorable (p=.001), 2 vs 14% in unfavorable karyotypes (p=.001), 25 vs 42% in low WBC (p<.001), 21 vs 38% in high WBC (p<.001), 23 vs 42% in low LDH (p<.001), 16 vs 38% in high LDH (p<.001), 30 vs 43% in low day 16 blasts (p<.001), 19 vs 38% in high day 16 blasts (p<.001) and even 50 vs 63% in pts with NPM+/Flt3- mutation (p=.020). In contrast, outcome does not vary by randomization for TAD-HAM vs HAM-HAM chemotherapy. Conclusions: The lack of dose response and the modest age related differences in defined risk profiles suggest hitherto unknown determinants of the poor outcome in older age AML across all subsets. These experiences may indicate the way toward novel experimental options instead of further escalation.

No significant financial relationships to disclose.

Regional hyperthermia (RHT) improves response and survival when combined with systemic chemotherapy in the management of locally advanced, high grade soft tissue sarcomas (STS) of the extremities, the body wall and the abdomen: A phase III randomised pros

10009

Background: Patients (Pts) with locally advanced, high-grade STS are at significant risk for local failure and for metastasis. We evaluated the ability of RHT to improve the outcome in pts who are treated with neoadjuvant chemotherapy. Methods: Eligibility included pts with STS = 5 cm, grade II/III, deep and extracompartmental, stratified according to site (E = extremity vs. Non-E = body wall and abdomen). Pts were randomly assigned to systemic chemotherapy (etoposide 250 mg/m2; ifosfamide 6 g/m2; adriamycin 50 mg/m2) alone (EIA) or to systemic chemotherapy combined with RHT (EIA + RHT) administered for 4 cycles every 3 weeks both prior and after local aggressive therapy (surgery + radiotherapy), respectively. Primary endpoints were local progression free survival (LPFS) and disease free survival (DFS). Objective (CR + PR) response rate (ORR) evaluated after 4 cycles (EIA vs EIA + RHT) was a secondary endpoint. A total of 340 pts was required to show an improvement in median LPFS of 19.2 mos for EIA + RHT (a=5% type I, 20% type II error). Results: Pts characteristics were well balanced between treatment arms. After median follow-up of 24.9 months (mos) an intention-to-treat analysis showed a significantly superior DFS for pts who received EIA + RHT (n=169) compared to those treated with EIA alone (n=172) (median DFS: 31,7 mos and 16,2 mos; log-rank p=0.003; Hazard ratio=0.65; CI95=0.48- 0.87, p=0.004). The median LPFS was estimated 45,3 mos for EIA + RHT and 23,7 mos for EIA (log-rank p=0.015; Hazard ratio=0.66; CI95=0.48 - 0.90, p=0.01). At 2 years, LPFS rates for E (149 pts) and for Non-E (192 pts) were significantly better for EIA + RHT vs EIA alone (E: 84% vs 64%; Non-E: 57% vs 39%) (p<0.02). The ORR was significantly better for EIA + RHT (28,7%) vs EIA alone (12,6%) (p=0.002). Conclusions: Compared to chemotherapy alone, RHT combined with chemotherapy yields a statistically significant improvement in tumor response , DFS and LPS, in patients with locally advanced, high-grade STS. (Supported by Deutsche Krebshilfe and HGF VH-VI- 140)

[Table: see text]

BH3 mimetic ABT-737 neutralizes resistance to FLT3 inhibitor treatment mediated by FLT3-independent expression of BCL2 in primary AML blasts

FLT3 defines a promising target for the treatment of acute myeloid leukemia (AML). In contrast to their efficacy in cell lines, FLT3-specific inhibitors as single agents have only modest clinical activity in patients with AML. As demonstrated here, overexpression of anti-apoptotic proteins of the BCL2 family leads to resistance against FLT3 inhibitors in a hematopoietic cell line model with activating FLT3 mutations. The susceptibility to FLT3 inhibition could be restored by treatment with the novel BH3 mimetic ABT-737. Primary AML samples tested in our study showed a high expression of BCL2 protein, but not of BCL-xL or MCL1. BCL2 protein levels were not reduced after dephosphorylation of FLT3 and its downstream target STAT5 in patient samples with FLT3 internal tandem duplications. Interestingly, treatment with ABT-737 caused apoptotic cell death in all primary AML samples at submicromolar level and synergized efficiently with FLT3 inhibition in AML samples with activating FLT3 mutations. In contrast to AML cell lines, BCR-ABL transformed human cells showed resistance to ABT-737, which might be due to the induction of MCL1 by BCR-ABL. Inhibition of BCL2 family members might define a novel highly efficient and specific strategy in the combined or monotreatment of AML.

[Fortuitous finding: thrombocytopenia and thrombocytosis]

Thrombocytopenia is present when the number of platelets drops to below 150 G/l. Leaving aside pseudothrombocytopenia, such a situation may be triggered by pregnancy or a range of different drugs, or may signify the presence of idiopathic thrombocytopenic purpura (ITP). Thrombocytosis is present when the platelet count exceeds 500 G/l. This condition includes a large variety of forms of reactive thrombocytosis, a clonal increase in thrombocytes in hematological diseases, and the rare condition of familial thrombocytosis.

[Elevated Hemoglobin--polyglobulia or polycythemia?]

An increase in Hb levels, haematocrit or the absolute number of red blood cells may be evidence of polycythemia rubra vera. Much more commonly, however, erythrocytosis is due to an underlying non-hematological disease. To establish the diagnosis of polycythemia, a secondary polyglobulia must first be excluded. If no evidence of polyglobulia is found, or if EPO levels are decreased, or splenomegaly not accountable for by portal hypertension is present, a specific diagnostic work-up must be performed by a hematologist/oncologist. This includes a bone marrow aspiration, cytological examination and molecular genetic testing.

Therapie des Mantelzelllymphoms

Mantle cell lymphoma is characterized by an aggressive clinical course and poor prognosis, with only few long-term survivors. Conventional chemotherapy has failed to substantially alter the natural course of the disease and remains a palliative approach. However, several randomized trials have recently clearly demonstrated the superiority of a combined immunochemotherapy containing the anti-CD20 antibody rituximab. In addition, a randomized trial has shown a significantly improved progression-free survival after myeloablative radiochemotherapy with autologous stem cell transplantation similar to other dose-intensified approaches (hyper-CVAD). Unfortunately, the vast majority of patients will eventually relapse. However, numerous molecular targeting strategies (e.g. proteasome inhibitors, immunomodulatory drugs or radiolabeled antibodies) have achieved promising results in early phase II studies.

The quality of molecular response to chemotherapy is predictive for the outcome of AML1-ETO-positive AML and is independent of pretreatment risk factors

The outcome of 45 AML1-ETO-positive acute myeloid leukemia (AML) patients was analyzed with special emphasis on the quality of molecular response to therapy. Patients received double induction therapy, either 6-thioguanine, cytarabine, and daunorubicin (TAD9)/high-dose cytosine arabinoside plus mitoxantrone (HAM) or HAM/HAM, followed by consolidation therapy (TAD9) according to the AML-Cooperative group 92 trial (AMLCG92) and AML-Cooperative group 99 trial (AMLCG99). All cases underwent cytomorphological, cytogenetical and molecular genetic analyses. AML1-ETO transcript levels were quantitatively assessed at diagnosis and during follow-up by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The median reduction of initial AML1-ETO expression level was 4 log (range 0-5) after both induction and consolidation therapies. The quality of molecular response after induction as well as consolidation therapies had significant impact on the cumulative incidence of relapse (P=0.021 and P=0.001, respectively), event free survival (EFS: P=0.001 and P=0.001, respectively) and overall survival (OS: P=0.013 and P=0.014, respectively). HAM/HAM improved the molecular response to induction therapy (P=0.042) but after consolidation, no differences in molecular response were detectable between TAD9/HAM and HAM/HAM. Patient- or disease-related factors had no impact on the molecular response to induction or consolidation therapy. The current study demonstrates that quantification of AML1-ETO transcript levels is a powerful tool for prediction of prognosis that is independent of pretreatment risk factors, and may be helpful for directing therapeutic decisions in the future.

Sequence-dependent synergy of the proteasome inhibitor bortezomib and cytarabine in mantle cell lymphoma

Single-agent bortezomib, a potent, selective and reversible inhibitor of the 26S proteasome, has demonstrated clinical efficacy in relapsed and refractory mantle cell lymphoma (MCL). Objective response is achieved in up to 45% of the patients; however, complete remission rates are low and duration of response proved to be short. These limitations may be overcome by combining proteasome inhibition with conventional chemotherapy. Here we present two case reports and in vitro data suggesting synergistic efficacy of bortezomib combined with cytarabine in MCL. Interestingly, efficacy in vitro correlated with sequence of treatment, indicating that pretreatment with cytarabine, followed by proteasome inhibition, may be the preferred approach.

Initial chemotherapy with mitoxantrone, chlorambucil, prednisone impairs the collection of stem cells in patients with indolent lymphomas—results of a randomized comparison by the German Low-Grade Lymphoma Study Group

Myeloablative radio-chemotherapy with subsequent autologous stem cell transplantation (ASCT) significantly prolongs progression free and probably overall survival in follicular lymphoma (FL) in first remission. The current trial explored prospectively the rate of successful stem cell mobilization in patients with advanced stage FL after initial therapy with either Mitoxantrone, Chlorambucil, Prednisone (MCP) or Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (CHOP) as part of a prospective randomized comparison of both regimens. ASCT patients received Dexa-BEAM (Dexamethasone, BCNU, Melphalan, Etoposide, Cytarabine) for mobilization of stem cells. Stem cells were collected and a minimum of 2x2.0x106/kg bw CD34+ was required for ASCT. Of 79 evaluable patients, 58 (73%) had follicular lymphoma, 13 (16%) mantle cell lymphoma and 8 (10%) lymphoplasmacytic lymphoma. In the 45 patients assigned to CHOP, stem cell collection was successful in 42 cases (93%, 95% CI 82% to 99%). This high mobilization rate after CHOP could be confirmed in 61 subsequent patients (87%). In contrast, after MCP therapy stem cell collection was successful in only 15 of 34 patients (44%, 95% CI 27% to 62%; P=0.0003). In conclusion, initial therapy with MCP significantly impairs the ability to collect stem cells and should be avoided for first line therapy of younger patients potentially qualifying for high dose consolidation and ASCT in first remission.

A prospective, randomized multicenter trial of the empirical addition of antifungal therapy for febrile neutropenic cancer patients: results of the Paul Ehrlich Society for Chemotherapy (PEG) Multicenter Trial II

BACKGROUND

The aim of the study was to compare the efficacy of empirical antifungals in combination with broad spectrum antibiotics with that of antibiotics alone in high risk febrile neutropenic cancer patients not responding to initial antibacterial therapy.

PATIENTS AND METHODS

A prospective, randomized controlled trial was conducted at 22 cancer centers in Germany. Patients with fever of unknown origin were randomized to either piperacillin (Pip) plus an aminoglycoside (AMG) (arm A) or a third generation cephalosporin (Ceph) plus AMG (arm B). Patients not responding after 4-6 days were randomized to either imipenem (Imi) plus glycopeptide (GLP) (arm C), or Imi/GLP plus amphotericin B deoxycholate (AmB) plus 5-flucytosine (5-FC) (arm D), or Imi/GLP plus fluconazole (Fluco) (arm E). A successful outcome was defined as resolution of fever.

RESULTS

In arm A, 192 of 373 patients (51.5%) responded as compared to 176 of 344 patients (51.2%) in arm B. The response rates of 155 patients randomized for further empirical treatment were 55.6%, 77.8% and 62.5% in arm C, D and E, respectively. The difference between arm C and D was of borderline statistical significance (p = 0.06) after correction for multiple testing.

CONCLUSION

In neutropenic cancer patients with persistent fever the combination of antibiotics with AmB/5-FC is superior to salvage antibacterial therapy alone. There is no difference in efficacy between Pip and third generation Ceph given as initial empirical therapy in combination with an AMG.

Proteomic identification of C/EBP-DBD multiprotein complex: JNK1 activates stem cell regulator C/EBPalpha by inhibiting its ubiquitination

Functional inactivation of transcription factors in hematopoietic stem cell development is involved in the pathogenesis of acute myeloid leukemia (AML). Stem cell regulator C/enhancer binding protein (EBP)alpha is among such transcription factors known to be inactive in AML. This is either due to mutations or inhibition by protein-protein interactions. Here, we applied a mass spectrometry-based proteomic approach to systematically identify putative co-activator proteins interacting with the DNA-binding domain (DBD) of C/EBP transcription factors. In our proteomic screen, we identified c-Jun N-terminal kinase (JNK) 1 among others such as PAK6, MADP-1, calmodulin-like skin proteins and ZNF45 as proteins interacting with DBD of C/EBPs from nuclear extract of myelomonocytic U937 cells. We show that kinase JNK1 physically interacts with DBD of C/EBPalpha in vitro and in vivo. Furthermore, we show that active JNK1 inhibits ubiquitination of C/EBPalpha possibly by phosphorylating in its DBD. Consequently, JNK1 prolongs C/EBPalpha protein half-life leading to its enhanced transactivation and DNA-binding capacity. In certain AML patients, however, the JNK1 mRNA expression and its kinase activity is decreased which suggests a possible reason for C/EBPalpha inactivation in AML. Thus, we report the first proteomic screen of C/EBP-interacting proteins, which identifies JNK1 as positive regulator of C/EBPalpha.

Identification of additional cytogenetic and molecular genetic abnormalities in acute myeloid leukaemia with t(8;21)/AML1-ETO

AML1-ETO collaborates with further genetic abnormalities to induce acute myeloid leukaemia (AML). We analysed 99 patients with an AML1-ETO rearrangement for additional aberrations. Frequent genetic abnormalities were, loss of a sex chromosome (56/99, 56.5%) and del(9)(q22) (24/99, 24.2%). The most frequent molecular aberrations were mutations of KITD816 (3/23, 13%) and NRAS (8/89, 8.9%). Further molecular abnormalities were FLT3 mutations (3/87, 3.4%), AML1 (1/26, 3.8%) and PU1 (1/14, 7.1%). MLL-PTD, KRAS and CEBPA mutations were not found. These clinical findings support the model that AML1-ETO collaborates with other genetic alterations, such as mutations of receptor tyrosine kinases, to induce AML.

Efficacy of radioimmunotherapy with (90Y) ibritumomab tiuxetan is superior as consolidation in relapsed or refractory mantle cell lymphoma: Results of two phase II trials of the European MCL Network and the PLRG

7533

Background: Radioimmunotherapy (RIT) has demonstrated high clinical efficacy in follicular lymphoma but varying results in mantle cell lymphoma (MCL). Methods: We performed a comparative analysis of two phase II studies with similar inclusion criteria to identify potential predictors of response. 32 patients with relapsed or refractory MCL, WHO performance status ≤2, appropriate hematopoesis (ANC > 1,500/mm3, platelets > 100,000/mm3) and adequate function of liver and kidneys were treated with RIT upfront (Arm A, n = 16) or as consolidation after initial cytoreduction (Arm B, n = 16). 28 patients (88%) had been previously treated with rituximab. Patients with >25% bone marrow involvement, known CNS lymphoma, HIV infection or other severe concurrent disease were excluded. Ibritumomab tiuxetan (Zevalin) was applied at a dose of 15 MBq 90Y/kg, whereas patients with reduced platelet counts (<150,000/mm3) received 11 MBq 90Y/kg. Results: The median age was 66.9 years (range 58–72) in Arm A and 63.1 years (range 45–79) in Arm B. The median number of prior regimens was 4 (range 2–6) in Arm A and 1 (1–5) in Arm B. RIT treatment was generally well tolerated with the most common toxicities being hematologic. Thrombocytopenia grade 3 and 4 was observed in 69% of patients, one patient died of hemorrhagic stroke. Granulocytopenia grade 4 occurred in 34% of patients, one patient developed a grade 4 infectious complication. Currently 22 patients are evaluable for response rate and duration of remission (DR). In Arm A a partial response (PR) was observed in 2 of 6 evaluable patients (33.3%) with a median DR of 3.9 months only. In Arm B chemoinduction achieved 2 complete responses (CR) and 14 PR. Following RIT seven of 14 PR patients (50%) converted to CR. Currently, 13 of 16 patients (81%) are still in remission. As expected the most important adverse risk factor was bulky disease before RIT with no responses seen in this patient population. Patients with less prior therapeutic lines (< 2) had significantly higher response rates. Conclusions: In future trials, RIT should be applied earlier in the treatment algorithm of MCL after a debulking strategy with combined immuno-chemotherapy.

[Table: see text]

Autologous or allogeneic stem cell transplantation versus chemotherapy in acute myeloid leukemia and subgroups: A multicenter trial by the German AML Cooperative Group

6556

Background: From the data available the role of autologous and allogeneic stem cell transplantation (auto/allo SCT) versus post-remission chemotherapy appears uncertain and is readdressed in the present trial. Methods: Pts were stratified for cytogenetic groups, de-novo/secondary AML, LDH, WBC, and were up-front randomized in one step to induction by HAM-HAM vs TAD-HAM, and to G-CSF priming vs. no G-CSF. These two randomizations did not result in different outcome. Pts were also upfront randomized to auto SCT vs monthly maintenance chemotherapy. Within the two randomized arms pts with histocompatible family donors underwent priority allo SCT. Results: Since 1999 840 pts 16–60 y of age entered the trial. 14%, 62%, 21%, and 3% of pts had favorable, intermediate, unfavorable and unknown karyotype, and 19% had secondary AML. 70% of pts went into complete remission (CR). The probability of overall survival (OS) at 3 years in the auto SCT and the maintenance arm is 43% vs 41% (p=0.52), the relapse-free survival (RFS) is 40% vs 40% (p=0.78), and the ongoing remission duration (RD) is 48% vs 46% (p=0.65). Among pts alive and in CR 73% did receive auto SCT or maintenance or allo SCT, similar to previous trials (NEJM 332:217,1995, Blood 90:2978,1997, Lancet 351:700,1998, NEJM 339:1649,1998). The outcome according to therapy given in the auto SCT arm and the maintenance arm shows ongoing RD of 44% vs 50% (p=0.31), RFS of 44% vs 48% (p=0.35), and OS of 53% vs 69% (p=0.005). 128 pts underwent allo SCT. In a matched pair analysis with concordance of pairs in karyotype, de-novo/secondary AML, induction chemotherapy, and RFS at the time of SCT, RD shows a superiority of allo SCT (p<0.001), while OS is similar between the two arms (p=0.65). No prognostic subgroup with a special benefit from auto or allo SCT can be identified so far. Conclusions: Among current alternative strategies only novel approaches in allo SCT reducing the high transplant related death rate may further improve the cure of pts with AML and subgroups.

No significant financial relationships to disclose.

Rituximab maintenance improves progression-free and overall survival rates after combined immuno-chemotherapy (R-FCM) in patients with relapsed follicular and mantle cell lymphoma: Final results of a prospective randomized trial of the German Low Grade Lymphoma Study Group (GLSG)

7502

Background: Rituximab (R) prolongs the progression-free survival (PFS) in patients with follicular lymphoma (FL) when given either simultaneously with or as maintenance after chemotherapy only. Methods: In the current study the impact of R maintenance after remission induction with an R-containing combined immuno-chemotherapy (R-FCM) was evaluated. Patients with advanced stage relapsed or refractory FL and mantle cell lymphoma (MCL) were eligible. The study design comprized 4 courses of chemotherapy with Fludarabine (25 mg/m2/d days 1–3), Cyclophosphamide (200 mg/m2/d days 1–3) and Mitoxantrone (8 mg/m2/d day 1) (FCM) ± Rituximab (375 mg/m2/d day 0). Patients entering a complete (CR) or partial remission (PR) underwent a second randomization for R maintenance (4 weekly doses (375 mg/m2/d) at three and nine months after end of induction) or observation only. Randomization was stratified for histology, prior therapies (up to 2 lines vs. >2), induction (±R), and response (CR vs. PR). After improved outcome of the R-FCM arm had been observed in the initial 147 randomized patients, all subsequent patients received a combined immuno-chemotherapy induction. Results: 176 of 195 randomized cases are evaluable, 138 of whom had received an R-containing induction. In these patients (as well as the total group) the median PFS after end of induction has not been reached in the R-maintenance arm in contrast to 17 months in patients with no further treatment (p = 0.001). This improvement was seen both in FL (n = 81; p = 0,035) and MCL (n = 47; p = 0,049). More importantly, overall survival rate was also improved after R maintenance with borderline significance (3 y rate 82% vs. 55%; p = 0,056). No major sided effects of R maintenance have been observed and the rate of serious infections was similar in both study arms (p = 0.72). Conclusions: The final analysis of this study confirms that R maintenance after combined immuno-chemotherapy (R-FCM) is highly effective and improves the progression-free survival—with a strong trend towards improved overall survival—of patients with relapsed FL and MCL.

[Table: see text]