Circulating endothelial cell count: a reliable marker of endothelial damage in patients undergoing hematopoietic stem cell transplantation

The physio-pathologic interrelationships between endothelium and GvHD have been better elucidated and have led to definition of the entity 'endothelial GvHD' as an essential early phase prior to the clinical presentation of acute GvHD. Using the CellSearch system, we analyzed circulating endothelial cells (CEC) in 90 allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients at the following time-points: T1 (pre-conditioning), T2 (pre-transplant), T3 (engraftment), T4 (onset of GvHD) and T5 (1 week after steroid treatment). Although CEC changes in allo-HSCT represent a dynamic phenomenon influenced by many variables (that is, conditioning, immunosuppressive treatments, engraftment syndrome and infections), we showed that CEC peaks were constantly seen at onset of acute GvHD and invariably returned to pre-transplant values after treatment response. Since we showed that CEC changes during allo-HSCT has rapid kinetics that may be easily missed if blood samples are drawn at pre-fixed time-points, we rather suggest an 'on demand' evaluation of CEC counts right at onset of GvHD clinical symptoms to possibly help differentiate GvHD from other non-endothelial complications. We confirm that CEC changes are a suitable biomarker to monitor endothelial damage in patients undergoing allo-transplantation and hold the potential to become a useful tool to support GvHD diagnosis (ClinicalTrials.gov NCT02064972).

Managing chronic myeloid leukaemia in the elderly with intermittent imatinib treatment

The aim of this study was to investigate the effects of a non-standard, intermittent imatinib treatment in elderly patients with Philadelphia-positive chronic myeloid leukaemia and to answer the question on which dose should be used once a stable optimal response has been achieved. Seventy-six patients aged ⩾65 years in optimal and stable response with ⩾2 years of standard imatinib treatment were enrolled in a study testing a regimen of intermittent imatinib (INTERIM; 1-month on and 1-month off). With a minimum follow-up of 6 years, 16/76 patients (21%) have lost complete cytogenetic response (CCyR) and major molecular response (MMR), and 16 patients (21%) have lost MMR only. All these patients were given imatinib again, the same dose, on the standard schedule and achieved again CCyR and MMR or an even deeper molecular response. The probability of remaining on INTERIM at 6 years was 48% (95% confidence interval 35-59%). Nine patients died in remission. No progressions were recorded. Side effects of continuous treatment were reduced by 50%. In optimal and stable responders, a policy of intermittent imatinib treatment is feasible, is successful in about 50% of patients and is safe, as all the patients who relapsed could be brought back to optimal response.

Myeloid Sarcoma: The Clinician's Point of View

Myeloid Sarcoma may occur in patients with an acute or chronic myeloproliferative disorder as well as de novo, with no apparent sign or symptom of concomitant haematological disease. The patients are preferentially young male and the site of disease localization may vary from central nervous system to pleura and thorax, with a common involvement of the reticuloendothelial system. The disease often shows chromosomal rearrangements, involving chromosomes 7, 8 and 3 and sometimes a complex karyotype (more than 3 abnormalities) is detected at diagnosis. The prognosis of this disease is dismal and only high-dose chemotherapy with autologous or allogeneic stem cells transplantation (auto or allo-SCT) may be potentially curative. In the absence of definitive elements that can define the prognosis of extra-medullary localization of “standard risk” AML, Clinicians should pursue the collection of data from different Centres and design of homogeneous treatment strategies, that could integrate standard chemotherapy with specific approaches, such as radiotherapy, transplant procedures or, in selected cases (such as those displaying molecular abnormalities involving protein tyrosine-kinases), molecularly targeted therapies.

Imatinib mesylate in the treatment of newly diagnosed or refractory/resistant c-KIT positive acute myeloid leukemia. Results of an italian multicentric phase II study

We evaluated safety and efficacy of imatinib (600 mg) in 36 c-KIT+ acute myeloid leukemia patients not amenable to receive conventional chemotherapy. No patient achieved complete remission. One patient obtained a hematologic improvement (platelet increase with transfusion independence). Median overall survival was 3 months (0.5-44+). Non-hematologic toxicity was overall mild.

Consolidation therapy for adult acute myeloid leukemia: a systematic analysis according to evidence based medicine

Post-remission therapy in acute myeloid leukemia (AML) remains problematic. It has been demonstrated that younger patients can maintain longer complete remissions (CR) with aggressive post-remission therapies after induction treatment: allogeneic (allo), autologous (auto) stem cell transplantation (SCT), or intensive chemotherapy (ICC). The purpose of our study was to identify the most important randomized and controlled studies comparing these three therapeutic options, in order to draw conclusions and possible suggestions for post-remission therapy of AML, according to the evidence based medicine (EBM) rules. We performed an exhaustive analysis of the literature, searching either in electronic databases or among the references of the identified articles (hand searching). We searched the MEDLINE computer database for reports from 1985 through January 2005 and selected for analysis the clinical trials conducted over adults affected by newly diagnosed AML aged less than 65 years. The study design had to satisfy strict methodological criteria and must consider global mortality and/or disease free survival as primary outcomes. Overall we found 7750 papers; by using the limits "clinical trial" as publication type, "all adults 19+ years", we were able to select 344 papers. Among these, a further selection was made, based on two main clinical queries: 1) is auto-SCT superior to ICC/no other therapy in improving DFS and/or OS in adult AML patients in first CR? 2) is allo-SCT superior to auto-SCT/other therapeutic options in improving DFS and/or OS in adult AML patients in first CR? Concerning the first query, a possible advantage of auto-SCT over ICC was not clearly supported by data from clinical trials; there is no evidence that auto-SCT is superior in terms of OS to chemotherapy. Nevertheless, the reported TRM has been significantly reduced within the past years. Thus, the percentage of patients suitable for auto-SCT in CR has increased. Moreover, the scarce data concerning the comparison between auto-SCT and chemotherapy in different subsets of patients are unable to suggest a differentiated approach in patients with high-risk, standard-risk or low-risk AML. Data from the literature show that patients with unfavorable risk disease are more often addressed to allo-SCT and patients with low-risk disease receive more often intensive consolidation chemotherapy. Concerning the second query, interpretation of data from the main prospective studies about the role of allo-SCT in previously untreated AML is not easy. The first problem is the lack of real randomized clinical trials; in fact, according to the reported studies, AML patients generally receive allo-SCT on the basis of donor availability (the so called "genetic randomization"). The second problem is the frequent absence of intention to treat analysis. Despite methodological limitations, it was possible to compare allo-SCT with auto-SCT on a donor versus no-donor analysis and within risk groups. No overall benefit of allo-grafting on survival was demonstrated by any trial. In conclusion, the EBM approach highlighted the limitations observed in the published studies concerning consolidation therapy in AML; some suggestions, emerging from non-randomized, as well as randomized studies, are adequate, but not conclusive. This point, coupled with the intrinsic complexity to study AML biological heterogeneity, is probably a major obstacle to draw conclusive evidences for consolidation therapy in AML. These observations should plan to address new randomized studies on AML therapy; however, due to the emergence of genetic subgroups and new drugs targeting specific abnormalities, these trials should probably be designed directly focusing on the single entities. In this way, the cure of AML could eventually become the cure of each specific AML subset with its peculiar biological, molecular and prognostic features.

Clinical efficacy and antiangiogenic activity of thalidomide in myelofibrosis with myeloid metaplasia. A pilot study

Increased neoangiogenesis has been reported in myelofibrosis with myeloid metaplasia (MMM). Thus we studied the effects of thalidomide, an antiangiogenic drug, in 12 MMM patients. Before treatment, all the cases showed a significantly increased micro-vessel density (MVD); in all eight tested cases bFGF and VEGF plasma levels were higher than controls. All patients presented disease progression in the last 3 months with standard therapy, regarding splenomegaly, anemia and/or thrombocytopenia and/or hyperleukocytosis. Thalidomide was administered at daily doses increasing from 100 to 600 mg. Eleven out of 12 patients were evaluable. No progression of disease was seen during the treatment in any case. In particular, spleen size decreased in 7/11 patients, anemia improved in 3/4 (two are now transfusion independent), thrombocytopenia in 2/2 and hyperleukocytosis in 2/5 patients. Side-effects were frequent, although not severe. After treatment, VEGF and bFGF plasma levels varied widely and in selected cases decreased. In particular, VEGF and/or bFGF decreased in 4/5 responders and in 1/3 non-responders. Moreover, MVD significantly decreased in all the responders evaluated after treatment. We conclude that thalidomide is a feasible therapy in MMM patients and looks promising at least to control the growth progression of disease.

Pulsed ATRA as single therapy restores long-term remission in PML-RARalpha-positive acute promyelocytic leukemia patients: real time quantification of minimal residual disease. A pilot study

All-trans retinoic acid (ATRA), alone or combined with chemotherapy (CHT) is widely used to induce complete remission (CR) in newly diagnosed acute promyelocytic leukemia (APL). If used alone, ATRA results in a substantial proportion of CRs. To maintain remission further, ATRA is commonly used with cycles of CHT, frequently followed by autologous (auto) or allogeneic (allo) stem cell transplantation (SCT), as early reports have shown that the continuous administration of ATRA as single therapy almost invariably leads to relapse in a short period of time (months). Pharmacokinetic studies have shown that induced resistance to ATRA is frequently suppressed by the intermittent use of the drug. In this study we applied an intermittent therapeutic protocol with ATRA in five APL patients who were either molecularly refractory after combined ATRA/CHT treatment, or relapsed, or at diagnosis, but not eligible for the combination treatment because of previous toxicity. They were treated with ATRA (45 mg/m2/day) for 21 days. The treatment was then prolonged continuously for 1 week every 2 weeks. Molecular analysis was performed by qualitative and quantitative reverse transcription-polymerase chain reaction (RT-PCR). All patients obtained molecular remission, as assessed by qualitative RT-PCR, in a median of 3 months (range 1-15). Quantitative RT-PCR confirmed these data, showing a progressive reduction (1 or 2 logs) to a 'negligible quantity' of PML-RARalpha fusion transcript (ratio PML-RARalpha/ABL x 10(4) ABL < 10(-1)) in all but one patient treated with pulsed ATRA therapy. These data were confirmed with qualitative and quantitative RT-PCR. After a median follow-up of 17 months from the start of ATRA therapy, 4/5 patients (80%) are in continuous complete molecular remission. To our knowledge, this is the first clinical observation that intermittent ATRA therapy (without chemotherapy) is effective not only in inducing but also in maintaining long-term molecular remission in APL patients. This approach could therefore be effective, if confirmed in larger series, in relapsed/refractory patients unsuitable for high-dose therapy and SCT; it may be proposed as induction therapy for selected older APL patients if considered not to be eligible for combined ATRA/CHT due to inadequate performance status or concurrent disease.

Combined action of PSC 833 (Valspodar), a novel MDR reversing agent, with mitoxantrone, etoposide and cytarabine in poor-prognosis acute myeloid leukemia

PSC 833 (Valspodar) can reverse multidrug resistance (MDR) in patients with hematologic malignancies, but alters the pharmacokinetics of concomitant anticancer agents. A phase I, dose-finding study was initiated to define a safe and effective regimen of mitoxantrone, etoposide, and cytarabine (MEC) when administered with PSC 833 to patients with early relapsed or refractory acute myeloid leukemia (AML). Poor-prognosis AML patients refractory to first-line induction therapy or relapsing within 9 months of attaining complete remission (CR) were treated with cytarabine (1.0 g/m2/day), etoposide (30 mg/m2/day), and mitoxantrone at a dose of either 3.0 mg/m2/day (cohort 1) or 4.5 mg/m2/day (cohorts 2 and 3) for 6 days plus continuous-infusion PSC 833 (10 mg/kg/24 h with a 2.0 mg/kg loading dose) for 6 or 7 days each 21-day cycle. Patients achieving CR were given a 4-day MEC plus PSC 833 consolidation cycle. Twenty-three patients were enrolled (eight with primary refractory AML and 15 in relapse). Dose-limiting toxicity occurred in one of six patients in cohort 2 (grade 4 mucositis) and one of seven patients in cohort 3 (grade 4 hyperbilirubinemia). The maximum tolerated dose of mitoxantrone was defined as 4.5 mg/m2/day. Clinically significant grade 4 hyperbilirubinemia, possibly related to PSC 833, occurred in four patients. Hematologic toxicities were as expected in this patient population, but were not dose limiting. Mild to moderate cerebellar ataxia and paresthesia occurred in six (26%) and five (22%) patients, respectively, but were not dose limiting. Overall, six of 23 (26%) patients achieved CR, including five patients with demonstrated P-glycoprotein expression and/or function. The median overall survival was 4 months. All six patients with a CR were alive and four (17%) patients were disease free at 12 months. Blood levels of PSC 833 were well above the target level of 1000 ng/ml, a concentration that is known to reverse MDR in vitro. PSC 833 reduced the clearance of etoposide by approximately two-fold. No correlation was observed between the mitoxantrone or etoposide area under the curve and response. In conclusion, the MEC plus PSC 833 tested regimen was well tolerated and the 26% CR rate warrants further testing of this regimen in a randomized, phase III trial.

The prognostic value of cytogenetics is reinforced by the kind of induction/consolidation therapy in influencing the outcome of acute myeloid leukemia--analysis of 848 patients

We studied the impact of cytogenetics and kind of induction/consolidation therapy on 848 adult acute myeloid leukemia (AML) patients (age 15-83). The patients received three types of induction/consolidation regimen: standard (daunorubicin and cytosine arabinoside (3/7); two cycles); intensive (idarubicin, cytosine arabinoside and etoposide (ICE), plus mitoxantrone and intermediate-dose Ara-C (NOVIA)); and low-dose (low-dose cytosine arabinoside). CR patients under 60 years of age, if an HLA-identical donor was available received allogeneic stem cell transplantation (allo-SCT); otherwise, as part of the program, they underwent autologous (auto)-SCT. CR rates significantly associated with 'favorable' (inv(16), t(8;21)), 'intermediate' ('no abnormality', abn(11q23), +8, del(7q)) and 'unfavorable' (del (5q), -7, abn(3)(q21q26), t(6;9), 'complex' (more than three unrelated cytogenetic abnormalities)) karyotypes (88% vs 65% vs 36%, respectively; P = 0.0001). These trends were confirmed in all age groups. On therapeutic grounds, intensive induction did not determine significant increases of CR rates in any of the considered groups, with respect to standard induction. Low-dose induction was associated with significantly lower CR rates. Considering disease-free survival (DFS), multivariate analysis of the factors examined (including karyotype grouping) showed that only age > 60 years significantly affected outcome. However, in cases where intensive induction was adopted, 'favorable' karyotype was significantly related to longer DFS (P = 0.04). This was mainly due to the favorable outcome of t(8;21) patients treated with intensive induction. Patients receiving allo-SCT had significantly longer DFS (P = 0.005); in particular, allo-SCT significantly improved DFS in the 'favorable' and 'intermediate' groups (P = 0.04 and P = 0.048, respectively). In conclusion our study could provide some guidelines for AML therapy: (1) patients in the 'favorable' karyotype group seem to have a longer DFS when treated with an intensive induction/consolidation regimen, adopted before auto-SCT instead of standard induction; this underlines the importance of reinforcement of chemotherapy, not necessarily based on repeated high-dose AraC cycles. Allo-SCT, independently of induction/consolidation therapy, should be considered an alternative treatment; (2) patients in the 'intermediate' karyotype group should receive allo-SCT; (3) patients in the 'unfavorable' karyotype group should be treated using investigational chemotherapy, considering that even allo-SCT cannot provide a significantly longer DFS, but only a trend to a better prognosis.

Double reinforcement with fludarabine/high-dose cytarabine enhances the impact of autologous stem cell transplantation in acute myeloid leukemia patients

Reinforced chemotherapy based on a double high-dose consolidation regimen could be a different way to enhance in vivo purging prior to autologous stem cell transplantation (auto-SCT) in acute myeloid leukemia (AML). We investigated the impact on outcome of auto-SCT after two different strategies of early intensification performed after an identical induction regimen in adult patients with AML. Between January 1993 and December 1998, 140 consecutive AML patients were enrolled in a program consisting of an identical anthracycline-based induction (ICE) and two different consolidation regimens: one cycle, cytarabine-based (single-NOVIA: 91 patients); two cycles, fludarabine-based (double-FLAN: 49 patients). Seventy out of 91 patients received single-NOVIA consolidation: 60 underwent a transplantation procedure (allogeneic bone marrow transplantation (allo-BMT):16 patients; auto-SCT: 44). Thirty-five out of 49 patients received double-FLAN consolidation: 31 underwent a transplantation procedure (allo-BMT: 10; auto-SCT: 21). The double consolidation regimen was well-tolerated with only minor side-effects. Median follow-up observation time for surviving patients was 38 months (range, 17-71) for the double-FLAN consolidation group and 70 months (range: 48-93) for the single-NOVIA consolidation group. Among the patients who received auto-SCT, the double consolidation strategy produced a superior disease-free survival curve at 36 months (78.6% (95%CI: 59.4-97.8) vs 47.7% (95%CI: 33-62.4)) compared with the single-NOVIA group. This difference was confirmed when the patients were analyzed for intention to treat (P = 0.04). In addition, the double-FLAN consolidation group showed a superior overall survival and lower relapse rate (P = 0.02). We conclude that the double-FLAN reinforcement strategy is safe and enhances the clinical impact of auto-SCT for AML patients in first complete remission. It may provide specific clinical benefit for patients undergoing auto-SCT.

Second chronic phase before transplantation is crucial for improving survival of blastic phase chronic myeloid leukaemia

Because successful outcome after transplantation seems to depend in acute myeloid leukaemia (AML) and in chronic phase chronic myeloid leukaemia (CML) on disease status at the time of transplantation, we investigated whether FLAN (fludarabine, cytosine arabinoside, mitoxantrone) induction before allogeneic stem cell transplantation (allo-SCT) may be useful in blastic phase (BP)-CML. Twenty patients with BP-CML were studied: 10 patients received FLAN induction chemotherapy before proceeding to early allo-SCT, whereas 10 patients were submitted to bone marrow transplantation (BMT) without remission induction. Eight out of 10 (80%) patients achieved second chronic phase after one course of therapy with FLAN and seven patients (six in second chronic phase and one with partial response) were then submitted to allo-SCT. Of the six patients transplanted in the second chronic phase, all achieved molecular remission, four are still in second chronic phase, with intervals ranging from 10 to 54 months, whereas one patient died from infection having relapsed 14 months after SCT and one died of transplant-related complications in the second chronic phase. Mean durations of second chronic phase and survival after allo-SCT were both significantly longer than in the group of 10 BP-CML patients submitted to allo-SCT without FLAN remission induction treatment [22.4 (range 1-61) vs. 3.5 months (range 1-10) with FLAN and 22.7 (range 2-61) vs. 6.4 (range 1-16) months without FLAN]. We conclude that FLAN induction therapy followed by early allo-SCT appears to be effective in the treatment of BP-CML and could provide a curative possibility for BP-CML patients.

Chemotherapy of secondary leukemias

Chemotherapy of secondary leukemias is currently still considered to be associated with poor results. However, recent data suggest that the response to remission induction may substantially differ according to the previous medical history of the patients. Therapy related leukemia, arising following exposure to previous alkylating agents or radiotherapy, is often associated with chromosomal abnormalities involving chromosomes 5 and 7 and has a particularly bad response, whereas AML after exposure to epipodophyllotoxins or topoisomerase-II active agents could have a somewhat better response. Acute promyelocytic leukemia secondary to treatment of a primary malignant neoplasm seems to be associated with a better response if compared to other cytotypes of AML or to AML arising after transformation of myelodysplasia. However, here the literature data are not in full agreement, as different kinds of approaches have been applied. In fact, even if the problems encountered in treating patients with secondary leukemia are similar to those seen in patients with AML arising in a background of myelodysplasia (resistant disease and prolonged cytopenia after treatment), there are data suggesting that the use of high dose ara-C, with or without fludarabine, can circumvent resistance in a small but significant number of cases. One of the unsolved problems which still remains is how to consolidate the CR induced with high dose ara-C or with cycles based on anthracycline derivatives. In addition, another question relates to the categories of patients in whom chemotherapy may change the expected survival. Intensive post-remission chemotherapy, with or without autologous HSCT, may constitute an appropriate alternative for patients lacking a suitable sibling donor or for older patients who are in remission after chemotherapy and also able to tolerate other cycles of intensive chemotherapy. In this respect, the specific cytogenetic abnormality involved should be considered the most important prognostic factor for response and disease free survival; patients with abnormalities of chromosome 5 and 7 have a particularly low possibility of response and duration of CR. Furthermore, it is still debatable whether patients, especially the elderly, with these characteristics should go through a series of conventional treatments or just receive supportive treatment. On the other hand, patients with better prognostic factors should be entitled to further intensive treatments, taking into account possible delayed recovery and/or possible less successful collection of peripheral or marrow stem cells.