The expression of cytotoxic T-lymphocyte antigen–4 (CTLA-4) molecule in human normal and neoplastic hematopoietic cells, both on the cell membrane and in the intracellular compartment, was evaluated. ...Flow cytometric analysis carried out with a panel of anti–CTLA-4 human single-chain fragment of variable domain (scFv) antibodies revealed that CTLA-4 was not expressed on the surface, whereas it was highly expressed within the cytoplasm, in freshly isolated peripheral blood mononuclear cells (PBMCs), T cells, B cells, CD34+ stem cells, and granulocytes. Various treatments with agents able to specifically activate each cell type induced CTLA-4 expression on the surface of these cells. Similarly, increased CTLA-4 expression was observed in different hematopoietic cell lines although they also expressed surface CTLA-4, at different degrees of intensity, before activation. Surprisingly, CTLA-4 RNA transcripts were detectable in such cell lines only after nested polymerase chain reaction (PCR) specific for CTLA-4 extracellular domain, suggesting a very fast CTLA-4 RNA processing accompanied by prolonged CTLA-4 protein accumulation. We further demonstrated surface expression of CTLA-4 in a variety of acute and chronic myeloid leukemias (AMLs and CMLs) and B- and T-lymphoid leukemias, either adult or pediatric. CTLA-4 was expressed in 25% to 85% of AMLs and CMLs depending on the leukemia subtype and the epitope analyzed, whereas in acute B- and T-leukemias CTLA-4 expression was mainly cytoplasmic. Chronic B leukemias appeared to express CTLA-4, both on the surface and in cytoplasm, whereas few cases tested of chronic T leukemias were negative. Two anti–CTLA-4 immunotoxins (scFvs-saporin) induced in vitro apoptosis of neoplastic cells from a representative AML, suggesting a novel immunotherapeutic approach to AML based on CTLA-4 targeting.
Abstract This retrospective study of the thrombocythemia Italian registry (RIT) documented that 71 (30.6%) out of 232 ET patients experienced 88 cardiovascular adverse events (CV-AEs) during ...anagrelide treatment (522 pt-y). The rate of CV-AEs was: 24.1% for palpitations, 4.3% for angina, 3.5% for arterial hypertension, 3.0% for congestive heart failure, 1.8% for arrhythmia, 0.9% for AMI, 0.4% for pericardial effusion. CV-AEs led to treatment discontinuation in nine (3.9%) patients, while in the remaining cases they were managed by pharmacological intervention and/or patient life style improvement. CV-AEs had no relationship with patient characteristics (including older age). A significant relationship was found only with a higher anagrelide induction dose. In the absence of any agreed protocol, a cardiovascular instrumental evaluation (CV-IE) was performed in 102 (44%) patients before commencement of anagrelide (with higher rate after the anagrelide/Xagrid EMA approval of 2004), and in 84 (36%) patients during treatment. Patients with and without CV-IEs, who resulted completely balanced for all their characteristics, did not significantly differ in the occurrence of CV-AEs. In conclusion, this study on ET patients treated with anagrelide shows that CV-AEs, equally distributed in younger and older subjects, were mostly mild and easily manageable, allowing safe treatment continuation in the majority of cases. Moreover, routinely performing a CV-IE did not appear to anticipate the occurrence of CV-AEs.
Imatinib induces complete cytogenetic response (CCyR) in up to 80% of chronic myeloid leukemia (CML) patients (pts) and major molecular response (MMR) in 33-60% of them. These patients enjoy life ...expectancy similar to general population. However even undetectable BCR-ABL may not equate to eradication of the disease because the sensitivity of the standard diagnostic method, the Q-RT-PCR, is limited. A new diagnostic method, the digital-PCR (dPCR), able to detect 1 BCR-ABL+ cell out of 107 cells, corresponding to a 100 times increased sensitivity as compared to conventional Q-RT-PCR, was developed (Goh HG et al., Leuk Lymphoma 52(5): 896-904. 2011). Therefore dPCR, assessing with more sensitivity the presence of minimal residual disease, could potentially identify pts in whom CML is eradicated. The Imatinib Suspension And Validation (ISAV) study is aimed at assessing the capability of dPCR to predict relapses after imatinib discontinuation in CML pts with negative Q-RT-PCR results.
This study involves 15 sites, 10 in Italy and 5 in each of the following countries: Germany, Spain, The Netherlands, Canada and Israel. In this study CML patients (Chronic Phase or Accelerated Phase) under imatinib therapy since more than 2 years and in complete molecular remission (CMR) were eligible. Patients had to be in CMR for at least 18 months, with a minimum of 3 Q-RT-PCR performed in their own centers. After signing the informed consent, pts were tested for dPCR and discontinued imatinib therapy. They are being monitored by standard Q-RT-PCR for 36 months to assess the maintenance of the molecular remission. At the end of this period, a peripheral blood sample for dPCR analysis will be obtained from those pts who will still have undetectable BCR-ABL transcripts by Q-RT-PCR, to verify CML eradication. The loss of molecular remission is defined as two consecutive positive Q-RT-PCR tests with at least one BCR-ABL/ABL value above 0.1%. Patients losing molecular remission resumed imatinib treatment at the same dosage used before interruption. Patients' quality of life during imatinib discontinuation/resumption is being evaluated trough the EORTC – C30 Quality of Life questionnaire.
The enrollment in the ISAV study began in November 2011 and ended in June 2013. The study enrolled 112 pts: Italy 69.6%, Berlin 21.4%, Montreal 5.3%, Zaragoza 2.6% and Tel Hashomer 0.9%. Sixty-one percent of the pts were male and 38% were aged 65 or older; median duration of imatinib treatment is 102 months with median duration of CMR of 32 months before imatinib discontinuation. To date, the median follow-up (FUP) time is 4.6 months 95% CI: 4.1-5.8 and 92 pts out of 112 (82%) had at least one Q-RT-PCR performed after imatinib discontinuation. The following analysis is restricted to 48 pts with a minimum of 6 months of FUP. Of these 48 pts, 20 remained Q-RT-PCR negative (42%, 95% CI:29-56%, median duration of negativity after imatinib discontinuation: 10.3 months). Nineteen pts (40%, 95% CI:27-53%) relapsed and resumed imatinib. All relapses occurred in the first 10 months and all but 3 of them in the first 6 months. A loss of CCyR happened in 5 pts out of 19 (26%): 1 pt regained CCyR after 3 months of re-treatment and is now in CMR, 1 pt died shortly after the diagnosis of relapse because of lung adenocarcinoma and 3 pts are now being monitored after imatinib resumption. No case of progression of CML was observed. After the resumption of imatinib the median time to either MMR or CMR, whichever came first, was 2.1 95% CI: 0.9-5.8 months. Finally, nine pts (18%, 95% CI:10-31%) regained Q-RT-PCR positivity but never lost MMR. The median time to Q-RT-PCR positivity in this group of pts was 2.92 months (range 1-5 months), and the range of duration of Q-RT-PCR positivity (below 0.1%) is between 2 and 14 months. No significant correlation between relapse and previous duration of imatinib treatment, time to CCyR or duration of CMR was present. Patients previously treated with interferon showed a trend toward lower risk of relapse which is not significant so far. Finally, 19% of pts complained of musculoskeletal/articular pain after imatinib discontinuation.
After 21 months from the beginning of the study with a median follow-up of 4.6 months, 40% of pts relapsed; the majority of relapses happened in the first 6 months after imatinib discontinuation. The correlation of dPCR results with clinical outcomes will be presented at the meeting.
le Coutre:Novartis: Honoraria; BMS: Honoraria; Pfizer: Honoraria; Novartis: Research Funding. Gozzini:Novartis: Consultancy; Bristol Myers Squibb: Consultancy.
Abstract 3263
Poster Board III-1▪▪This icon denotes an abstract that is clinically relevant.
In the last years, tyrosine kinase inhibitors, as imatinib mesylate (Gleevec, Novartis, formerly known as ...STI571) are confirmed the first line treatment of Chronic Myelogenous Leukemia (CML) and of a rare form of gastroenteric stromal cancer. In the latter case, the response to the drug in vivo is mainly due to immunocompetent cells, able to produce cytokines with antineoplastic activity. In this study, 30 CML patients, prior and during treatment with imatinib mesylate, underwent bone marrow (BM) aspirates every 6 months to assess morphologic phenotypic, cytogenetic and biomolecular patterns, compared to peripheral blood. Plasma from BM and peripheral blood (PB) was also tested for cytokines able to induce B lymphocytes differentiation, such as interleukin IL-4, IL-6 (whose receptor is CD126), IL-3, IL-10 or IL-21 (by ELISPOT and real time polymerase chain reaction) togheter with the expression of MCP-1, SDF-1, BMP4, BMP7, IP-10 and IL-8 . We report that in 24 out of 30 CML patients a significant increase in the percentage of BM lymphoplasmocytoid cells was observed upon treatment with imatinib mesylate, with >10% (range 8–12%) of CD20+CD126+cells. Among this population, two third of cells coexpressed IgM and one third was IgD+, whereas a lower fraction of IgM+CD126+CD20- (3–4%) or IgD+CD126+CD20- (2–3%) cells was detected , too. In all these patients SDF1 increased in the BM plasma after imatinib (from 10–80pg/ml to 150–450pg/ml) and its receptor CXCR4 was up-regulated on CD20+CD126+cells. In some cases also IP-10 and its receptor CXCR3 were up-.regulated. No significant increase in transcription and secretion of IL-3, IL-4, IL-6, IL-10, IL-21, IL-8 or MCP1 were observed. The lasting 6 patients had<5% of CD20 +CD126+ lymphocytes (range2-4%), 2/3 coexpressing IgM and 1/3 coexpressing IgD. Every patients with increased number of CD126+ B lymphocytes achieved hematologic remission, most of them complete cytogenetic and molecular remission. On the other hand, among the patients with low or undetectable CD20+CD126+cells, only 4 obtained hemathological remission and none of them stable cytogenetyc and molecular remission. In 4 patients relapsed after six months of treatment, the fraction of BM CD20+CD126+ lymphocytes decreased from 11% and 8% to 7 and 5%, respectively, with undetectable IgM+ CD126+CD20- or IgD+ CD126+CD20- cells. The increased production of SDF-1,(partially mediated by production of BMP4 and BMP7), following imatinib administration might increase BM lymphoplasmocitoid cells, thanks to the double proliferative/chemotactic effect of the cytokine on B cells, with redistribution and in situ differentiation of CD20+ CD126+ lymphocytes. These findings shed some light on the possibility that, even in CML,immunological events may play a role in disease control ; moreover they could be useful in monitoring disease outcome .
No relevant conflicts of interest to declare.
Abstract For more than 20 years erythropoietin (rHEPO) has largely been used to treat anemia in myelodysplastic syndromes (MDS). Early clinical trials showed erythroid responses in no more than ...15–25% of patients. In the last decade, a better selection of MDS patients suitable for a therapeutic challenge with rHEPO, alone or in combination with G-CSF, allowed for an increased response-rate, averaging around 40%. More recently, an even higher percentage of responses have been obtained using higher-doses of rHEPO (up to 80,000 IU/weekly) in lower-risk MDS patients. This treatment however, especially at such high doses, is costly and not easily affordable for prolonged periods. The aim of this study was to verify if the use of “standard” doses of rHEPO could induce a satisfying response-rate with a less expensive treatment schedule in IPSS-defined “lower-risk” MDS anemic patients. From January 2005 to December 2009 a total of 55 consecutive anemic (Hb ≤ 10 g/dL) patients (29 males, 26 females, median age 78 years) with low-intermediate-1 risk MDS were treated after informed consent with rHEPO (40,000 IU once a week subcutaneously) for at least 3 months; at the end of this period, erythroid response was assessed, and responders were allowed to continue the treatment indefinitely, whereas non-responders were considered “off study”. Both efficacy and safety of the treatment were recorded and evaluated. After 3 months of treatment, 36 out of 55 (65.5%) patients achieved an erythroid response to rHEPO according to IWG 2006 criteria. Higher response-rates to rHEPO were related with both lower IPSS and particularly WPSS scores. Treatment was safe, and only 1 patient had to discontinue the treatment because of unmanageable side-effects. Among the 36 responders, 28 (77%) maintained the response after a median follow-up of 46 months. Our data indicate that standard doses of rHEPO are at least as effective as higher-doses for correcting anemia in lower-risk MDS patients; in this clinical scenario, this schedule allows for a consistent reduction of costs without precluding the achievement of a durable erythroid response.
Acquired resistance to imatinib in the advanced phase of chronic myeloid leukemia (CML) has been associated with mutations in the kinase domain (KD) of BCR-ABL. On the contrary, the prognostic ...implication of KD mutations in early chronic phase (CP) patients at diagnosis before imatinib-based therapy has not yet been established. We have reviewed the status of mutations in 43 patients with early CP-CML on the samples collected at diagnosis. Mutations were identified by direct sequencing (DS) with BidDye Terminator v 1.1. cycle sequencing kit and analyzed with a 3130 ABI capillary electrophoresis system. Eight out 13 (61.5%) high Sokal risk patients showed the following mutations: Y253C, S265R, E255K, F359Y, N374S, E255V, E255V, E255V. Three patients progressed during imatinib and second-line inhibitors and died of blastic phase CML at 23, 33, and 69 months. Another patient with intermediate Sokal risk showed D363G mutation at diagnosis, progressed under imatinib, was allografted and he is now alive in major molecular remission (MMR). No low-risk patient carried KD mutation at diagnosis. In conclusion, KD mutations conferring high-level imatinib resistance are present in patients with de novo CML and in some of them lead to disease progression.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Summary
We report the final results of a prospective multi‐centre trial testing the combination of chemotherapy (fludarabine, cytosine arabinoside and idarubicin; FLAI) followed by low‐dose ...gemtuzumab ozogamicin (GO), for induction treatment of patients with CD33+ acute myeloid leukaemia (AML). Forty‐six consecutive patients were treated: the median age was 66 (range: 60–80) years; the karyotype was unfavourable in 12 patients (26%), intermediate in 33 (71%) and favourable in one (3%). Eleven major infectious complications were recorded. There was one early death. Of the 45 evaluable patients, 24 achieved a complete response (CR; 52%), 66% and 33% in good‐intermediate/poor karyotype patients. Median duration of CR was 7 (3–24) months. The cumulative incidence of relapse was 37% with an actuarial 2‐year survival of 54%. These results were compared with 47 patients matched for age and karyotype who received FLAI, without GO. The proportion of patients achieving CR was comparable. However, patients with de novo AML receiving GO (n = 26) had a significantly lower risk of relapse at 2 years when compared with patients not receiving GO (n = 35) (40% vs. 80%, P = 0·01) and significantly better overall 2‐year survival (40% vs. 14%P = 0·02). Patients with secondary AML had comparable outcome whether or not they received GO. This GO‐based induction chemotherapy has a good toxicity profile. In keeping with a recent prospective randomised trial, the addition of GO seems to prolong disease‐free survival.
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BACKGROUND: The INTERIM study (ClinicalTrials.gov NCT 00858806) showed that in elderly (> 65 years) Ph+ CML patients selected for a stable complete cytogenetic response (CCgR) lasting > 2 years, ...the policy of intermittent imatinib treatment (one month on/one month off) may affect the markers of residual disease (CCgR and major molecular response, MMR or MR3.0), but not the clinical outcomes (overall survival and progression-free survival) (Russo D et al, Blood 2013; 121(26):5138-44).
AIMS: To update the results of the INTERIM Study, with a follow up ≥ 5 years.
METHODS: After 4 years of follow up, patients continouing INTERIM treatment were monitored with peripheral blood RT-Q-PCR every 3 months according to the ELN-2013 guidelines.
RESULTS: At 48thmonth, out of 76 patients enrolled in the INTERIM study, 13 (17%) had lost CCgR and MMR, 14 (18%) had lost MMR only and 50 patients (75%) continued INTERIM. The patients who had lost CCgR and/or MMR resumed imatinib continuously and all of them regained the CCgR and the MMR, within 3 to 12 months. No patient progressed to accelerated or blastic phase, or developed clonal chromosomal abnormalities in Ph+ cells, or BCR-ABL mutations. No patient complained of new or more severe side effects during the months “on”.
After a follow up ≥ 5 years, 45/76 (59%) enrolled patients are on INTERIM, with a probability of maintaining intermittent administration of 59% (95% CI: 46-69). No patient lost the CCgR and only 9 additional patients lost the MMR while on intermittent treatment. All these patients resumed continuous imatinib treatment and regained the MMR. Thus, at ≥ 5 years, the probability of maintaing CCgR is 80% (95% CI 68-87) and the probability of maintaining the MMR is 61% (95% CI: 48-71). From start of INTERIM, 6 patients died but no deaths were related to CML progression (3 cases of other non haematological neoplasms, 1 stroke, 1 myocardial infarction, 1 chronic obstructive pulmonary disease).The PFS at ≥ 5 years is 94% (95% CI: 89-100)
CONCLUSIONS: In summary, with a follow up ≥ 5 years, intermittent imatinib administration (INTERIM) confirmed to be safe, to produce a reversible increase of residual molecular disease in about one third of patients, but not to affect the long-term outcome.
Aknowledgments: This work was supported in part by EuropeanLeukemiaNet (contract LSHC-CT-2004-503216) through the European Treatment and Outcome Study (EUTOS), supported by Novartis Oncology Europe, and COFIN 2009
Russo:Celgene: Research Funding; Gilead: Research Funding; Novartis: Consultancy. Martinelli:Novartis: Speakers Bureau; Bristol-Meyers and Squibb: Speakers Bureau; Pfizer: Speakers Bureau. Soverini:Novartis: Consultancy, Honoraria; Bristol-Meyers Squibb: Consultancy, Honoraria; Ariad: Consultancy, Speakers Bureau. Turri:Novartis: Consultancy, Honoraria; Bristol-Meyers Squibb: Consultancy, Honoraria. Castagnetti:Novartis: Consultancy, Honoraria; Bristol-Meyers Squibb: Consultancy, Honoraria. Breccia:novartis: Consultancy; BMS: Consultancy; Celgene: Consultancy. Abruzzese:Novartis: Consultancy. Tiribelli:Novartis: Consultancy, Honoraria; Bristol-Meyers and Squibb: Consultancy, Honoraria. Rosti:Consultant: Consultancy, Speakers Bureau; Bristol-Meiers Squibb: Consultancy, Speakers Bureau; Ariad: Consultancy, Speakers Bureau.
Summary
We have previously reported that about 80% of acute myeloid leukaemia (AML) samples tested at diagnosis constitutively expressed cytotoxic T‐lymphocyte‐associated antigen‐4 (CTLA‐4). The ...present study compared CTLA‐4 expression and function of leukaemic cells from AML patients at diagnosis with those from AML patients resistant to conventional chemotherapy. We also explored the possibility of targeting CTLA‐4 for apoptosis induction in chemoresistant AML cells. AML cells either from untreated patients (n = 15) or in chemoresistant phase (n = 10) were analysed for CTLA‐4 protein and transcript expression by flow cytometry and reverse transcription‐polymerase chain reaction respectively. CTLA‐4 expression was similar in untreated and in chemoresistant samples and was not associated with patients’ clinical features. In chemoresistant AML cells, CTLA‐4 transduced an apoptotic signal on engagement with its recombinant ligands r‐CD80 and r‐CD86, which induced an average of 71% and 62% apoptotic cells, respectively, at highest concentration. Apoptosis was equally induced in untreated leukaemic cells accompanied by cleavage of procaspase‐8 and ‐3. Thus, this study provides the first evidence that killing of leukaemic cells from AML patients may be obtained by the engagement of CTLA‐4 with its ligands, opening the way to a novel potential therapeutic approach based on triggering the CTLA‐4 molecule to circumvent chemoresistance in AML.
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