A novel cell line panel reveals non-genetic mediators of platinum resistance and phenotypic diversity in high grade serous ovarian cancer.

OBJECTIVES: Resistance to cancer therapy is an enduring challenge and accurate and reliable preclinical models are lacking. We interrogated this unmet need using high grade serous ovarian cancer (HGSC) as a disease model. METHODS: We created five in vitro and two in vivo platinum-resistant HGSC models and characterised the entire cell panel via whole genome sequencing, RNASeq and creation of intraperitoneal models. RESULTS: Mutational signature analysis indicated that platinum-resistant cell lines evolved from a pre-existing ancestral clone but a unifying mutational cause for drug resistance was not identified. However, cisplatin-resistant and carboplatin-resistant cells evolved recurrent changes in gene expression that significantly overlapped with independent samples obtained from multiple patients with relapsed HGSC. Gene Ontology Biological Pathways (GOBP) related to the tumour microenvironment, particularly the extracellular matrix, were repeatedly enriched in cisplatin-resistant cells, carboplatin-resistant cells and also in human resistant/refractory samples. The majority of significantly over-represented GOBP however, evolved uniquely in either cisplatin- or carboplatin-resistant cell lines resulting in diverse intraperitoneal behaviours that reflect different clinical manifestations of relapsed human HGSC. CONCLUSIONS: Our clinically relevant and usable models reveal a key role for non-genetic factors in the evolution of chemotherapy resistance. Biological pathways relevant to the extracellular matrix were repeatedly expressed by resistant cancer cells in multiple settings. This suggests that recurrent gene expression changes provide a fitness advantage during platinum therapy and also that cancer cell-intrinsic mechanisms influence the tumour microenvironment during the evolution of drug resistance. Candidate genes and pathways identified here could reveal therapeutic opportunities in platinum-resistant HGSC.

A phase 2 trial of ponatinib in Philadelphia chromosome-positive leukemias.

BACKGROUND: Ponatinib is a potent oral tyrosine kinase inhibitor of unmutated and mutated BCR-ABL, including BCR-ABL with the tyrosine kinase inhibitor-refractory threonine-to-isoleucine mutation at position 315 (T315I). We conducted a phase 2 trial of ponatinib in patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL). METHODS: We enrolled 449 heavily pretreated patients who had CML or Ph-positive ALL with resistance to or unacceptable side effects from dasatinib or nilotinib or who had the BCR-ABL T315I mutation. Ponatinib was administered at an initial dose of 45 mg once daily. The median follow-up was 15 months. RESULTS: Among 267 patients with chronic-phase CML, 56% had a major cytogenetic response (51% of patients with resistance to or unacceptable side effects from dasatinib or nilotinib and 70% of patients with the T315I mutation), 46% had a complete cytogenetic response (40% and 66% in the two subgroups, respectively), and 34% had a major molecular response (27% and 56% in the two subgroups, respectively). Responses were observed regardless of the baseline BCR-ABL kinase domain mutation status and were durable; the estimated rate of a sustained major cytogenetic response of at least 12 months was 91%. No single BCR-ABL mutation conferring resistance to ponatinib was detected. Among 83 patients with accelerated-phase CML, 55% had a major hematologic response and 39% had a major cytogenetic response. Among 62 patients with blast-phase CML, 31% had a major hematologic response and 23% had a major cytogenetic response. Among 32 patients with Ph-positive ALL, 41% had a major hematologic response and 47% had a major cytogenetic response. Common adverse events were thrombocytopenia (in 37% of patients), rash (in 34%), dry skin (in 32%), and abdominal pain (in 22%). Serious arterial thrombotic events were observed in 9% of patients; these events were considered to be treatment-related in 3%. A total of 12% of patients discontinued treatment because of an adverse event. CONCLUSIONS: Ponatinib had significant antileukemic activity across categories of disease stage and mutation status. (Funded by Ariad Pharmaceuticals and others; PACE ClinicalTrials.gov number, NCT01207440 .).

Revealing stiffening and brittling of chronic myelogenous leukemia hematopoietic primary cells through their temporal response to shear stress.

Cancer cell transformation is often accompanied by a modification of their viscoelastic properties. When capturing the stress-to-strain response of primary chronic myelogenous leukemia (CML) cells, from two data sets of CD34+ hematopoietic cells isolated from healthy and leukemic bone marrows, we show that the mean shear relaxation modulus increases upon cancer transformation. This stiffening of the cells comes along with local rupture events, detected as reinforced sharp local maxima of this modulus, suggesting that these cancer cells respond to a local mechanical stress by a cascade of local brittle failure events.

Actinomycosis after allogeneic hematopoietic stem cell transplantation despite penicillin prophylaxis.

Actinomycosis is a rare chronic and multifaceted disease caused by Actinomyces species frequently mimicking malignancy or other chronic granulomatous lung diseases. We report 4 original presentations of actinomycosis arising under supposed penicillin prophylaxis in allogeneic stem cell transplantation recipients.

Phase 2 study of subcutaneous omacetaxine mepesuccinate for chronic-phase chronic myeloid leukemia patients resistant to or intolerant of tyrosine kinase inhibitors.

Omacetaxine mepesuccinate (omacetaxine) is a first-in-class cephalotaxine with a unique mode of action, independent of BCR-ABL, that has shown promising activity in patients with chronic myeloid leukemia (CML). This multicenter, noncomparative, open-label phase 2 study evaluated the efficacy and safety of subcutaneous omacetaxine in CML patients with resistance or intolerance to two or more tyrosine kinase inhibitors (TKIs); results in patients in chronic phase are reported here. Patients received subcutaneous omacetaxine 1.25 mg/m² twice daily days 1-14 every 28 days until hematologic response (up to a maximum of six cycles), then days 1-7 every 28 days as maintenance. Primary endpoints were rates of hematologic response lasting >8 weeks and major cytogenetic response (MCyR). Forty-six patients were enrolled: all had received imatinib, 83% had received dasatinib, and 57% nilotinib. A median 4.5 cycles of omacetaxine were administered (range, 1-36). Hematologic response was achieved or maintained in 31 patients (67%); median response duration was 7.0 months. Ten patients (22%) achieved MCyR, including 2 (4%) complete cytogenetic responses. Median progression-free survival was 7.0 months [95% confidence interval (CI), 5.9-8.9 months], and overall survival was 30.1 months (95% CI, 20.3 months-not reached). Grade 3/4 hematologic toxicity included thrombocytopenia (54%), neutropenia (48%), and anemia (33%). Nonhematologic adverse events were predominantly grade 1/2 and included diarrhea (44%), nausea (30%), fatigue (24%), pyrexia (20%), headache (20%), and asthenia (20%). Subcutaneous omacetaxine may offer clinical benefit to patients with chronic-phase CML with resistance or intolerance to multiple TKI therapies.

Invasive aspergillosis: an important risk factor on the short- and long-term survival of acute myeloid leukemia (AML) patients.

Invasive aspergillosis (IA) during induction chemotherapy of acute myeloid leukemia (AML) could worsen the prognosis. Our objective was to study how the development of IA during AML interferes with the therapeutic strategy and to evaluate its impact on the short- and long-term survival. Newly diagnosed AML patients between the years 2004 and 2007 were retrospectively analyzed. The outcome was death of the patient. A Cox proportional hazards model with the diagnosis of IA and post-induction response evaluation as the main exposure was fitted. Overall, 262 patients were analyzed and 58 IA were observed. The 2-year survival of patients having had remission of AML was 54% and, for patients with failure of chemotherapy, it was 5% (p < 0.001). The 2-year survival of patients having had IA was 14%, and without IA, it was 32% (p = 0.01). Multivariate analysis showed that IA was associated with a higher risk of death in case of remission compared to no IA (hazard ratio [HR] = 1.66 [1.05-2.65], p = 0.031) and also in case of failure (HR = 6.43, p < 0.001). IA was associated with an increased risk of death for patients if they were either in remission or in failure after induction chemotherapy.

Immune checkpoint inhibitor treatment of a first cancer is associated with a decreased incidence of second primary cancer.

BACKGROUND: Second primary cancers (SPCs) are diagnosed in over 5% of patients after a first primary cancer (FPC). We explore here the impact of immune checkpoint inhibitors (ICIs) given for an FPC on the risk of SPC in different age groups, cancer types and treatments. PATIENTS AND METHODS: The files of the 46 829 patients diagnosed with an FPC in the Centre Léon Bérard from 2013 to 2018 were analyzed. Structured data were extracted and electronic patient records were screened using a natural language processing tool, with validation using manual screening of 2818 files of patients. Univariate and multivariate analyses of the incidence of SPC according to patient characteristics and treatment were conducted. RESULTS: Among the 46 829 patients, 1830 (3.9%) had a diagnosis of SPC with a median interval of 11.1 months (range 0-78 months); 18 128 (38.7%) received cytotoxic chemotherapy (CC) and 1163 (2.5%) received ICIs for the treatment of the FPC in this period. SPCs were observed in 7/1163 (0.6%) patients who had received ICIs for their FPC versus 437/16 997 (2.6%) patients receiving CC and no ICIs for the FPC versus 1386/28 669 (4.8%) for patients receiving neither CC nor ICIs for the FPC. This reduction was observed at all ages and for all histotypes analyzed. Treatment with ICIs and/or CC for the FPC are associated with a reduced risk of SPC in multivariate analysis. CONCLUSION: Immunotherapy with ICIs alone and in combination with CC was found to be associated with a reduced incidence of SPC for all ages and cancer types.

A randomised phase II trial of hydroxychloroquine and imatinib versus imatinib alone for patients with chronic myeloid leukaemia in major cytogenetic response with residual disease.

In chronic-phase chronic myeloid leukaemia (CP-CML), residual BCR-ABL1+ leukaemia stem cells are responsible for disease persistence despite TKI. Based on in vitro data, CHOICES (CHlorOquine and Imatinib Combination to Eliminate Stem cells) was an international, randomised phase II trial designed to study the safety and efficacy of imatinib (IM) and hydroxychloroquine (HCQ) compared with IM alone in CP-CML patients in major cytogenetic remission with residual disease detectable by qPCR. Sixty-two patients were randomly assigned to either arm. Treatment 'successes' was the primary end point, defined as ≥0.5 log reduction in 12-month qPCR level from trial entry. Selected secondary study end points were 24-month treatment 'successes', molecular response and progression at 12 and 24 months, comparison of IM levels, and achievement of blood HCQ levels >2000 ng/ml. At 12 months, there was no difference in 'success' rate (p = 0.58); MMR was achieved in 80% (IM) vs 92% (IM/HCQ) (p = 0.21). At 24 months, the 'success' rate was 20.8% higher with IM/HCQ (p = 0.059). No patients progressed. Seventeen serious adverse events, including four serious adverse reactions, were reported; diarrhoea occurred more frequently with combination. IM/HCQ is tolerable in CP-CML, with modest improvement in qPCR levels at 12 and 24 months, suggesting autophagy inhibition maybe of clinical value in CP-CML.

European LeukemiaNet 2020 recommendations for treating chronic myeloid leukemia.

The therapeutic landscape of chronic myeloid leukemia (CML) has profoundly changed over the past 7 years. Most patients with chronic phase (CP) now have a normal life expectancy. Another goal is achieving a stable deep molecular response (DMR) and discontinuing medication for treatment-free remission (TFR). The European LeukemiaNet convened an expert panel to critically evaluate and update the evidence to achieve these goals since its previous recommendations. First-line treatment is a tyrosine kinase inhibitor (TKI; imatinib brand or generic, dasatinib, nilotinib, and bosutinib are available first-line). Generic imatinib is the cost-effective initial treatment in CP. Various contraindications and side-effects of all TKIs should be considered. Patient risk status at diagnosis should be assessed with the new EUTOS long-term survival (ELTS)-score. Monitoring of response should be done by quantitative polymerase chain reaction whenever possible. A change of treatment is recommended when intolerance cannot be ameliorated or when molecular milestones are not reached. Greater than 10% BCR-ABL1 at 3 months indicates treatment failure when confirmed. Allogeneic transplantation continues to be a therapeutic option particularly for advanced phase CML. TKI treatment should be withheld during pregnancy. Treatment discontinuation may be considered in patients with durable DMR with the goal of achieving TFR.

Chronic disseminated candidiasis and acute leukemia: Impact on survival and hematopoietic stem cell transplantation agenda.

OBJECTIVES: To study the management of chronic disseminated candidiasis (CDC) in patients presenting with acute leukemia. PATIENTS AND METHODS: Single-center retrospective study of acute leukemia patients (2006-2015) to investigate three aspects of CDC: its impact on the time interval between diagnosis and hematopoietic stem cell transplantation, when required (non-parametric Wilcoxon-Mann-Whitney test); its impact on overall survival (Cox proportional hazard regression model); antifungal therapeutic strategies implemented. RESULTS: A total of 639 patients presenting with acute leukemia were included; 144 were transplanted and 29 developed CDC. CDC did not significantly increase the time interval between diagnosis and transplantation, nor did it impact the overall survival of recipients. An improved overall survival was observed in non-transplanted acute leukemia patients presenting with CDC. CONCLUSION: CDC should not postpone transplantation if antifungal treatment is optimized.

Previously undetected human hematopoietic cell populations with short-term repopulating activity selectively engraft NOD/SCID-beta2 microglobulin-null mice.

Increasing use of purified or cultured human hematopoietic cells as transplants has revealed an urgent need for better methods to predict the speed and durability of their engraftment potential. We now show that NOD/SCID-beta2 microglobulin-null (NOD/SCID-beta2m-/-) mice are sequentially engrafted by two distinct and previously unrecognized populations of transplantable human short-term repopulating hematopoietic cells (STRCs), neither of which efficiently engraft NOD/SCID mice. One is predominantly CD34+CD38+ and is myeloid-restricted; the other is predominantly CD34+CD38- and has broader lymphomyeloid differentiation potential. In contrast, the long-term repopulating human cells that generate lymphoid and myeloid progeny in NOD/SCID mice engraft and self-renew in NOD/SCID-beta2m-/- mice equally efficiently. In short-term expansion cultures of adult bone marrow cells, myeloid-restricted STRCs were preferentially amplified (greater than tenfold) and, interestingly, both types of STRC were found to be selectively elevated in mobilized peripheral blood harvests. These results suggest an enhanced sensitivity of STRCs to natural killer cell-mediated rejection. They also provide new in vivo assays for different types of human STRC that may help to predict the engraftment potential of clinical transplants and facilitate future investigation of early stages of human hematopoietic stem cell differentiation.

Mutation status and clinical outcome of 89 imatinib mesylate-resistant chronic myelogenous leukemia patients: a retrospective analysis from the French intergroup of CML (Fi(phi)-LMC GROUP).

The emergence of ABL point mutations is the most frequent cause for imatinib resistance in chronic myelogenous leukemia (CML) patients and can occur during any phase of the disease; however, their clinical impact remains controversial. In this study, we retrospectively analyzed the predictive impact of 94 BCR-ABL kinase domain mutations (18 T315I, 26 P-loop, 50 in other sites) found in 89 imatinib-resistant CML patients. At imatinib onset, 64% of patients (57/89) were in chronic phase (CP), 24% (21/89) in accelerated phase (AP) and 12% (11/89) in blastic phase (BP). T315I and P-loop mutations were preferentially discovered in accelerated phase of BP CML, and other types of mutations in CP (P=0.003). With a median follow-up of 39.2 months (6.3-67.2), since imatinib initiation, overall survival (OS) was significantly worse for P-loop (28.3 months) and for T315I (12.6 months), and not reached for other mutations (P=0.0004). For CP only, multivariate analysis demonstrated a worse OS for P-loop mutations (P=0.014), and a worse progression-free survival (PFS) for T315I mutations (P=0.014). Therefore, P-loop and T315I mutations selectively impair the outcome of imatinib-resistant CML patients, in contrast to other mutations, which may benefit from dose escalation of imatinib, able to improve or stabilize disease response.

A matched case-control study of toxoplasmosis after allogeneic haematopoietic stem cell transplantation: still a devastating complication.

Toxoplasmosis (TXP) is a life-threatening complication of allogeneic haematopoietic stem cell transplantation (AHSCT). Little is known about the risk factors and there is no consensus on prophylactic measures. To investigate the risk factors, we conducted a single-centre, retrospective matched case-control study among adults who underwent AHSCT from January 2006 to March 2015 in our hospital. TXP cases were identified from the prospectively maintained hospital's database. The 1:2 control population consisted of the two patients who received an AHSCT immediately before and after each case with similar donor relationship (related, unrelated) but who did not develop TXP. Risk factors were identified by conditional logistic regression. Clinical features and outcome of TXP were examined. Twenty-three (3.9%) cases of TXP (20 diseases, three infections) were identified among 588 AHSCT recipients. Twenty (87%) cases had a positive pre-transplant Toxoplasma gondii serology. In comparison with 46 matched control patients, risk factors were the absence of effective anti-Toxoplasma prophylaxis (odds ratio (OR) 11.95; 95% CI 3.04-46.88; p <0.001), high-grade (III-IV) acute graft-versus-host-disease (OR 3.1; 95% CI 1.04-9.23; p 0.042) and receipt of the tumour necrosis factor-α blocker etanercept (OR 12.02; 95% CI 1.33-108.6; p 0.027). Mortality attributable to TXP was 43.5% (n = 10). Non-relapse mortality rates during the study period of cases and controls were 69.6% (n = 16) and 17.4% (n = 8), respectively. Lung involvement was the dominant clinical feature (n = 14). Two cases were associated with graft failure, one preceded by haemophagocytic syndrome. Given TXP-related morbidity and attributable mortality, anti-Toxoplasma prophylaxis is essential for optimized management of seropositive AHSCT recipients.

Concurrent nitroglycerin administration decreases thrombolytic potential of tissue-type plasminogen activator.

Dynamic coronary vasoconstriction may play a role in coronary artery reocclusion after successful thrombolysis. The effect of nitroglycerin on the thrombolytic effects of recombinant tissue-type plasminogen activator (rt-PA) was examined in dogs with an electrically induced occlusive coronary artery thrombus. Eleven dogs were randomly given rt-PA alone and seven rt-PA with nitroglycerin. The dose of rt-PA was 0.75 mg/kg body weight given over 20 min and the dose of nitroglycerin was 125 micrograms/min for 40 min. The reperfusion rate in the dogs given rt-PA alone was 73% (8 of 11 dogs) and that in the rt-PA plus nitroglycerin group was 57% (four of seven dogs) (p = NS). The time to thrombolysis (or reperfusion) in dogs receiving rt-PA plus nitroglycerin was 70% greater than in those receiving rt-PA alone (means +/- SD/29.8 +/- 9.9 versus 17.6 +/- 5.9 min, p less than 0.02), and the duration of reperfusion much shorter (11 +/- 17 versus 42 +/- 16 min, p less than 0.02). Peak coronary blood flow after reperfusion in dogs receiving rt-PA plus nitroglycerin was also less than in those receiving rt-PA alone (36 +/- 52 versus 63 +/- 20 ml/min, p less than 0.02). Reocclusion occurred in all dogs given rt-PA with nitroglycerin and in six of eight given rt-PA alone (p = NS). Plasma concentrations of rt-PA were lower when nitroglycerin was given with rt-PA alone (427 +/- 279 versus 1,471 +/- 600 ng/ml, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Verapamil and aspirin modulate platelet-mediated vasomotion in arterial segments with intact or disrupted endothelium.

OBJECTIVES: This study was designed to examine the effects of verapamil and aspirin, which decrease thromboxane A2 and serotonin release, on the modulation of vascular tone by platelets. BACKGROUND: Aggregating platelets cause constriction of de-endothelialized arterial segments through thromboxane A2 and serotonin release. These cells cause relaxation of arterial segments with intact endothelium through release of the endothelium-derived relaxing factor. METHODS: Healthy subjects were given either no drug, verapamil or aspirin for > or = 5 days before their platelets were obtained. The effects of platelets obtained from subjects before and after treatment with aspirin or verapamil on the tone of rat aortic rings were determined. RESULTS: As expected, control platelets (before verapamil or aspirin treatment) induced concentration-dependent relaxation of rat aortic rings with intact endothelium and a concentration-dependent contraction of de-endothelialized rings. Verapamil treatment enhanced (p < 0.02) the platelet-mediated relaxation in rings with intact endothelium and abolished platelet-mediated constriction (p < 0.01) in the de-endothelialized rings. Aspirin treatment also abolished (p < 0.05) platelet-mediated constriction of the de-endothelialized rings. The de-endothelialized rings contracted normally in response to the synthetic thromboxane A2 analogue U46,619, as well as to serotonin, indicating that the vascular smooth muscle response to thromboxane A2 and serotonin was intact. CONCLUSIONS: This study provides evidence for the modulation of platelet-mediated vasoconstriction of de-endothelialized arterial segments by prior treatment of subjects with verapamil or aspirin. In clinical syndromes characterized by endothelial dysfunction or disruption, treatment with verapamil or aspirin may modify platelet-vessel wall interactions.

Limited posterior left atrial cryoablation in patients with chronic atrial fibrillation undergoing valvular heart sugery.

OBJECTIVES: We sought to evaluate whether a limited surgical cryoablation of the posterior region of the left atrium was safe and effective in the cure of atrial fibrillation (AF) in patients with associated valvular heart disease. BACKGROUND: Extensive surgical ablation of AF is a complex and risky procedure. The posterior region of the left atrium seems to be important in the initiation and maintenance of AF. METHODS: In 32 patients with chronic AF who underwent heart valve surgery, linear cryolesions connecting the four pulmonary veins and the posterior mitral annulus were performed. Eighteen patients with AF who underwent valvular surgery but refused cryoablation were considered as the control group. RESULTS: Sinus rhythm (SR) was restored in 25 (78%) of 32 patients immediately after the operation. The cryoablation procedure required 20 +/- 4 min. There were no intraoperative and perioperative complications. During the hospital period, one patient died of septicemia. Thirty-one patients reached a minimum of nine months of follow-up. Two deaths occurred but were unrelated to the procedure. Twenty (69%) of 29 patients remained in SR with cryoablation alone, and 26 (90%) of 29 patients with cryoablation, drugs and radiofrequency ablation. Three (10%) of 29 patients remained in chronic AF. Right and left atrial contractility was evident in 24 (92%) of 26 patients in SR. In control group, two deaths occurred, and SR was present in only four (25%) of 16 patients. CONCLUSIONS: Linear cryoablation with lesions connecting the four pulmonary veins and the mitral annulus is effective in restoration and maintenance of SR in patients with heart valve disease and chronic AF. Limited left atrial cryoablation may represent a valid alternative to the maze procedure, reducing myocardial ischemic time and risk of bleeding.

Attenuation of coronary flow reserve and myocardial function after temporary subtotal coronary artery occlusion and increased myocardial oxygen demand in dogs.

OBJECTIVES: We examined whether subtotal coronary artery occlusion and reperfusion alter coronary flow reserve and regional myocardial function. BACKGROUND: Total coronary artery occlusion followed by reperfusion results in decreased coronary flow reserve and regional myocardial dysfunction. METHODS: Thirteen anesthetized dogs were subjected to subtotal occlusion of the left anterior descending coronary artery for 1 h, followed by reperfusion for 1 h. During subtotal left anterior descending occlusion, heart rate was increased by atrial pacing. After reperfusion, coronary flow reserve, indicated by reactive hyperemia, as well as coronary flow responses to acetylcholine and nitroglycerin, regional myocardial function and myocardial leukocyte accumulation were measured. RESULTS: After reperfusion, coronary flow reserve was decreased in the ischemic left anterior descending but not the nonischemic circumflex coronary artery region. Myocardial function was also depressed in the left anterior descending coronary region and did not improve on reperfusion. Histologic study showed no leukocyte infiltration in the ischemic left anterior descending coronary region. Myeloperoxidase, an index of myocardial leukocyte accumulation, was similar in the left anterior descending and circumflex coronary regions. Sensitivity of epicardial left anterior descending coronary artery rings to the thromboxane A2 analog U46,619 was enhanced, and relaxation of these rings in response to endothelium-dependent relaxants was decreased. CONCLUSIONS: Coronary flow reserve is reduced and regional myocardial function depressed after subtotal coronary artery occlusion and increased heart rate. A decreased synthesis or increased breakdown of endothelium-derived relaxing factor may be related to a decrease in coronary flow reserve. However, the reduction in coronary flow reserve appears to be unrelated to leukocyte accumulation in the reperfused region.

Sustained reflow in dogs with coronary thrombosis with K2P, a novel mutant of tissue-plasminogen activator.

Coronary artery reocclusion after thrombolysis with human recombinant tissue-type plasminogen activator (rt-PA) is related to the short half-life of this agent in plasma. K2P, a mutant of rt-PA lacking the fibronectin fingerlike, epidermal growth factor-like and first kringle domains (amino acids 6 to 173) and having the glycosylation site Asn184 mutagenized to Gln, has been produced in Chinese hamster ovary cells. In this study we compared the thrombolytic effect of K2P and rt-PA in dogs with electrically induced coronary artery thrombosis. Both agents were given intravenously in equimolar amounts over 20 min after the occlusive thrombus was stable for 30 min; dogs were monitored for 1 h after reperfusion if flow occurred. Coronary blood flow was restored by rt-PA in 6 (60%) of 10 dogs. The restored flow lasted for 49 +/- 12 min and mean flow at 60 min from the start of reperfusion was 7 +/- 3 ml/min. The reocclusion rate was 50% (three of six dogs). Flow was restored in five (100%) of five dogs by K2P. The restored blood flow lasted during the entire 1-h observation period in all but one dog and mean flow at 60 min was 49 +/- 16 ml/min (p less than 0.02 vs. flow in rt-PA-treated dogs). Restored coronary blood flow showed marked cyclic flow variations in rt-PA-treated but not in K2P-treated dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Selective inhibition of factor Xa is more efficient than factor VIIa-tissue factor complex blockade at facilitating coronary thrombolysis in the canine model.

OBJECTIVES: We determined the effect of adjunctive inhibition of the extrinsic coagulation pathway by factor VIIa-tissue factor complex inhibitors, DEGR VIIa and tissue factor pathway inhibitor (TFPI), and the selective factor Xa inhibitor, tick anticoagulant peptide (TAP), after thrombolytic therapy with tissue-type plasminogen activator (t-PA) in a canine model of electrically induced coronary thrombosis. BACKGROUND: Ongoing thrombin generation is considered an important component of the heightened thrombin activity associated with thrombolytic therapy and may be responsible for reperfusion failure and reocclusion. METHODS: Forty-two dogs with electrically induced coronary thrombus undergoing thrombolysis with t-PA (1 mg/kg over 20 min) were randomly assigned to one of the following adjunctive regimens: TAP (30 micrograms/kg body weight per min for 90 min, n = 10); TFPI (100 to 150 micrograms/kg per min for 90 min, n = 10); DEGR VIIa (1- to 2-mg/kg bolus, n = 10) and saline control (n = 12). The dogs were observed for 120 min after thrombolysis for reocclusion. RESULTS: All three active study agents accelerated the time to reperfusion by an average of 12 min (all p < 0.05). Duration of reflow was greatest with TAP (117 +/- 8 min, p < 0.05 compared with saline control), whereas DEGR VIIa and TFPI did not prolong the duration of reflow. Reocclusion rates were similar among control, DEGR VIIa and TFPI groups (70%, 78% and 67%, respectively). Tick anticoagulant peptide reduced the occurrence of reocclusion (0%, p < 0.05 compared with saline control). CONCLUSIONS: In this experimental model, during systematic blockade of various extrinsic coagulation pathway proteins, we demonstrated that whereas acceleration of thrombolysis occurs with factor VIIa-tissue factor complex inhibition, optimal enhancement of thrombolysis was achieved through specific factor Xa blockade.

Outcome and long-term follow-up of alloreactive donor lymphocyte infusions given for relapse after myeloablative allogeneic hematopoietic stem cell transplantations (HSCT).

In order to study efficacy, toxicity and the long-term results of donor lymphocyte infusions (DLI), we retrospectively analyzed DLI given for relapse after conventional allogeneic hematopoietic stem cell transplantation (HSCT) in 30 patients with a median delay of 107.5 months after transplant and 58 months after DLI. After DLI, 15 patients established full donor chimerism, three patients developed grade III and one grade IV acute GVHD. A total of 15 patients achieved a disease response. Among the 14 patients with chronic myeloid leukemia (CML), 11 are alive at the last follow-up: five are in complete molecular response (CMR) and two in complete cytogenetic response (CCR) with no other intervention after DLI, three in CMR after imatinib mesylate given after DLI and one in complete hematological response after imatinib mesylate and reduced-intensity conditioning allogeneic SCT performed after DLI. At the time of the last follow-up, 19 (63%) patients died and 11 (37%) remain alive. The 3-year probability of survival for the entire population, CML patients and non-CML patients, was 60, 93, 62% after transplantation, and 48, 80 and 48% after DLI, respectively. A multivariate analysis demonstrated a significantly worse survival rate after transplantation for female recipients, advanced disease and acute leukemia before transplantation.