Montserrat Arnan

Dasatinib crosses the blood-brain barrier and is an efficient therapy for central nervous system Philadelphia chromosome–positive leukemia

Although imatinib, a BCR-ABL tyrosine kinase inhibitor, is used to treat acute Philadelphia chromosome-positive (Ph(+)) leukemia, it does not prevent central nervous system (CNS) relapses resulting from poor drug penetration through the blood-brain barrier. Imatinib and dasa-tinib (a dual-specific SRC/BCR-ABL kinase inhibitor) were compared in a preclinical mouse model of intracranial Ph(+) leukemia. Clinical dasatinib treatment in patients with CNS Ph(+) leukemia was assessed. In preclinical studies, dasatinib increased survival, whereas imatinib failed to inhibit intracranial tumor growth. Stabilization and regression of CNS disease were achieved with continued dasa-tinib administration. The drug also demonstrated substantial activity in 11 adult and pediatric patients with CNS Ph(+) leukemia. Eleven evaluable patients had clinically significant, long-lasting responses, which were complete in 7 patients. In 3 additional patients, isolated CNS relapse occurred during dasatinib therapy; and in 2 of them, it was caused by expansion of a BCR-ABL-mutated dasatinib-resistant clone, implying selection pressure exerted by the compound in the CNS. Dasatinib has promising therapeutic potential in managing intracranial leukemic disease and substantial clinical activity in patients who experience CNS relapse while on imatinib therapy. This study is registered at ClinicalTrials.gov as CA180006 (#NCT00108719) and CA180015 (#NCT00110097).

R-ESHAP as salvage therapy for patients with relapsed or refractory diffuse large B-cell lymphoma: the influence of prior exposure to rituximab on outcome. A GEL/TAMO study

The findings of this study suggest that combined therapy wih rituximab, etoposide, cytarabine, cisplatinum and methylprednisolone may be effective prior to autologous stem cell transplantation in patients with refractory or relapsed diffuse large B-cell lymphoma. See related perspective article on page 1776. Background The role of re-treatment with rituximab in aggressive B-cell lymphomas still needs to be defined. This study evaluated the influence of prior exposure to rituximab on response rates and survival in patients with diffuse large B-cell lymphoma treated with rituximab plus etoposide, cytarabine, cisplatinum and methylprednisolone (R-ESHAP). Design and Methods We retrospectively analyzed 163 patients with relapsed or refractory diffuse large B-cell lymphoma who received R-ESHAP as salvage therapy with a curative purpose. Patients were divided into two groups according to whether rituximab had been administered (n=94, “R+” group) or not (n=69, “R-” group) prior to R-ESHAP. Results Response rates were significantly higher in the R- group in the univariate but not in the multivariate analysis. In the analysis restricted to the R+ group, we observed very low complete remission and overall response rates in patients with primary refractory disease (8% and 33%, respectively), as compared to those in patients who were in first partial remission (41% and 86%) or who had relapsed disease (50% and 75%) (p<0.01 in both cases). Overall, 60% and 65% of patients in the R+ and R- groups, respectively, underwent stem-cell transplantation after the salvage therapy. With a median follow-up of 29 months (range, 6–84), patients in the R+ group had significantly worse progression-free survival (17% vs. 57% at 3 years, p<0.0001) and overall survival (38% v 67% at 3 years, p=0.0005) than patients in the R- group. Prior exposure to rituximab was also an independent adverse prognostic factor for both progression-free survival (RR: 2.0; 95% CI: 1.2–3.3, p=0.008) and overall survival (RR: 2.2; 95% CI: 1.3–3.9, p=0.004). Conclusions R-ESHAP was associated with a high response rate in patients who were not refractory to upfront rituximab-based chemotherapy. However, the survival outcome was poor for patients previously exposed to rituximab, as compared to in those who had not previously been treated with rituximab.

Bacteraemia due to extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) in cancer patients: clinical features, risk factors, molecular epidemiology and outcome

OBJECTIVES To assess the clinical features, risk factors, molecular epidemiology and outcome of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) bacteraemia in hospitalized cancer patients. METHODS Episodes of ESBL-EC bacteraemia were compared with a susceptible control group in a 3 year prospective study. ESBL-EC strains were studied by PCR and isoelectric focusing, and molecular typing was performed by PFGE. RESULTS Out of 531 episodes of bacteraemia, 135 were caused by E. coli. Seventeen of these cases involved ESBL-EC-producing strains (12.6%). In the multivariate analysis, female gender [odds ratio (OR) 3.43; 95% confidence interval (CI) 1.03-11.4] and previous antibiotic therapy (OR 3.22; 95% CI 1.00-10.3) were found to be independent risk factors for ESBL acquisition. An analysis of ESBL-EC isolates revealed a polyclonal distribution with CTX-M predominance (59%). Patients with ESBL-EC bacteraemia were more likely to have received an inadequate empirical antibiotic therapy (65% versus 6%; P = 0.000), and the time to adequate therapy was longer in this group (0 versus 1.50 days; P = 0.000). The overall mortality rate was 22%, ranging from 20% to 35% (P = 0.20). Risk factors for mortality were solid tumour (OR 19.41; 95% CI 4.66-80.83), corticosteroid therapy (OR 3.04 95% CI 1.05-8.81) and intensive care unit admission (OR 248.24, 95% CI 18.49-3332.14). In neutropenic patients, ESBL-EC bacteraemia was associated with poorer outcome and a higher overall mortality rate (37.5% versus 6.5%; P = 0.01). CONCLUSIONS In our centre, ESBL-EC bacteraemia is frequent among cancer patients, especially in those exposed to antibiotic pressure. All ESBL-EC strains were unrelated and most of them carried a CTX-M group enzyme. Patients with ESBL-EC bacteraemia received inadequate empirical antibiotic therapy more frequently than patients carrying a susceptible strain, but significant differences in mortality could not be demonstrated.

Serum Galactomannan–Based Early Detection of Invasive Aspergillosis in Hematology Patients Receiving Effective Antimold Prophylaxis

BACKGROUND There is a practical need to investigate the performance of the serum galactomannan (GM) assay in hematology patients with a potentially low pretest risk of invasive aspergillosis following effective antimold prophylaxis. METHODS We present a 4-year study with 262 unselected consecutive high-risk episodes, prospectively managed with posaconazole primary prophylaxis and a uniform diagnostic algorithm, including biweekly serum GM quantification for early detection of invasive aspergillosis. RESULTS A total of 2972 serum GM tests were performed (median, 11 per episode [range, 3-30]); the vast majority were negative (96.7% of tests and 83.6% of episodes). The incidence of breakthrough invasive aspergillosis was 1.9% (5/262), all with true-positive GM test results. Our study identified 30 false-positive GM evaluable episodes (85.7%; 13.8% of all evaluable episodes), validating with real-life data the low positive predictive value of the assay in this setting (12%). In 26 of these 30 episodes (86.7%), the false-positive result(s) occurred in tests performed as preemptive surveillance only. Conversely, in evaluable cases with positive GM tests and a clinical suspicion of invasive fungal disease, the performance of diagnostic-driven GM tests improved, with a positive predictive value of 89.6%. CONCLUSIONS The low pretest risk of invasive aspergillosis in the context of effective antimold prophylaxis renders serum GM surveillance of asymptomatic patients unreliable, as all results would be either negative or false positive. The test remains useful to diagnose patients with a clinical suspicion of invasive fungal disease, calling for a more efficient copositioning of effective prophylaxis and GM testing in this clinical setting.

Clinical efficacy and safety of primary antifungal prophylaxis with posaconazole vs itraconazole in allogeneic blood and marrow transplantation

Posaconazole has been recently approved for primary antifungal prophylaxis in patients with prolonged neutropenia after AML induction chemotherapy and patients with GVHD. We now present the first experience of the efficacy and safety of posaconazole during the early phase of post-allogeneic BMT (n=33; from June 2007), in comparison with itraconazole primary prophylaxis (n=16; up to May 2007). More patients receiving posaconazole were T-cell depleted (P=0.003). Groups were otherwise comparable in terms of age, sex, disease, neutrophil engraftment, incidence of GVHD, use of unrelated donors and type of conditioning. Safety data as well as the incidence of fever (84%) and persistent fever (27%) during the 100-day treatment period were comparable for both antifungal agents. Patients receiving posaconazole had a lower cumulative incidence of proven or probable invasive fungal disease, as defined by the European Organization for Research and Treatment of Cancer criteria (0 vs 12%; P=0.04), which associated with a higher probability of fungal-free survival (91 vs 56%; P=0.003) and an improved probability of OS (91 vs 63%; P=0.011) compared with patients receiving itraconazole. Our single-centre experience suggests that antifungal prophylaxis with posaconazole may lead to a better outcome than itraconazole for patients in the early high-risk neutropenic period after allogeneic BMT.

Etiology, clinical features and outcomes of pre-engraftment and post-engraftment bloodstream infection in hematopoietic SCT recipients

We conducted an observational study to assess the etiology, clinical features and outcomes of bloodstream infection (BSI) in 172 hematopoietic SCT (HCST) recipients. One hundred episodes of BSI in the pre-engraftment period (early onset) were compared with 89 episodes in the post-engraftment phase (late onset). More patients with late-onset BSI received an allogeneic HSCT, had GVHD and had received corticosteroids, whereas patients with early-onset BSI were more likely to have neutropenia, severe mucositis and a central venous catheter (CVC) in place. CVC was the most frequent site of infection, followed by an endogenous source. Pneumonia and gastrointestinal infection were particularly frequent in late-onset BSI, whereas mucositis was more frequent in the early-onset group. Gram-positive organisms predominated over Gram negatives. Streptococcus pneumoniae was more frequent in patients with late-onset BSI. Patients with late-onset BSI presented worse outcomes regarding septic shock, intensive care unit admission and early and overall case-fatality rates. Early-onset BSI was mainly related to the presence of neutropenia, mucositis and CVC, whereas late-onset BSI mainly affected severely immunosuppressed allogeneic HSCT recipients with GVHD and corticosteroids. Late-onset BSI caused high case-fatality rates. BSI due to S. pneumoniae was especially frequent late after transplantation. The development of better vaccination strategies is needed.

Bloodstream infections in neutropenic patients with cancer: Differences between patients with haematological malignancies and solid tumours

OBJECTIVES We sought to identify the characteristics, aetiology, antibiotic resistance and outcomes of bloodstream infection (BSI) in neutropenic patients with haematological malignancies (HM) and in those with solid tumours (ST) and assess their impact on empirical therapy and outcomes. METHODS All episodes of BSI in neutropenic patients with HM and ST were prospectively recorded and compared. RESULTS Of 579 episodes of BSI, 493 occurred in patients with HM and 86 in patients with ST. An endogenous source and catheter-related infection were more frequent in patients with HM, whereas pneumonia and urinary tract were more common in the ST group. BSI was mainly due to Gram-negative bacilli. Coagulase-negative staphylococci were more frequent in patients with HM, while Pseudomonas aeruginosa was more common in patients with ST and was the leading cause of pneumonia. Multidrug-resistant Gram-negative bacilli (MDRGNB) were more frequently isolated in haematological patients who more often received inadequate empirical therapy than those with ST. Case-fatality rates were higher in patients with ST. CONCLUSIONS We identified significant differences in BSI in neutropenic patients with HM and ST. MDRGNB were more often isolated in patients with HM. Pneumonia due to P. aeruginosa was particularly frequent among patients with ST. Case-fatality rates were higher in patients with ST.

Increase in Bloodstream Infection Due to Vancomycin-Susceptible Enterococcus faecium in Cancer Patients: Risk Factors, Molecular Epidemiology and Outcomes

We conducted a prospective study to assess the risk factors, molecular epidemiology and outcome of bloodstream infection (BSI) due to Enterococcus faecium in hospitalized cancer patients. Between 2006 and 2012, a significant increase in vancomycin-susceptible E. faecium BSI was observed among cancer patients. Comparison of 54 episodes of BSI due to E. faecium with 38 episodes of BSI due to E. faecalis showed that previous use of carbapenems was the only independent risk factor for E. faecium acquisition (OR 10.24; 95% CI, 1.35-77.66). All E. faecium isolates were susceptible to glycopeptides, whereas 97% showed high-level resistance to ampicillin and ciprofloxacin. All 30 isolates available for genotyping belonged to the hospital-associated E. faecium lineages 17, 18 and 78. After 2009, most of the isolates belonged to ST117 (lineage 78). Patients with E. faecium BSI were more likely to receive inadequate initial empirical antibiotic therapy than patients with E. faecalis BSI, and time to adequate empirical antibiotic therapy was also longer in the former group. No significant differences were found between the two groups regarding early and overall case-fatality rates. Independent risk factors for overall case-fatality were current corticosteroids (OR 4.18; 95% CI, 1.34-13.01) and intensive care unit admission (OR 9.97; 95% CI, 1.96-50.63). The emergence of E. faecium among cancer patients is a concern since there are limited treatment options and it may presage the emergence of vancomycin-resistant enterococci. A rationale approach that combines infection control with antimicrobial stewardship.

Dasatinib as Salvage Therapy for Steroid Refractory and Imatinib Resistant or Intolerant Sclerotic Chronic Graft-versus-Host Disease

Sclerotic chronic graft-versus-host disease (scGVHD) is a severe form of this disease that resembles systemic sclerosis and has limited and disappointing treatment options. Tyrosine kinase inhibitors (TKI) targeting up-regulated profibrotic pathways, such as imatinib mesylate, have been proposed as a potential therapeutic approach for patients with scGVHD. Dasatinib, a second-generation TKI with a well-established safety and efficacy profile in chronic myeloid leukemia patients, who are refractory or intolerant to imatinib, has also shown potent antifibrotic effects. We present here the first direct clinical evidence, from 3 patients treated in a small single-center series, suggesting that dasatinib can be a therapeutic option for patients with severe scGVHD resistant or intolerant to imatinib. All patients achieved partial response, with improvement in scGHVD target organs severity, joint mobility, lung impairment, and deep fibrotic lesions. This clinical response has remained stable or continued to improve after a median of 22 months (20-25) on dasatinib treatment, with very good tolerance. In addition, corticosteroids could be discontinued or significantly reduced in all patients. This clinical evidence suggests that dasatinib could be a safe and effective alternative for scGVHD patients refractory to corticosteroids and resistant or intolerant to imatinib. Based on these preliminary findings, and in order to address appropriate patient selection, time of intervention, and choice of drug, future larger studies should more formally establish the efficacy and safety of second-generation TKI for the treatment of scGVHD.

CCR5 Δ32 homozygous cord blood allogeneic transplantation in a patient with HIV: a case report

BACKGROUND Allogeneic donor CCR5 Δ32 homozygous haemopoietic cell transplantation (HCT) provides the only evidence to date of long-term control of HIV infection. However, availability of conventional CCR5 Δ32 homozygous donors is insufficient to develop this as a therapeutic strategy further. METHODS We present a 37-year-old patient with HIV-1 infection and aggressive lymphoma who had disease progression after five lines of radiochemotherapy including an autologous HCT, and in the absence of matched sibling donors, received an allogeneic HCT with four of six HLA-matched CCR5 Δ32 homozygous cord blood cells (StemCyte, Covina, CA), supported with purified CD34+ cells from a haploidentical sibling. Blood or tissue samples were obtained before and weekly after HCT to monitor transplant and HIV infection, including chimerism analysis, CCR5 genotyping and viral tropism, viral isolation and sequence, viral reservoir analysis, immune activation and proliferation, and ex-vivo cell infectivity assays. Combined antiretroviral therapy continued during the procedure. FINDINGS The patients HIV was CCR5-tropic by genotypic and phenotypic analyses. Baseline latent reservoir tests showed HIV DNA copies in bulk and resting CD4 T cells and in gut-associated lymphoid tissue, CD4 T-cell-associated HIV RNA, replication competent viral size of 2·1 copies per 10(7) CD4 T cells, and single copy assay of 303 copies per mL. After HCT, plasma HIV DNA load was undetectable by ultrasensitive analyses. Upon cord blood full chimerism, the patients CCR5 Δ32 homozygous CD4 T cells responded to proliferation and activation stimuli and became resistant to infection by the patients viral isolate and by laboratory-adapted HIV-1 strains. Death related to lymphoma progression regretfully prevented long-term monitoring of the patients viral reservoir. INTERPRETATION CCR5 Δ32 homozygous cord blood reconstitution can successfully eliminate HIV-1 and render the allogeneic graft recipients T lymphocytes resistant to HIV infection. Thus, they build on the evidence available to strongly support the use of cord blood as a strategic platform for a broader application of non-functional CCR5 transplantation to other infected individuals. FUNDING Spanish Secretariat of Research, the American Foundation for AIDS Research (amfAR).