Extended spectrum cephalosporin resistant enterobacteriaceae carriage and infection in patients admitted with newly-diagnosed acute leukemia.

BACKGROUND: Current information is limited on the incidence, risk factors, and consequences of extended-spectrum cephalosporin resistant Enterobacteriaceae (ESCRE) carriage in patients undergoing therapy for newly-diagnosed acute leukemia. METHODS: We monitored 300 consecutive patients who submitted a first stool within the first week of initial hospitalization for initial and hospital acquired ESCRE carriage. Selected available isolates underwent DNA sequencing for determination of strain typing and resistance genes. RESULTS: 19 (6%) patients had ESCRE in their initial stool, and there was continued risk for new acquisition throughout their multiple hospitalizations. Patients with AML had more acquired carriage during their initial hospitalization. Increased hospitalizations and male sex were risk factors for detected acquired ESCRE carriage. ESCRE stool carriage was predictive for ESCRE BSI but not for overall survival. Sequencing revealed that E. coli ESCRE isolates contained primarily ESBL, while Enterobacter spp. and Citrobacter spp. showed primarily AmpC genes. The antibiotic sensitivity patterns for ESCRE BSI isolates reflected these genome findings. DISCUSSION/CONCLUSIONS: ESCRE carriage is common in patients with acute leukemia undergoing repeated hospitalizations and increases the risk for ESCRE BSI. ESCRE genera express differing resistance genes which may be predictive for empiric antibiotic efficacy.

Successful administration of chimeric antigen receptor (CAR) T-cell therapy in patients requiring hemodialysis.

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of relapsed/refractory B-cell malignancies. However, there is no data on the safety and efficacy of CAR T-cell therapy in patients with end stage renal disease (ESRD) requiring dialysis. In this report, we present two patients with DLBCL and ESRD who were successfully treated with different CAR T-cell products. Patient #1 is a 66 year-old woman with a history of HIV who was treated to complete response with axicabtagene ciloleucel with treatment complicated by grade 1 cytokine release syndrome (CRS) and grade 2 immune effector cell-associated neurolotoxicity syndrome (ICANS). Patient #2 is 52 year old woman whose ESRD was caused by ifosphamide toxicity and was treated to complete response with lisocabtagene maraleucel and did not experience either CRS or ICANS. Both patients received lymphodepletion chemotherapy with fludarabine and cyclophosphamide, which was dose-adjusted for ESRD with scheduled dialysis 12 h after each dose of lymphodepletion chemotherapy. Patients with DLBCL and ESRD can be safely administered both lymphodepletion chemotherapy and CAR T-cell therapy. Additionally, the fact that both patients achieved complete response to therapy suggests that CAR T-cell therapy should be strongly considered in patients with ESRD. Long-term follow up is needed to determine if therapy in this setting is of curative intent.

Clostridioides difficile colonization and infection in patients with newly diagnosed acute leukemia: Incidence, risk factors, and patient outcomes.

BACKGROUND: The frequency, risk factors, and outcomes for Clostridioides difficile infection (CDI) in patients with newly diagnosed acute leukemia (AL) admitted for induction therapy are unclear. METHODS: We studied 509 consecutive patients with AL admitted between 2006 and 2017 and conducted a prospective C difficile surveillance and ribotyping analysis in a subset of these. RESULTS: The incidence of CDI was 2.2/1,000 inpatient days during induction, and CDI was rare after discharge. CDI was highest in patients with acute myelogenous leukemia. A hospitalization shortly before admission and administration of a greater number of antibiotics increased the risk for CDI. No single class of antibiotics conveyed an increased risk. All cases were successfully treated, and CDI was not associated with an increase in length of stay, costs, or mortality. In a subgroup analysis, 16% of patients with acute myelogenous leukemia and 4% with other leukemia types were colonized on admission. Colonization was associated with a higher risk of CDI. Ribotyping of available isolates showed 27 different strain types with 014/020 and 027 being the most frequent. CONCLUSIONS: The number of antibiotics administered are a major risk factor for CDI in patients with AL. However, CDI appears to have minimal clinical impact in this population.

SCF-KIT signaling induces endothelin-3 synthesis and secretion: Thereby activates and regulates endothelin-B-receptor for generating temporally- and spatially-precise nitric oxide to modulate SCF- and or KIT-expressing cell functions.

We demonstrate that SCF-KIT signaling induces synthesis and secretion of endothelin-3 (ET3) in human umbilical vein endothelial cells and melanoma cells in vitro, gastrointestinal stromal tumors, human sun-exposed skin, and myenteric plexus of human colon post-fasting in vivo. This is the first report of a physiological mechanism of ET3 induction. Integrating our finding with supporting data from literature leads us to discover a previously unreported pathway of nitric oxide (NO) generation derived from physiological endothelial NO synthase (eNOS) or neuronal NOS (nNOS) activation (referred to as the KIT-ET3-NO pathway). It involves: (1) SCF-expressing cells communicate with neighboring KIT-expressing cells directly or indirectly (cleaved soluble SCF). (2) SCF-KIT signaling induces timely local ET3 synthesis and secretion. (3) ET3 binds to ETBR on both sides of intercellular space. (4) ET3-binding-initiated-ETBR activation increases cytosolic Ca2+, activates cell-specific eNOS or nNOS. (5) Temporally- and spatially-precise NO generation. NO diffuses into neighboring cells, thus acts in both SCF- and KIT-expressing cells. (6) NO modulates diverse cell-specific functions by NO/cGMP pathway, controlling transcriptional factors, or other mechanisms. We demonstrate the critical physiological role of the KIT-ET3-NO pathway in fulfilling high demand (exceeding basal level) of endothelium-dependent NO generation for coping with atherosclerosis, pregnancy, and aging. The KIT-ET3-NO pathway most likely also play critical roles in other cell functions that involve dual requirement of SCF-KIT signaling and NO. New strategies (e.g. enhancing the KIT-ET3-NO pathway) to harness the benefit of endogenous eNOS and nNOS activation and precise NO generation for correcting pathophysiology and restoring functions warrant investigation.

Phase II study of amrubicin (SM-5887), a synthetic 9-aminoanthracycline, as first line treatment in patients with metastatic or unresectable soft tissue sarcoma: durable response in myxoid liposarcoma with TLS-CHOP translocation.

PURPOSE: Amrubicin is a third generation synthetic 9-aminoanthracycline that specifically inhibits topoisomerase II. Amrubicin preferentially concentrates in tumor cells leading to tumor cell death without causing cardiac toxicity. This phase II multicenter study was done to evaluate the efficacy and tolerability of amrubicin in advanced soft tissue sarcoma (STS). PATIENTS AND METHODS: 24 eligible patients with chemotherapy-naive metastatic or unresectable STS were treated with amrubicin 40 mg/m(2) intravenously daily for three consecutive days in 21 days cycles with growth factor support. Patients continued to receive treatment, as long as it was tolerated, in the absence of significant disease progression. The disease was followed on imaging scans every 6 weeks. The primary endpoint of the study was the best overall response rate. RESULTS: The best overall response rate was 13% in 23 evaluable patients. Median progression-free survival was 5.8 months, and median overall survival was 26 months. Grade 3 to 4 toxicities of febrile neutropenia and anemia occurred in 21% of treated patients. One patient with metastatic myxoid liposarcoma with TLS-CHOP translocation had a durable response and received 40 cycles of amrubicin. There was no significant cardiac toxicity. CONCLUSIONS: Amrubicin has efficacy comparable to doxorubicin in adult STS, is well tolerated and has no significant cardiac toxicity up to a cumulative dose of 4800 mg /m(2). Topoisomerase II inhibition with amrubicin warrants further study as a potential 'targeted therapy' for TLS-CHOP-translocated myxoid liposarcoma. Results from this trial favor the use of amrubicin for the treatment of STS.

Investigational Aurora A kinase inhibitor alisertib (MLN8237) as an enteric-coated tablet formulation in non-hematologic malignancies: phase 1 dose-escalation study.

BACKGROUND: This phase 1b study evaluated an enteric-coated tablet (ECT) formulation of the investigational Aurora A kinase inhibitor, alisertib (MLN8237). METHODS: Patients with advanced, non-hematologic malignancies received oral alisertib ECT for 7 d BID followed by 14 d treatment-free (21-day cycles; 3 + 3 dose escalation schema). Objectives were to assess safety, pharmacokinetics, and antitumor activity, and to define a recommended phase 2 dose (RP2D) of alisertib. RESULTS: 24 patients were treated. Median age was 57 years. Patients received a median of 2 cycles (range 1-12). The RP2D was determined as 50 mg BID for 7 d (21-day cycles). A cycle 1 dose-limiting toxicity of grade 4 febrile neutropenia was observed in 1 of 13 patients at RP2D. The most common drug-related adverse event (AE) was neutropenia (50%). At doses ≥ 40 mg BID, 7 patients had drug-related AEs that were serious but largely reversible/manageable by dose reduction and supportive care, including 3 with febrile neutropenia. Pharmacokinetic data were available in 24 patients. Following administration of alisertib ECT, the plasma peak concentration of alisertib was achieved at ~3 h; systemic exposure increased with increasing dose over 10-60 mg BID. Mean t½ was ~21 h following multiple dosing. Renal clearance was negligible. Nine patients achieved stable disease (3.98*, 5.59, 1.28*, 2.56, 5.45*, 3.48, 3.15, 8.31, and 6.93* months; *censored). CONCLUSIONS: Alisertib ECT was generally well tolerated in adults with advanced, non-hematologic malignancies. The RP2D is 50 mg BID for 7 d and is being evaluated in ongoing phase 2 studies.

Combining targeted therapy with immunotherapy (interferon-α): Rational, efficacy in gastrointestinal stromal tumor model and implications in other malignancies.

Imatinib revolutionized gastrointestinal stromal tumor (GIST) treatment but median-progression-free-survival of unresectable/metastatic disease is < 2 y. B-RAF(V600)-mutated-melanoma responds to vemurafenib dramatically but median-progression-free-survival is < 9 mo. Combining imatinib with immunotherapy (peginterferon α-2b) in GIST showed significant induction of antitumor immunity and highly promising clinical outcomes. This strategy warrants further testing in other malignancies.

Exploiting antitumor immunity to overcome relapse and improve remission duration.

Cancer survivors often relapse due to evolving drug-resistant clones and repopulating tumor stem cells. Our preclinical study demonstrated that terminal cancer patient's lymphocytes can be converted from tolerant bystanders in vivo into effective cytotoxic T-lymphocytes in vitro killing patient's own tumor cells containing drug-resistant clones and tumor stem cells. We designed a clinical trial combining peginterferon α-2b with imatinib for treatment of stage III/IV gastrointestinal stromal tumor (GIST) with the rational that peginterferon α-2b serves as danger signals to promote antitumor immunity while imatinib's effective tumor killing undermines tumor-induced tolerance and supply tumor-specific antigens in vivo without leukopenia, thus allowing for proper dendritic cell and cytotoxic T-lymphocyte differentiation toward Th1 response. Interim analysis of eight patients demonstrated significant induction of IFN-γ-producing-CD8(+), -CD4(+), -NK cell, and IFN-γ-producing-tumor-infiltrating-lymphocytes, signifying significant Th1 response and NK cell activation. After a median follow-up of 3.6 years, complete response (CR) + partial response (PR) = 100%, overall survival = 100%, one patient died of unrelated illness while in remission, six of seven evaluable patients are either in continuing PR/CR (5 patients) or have progression-free survival (PFS, 1 patient) exceeding the upper limit of the 95% confidence level of the genotype-specific-PFS of the phase III imatinib-monotherapy (CALGB150105/SWOGS0033), demonstrating highly promising clinical outcomes. The current trial is closed in preparation for a larger future trial. We conclude that combination of targeted therapy and immunotherapy is safe and induced significant Th1 response and NK cell activation and demonstrated highly promising clinical efficacy in GIST, thus warranting development in other tumor types.

Sarcoma immunotherapy.

Much of our knowledge regarding cancer immunotherapy has been derived from sarcoma models. However, translation of preclinical findings to bedside success has been limited in this disease, though several intriguing clinical studies hint at the potential efficacy of this treatment modality. The rarity and heterogeneity of tumors of mesenchymal origin continues to be a challenge from a therapeutic standpoint. Nonetheless, sarcomas remain attractive targets for immunotherapy, as they can be characterized by specific epitopes, either from their mesenchymal origins or specific alterations in gene products. To date, standard vaccine trials have proven disappointing, likely due to mechanisms by which tumors equilibrate with and ultimately escape immune surveillance. More sophisticated approaches will likely require multimodal techniques, both by enhancing immunity, but also geared towards overcoming innate mechanisms of immunosuppression that favor tumorigenesis.

Proteolytic cleavage of ataxin-7 by caspase-7 modulates cellular toxicity and transcriptional dysregulation.

Spinocerebellar ataxia type 7 (SCA7) is a polyglutamine (polyQ) disorder characterized by specific degeneration of cerebellar, brainstem, and retinal neurons. Although they share little sequence homology, proteins implicated in polyQ disorders have common properties beyond their characteristic polyQ tract. These include the production of proteolytic fragments, nuclear accumulation, and processing by caspases. Here we report that ataxin-7 is cleaved by caspase-7, and we map two putative caspase-7 cleavage sites to Asp residues at positions 266 and 344 of the ataxin-7 protein. Site-directed mutagenesis of these two caspase-7 cleavage sites in the polyQ-expanded form of ataxin-7 produces an ataxin-7 D266N/D344N protein that is resistant to caspase cleavage. Although ataxin-7 displays toxicity, forms nuclear aggregates, and represses transcription in human embryonic kidney 293T cells in a polyQ length-dependent manner, expression of the non-cleavable D266N/D344N form of polyQ-expanded ataxin-7 attenuated cell death, aggregate formation, and transcriptional interference. Expression of the caspase-7 truncation product of ataxin-7-69Q or -92Q, which removes the putative nuclear export signal and nuclear localization signals of ataxin-7, showed increased cellular toxicity. We also detected N-terminal polyQ-expanded ataxin-7 cleavage products in SCA7 transgenic mice similar in size to those generated by caspase-7 cleavage. In a SCA7 transgenic mouse model, recruitment of caspase-7 into the nucleus by polyQ-expanded ataxin-7 correlated with its activation. Our results, thus, suggest that proteolytic processing of ataxin-7 by caspase-7 may contribute to SCA7 disease pathogenesis.

Expression of the Rho-family GTPase gene RHOF in lymphocyte subsets and malignant lymphomas.

We have studied the expression of RHOF, a member of the Rho-GTPase family, in an array of lymphoid cells and tissues. Previous microarray studies demonstrated RHOF upregulation in a subset of transformed follicular lymphomas. Real-time quantitative polymerase chain reaction evaluated RHOF expression in lymphocyte subpopulations, and normal and malignant lymphoid tissue. Cells and tissues of B-cell origin expressed higher RHOF levels than their T-cell counterparts. Neoplastic cells and tissues of B-cell origin expressed higher levels of RHOF than their benign cellular counterparts. Relatively elevated levels of RHOF were seen in lymphomas derived from germinal centre origin.