A randomized trial of a single-dose rasburicase versus five-daily doses in patients at risk for tumor lysis syndrome

BACKGROUND

Tumor lysis syndrome (TLS) is a life-threatening disorder characterized by hyperuricemia and metabolic derangements. The efficacy of rasburicase, administered daily for 5 days, has been well established. However, the optimal duration of therapy is unknown in adults.

PATIENTS AND METHODS

We evaluated the efficacy of rasburicase (0.15 mg/kg) administered as single dose followed by as needed dosing (maximum five doses) versus daily dosing for 5 days in adult patients at risk for TLS.

RESULTS

Eighty of the 82 patients enrolled received rasburicase; 40 high risk [median uric acid (UA) 8.5 mg/dl; range, 1.5-19.7] and 40 potential risk (UA = 5.6 mg/dl; range, 2.4-7.4). Seventy-nine patients (99%) experienced normalization in their UA within 4 h after the first dose; 84% to an undetectable level (<0.7 mg/dl). Thirty-nine of 40 (98%) patients in the daily-dose arm and 34 of 40 (85%) patients in single-dose arm showed sustained UA response. Six high-risk patients within the single-dose arm required second dose for UA >7.5 mg/dl. Rasburicase was well tolerated; one patient with glucose-6-phosphate dehydrogenase deficiency developed methemoglobinemia and hemolysis.

CONCLUSIONS

Rasburicase is highly effective for prevention and management of hyperuricemia in adults at risk for TLS. Single-dose rasburicase was effective in most patients; only a subset of high-risk patients required a second dose.

Prevalence of painful diabetic peripheral neuropathy among patients with diabetes mellitus in the Middle East region

The prevalence of painful diabetic peripheral neuropathy (DPN) was evaluated in type 1 or type 2 diabetes mellitus patients (n = 4097) attending outpatient clinics across the Middle East. Overall, 53.7% of 3989 patients with DN4 data met the criteria for painful DPN (Douleur Neuropathique-4 [DN4] scores ≥ 4). Significant predictors of painful DPN included long history (≥ 10 years) of diabetes (odds ratio [OR] 2.43), age ≥ 65 years (OR 2.13), age 50 - 64 years (OR 1.75), presence of type 1 versus type 2 diabetes (OR 1.59), body mass index > 30 kg/m(2) (OR 1.35) and female gender (OR 1.27). Living in one of the Gulf States was associated with the lowest odds of having painful DPN (OR 0.44). The odds of painful DPN were highest among patients with peripheral vascular disease (OR 4.98), diabetic retinopathy (OR 3.90) and diabetic nephropathy (OR 3.23). Because of the high prevalence and associated suffering, disability and economic burden of painful DPN, it is important that diabetic patients are periodically screened, using a simple instrument such as the DN4, and receive appropriate treatment if symptoms develop.

Marizomib, a proteasome inhibitor for all seasons: preclinical profile and a framework for clinical trials

The proteasome has emerged as an important clinically relevant target for the treatment of hematologic malignancies. Since the Food and Drug Administration approved the first-in-class proteasome inhibitor bortezomib (Velcade) for the treatment of relapsed/refractory multiple myeloma (MM) and mantle cell lymphoma, it has become clear that new inhibitors are needed that have a better therapeutic ratio, can overcome inherent and acquired bortezomib resistance and exhibit broader anti-cancer activities. Marizomib (NPI-0052; salinosporamide A) is a structurally and pharmacologically unique β-lactone-γ-lactam proteasome inhibitor that may fulfill these unmet needs. The potent and sustained inhibition of all three proteolytic activities of the proteasome by marizomib has inspired extensive preclinical evaluation in a variety of hematologic and solid tumor models, where it is efficacious as a single agent and in combination with biologics, chemotherapeutics and targeted therapeutic agents. Specifically, marizomib has been evaluated in models for multiple myeloma, mantle cell lymphoma, Waldenstrom's macroglobulinemia, chronic and acute lymphocytic leukemia, as well as glioma, colorectal and pancreatic cancer models, and has exhibited synergistic activities in tumor models in combination with bortezomib, the immunomodulatory agent lenalidomide (Revlimid), and various histone deacetylase inhibitors. These and other studies provided the framework for ongoing clinical trials in patients with MM, lymphomas, leukemias and solid tumors, including those who have failed bortezomib treatment, as well as in patients with diagnoses where other proteasome inhibitors have not demonstrated significant efficacy. This review captures the remarkable translational studies and contributions from many collaborators that have advanced marizomib from seabed to bench to bedside.

Prevalence of transferable blaCTX-M-15 from hospital- and community-acquired Klebsiella pneumoniae isolates in Scotland

OBJECTIVES

This study was performed to investigate the prevalence and genetic characteristics of transferable bla(CTX-M-15) from hospital- and community-acquired Klebsiella pneumoniae isolates in Scotland.

METHODS

A total of 219 clinical isolates of K. pneumoniae collected in 2006 and 2007 at the Royal Infirmary of Edinburgh, Scotland, were tested for antimicrobial susceptibility by the agar double dilution method. PCR and sequencing were used to detect bla(CTX-M), bla(TEM), bla(SHV) and qnr genes. Clonality of the isolates was assessed by PFGE.

RESULTS

Sixteen (7.3%) isolates were found to be producers of CTX-M-15 extended-spectrum β-lactamases (ESBLs), of which two isolates (12.5%) were reported to be from patients with community-acquired infections. The ISEcp1 was detected by sequencing 48 nucleotides upstream of bla(CTX-M-15) in all isolates but one. A total of one to two plasmids, ranging in size from ~40 to 210 kb, were observed per strain. By a PCR-based replicon typing method, plasmids carrying bla(CTX-M-15) were assigned to IncFII or IncN types. Sequencing and PCR analysis revealed the presence of complex class 1 integrons in all isolates but one. Two isolates positive for class 1 integrons were positive for class 2 integrons as well. Five different clones of CTX-M-15-producing isolates were identified by PFGE.

CONCLUSIONS

This work reports the emergence of hospital- and community-acquired CTX-M-type enzymes in the Edinburgh area of Scotland.

A Phase 1b/2 trial of mapatumumab in patients with relapsed/refractory non-Hodgkin's lymphoma

Background:

We conducted a multicentre Phase 1b/2 trial to evaluate the safety and efficacy of mapatumumab, a fully human agonistic monoclonal antibody to the tumour necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) in patients with relapsed non-Hodgkin's lymphoma (NHL).

Methods:

Forty patients with relapsed or refractory NHL were treated with either 3 or 10 mg kg⁻¹ mapatumumab every 21 days. In the absence of disease progression or prohibitive toxicity, patients received a maximum of six doses.

Results:

Mapatumumab was well tolerated, with no patients experiencing drug-related hepatic or other dose-limiting toxicity. Three patients with follicular lymphoma (FL) experienced clinical responses, including two with a complete response and one with a partial response. Immunohistochemistry staining of the TRAIL-R1 suggested that strong staining in tumour specimens did not appear to be a requirement for mapatumumab activity in FL.

Conclusions:

Mapatumumab is safe and has promising clinical activity in patients with FL.