Purpose: A first-in-human phase I study was conducted to characterize safety, efficacy, and pharmacokinetic (PK) and pharmacodynamic (PD) properties of lumretuzumab, a humanized and glycoengineered anti-HER3 monoclonal antibody, in patients with advanced cancer.Experimental Design: Twenty-five patients with histologically confirmed HER3-expressing tumors received lumretuzumab (100, 200, 400, 800, 1,600, and 2,000 mg) every two weeks (q2w) in 3þ3 dose-escalation phase. In addition, 22 patients were enrolled into an extension cohort at 2,000 mg q2w.Results: There were no dose-limiting toxicities. Common adverse events (any grade) included diarrhea (22 patients, 46.8%), fatigue (21 patients, 44.7%), decreased appetite (15 patients, 31.9%), infusion-related reactions (13 patients, 27.7%), and constipation (10 patients, 21.3%). The peak concentration (C max ) and area under the concentration-time curve up to the last measurable concentration (AUC last ) of lumretuzumab increased more than dose proportionally from 100 mg up to 400 mg. Linear PK was observed with doses !400 mg q2w indicating target-mediated drug disposition saturation. Downregulation of HER3 membranous protein was observed in ontreatment tumor biopsies from 200 mg, and was maximal at and above 400 mg. An ex vivo assay demonstrated increased activation potential of peripheral NK lymphocytes with lumretuzumab compared with a non-glycoengineered anti-HER3 antibody. Ten patients (21.3%) had stable disease and remained on study at a median of 111 days (range, 80-225 days).Conclusions: Lumretuzumab was well tolerated and showed evidence of clinical activity. Linear serum PK properties and plateauing of PD effects in serial tumor biopsies indicate optimal biologically active doses of lumretuzumab from 400 mg onwards.
# These authors contributed equally to this work.
AbstractPurpose-We evaluated biodistribution and tumor targeting of 89 Zr-lumretuzumab before and during treatment with lumretuzumab, a human epidermal growth factor receptor 3 (HER3)-targeting monoclonal antibody.Experimental design-20 patients with histologically confirmed HER3-expressing tumors received 89 Zr-lumretuzumab and underwent Positron Emission Tomography (PET). In Part A, 89 Zr-lumretuzumab was given with additional, escalating doses of unlabeled lumretuzumab and scans were performed 2, 4 and 7 days postinjection to determine optimal imaging conditions. In Part B, patients were scanned following tracer injection before (baseline) and after a pharmacodynamic (PD)-active lumretuzumab dose for saturation analysis. HER3 expression was determined immunohistochemically in skin biopsies. Tracer uptake was calculated as standardized uptake value (SUV).Results-Optimal PET conditions were found to be 4 and 7 days after administration of 89 Zrlumretuzumab with 100 mg unlabeled lumretuzumab. At baseline using 100 mg unlabeled lumretuzumab, the tumor SUVmax was 3.4 (±1.9) at 4 days postinjection. SUVmean for normal blood, liver, lung and brain tissues were 4.9, 6.4, 0.9 and 0.2, respectively. Saturation analysis (n=7) showed that 4 days after lumretuzumab administration, tumor uptake decreased by 11.9% (±8.2), 10.0% (±16.5) and 24.6% (±20.9) at PD-active doses of 400, 800 and 1600 mg, respectively, when compared to baseline. Membranous HER3 was completely downregulated in paired skin biopsies already at and above 400 mg lumretuzumab.Conclusions-PET imaging showed biodistribution and tumor specific 89 Zr-lumretuzumab uptake. Although, PD-active lumretuzumab doses decreased 89 Zr-lumretuzumab uptake, there was no clear evidence of tumor saturation by PET imaging as the tumor SUV did not plateau with increasing doses.
This paper describes the use of fluorescence two-dimensional differential in-gel electrophoresis in a multiplex analysis of two distinct proteomes. As a model system, cerebral cortex tissues were analyzed from neurokinin1 receptor knockout (NK 1 R2/2) and wild type (NK 1 R1/1) mice in an attempt to identify molecular pathways involved in the function of this protein. Paired NK 1 R2/2 and NK 1 R1/1 samples were labeled with fluorescent Cy3 and Cy5 dyes and electrophoresed on the same two-dimensional gels. Scanning the gels at wavelengths specific for each dye revealed the two different proteomes which were overlaid and the differences in abundance of specific protein spots were determined by the Amersham Biosciences DeCyder Differential In-gel Analysis software. A Cy2-labeled sample pool was co-electrophoresed with all Cy3-and Cy5-labeled sample pairs as an internal standard providing a link for inter-gel comparisons and for more robust statistical analysis of the data. Eight spots were found to be upregulated and two downregulated in the NK 1 R2/2 mice compared to NK 1 R1/1 controls. Matrix assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass fingerprinting was used to identify the proteins. The results illustrate the power of this multiplex proteomics technology and illustrate how proteomics can be used to understand gene function.
Previous cellular, animal, and human studies suggest that increasing plasma HDL cholesterol may modulate insulin secretion. 5,[20][21][22] Cholesteryl ester transfer protein (CETP) inhibition increases plasma HDL cholesterol via a reduction in the transfer of neutral lipids (triglycerides and cholesteryl esters) between HDL and triglyceride-rich lipoprotein particles. The efficacy of this strategy to improve cardiovascular outcomes has not yet been determined, and there is controversy regarding whether CETP inhibition might produce a dysfunctional form of HDL cholesterol, which is less efficient at promoting reverse cholesterol transport than native HDL. 23 This controversy has arisen, in part, because of the early termination of 2 CETP inhibitor trials resulting from adverse events in the case of torcetrapib 24
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.