Evaluation of ALK-1 expression in circulating endothelial cells (CECs) as an exploratory biomarker for PF-03446962 undergoing phase I trial in cancer patients

3573

Background: ALK-1 is a member of the TβRI family & a novel target for antiangiogenic therapy (Rx). PF- 03446962 (PF) is a fully human mAB (IgG2, κ) generated against ALK-1 with dose-dependent preclinical antiangiogenic activities (Hu-Lowe et al, Proc AACR, 2009). This study's objectives were to determine whether: 1) CECs in cancer patients express ALK-1; and 2) whether therapy with PF against ALK-1 will modulate ALK-1 expression or CEC function in an ongoing Ph I trial. Methods: The human mAb was conjugated with alexa fluor 647. ALK-1 expression was assayed by a standardized multicolor flow cytometry assay (Mancuso et al, CCR 2009). Results: ALK-1 expression was characterized on human vascular (HUVEC) & lymphatic (HDLC) endothelial cells; HUVEC & HDLC cells highly express ALK-1 (>99% of these cells are ALK- 1+). ALK-1 expression was assessed in healthy controls (n=17) & cancer patients after normalizing for CEC viability. Patients with advanced malignancies had increased numbers of ALK-1+ CECs: Patients with breast ca (n=12), melanoma (n=8), NSCLC (n=11), & CRC (n=4) had 16±12, 39±23, 50±30, & 62±25 ALK-1+ CECs/mL, respectively, vs 7±6 ALK-1+ CECs/mL in controls. In contrast, ALK-1 expression was minimally or not expressed in pts with hematologic malignancies; ALK-1 was absent in CD117+ or CD34+ bone marrow cells. In the Ph I trial, preliminary evidence suggests that PF may alter CEC function; ALK-1+ CECs were markedly reduced in the 1st two pts studied at EIO after 22 days on Rx. Conclusions: ALK-1 is expressed in CECs. Flow cytometry enables rapid assay of ALK-1 expression in cancer patient blood. ALK-1 is expressed in an increased number of CECs/mL in cancer pts with solid malignancies vs controls. ALK-1 expression in CECs in pts with NSCLC & CRC may correspond to high ALK-1 expression observed in corresponding nonmatched tumor microarrays in addition to other malignancies such as sarcoma, SCLC & neuroendrocine pancreatic ca (Fiedler, Proc ASCO, 2009). Additional preliminary Ph I results will be reported as part of assessing whether CECs may have any role as biomarkers to potentially detect patients with ALK-1+ solid malignancies or monitor anti-ALK-1 therapy.

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hCNT1 in Waldenström’s macroglobulinemia (WM) and small lymphocytic lymphoma (SLL) patients (pts): A possible predictive biomarker of 2-chloro-2`-deoxyadenosine (2-CDA) clinical activity

13087

Background: The resistance mechanism to 2-CDA is not completely known. In this study we used pharmacogenomic to identify genetic factors that influence drug response and to better investigate 2-CDA complex intracellular metabolism. Methods: Using Real-time PCR method (ABI-PRISM 7000 machine) we amplified seven genes, encoding for equilibrative and concentrative nucleoside transporter (hENT1, hCNT1), deoxycytidine and deoxyguanosine kinase (dCK, dGK), 5`-nucleotidase (5`NT), ribonucleotide reductase catalytic and regulatory (RR1, RR2) subunits, in bone marrow (BM) at baseline of 17 pts with WM or SLL in order to verify the correlation between gene expression and clinical outcome. All pts were treated with a combination therapy (2-CDA 0.1 mg/kg sc injection and Rituximab at standard schedule). Quantitation was performed using the Delta CT calculation: the value of gene expression was normalised to the calibrator (healthy tissue cells). Results: hCNT1 and 5’NT gene expression analysis has shown lower values in pts than in controls. The other markers didn’t show any significance. Two pts achieving partial remission (PR) presented 100 times lower hCNT1 levels (median 6.8*10−4, range 6.8–6.9*10−4) than pts (n = 10) in complete remission (median 7.9*10−2, range 0.1–4.6*10−1; p = 0.03). Conclusions: hCNT1 seems to be the most important gene involved in 2-CDA clinical activity and its expression may correlate with prognosis. Compared to controls, the low plasmatic RNA level of hCNT1 exhibited by our pts doesn’t seem to be predictive of lack of clinical activity of 2-CDA. However the lower level of hCNT1 plasmatic expression detected in the two pts who achieved only PR could suggest a possible relationship between reduced hCNT1 plasmatic expression and a diminished clinical activity of 2-CDA. Thus it might be important to explore the possibility of standardizing a quantitative method in order to identify a threshold value which could be predictive of drug resistance.

No significant financial relationships to disclose.

Dot immunobinding assay for detection of mite antigens in house-dust samples

A new test was developed specifically to detect mite antigens in house-dust. It uses a nitrocellulose dipstick spotted with specific antimite antibodies that act as a capture matrix; the same antibodies act as a detecting reagent when conjugated with colloidal dye particles. Aclotest is a 1-step assay, where a spotted dipstick is placed in a tube containing the detecting reagent and the house-dust sample. No instrumentation or previous extraction procedure of the sample is required, and the test response is visible as a colored spot, after 1 h incubation. The sensitivity and specificity of the new test were compared with those of Acarex and Der p1/Der f1 ELISA tests.

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Abstract

<title> SUMMARY </title>Taddei's image is linked to that branch of scientific research that was born in the first half of the nineteenth century, from the interaction of chemistry and physiology. Taddei's studies were a such and so many that it is difficult to put them into a specific branch of research. His works concerning relation of live and inanimate nature become in scientific terms the study of the interaction of organic and inorganic substances. Taddei graduated in medicine and immediately began his research in chemistry at the Accademia of Georgofili. The first works were about the composition of manure and the relation between these and the composition of soil and plants. The studies about glutin are linked to the researches on the chemical composition of foods. His work concerning wheat meal and cereals brought Taddei to discover two distinct substances, « gloiodina » and « zimoma », in the glutin. During his research on glutin and about the possibility of some mercury salts breaking the fermentation of the meals, he observed some interesting phenomena that shifted his attention to toxicology. The interest of Taddei not only about pure science but applied science too, allowed him to obtain results recognized both in Italy and in foreign countries. His researches concerning glutin led him to discover in that substance the property to operate as an antidote towards a dreadful poison: the corrosive sublimate. Taddei's glutin became the best antidote towards the corrosive sublimate after the albumen of Orfila (considered the phomoter of Toxicology). The controversy about the effectiveness of these antidotes is linked to the treatment of a very diffuse disease, syphilis. The syphilitic disease had been treated for many years with drugs containing the corrosive sublimate and the major part of the patient were poisoned by this substance.