Paul E. Hurtubise

A Phase II trial of Denileukin Diftitox in patients with previously treated advanced non-small cell lung cancer.

Introduction:Denileukin diftitox, a chimeric protein, uses the cytocidal properties of diphtheria toxin to cells expressing interleukin-2 receptors. The aim of this study was to evaluate the efficacy and safety of denileukin diftitox in the treatment of advanced relapsed nonsmall cell lung cancer (NSCLC). Patients And Methods:Multicenter phase II trial in patients with NSCLC with Eastern Cooperative Oncology Group PS 0–2, stage IIIB/IV at diagnosis, who had failed at least 1 previous chemotherapy regimen. Denileukin diftitox was infused at 18 &mgr;g/kg/d × 5 days, every 21 days for 6 cycles. Results:For the 41 patients enrolled, the median age was 56 years (range, 21–80), 25 were men, and the median number of previous chemotherapy regimens was 2 (range, 1–5). The median number of treatment cycles was 2 (range, 1–6). By RECIST criteria, 18 (44%) had stable disease, 10 (24%) progressive disease, and 13 (32%) were not evaluable for response as they received less than 2 treatment cycles. The median time to disease progression was 1.8 months [range, 0.3–11.3; 95% confidence interval (CI) 1.3–2.6]. Median survival was 5.8 months (range, 0.3–33.6; 95% CI 3.4–11.4). The median follow-up time was 16.1 month. One death from myocarditis verified at autopsy was attributed to treatment. One grade 4 toxicity (vascular leak syndrome) was encountered, and 18 grade 3 toxicities, primarily gastro-intestinal, vascular leak syndrome, and constitutional symptoms. Conclusion:Denileukin diftitox at current dose schedule has limited activity in patients with previously treated NSCLC, manifested by disease control without impact on survival.

Studies on the binding of C3b-coated microspheres to human neutrophils

A method is described for the quantitation of C3b receptors on human neutrophils using a mixture of C3b-coated fluorescent and C3b-coated non-fluorescent microspheres. The method measures the sterically available" C3b receptors on the cells, for example, the receptors available to opsonized bacteria. The use of mixtures of fluorescent and non-fluorescent microspheres resulted in lowered fluorescence intensities of the microsphere-coated neutrophils that were well within the fluorescence limitations of fluorescence activated cell analyzers or sorters used in the assay procedure. These mixtures also allowed the distribution of the C3b-coated microspheres around the neutrophils to be easily visualized in the fluorescence microscope. The binding of the C3b-coated microspheres to the neutrophils was shown to be receptor mediated by typical saturable binding kinetics, by complete inhibition by fluid phase C3b, but not by other proteins and by nearly complete inhibition by anti-C3b receptor antibody. Several parameters that could affect the binding of C3b-coated microspheres to neutrophils were studied; these included time and temperature of incubation of the microspheres with the cells, the diameter of the microspheres, the C3b content of the C3b-coated microspheres, the presence of metal ions, azide, EDTA, protein (BSA, IgG), soybean trypsin inhibitor in the buffers, and the method of isolation of the neutrophils. The C3b-coated microspheres were evenly distributed around the neutrophils in almost all of the cases; however, the neutrophils used in these studies were not activated and were not phagocytosing. The method is extremely reproducible and sensitive in detecting small changes in number of C3b receptors on cells.

Expression of hematopoietic progenitor cell associated antigen CD34 in chronic myeloid leukemia.

The expression of progenitor cell associated antigen CD34 was investigated in cells from 28 patients with chronic myeloid leukemia (CML). The CD34 positivity varied from 0-26% in patients with chronic phases CML (n = 17); from 6-64% in patients with accelerated phase CML (n = 4); and from 27-97% in the patients with blastic crisis of CML (n = 8). The difference in CD34 positivity between chronic (mean 10.1 +/- 2.3%), accelerated (37.7 +/- 13.3%) and blastic (58.0 +/- 7.3%) phases of CML is statistically significant (p less than 0.05), however, the number of patients studied, especially in accelerated and blastic phases is very small. There was no difference in the CD34 positivity of the cells in the peripheral blood and in the bone marrow. CD34 positivity was higher in patients with chronic phase CML at diagnosis (untreated patients) than in those who were studied during treatment. The possible importance of serially studying CD34 positivity in patients with CML is discussed in the paper.

Strong Epidermal Growth Factor Receptor Expression But Not HER2/neu Expression Correlates with Cell Proliferation in Anal Canal Carcinomas

Twenty-eight anal carcinomas were analyzed for their proliferative status and immunoreactivity to epidermal growth factor receptor (EGFR), HER2/neu, and proliferating cell nuclear antigen (PCNA). EGFR was expressed in 97.3% of tumors. Strong EGFR immunoreactivity correlated with a high proliferative rate (p=0.0 14). No obvious relationship existed between HER2/neu immunoreactivity and proliferative rate. The strong correlation between strong EGFR immunoreactivity and tumor proliferation suggests that the EGFR may represent a therapeutic target in anal cancers.

Delineation of the Proliferative Component of Inflammatory Fibroid Polyps of the Intestine

Formalin-fixed, paraffin-embedded tissues from eight intestinal inflammatory fibroid polyps were analyzed using immunohistochemistry and flow cytometry to determine their immunohistochemical properties, DNA content, and the nature of the proliferat ing cells. In all cases, stromal cells stained diffusely for vimentin and focally for actin and histiocytic markers. Cell proliferative activity was assessed by flow cytometry and proliferating cell nuclear antigen staining. The S phase fraction was significantly in creased in inflammatory fibroid polyp when compared to control normal bowel tissues (10.8% ± 8.6% vs 6.7% ± 1.6%, P < .02). S phase fraction and proliferating cell nuclear antigen correlated in the stromal cells (r = 0.78, P < .05). Our data indicate that inflammatory fibroid polyps represent reactive, benign lesions containing poly clonal cell populations with diploid DNA content, and they have increased proliferative activity compared with normal intestinal tissues. Both the stromal cells and the vascu lar cells contributed to the proliferative activity of the lesion. Int J Surg Pathol 2(3): 207-214, 1995