ALBERT

Description: L’abolition de l’Apartheid en Afrique du Sud marque une victoire importante pour les idées démocratiques et pacifiques. Cette passation politique est l’aboutissement de plus de dix ans de mobilisation populaire contre les classifications dites chromatiques: « black », « white », « colored ». Aujourd’hui il subsiste une zone d’ombre sur ces forces antiapartheid. Quel fut le rôle des personnes classées « white » ? Ce livre décrit les trajectoires de trois associations: Black Sash, End Conscription Campaign, Five freedoms Forum. De plus, sont examinées les importantes contributions apportées par les historiens et les artistes. Enfin, l’analyse des symboles d’unité nationale permet de comprendre comment a pu naître une nouvelle identité sud-africaine.

Description: VEGF is a potent angiogenic regulator implicated in increased angiogenesis, which is characteristic of CML. VEGF interacts with its two tyrosine kinase (TK) receptors, Flt-1 (VEGFR-1) and KDR (Flk-1/VEGFR-2). CML therapy with imatinib mesylate, which targets BCR-ABL TK activity, induces haematological remission in 95% and complete cytogenetic remission (CCR)/ major response (MR) in 60% of cases. We describe the serial evaluation of patient bone marrow (BM) trephines and the analysis of the impact of imatinib on VEGF in all stages of CML during therapy. Consecutive CML (n=38) patients (25 males, 13 females, median age of 56 years (19 to 81) were sequentially analysed during the course of imatinib therapy. Chronic phase (CP) n=24, accelerated phase (AP) n=11 and blast crisis (BC) n=3 prior to imatinib therapy. BM examination was performed at diagnosis, at 1 month, then 3 monthly following imatinib therapy. Immunohistochemical analysis determined expression of VEGF, VEGFR1/Flt-1 or VEGFR2/KDR. Results were correlated with cytogenetic response. In normal BM cellular VEGF and its receptors were expressed in megakaryocytes and macrophages, but rarely in myeloid cells. VEGF was not expressed in erythroblasts, lymphocytes or plasma cells. A weak VEGFR1 signal was observed in monocytes/histiocytes and VEGFR2 in histiocytes only. VEGF expression in CML was detected as a diffuse cytoplasmic pattern in myeloid and monocyte precursors, classified as 4+ (very intense staining), 3+ (strong), 2+ (moderate), 1+ (weak), or 0 (completely negative) throughout. The intensity of staining varied and did not correlate with the stage of disease, but VEGF was strongly expressed in the megakaryocytes. Both VEGFR1/Flt-1 and VEGFR2/KDR were expressed in monocytic/myeloid population and in megakaryocytes. The staining intensity varied from borderline detectable to a very strong staining intensity. 14/38 (37%) of patients showed a reduction in VEGF expression, which was particularly marked with respect to VEGFR2 receptor staining. Of these, 10/14 patients (71%) achieved CCR, one MR (major response) and 3 minimal/NR (no response). All patients in this group had a reduction in BM cellularity, median 30% (15–70%). No change in VEGF receptor expression was detected in 10/38 (26%). Only 1 patient achieved CCR, 3 MR, with a minor/NR in the rest (60%), and a median BM cellularity of 30% (10–100%). Increasing VEGF expression was observed in 14/38 patients (37%). Here 6/14 (43%) patients showed NR (2 minor/minimal responses) with CCR in only 4 of the evaluable patients. The median BM cellularity was 25% (10–95%). 3/14 patients went on to develop progressive disease In summary, reduced expression of VEGF and its receptors, particularly KDR, can predict a favourable response to imatinib and correlates with a reduced BM cellularity and cytogenetic response. In patients with an increase or no change in VEGF expression there is a greater incidence of a poor cytogenetic response and a higher tendency to relapse despite a reduction in BM trephine cellularity, but a longer follow-up may be necessary.

Description: Background: AG-013736 is a potent and selective inhibitor of VEGF, PDGF and cKit receptor tyrosine kinases with broad preclinical activity in solid tumors and an AML model. To investigate the anti-leukemic effects of AG-013736 in patients with poor prognosis AML and MDS, we performed a multicenter Phase II Trial. Methods: Eligible patients (pts) had poor prognosis AML (defined as age of pt ≥65 years, secondary AML, or unfavorable cytogenetics) or poor prognosis MDS (defined as ≥10% myeloblasts in marrow or blood). A 2-stage Simon design was employed with an “unimportant” response rate set at 10% and an “important” rate at 30%. The α and β rates were set at 0.1 with 1 response (complete or partial) in 11 pts in the first stage required before proceeding to the second stage. A successful trial required at least 5 responses in 25 pts. AG-013736 was dosed orally at 5 mg twice a day. Marrow and blood samples were taken for various markers of angiogenesis and microvessel density. Results: 12 pts (8 AML; 4 MDS) were enrolled including 1 pt who replaced a patient who was withdrawn for lack of compliance after 1 dose. Average age was 77 (range 58–88) years; 7 men, 5 women; 10 white and 2 Asian. All pts were ECOG performance status 0 (5 pts) or 1 (7). 8 pts required blood and 9 platelet transfusions. 8 pts discontinued for lack of efficacy, 3 for non-compliance, and 1 for refusal to participate further. AG-013736-related Grade 3 and 4 adverse events (AEs) included hypertension or blood pressure (BP) elevation (4), mucosal inflammation (1), and deep vein thrombosis (1). Common (〉10%) mild-moderate AEs included hoarseness (8 pts), diarrhea (5), BP increased or hypertension (4), proteinuria (3), and mucosal inflammation (2). 9 (75%) pts required at least 1 antihypertensive medication. There were no responses, and therefore enrollment was stopped at 12 patients. Patients received study drug for a median of 53 (range 1–190) days, and 2 pts, one with AML and one with MDS, had stable disease for 132 and 190 days, respectively. Treatment-related changes in biomarkers are being assessed. Conclusion: AG-013736 was generally well tolerated in this small cohort of elderly pts, 2 of whom had stable disease of significant duration. The combination of AG-013736 with other targeted therapies or cytotoxic agents appears feasible and may be warranted in future studies in patients with poor prognosis AML/MDS.

Description: Abstract 2918 Natural killer cells (NK) have the unique ability to kill target cells without priming. While their therapeutic potential against various malignancies is becoming more apparent, it has been restricted to the allogeneic setting; NK cells are inhibited by autologous targets by engaging killer immunoglobulin-like receptors with their ligands. Another major challenge to the clinical utility of NK cells is obtaining a sufficient number of NK cells for infusion. Co-culture of blood mononuclear cells (PBMNC) with the leukemic cell line K562, genetically modified to express membrane-bound IL15 and the co-stimulatory molecule 41BBL (K562mbIL15-41BBL) in the presence of IL2 results in robust expansion and activation of NK cells. To determine if NK cells derived from myeloma (MM) patients can be used therapeutically in the autologous setting, we explored the expansion of NK cells from MM patients, their gene expression profiles (GEP), and their ability to kill autologous and allogeneic MM cells from high-risk patients in vitro and in vivo, and compared these to NK cells from healthy donors (HD). PBMNC from MM patients (N=30) co-cultured with irradiated K562mbIL15-41BBL cells expanded a median of 351 fold (range20–10, 430), comparable to the expansion of HD-derived NK cells (N=15, median 803, range 127–1, 727; p=0.5). GEP of MM non-exp-NK differed from HD non-exp-NK in the expression of only one gene (PRKCi), underexpessed in MM (false discovery rate (FDR)

Description: Vascular endothelial growth factor (VEGF) plays a seminal role in neo-angiogenesis. VEGF is present on myeloma cells, and its receptors, VEGFR1 (Flt-1) and VEGFR2 (KDR) are detectable on the surface of neighboring myeloid and monocytic elements. Hence, VEGF is implicated in the pathogenesis of multiple myeloma (MM). Thalidomide, an important agent in the treatment of MM, among its many postulated mechanisms of actions also inhibits VEGF-mediated neo-angiogenesis. We set out to test the feasibility and explore the efficacy of combining an anti-VEGF agent with thalidomide. With the availability of the anti-VEGF antibody rhuMAB bevacizumab, a trial of bevacizumab 10 mg/kg given intravenously every 2 weeks alone (in thalidomide-exposed patients) versus a randomized comparison of bevacizumab +/− thalidomide 50–400 mg/day (in thalidomide naive patients) was initiated by the California Cancer Consortium. Twelve patients (median age:58 years; range:50–75) with initial stages of I (n:2), II (n:2) and III (n: 8), all with refractory MM have been enrolled. Patients received a median of 1 prior regimen (range:0–5). Six patients had failed an autologous stem cell transplant prior to enrollment. In patients who have received bevacizumab alone, grade 3 toxicities included fatigue and neutropenia (1), hypertension (1), and hyponatremia (1). In the group receiving bevacizumab and thalidomide, grade 3 lymphopenia was observed in 1 patient during cycle 3, and one patient was taken off study due to exacerbation of pre-exisiting (diet pill induced) pulmonary hypertension and was considered inevaluable. Median time to progression for the 6 patients treated with bevacizumab alone was 2 (range 1–4) months. Progression-free survival for the 5 evaluable patients treated with bevacizumab and thalidomide is 6 +, 7, 8 +, 10, and 30 + months, with 2 patients still on study and in response. Two of these patients did not progress but were taken off study (one for patient’s choice, and one due to the physician’s choice to pursue a stem cell transplant at 7.5 months, this patient is listed above as in response at 30 + months). Immunohistochemical staining (IHC) revealed 2 + to 4 + expression of VEGF on myeloma cells in 7 cases of the available 8 pre-treatment bone marrow samples. Weak staining (1+) of VEGFR1 was observed on the surface of myeloma cells in 5 cases. VEGFR2 expression was also observed on plasma cells by IHC (1+ to 2+) in 5 cases. Myeloma cells from a patient treated with bevacizumab alone for a duration of 4 months, and from a patient receiving bevacizumab and thalidomide for 7.5 months before going on to transplant, demonstrated the strongest staining intensity for VEGF. Due to slow accrual the study had been closed to accrual, although 2 patients continue on the bevacizumab and thalidomide arm. However, in light of our findings further testing of bevacizumab, preferably in combination with other active agents is warranted. Supported by NO1 CM 17101.

Description: In addition to its role in diagnosis and assessing the prognosis of numerous malignancies, immunohistochemistry (IHC) is an important tool for the analysis of protein biomarker expression in tissue sections. The combination of bone marrow (BM) biopsy and IHC is frequently used to study histopathological alterations in diseases such as multiple myeloma (MM). However, due to the harsh decalcification process generally used for processing of bone marrow biopsies, protein epitopes are occasionally rendered unsuitable for IHC detection. We have developed a novel technique for processing BM spicule samples into a fibrin-clot matrix that allows for IHC detection of MM protein markers. This method does not require decalcification and results in a consistent, reliable assay. Briefly, bone marrow aspirates drawn from MM patients were subjected to a brief processing step to isolate the marrow spicules. Once isolated, the spicules were admixed with thromboplastin and pooled normal human plasma to create a clot. The clot was allowed to harden at 37°C after which it was placed into an embedding cassette for fixation and histological processing. The result was a formalin-fixed, paraffin-embedded clot suitable for IHC studies, including the construction of TMAs. Using patient paired spicule-clot and core biopsies from patients diagnosed with myeloma, we studied several antibodies including, but not limited to, kappa and lambda immunoglobulin light chains, CD138 and Cyr61, a member of the CCN family of extracellular matrix-associated signaling proteins. Results demonstrated that IHC staining for all antibodies was comparable in both the spicules and in the cores. While BM core biopsies had areas of non specific staining for several antibodies, this was not generally observed in the BM spicule samples with the exception of immunoglobulin light chains which displayed an element of non-specific staining with both samples. Moreover, we observed a consistently superior morphology in the BM spicule samples than in matched bone marrow core biopsies. In conclusion, our study demonstrates that BM spicule samples processed from MM patients using this novel fibrin-clot matrix technique were suitable for IHC and had generally lower background and non-specific staining coupled with better morphology when compared to matched core biopsies.