The "atheroprotective" mediators apolipoprotein A-I and Foxp3 are over-abundant in unstable carotid plaques

OBJECTIVE

Inflammation is important in plaque vulnerability but the role of atheroprotective mediators in unstable plaques is not defined. The apolipoproteinA-I (apoA-I) component of HDL, and CD4+/CD25+ regulatory T cells (with their major transcription factor, Foxp3), have been implicated in the suppression of vascular inflammation. Our aim was to characterise the presence of these novel "protective" markers (apoA-I and Foxp3) in carotid plaques from symptomatic and asymptomatic subjects.

METHODS AND RESULTS

Plaques from 57 patients (25 symptomatic, 32 asymptomatic) were stained immunohistochemically for macrophages (CD68), T cells (CD3), monocyte chemotactic protein-1 (MCP-1), matrix metalloproteinase-2 (MMP-2), myeloperoxidase (MPO), apoA-I and Foxp3. Twelve randomly selected plaques (6 asymptomatic, 6 symptomatic) were immunostained for interleukin-10 (IL-10) and interleukin-17 (IL-17). Staining was quantified using Image-Pro Plus software. Significantly greater areas of positive immunostaining for CD68, CD3, MCP-1, MMP-2, IL-17 and MPO were found in plaques from symptomatic patients compared with asymptomatic patients (p<0.05 for all). Furthermore, significantly greater areas of positive immunostaining for apoA-I, Foxp3 and IL-10 were found in symptomatic versus asymptomatic plaques (p<0.05 for all). The presence of apoA-I was correlated significantly and co-localised with CD3, CD68, MCP-1, MMP-2 and MPO immunostaining (R=0.70, 0.63, 0.52, 0.55 and 0.79, respectively; p<0.01 for all). Foxp3 immunostaining also correlated significantly with CD3 (R=0.42), CD68 (R=0.47), MCP-1 (R=0.55) and MMP-2 (R=0.44) immunostaining (p<0.05 for all).

CONCLUSIONS

ApoA-I and Foxp3 are over-abundant in plaques from symptomatic subjects and co-localise with key inflammatory mediators. These data suggest ineffective/insufficient protection against atherosclerosis-mediated inflammation by these "atheroprotective" moieties.

A SARC global collaborative phase II trial of R1507, a recombinant human monoclonal antibody to the insulin-like growth factor-1 receptor (IGF1R) in patients with recurrent or refractory sarcomas

10503

Background: The IGF1 system has been implicated in sarcoma development and inhibition of IGF1R function has been shown to induce clinical responses in select sarcomas. Methods: Objectives included response rate (RR) and progression-free survival (PFS) to R1507 in patients with recurrent or refractory Ewing's (ES, 2 cohorts- primary refractory vs. others) osteo (OS), synovial (SS), rhabdomyosarcoma (RMS), and other sarcomas. Eligibility included recurrent/refractory measurable disease, age ≥ 12 yrs, life expectancy ≥ 6 weeks, Karnofsky PS ≥ 70, adequate renal, hepatic and bone marrow function. R1507 was administered i.v. at 9 mg/kg over one hour weekly. Response was assessed by WHO criteria every 6 wks X 4 and every 12 wks thereafter. A two-stage design (Green and Dahlberg) was used. The endpoint for the primary refractory ES cohort was PFS at week 18 (planned n=65). RR was the primary endpoint for the remaining cohorts (planned n=240). Results: From 12/07–12/08, 203 eligible patients from 29 centers across the US, Europe and Australia were enrolled. Age ranged from 12–85 yrs (median=27 yrs) and 126 were male. Verified histologic subtypes were ES (n=71), OS (n=43), RMS (n=28), SS (n=25), and others (n=25). 15 severe adverse events were reported in 9 patients, the most common being fatigue (n=2), thrombocytopenia (n=2), dehydration (n=2), and hyperglycemia (n=2). Clinically significant activity has been observed in ES, RMS and OS with several dramatic responses seen in ES and RMS. Independent radiologic review is currently ongoing and updated data will be presented. Conclusions: The rapid accrual amongst many centers in diverse geographical locations demonstrates the feasibility of collaborative research in sarcomas. R1507 is well tolerated and a promising new agent for the treatment of various sarcomas. SARC and Roche are collaborating in additional clinical trials to better define the role of R1507 in the treatment of selected sarcomas.

[Table: see text]

A randomized phase II study of perifosine (P) plus imatinib for patients with imatinib-resistant gastrointestinal stromal tumor (GIST)

10563

Background: P inhibits activation of the Akt pathway which results in apoptosis and block cancer cell proliferation. Since AKT is a molecule downstream of Kit, its inhibition may overcome Kit-dependent imatinib resistance. We performed a phase II trial to assess antitumor activity of perifosine in patients with advanced GIST who were refractory to imatinib mesylate. Methods: Pts with Kit(+) advanced GIST who have PD on IM were eligible. Pts continued their current dose of IM and were randomized to one of two dosing schedules of P (Arm A: 100 mg p.o. qd x 28 + IM or Arm B: 900 mg [300 mg p.o tid] qweekly + qd IM). A Bayesian approach was utilized to assess a target response rate or 20% with an unacceptable toxicity rate of 15% or less. Response was measured at q8 wk intervals by RECIST and Choi criteria. The primary endpoint was to determine the efficacy of P with IM in pts with advanced GIST with PD while receiving IM. Results: From 8/2005 to 7/2008, 41 pts were accrued. After 1 pt exclusion and 2 cross-overs, 22 pts were in Arm A and 18 pts in Arm B. Median age was 58 (range, 32–82), 51% were male, and median ECOG PS was 1. The most common primary site of disease and metastasis was the stomach (29%) and liver (66%), respectively. KIT genotype was available for 22 pts(54%); 5(12%) WT, 13(32%) exon 11 mutations, and 4(10%) exon 9 mutations. The median number of cycles was 2 (range, 1–24). By Choi and RECIST, 30 pts(73%) and 36 pts(87%) were available for response, respectively. No CR was identified but the PR rate was 4/36 (11%) by Choi (4 PR, 9 SD) and 0/36 (0%) by RECIST (16 SD). 4/5 (80%) of pts with WT KIT appeared to benefit (Choi: 1 PR, 3 SD; RECIST: 4 SD). Median PFS and OS for 40 pts were 2.2 months and 18.3 months. No difference in PFS was noted for the 2 schedules. Toxicity was assessed in 39 pts; 46 grade 3 events and 4 grade 4 events (ALT elevation, blurred vision, fatigue, and mood alteration) were noted. The most common grade 3 event was fatigue (20%). Three pts (7%) were removed from the study for toxicity (Arm A:1 pt, Arm B:2 pts). Conclusions: The addition of P to IM has minimal activity in IM-refractory GIST although its activity in GIST with WT KIT may be further investigated.

No significant financial relationships to disclose.

Evaluation of AMG 531 in chemotherapy-induced thrombocytopenia (CIT): Results of a phase I/II study

e20616

Background: AMG 531 is a Fc-peptide fusion protein (peptibody) that increases platelet production by stimulating thrombopoietin (TPO) receptors. Prior studies have shown the importance of schedule of recombinant TPO to overcome cumulative thrombocytopenia (TCP) caused by high-dose chemotherapy with carboplatin (C), a late-nadir regimen, and doxorubicin and/or ifosfamide (AI), early-nadir regimen. Methods: The objectives of this study were to evaluate the safety and biologic activity of AMG 531 in CIT. Pts receiving high dose C (AUC=11) or AI received CT alone in the study cycle-1 and CT + AMG 531 in the study cycle-2 and subsequent cycles. At least 6 pts were enrolled at each dose level of AMG 531 (1, 3, and 10 mcg/kg). AMG 531 was administered SC as 2 doses given 2 days apart, starting from the day after CT (post-dosing schedule). An additional cohort of 6 pts received AMG 531 (10 mcg/kg) 2 doses administered as predose (day -5) and postdose given on day after CT (pre-/postdosing schedule). Results: Twenty-four of the 27 pts enrolled received the study drug and are evaluable. Treatment with AMG 531 was well tolerated; one pt experienced pulmonary embolism during cycle-6. In the 4 pts that received C with AMG 531 (1 mcg/kg) by post-dosing schedule, there was a reduction in duration of TCP (days < 100,000/mm3; 10 vs 7, p = 0.023, and days < 50,000mm3; 6 vs 2, p = 0.001, in cycles 1 and 2, respectively) and the PLT nadir count was stable (2 pts), increased < 2-fold (1 pt) or > 2-fold (1 pt) in C-2 as compared to C-1. In pts that received AI with AMG 531, there was a trend for increase in PLT nadir count with pre/post dosing schedule with a regimen known to cause cumulative thrombocytopenia from C-1 to C-2 ( Table ). Conclusions: AMG 531 is well tolerated and shows biologic activity in pts receiving CT. These findings suggest that postdosing may be effective with late-nadir regimen such as C. Ongoing study will determine if pre-/postdosing may be more effective with early-nadir regimens such as AI.

[Table: see text]

[Table: see text]

A phase II study of gefitinib in patients with metastatic melanoma

9057

Background: Gefitinib is an inhibitor of epidermal growth factor receptor (EGFR), which is frequently expressed on both choroidal and non-choroidal melanoma cells. We evaluated the clinical efficacy of gefitinib in patients (pts) with metastatic melanoma. Methods: Pts with stage IV or unresectable or recurrent stage III melanoma and Zubrod performance status of 0 to 2 were eligible. For non-choroidal melanoma, pts must have received systemic cytotoxic therapy, but no more than 2 regimens; for choroidal melanoma, pts could be either chemo-naïve or have received up to 2 systemic cytotoxic therapies. The dose of oral gefitinib was 250 mg daily, and tumor response was evaluated every 6 weeks per RECIST. Ten patients with cutaneous disease were also consented for paired biopsies and blood collection for correlative studies at baseline and after 3 weeks of treatment. Results: Fifty-two pts (46 non-choroidal; 6 choroidal primay) were treated and evaluated for toxicity, and 50 pts were evaluable for response. Median age of pts was 62.5 years, with median Zubrod PS Score of 1. The median number of prior systemic treatments was 1. Forty-one pts (79%) had stage M1c disease. There were no drug-related grade 4 or 5 adverse events (AEs), and fatigue was the only grade 3 AEs in >5% of the patients. There were 2 (4%) partial responses, including a pt with metastatic choroidal melanoma, and 13 pts (26%) had disease stabilization. A median duration of response was 9.5 months among the responders. Median time to progression was 6 weeks, and median overall survival was 4.6 months. Among 7 pts with sufficient tissue on paired biopsies, there were no notable trends in the changes of the expression of pERK1/2, pAKT, or pPAK1 with treatment. Additionally, no trends were identified in serum VEGF or IL-8 levels after treatment. Conclusions: Gefitinib was well tolerated, but had minimal clinical efficacy as a single-agent therapy for metastatic melanoma of cutaneous origin. There were no consistent changes in the expressions of downstream kinase proteins with gefitinib treatment.

No significant financial relationships to disclose.

IL2- and IL4-dependent proliferation of T-cell clones derived early after allogeneic bone marrow transplantation: Studies of patients with chronic myelogenous leukaemia

In an attempt to explore T-cell functions shortly after allogeneic bone marrow transplantation more fully, IL2- and IL4-dependent proliferation was assessed on CD4+ TCR alpha beta+ T-cell clones derived 4-6 weeks after transplantation. Both allogeneic pooled peripheral blood mononuclear cells and Epstein-Barr virus-transformed B-cell lines (BCL) could function as accessory cells (AC) for PHA activation of T-cell clones. Although minimal clonal proliferation was seen when the T-cell activation signal was BCL+PHA+IL4, a majority of the clones could undergo IL4-dependent proliferation after previous activation with AC+PHA+IL2. For certain clones, IL4 also showed an additive effect with IL2. Thus, IL4 was a growth factor for a majority of the investigated posttransplant T-cell clones, and in vivo modulation of IL4-dependent T-cell functions may thus become a future therapeutic possibility to enhance graft-versus-leukaemia effects in bone marrow transplant recipients.

New dimensions in endodontic imaging: part 1. Conventional and alternative radiographic systems

Conventional radiographs used for the management of endodontic problems yield limited information because of the two-dimensional nature of images produced, geometric distortion and anatomical noise. These factors often act in combination. This review paper assesses the limitations of periapical radiographs and seeks to clarify three-dimensional imaging techniques that have been suggested as adjuncts to conventional radiographs. These include tuned aperture computed tomography, magnetic resonance imaging, ultrasound, computed tomography and cone beam computed tomography (CBCT). Of these techniques, CBCT appears to be an effective and safe way to overcome some of the problems associated with conventional radiographs.