Heterogeneity of intermediate prognosis patients (pts) with metastatic renal cell cancer (mRCC) treated with sunitinib

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Background: The Memorial Sloan Kettering Cancer Center risk model (MSKCC) stratifies pts with mRCC into 3 prognostic groups based on 5 risk factors. The Intermediate Prognosis (INTMP) risk group is characterized by the presence of 1 or 2 factors, equivalent to 15 possible distinct entities. This heterogeneity suggests that the efficacy of tyrosine kinase inhibitors may be less predictable in the INTMP than in the other groups. Methods: We identified 548 patients with INTMP mRCC from a pooled analysis of patients treated with sunitinib in 6 prospective phase II and III clinical trials. Statistical analysis was performed using Cox regression and Kaplan-Meier methods and Pearson chi-square tests. Results: Most INTMP pts were male (69%), with clear cell carcinoma (93%), good ECOG performance status (PS) (60.5% PS 0; 38% PS 1; 1.5% PS 2) and median age 60. There were 325 pts (56%) with 1risk factor, and the most common were <1 year from diagnosis (38%); low hemoglobin (Hg) (29%), or both (16%). Objective response rate (RR) was 35.4%, progression free survival (PFS) was 8.4 months (m) and overall survival (OS) was 20.5 m. The 325 (59.3%) pts with one risk factor fared better than the 223 (40.7%) patients with two: PFS 10.7 vs 6.5 m, HR 0.684(95% CI 0.563-0.832, p<0.001); OS 26.3 vs 14.1 m, HR 0.522 (95% CI 0.420-0.648, p<0.001). RR was similar (38.5% vs 30.9%, p=0.071). Sunitinib was more effective in pts with PS 0: PFS 9.7 vs 7.8 m, HR 0.797 (95% CI 0.654-0.972, p=0.0242); OS 24.7 vs 14.0 m, HR 0.529 (95% CI 0.426-0.657, p<0.001), RR 38.9% vs 30.1%, (p=0.036). The most common grade 3/4 adverse events (AE) were fatigue (17%), hypertension (10%), hand foot skin reaction (9%), and nausea (4%). Overall, 17% of patients discontinued due to AE, and the overall pattern of AEs did not vary among the subgroups. Conclusions: MSKCC INTMP is a heterogeneous group comprised mostly of pts with low Hg and/or < 1 year from diagnosis. PFS and OS are superior in pts with 1 vs. 2 risk factors, and PS is also an important factor in the INTMP group. Sunitinib is active and well-tolerated in INTMP pts. Clinical trial information: NCT00077974, NCT00083889, NCT00137423, NCT00267748, NCT00338884, NCT00054886.

Prognostic significance of bone metastases (BM) and bisphosphonate (BIS) therapy in patients with metastatic renal cell carcinoma (mRCC) treated with molecularly targeted agents (MTAs)

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Background: BM are frequently present in patients with mRCC. BM cause significant morbidity and are associated with high rates of skeletal related events (SREs). The purpose of this retrospective analysis was to assess the impact of BM and BIS use on outcomes including progression-free survival (PFS) and overall survival (OS) in patients with mRCC. Methods: We conducted a pooled analysis of patients with mRCC treated from 2003-2011 on phase III (NCT00083899, NCT00065468, NCT00678392) and phase II trials (NCT00054886, NCT00077974, NCT00083889, NCT00338884, NCT00137423). Statistical analyses were performed using Cox regression and the Kaplan-Meier method. Results: We identified 2,749 patients treated with sunitinib (n=1,059), sorafenib (n=335), axitinib (n=359), temsirolimus (TEM) (n=208), TEM + interferon-alfa (IFN) (n=208), or IFN (n=560). Most patients were male (71%), had baseline ECOG PS of 0 (47%) or 1 (51%), clear cell histology (91%), and prior nephrectomy (84%). 285 patients (10.4%) received treatment with BIS (zoledronic acid n=233, pamidronate n=57, unspecified n=1). No patients received denosumab. Of the 2,504 patients with data regarding site of metastasis at diagnosis, 31.9% (n=781) had BM. The rate of SREs in patients with BM compared to patients without BM was 6.4% versus 1.4% (p<0.0001). Presence of BM was associated with shorter PFS (5.1 vs. 6.7 months (mo), HR 1.195, 95% CI 1.076-1.328, p<0.0008) and OS (13.2 vs. 20.2 mo, HR 1.292, 95% CI 1.145-1.456, p<0.0001) when compared to those without BM. In patients with BM, the use of BIS was not associated with improved PFS (5.1 vs. 4.9 mo, HR 0.867, 95% CI 0.704-1.067, p=0.1785) or OS (13.3 vs. 13.1 mo, HR 0.904, 95% CI 0.722-1.132, p=0.3801) when compared to patients who did not receive BIS. In patients with BM stratified by type of first-line MTA (TKI, mTOR inhibitor, or IFN-based), use of BIS was not associated with improved PFS or OS. Conclusions: In this analysis, we confirm that the presence of BM is an adverse risk factor for shorter PFS and OS in patients with mRCC treated with MTAs. Treatment with BIS did not have a positive impact on survival in this cohort.

Final results of a phase I study evaluating the combination of linsitinib, a dual inhibitor of insulin-like growth factor-1 receptor (IGF-1R), and insulin receptor (IR) with weekly paclitaxel (PAC) in patients (Pts) with advanced solid tumors

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Background: Linsitinib (OSI-906) is an oral inhibitor of IGF-1R and IR. Increased IGF-1R and IR activity is observed in human cancers and implicated in resistance to chemotherapy. In preclinical studies, linsitinib blocked IGF-1R/IR-AKT pathway activity evoked by PAC treatment. This study combines linsitinib + a cytotoxic agent. Methods: Pts with advanced solid tumors received weekly IV PAC (80mg/m2) in 21-day cycles with intermittent linsitinib (Arm A, d1-3q7d) or continuous linsitinib (Arm B, B2 and B3, twice daily (BID) d1-21). The primary objective was to determine the maximum tolerated dose (MTD) of linsitinib + PAC using a standard 3+3 phase I design. Results: 58 pts were treated (49F:9M, median age 58 yrs). Linsitinib doses of 300mg to 600mg daily (QD) d1-3q7d in Arm A and 75mg to 150 mg BID in Arm B were evaluated. Dose limiting toxicities in Arm A (n=27) were grade G3 neutropenia, G2 neuropathy and G3 deep vein thrombosis (DVT), and in Arm B (n=31) were G3 hyperglycemia, G3 fatigue (n=2) and G4 pulmonary embolism (PE). DVT and PE were reported as unrelated to linsitinib. MTD: Arm A = 600mg QD d1-3q7d Arm B = 150mg BID. Most common drug-related toxicities in ≥20%were (any grade; G3): fatigue (60%; 15.5%), nausea (48%; 0%), alopecia (48%; 0%), diarrhea (36%; 5%), drug eruption (21%; 2%), neuropathy (26%; 2%) and dysgeusia (24%; 0%). The median duration of exposure (days) for Arm A was 64.5, 91.0, 132.0 and 159.5 for the 300mg, 400mg, 450mg and 600mg doses, respectively. In Arm B, median duration of exposure (days) was 232.0 and 87.5 for the 75mg and 150mg doses, respectively. Partial response was achieved in 6 pts (10%)-3 ovarian, 1 primary peritoneal, 1 endometrial, and 1 esophageal. Stable disease was achieved in 25 pts (43%) - 10 ovarian, 2 primary peritoneal, 1 endometrial, and 12 pts in other tumor types. Pharmacokinetic (PK) results suggested no substantial PK interaction when linsitinib was administered 2 hours prior to PAC. Conclusions: Linsitinib + PAC did not show any unexpected safety concerns given the known mechanism of action, at doses up to the single agent MTDs. Clinical trial information: NCT00889382.

Retrospective analysis of risk factors for fatigue in clinical trial patients (pts) with metastatic renal cell carcinoma (mRCC)

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Background: Fatigue is a common toxicity in pts with mRCC, often associated with therapy, particularly with tyrosine kinase inhibitors (TKI). We performed a pooled retrospective analysis of pts with mRCC treated in clinical studies in order to explore predictors for fatigue. Methods: Data from pts treated in Pfizer mRCC trials (2003-2011) from phase III (NCT00083899, NCT00065468, NCT00678392) and phase II trials (NCT00054886, NCT00077974, NCT00083889, NCT00338884, NCT00137423) were included. Adverse event (CTCAE v3.0) terms of “fatigue” and “asthenia” were used. Hypothyroidism was defined as TSH>ULN or T4<LLN. A multivariate logistic regression analysis was performed to identify significant risk factors for grade (G) 2 (moderate or causing difficulty performing some ADL) or higher fatigue. Results: 2749 pts (71% male) with a median age 60 (33% ≥65) were treated (median 162 days) with axitinib (n=359), sunitinib (n=1059), temsirolimus (TEM) (n=208), interferon-alfa (IFN) (n=560), sorafenib (n=335), or TEM + IFN (n=208). Most pts had baseline ECOG PS of 0 (47%) or 1 (51%), clear cell histology (91%), and nephrectomy (84%). 553 (20%) pts reported fatigue prior to starting study therapy. During study, fatigue was reported in 1794 (65%) pts (21% G1, 26% G2, 17% G3, 1% G4); in 61% pts worst grade was reported within the first 2 months of therapy. Fatigue led to discontinuation in 2%, and dose interruption or adjustment in 8%. Of 1773 pts treated with TKIs, 42% had ≥G2 fatigue. Of pts treated with TEM, IFN or both, 39%, 50% and 50%, respectively, had ≥G2 fatigue. Baseline factors [Odds Ratio] associated (p < 0.05) with ≥G2 fatigue were pretreatment fatigue [1.7] or hypothyroidism [1.6], age ≥65 [1.6], time from diagnosis ≥1 yr [1.4], female gender [1.3], ECOG PS 0 [0.7], and Asian vs Caucasian race [0.5]. Baseline LDH, calcium, and anemia were not significant. Conclusions: Pt attributes and comorbidities at baseline, independent of therapy, are associated with increased risk of clinically significant fatigue in pts treated for mRCC, and can be used to generate a predictive model. Appropriate counseling and control of co-morbid conditions may be important in managing fatigue in pts on TKI therapy.

Comparison of central and intraesophageal factors between gastroesophageal reflux disease (GERD) patients and those with GERD-related noncardiac chest pain

Gastroesophageal reflux disease (GERD) causes a wide range of symptoms. Some patients present with typical symptoms such as heartburn and regurgitation and others with atypical symptoms such as chest pain. The mechanism responsible for the varying clinical presentation of GERD is still not fully elucidated. The aim of this study was to prospectively evaluate differences in central and local intraesophageal factors between patients with typical GERD symptoms and those with noncardiac chest pain (NCCP). Patients presenting with typical and atypical symptoms suspicious of GERD underwent upper endoscopy and 24-hour pH monitoring with four sensors, each positioned at a different esophageal level. All patients completed GERD symptom, Hospital Anxiety and Depression Scale, and Symptom Stress Rating questionnaires. From January 2006 to December 2009, 50 patients were recruited, 29 with typical symptoms, and 21 with NCCP. Patients with proven GERD and NCCP had higher proximal extension of acid during reflux episodes than patients with typical symptoms. They were found to be older, had a shorter history of symptom onset, worse anxiety scores, and more endoscopic findings compatible with gastritis. Proximal extension of acid during the reflux episodes in patients with GERD presenting with NCCP may play a role in symptom generation.

Comparison of central and intraesophageal factors between gastroesophageal reflux disease (GERD) patients and those with GERD-related noncardiac chest pain

Gastroesophageal reflux disease (GERD) causes a wide range of symptoms. Some patients present with typical symptoms such as heartburn and regurgitation and others with atypical symptoms such as chest pain. The mechanism responsible for the varying clinical presentation of GERD is still not fully elucidated. The aim of this study was to prospectively evaluate differences in central and local intraesophageal factors between patients with typical GERD symptoms and those with noncardiac chest pain (NCCP). Patients presenting with typical and atypical symptoms suspicious of GERD underwent upper endoscopy and 24-hour pH monitoring with four sensors, each positioned at a different esophageal level. All patients completed GERD symptom, Hospital Anxiety and Depression Scale, and Symptom Stress Rating questionnaires. From January 2006 to December 2009, 50 patients were recruited, 29 with typical symptoms, and 21 with NCCP. Patients with proven GERD and NCCP had higher proximal extension of acid during reflux episodes than patients with typical symptoms. They were found to be older, had a shorter history of symptom onset, worse anxiety scores, and more endoscopic findings compatible with gastritis. Proximal extension of acid during the reflux episodes in patients with GERD presenting with NCCP may play a role in symptom generation.

Abstract A8: GPNMB is an independent prognostic indicator of recurrence and a therapeutic target in triple negative breast cancer

Purpose: While the murine orthologue of GPNMB (Glycoprotein non-metastatic B, DC-HIL, HGFIN), Osteoactivin, has been shown to promote breast cancer metastasis in an in vivo mouse model, its importance in human breast cancer is unknown. We have examined the significance of GPNMB expression as a prognostic indicator of recurrence and assessed its potential as a novel therapeutic target in breast cancer.

Experimental Design: The clinical significance of GPNMB expression in breast cancer was addressed by analyzing GPNMB mRNA levels in several published gene expression datasets and by determining GPNMB protein expression in two independent tissue microarrays derived from human breast tumors. Human breast cancer cell lines endogenously or exogenously expressing GPNMB were further used to validate a toxin-conjugated anti-GPNMB antibody as a novel therapeutic agent.

Results: GPNMB expression correlates with shorter times to recurrence and reduced overall survival of breast cancer patients. Epithelial-specific staining of GPNMB serves as an independent prognostic indicator for breast cancer recurrence. GPNMB is highly expressed in basal and triple-negative (TN) breast cancers and is associated with increased risk of recurrence within this subtype. GPNMB expression confers a more migratory and invasive phenotype on breast cancer cells. Treatment of mice harbouring endogenous GPNMB-expressing human breast cancer xenografts with CDX-011 (glembatumumab vedotin, CR011-vcMMAE), a GPNMB-targeted antibody-drug conjugate, induces and sustains tumor regression in vivo.

Conclusions: GPNMB expression is associated with the basal/TN subtype and is a prognostic marker of poor outcome in patients with breast cancer. CDX-011 (glembatumumab vedotin) is a promising new targeted therapy for patients with metastatic TN breast cancers, a patient population that currently lacks targeted-therapy options.

Citation Information: Clin Cancer Res 2010;16(7 Suppl):A8

Glycoprotein nonmetastatic B is an independent prognostic indicator of recurrence and a novel therapeutic target in breast cancer

PURPOSE

Although the murine orthologue of glycoprotein nonmetastatic B (GPNMB), Osteoactivin, promotes breast cancer metastasis in an in vivo mouse model, its importance in human breast cancer is unknown. We have examined the significance of GPNMB expression as a prognostic indicator of recurrence and assessed its potential as a novel therapeutic target in breast cancer.

EXPERIMENTAL DESIGN

The clinical significance of GPNMB expression in breast cancer was addressed by analyzing GPNMB levels in several published gene expression data sets and two independent tissue microarrays derived from human breast tumors. GPNMB-expressing human breast cancer cell lines were further used to validate a toxin-conjugated anti-GPNMB antibody as a novel therapeutic agent.

RESULTS

GPNMB expression correlates with shorter recurrence times and reduced overall survival of breast cancer patients. Epithelial-specific GPNMB staining is an independent prognostic indicator for breast cancer recurrence. GPNMB is highly expressed in basal and triple-negative breast cancers and is associated with increased risk of recurrence within this subtype. GPNMB expression confers a more migratory and invasive phenotype on breast cancer cells and sensitizes them to killing by CDX-011 (glembatumumab vedotin), a GPNMB-targeted antibody-drug conjugate.

CONCLUSIONS

GPNMB expression is associated with the basal/triple-negative subtype and is a prognostic marker of poor outcome in patients with breast cancer. CDX-011 (glembatumumab vedotin) is a promising new targeted therapy for patients with metastatic triple-negative breast cancers, a patient population that currently lacks targeted-therapy options.

Pharmacokinetics (PK) of CR011-vcMMAE, an antibody-drug conjugate (ADC), in a phase (Ph) I study of patients (pts) with advanced melanoma

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Background: CR011-vcMMAE, an ADC of fully-human monoclonal anti-GPNMB antibody (Ab) with monomethylauristatin E (MMAE), is in Ph I/II trials in pts with melanoma and breast cancer. We report PK and toxicity data from a Ph I study in melanoma pts treated every (q) 3 weeks (w), qw, or 2 of 3w. Methods: Enzyme-linked immunosorbent assays were used to measure ADC, total Ab (TA), soluble GPNMB (sGPNMB), and anti-ADC Ab in pt samples. Free MMAE was measured by liquid chromatography/mass spectrometry. Results: Initially, 32 pts were treated in 9 cohorts of 0.03 to 2.63 mg/kg iv q3w using standard 3+3 dose escalation. Noncompartmental PK analysis showed dose-proportional TA, ADC and free MMAE levels. As previously reported, maximum tolerated dose (MTD) was 1.88 mg/kg iv q3w; dose limiting toxicity (DLT) was rash. At MTD (n=15), terminal phase half life (T½) of TA was 41 ± 25h and T½ of ADC was 29 ± 13h. Mean maximum plasma concentrations of free MMAE was 1.3–2.9% of TA concentration across all doses. Mean sGPNMB at baseline was 12 ng/ml (range 1.3–32 ng/ml), corresponding to 0.024 % of TA concentration at MTD. Anti-ADC Ab were detectible in 8/240 (3.3%) samples (n=54). Based on the T½, two additional dose schedules (qw and 2 out of 3w) were initiated (n=14). Pts received 0.75 mg/kg (n=3) and 1.0 mg/kg (n=5) in the qw schedule and 1.25 mg/kg (n=3) and 1.5 mg/kg (n=3) in 2 of 3w. The most common adverse events (AEs) were rash (n=6), pruritus (n=5) and fatigue (n=4). 1 DLT (Gr 3 rash) was observed at 1.0 mg/kg qw. Enrollment is ongoing in both schedules. Conclusions: The relatively short T½ of CR011-vcMMAE (∼40h) does not appear to be due to immunogenicity or sGPNMB-mediated clearance. Preliminary data suggest that weekly dosing is tolerated at higher per-cycle cumulative doses than the q3w schedule.

[Table: see text]

A phase I/II study of CR011-vcMMAE, an antibody-drug conjugate (ADC) targeting glycoprotein NMB (GPNMB) in patients (pts) with advanced melanoma

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Background: GPNMB is expressed on melanoma cells and represents a potential target for ADCs. CR011-vcMMAE is a fully-human monoclonal antibody to GPNMB conjugated to the tubulin inhibitor monomethylauristatin E (MMAE). Dose limiting toxicity in Phase I (n=32) was rash; tumor shrinkage including one partial response (PR) was observed. We now report Phase II data at the maximum tolerated dose of 1.88 mg/kg iv q3w. Methods: Eligible pts had unresectable stage III or stage IV melanoma and had received no more than 1 prior cytotoxic regimen but any number of other therapies. Pts received CR011-vcMMAE until disease progression (PD) or intolerable toxicity. The primary endpoint was overall response (ORR) by RECIST using a minimax two-stage design (p0=0.5; p1=0.2, α=β=0.1) with 18 patients in the first stage and a total of 32 pts. Secondary endpoints included progression free survival (PFS) and duration of response. Results: 36 pts (median age 67 years [range 37–79]; 94% stage IV; 68% M1c) were treated for a median of 2.4 months (m)(range 0.5–7.5m). 18 pts discontinued (14 PD, 2 consent, 1 adverse event [AE], 1 stable disease [SD]) and 18 pts were ongoing. The study met the criteria for advancement to the second stage; 4 PRs (1 unconfirmed) and 19 SD (range 1.7–7.5 mo) have been observed; final ORR is pending. The unconfirmed PR was in a pt with 96% tumor reduction and PD 6 weeks later. Median PFS was 4m. The most common AEs were rash (81%), fatigue (72%), alopecia (63%) and pruritus (56%). The most common grade 3/4 AEs were neutropenia (22%) and rash (19%). Grade 2 or higher rash was associated with longer PFS. Conclusions: CR011-vcMMAE is active and well-tolerated in heavily pretreated pts with advanced melanoma. Rash may be a useful biomarker for activity. More frequent dosing is being explored.

[Table: see text]

A phase I/II study of CR011-vcMMAE, an antibody-drug conjugate, in patients (pts) with locally advanced or metastatic breast cancer (MBC)

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Background: Glycoprotein NMB (GPNMB), also known as osteoactivin, has been shown to regulate metastasis of breast cancer in vivo. CR011-vcMMAE, a fully-human monoclonal anti-GPNMB antibody conjugated to the tubulin inhibitor monomethylauristatin E, is safe and active in pts with advanced melanoma. This is the first study of CR011-vcMMAE in breast cancer. Methods: Eligible pts with MBC had ≥ 2 prior chemotherapy regimens, including a taxane, an anthracycline, and capecitabine; and ECOG PS ≤ 2. Doses were escalated to 1.88 mg/kg IV q3w (the maximum tolerated dose [MTD] in melanoma) using a standard 3+3 design. Immunohistochemistry (IHC) with goat polyclonal antibody to GPNMB was performed on pt biopsy specimens and on tissue microarrays containing normal breast, DCIS, breast tumor and lymph node metastases. Results: 10 pts with MBC (median age 57, range 36 - 69) had a median of 7 prior regimens and were treated with CR011-vcMMAE for a median of 2 cycles (range 1–4). In the first 2 pts at 1.34 mg/kg, dose limiting toxicity of worsening peripheral sensory neuropathy was observed. Pts with baseline neuropathy worse than grade 1 were subsequently excluded. Pts were treated at 1.0 mg/kg (n = 3), 1.34 mg/kg (n = 5), and 1.88 mg/kg (n = 2); enrollment at 1.88 mg/kg is continuing. Other adverse events (AEs) were grade 1/2 anorexia and pain in 4 pts; diarrhea, rash, fatigue, and neuropathy in 3 pts; and grade 3 rash in 1 pt. Evidence of antitumor activity has been observed. A response of 37% tumor shrinkage was seen in a pt after only 2 cycles and is ongoing. A second pt had a 51% reduction after 2 cycles, but had PD after 12 weeks. Breast tumor samples were more likely to stain positive for GPNMB than normal breast tissues. Conclusions: CR011-vcMMAE 1.34 mg/kg IV q3w is well-tolerated in heavily pretreated pts with MBC. The 1.88 mg/kg q3w dose is being assessed and phase II expansion is planned at the MTD. IHC of pt tumor specimens is being evaluated.

[Table: see text]

Amniotic stem cell international

Cells derived from the amniotic fluid for genetic diagnosis share many biological characteristics of stem cells. Recent studies at the single cell (clonal) level identified cells of the three embryonic germ layers in the amniotic fluid. It was therefore decided to establish an international non-profit alliance to create a repository of stem cells from the surplus cells remaining after completion of the cytogenetic analysis.

Final results of the randomized phase III trial of sorafenib in advanced renal cell carcinoma: Survival and biomarker analysis

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Background: Based on the significant PFS benefit of sorafenib (SOR) vs placebo (P) in a Phase III advanced RCC trial, P patients were unblinded and crossed over to SOR in May 2005. Final OS and biomarker data are reported. Methods: Final OS analysis was planned at ∼540 events (a=0.037 after adjusting for previous analyses). To minimize effect of crossover on OS, a secondary analysis was planned censoring P data on June 30, 2005 (a=0.037). Plasma VEGF and sVEGFR2 were measured by ELISA at baseline (BL), cycle (C) 1 day (D) 21, and C3D1. pERK was assayed by IHC. Results: 903 patients were randomized (SOR, 451; P, 452). The only OS analysis before crossover (May 2005) showed an estimated 39% OS improvement for SOR vs P (HR=0.72; p=0.018) (ECCO 2005); 216 P patients had crossed to SOR. OS analysis 6 months after crossover (Nov 2005) showed a 30% improvement in OS for SOR vs P (HR=0.77, p=0.015) (ASCO 2006). These OS differences did not reach prespecified O’Brien-Fleming statistical boundaries. Final OS (Sep 2006) at 561 deaths showed an improvement of 13.5% for SOR vs P and was not significant (median 17.8 vs 15.2 months; HR=0.88; p=0.146; a=0.037). Secondary analysis censoring P data (June 2005) showed a significant OS benefit for SOR vs P (HR=0.78, 95% CI: 0.62, 0.97; p=0.0287; a=0.037), suggesting crossover had confounded OS. Changes in VEGF (n=712) and sVEGFR2 (n=717) were observed after SOR treatment (AACR 2006); VEGF increased 32% (n=279) at C1D21 and 47% (n=203) at C3D1, and sVEGFR2 decreased 18% (n=282) and 24% (n=206). Using a COX proportional hazards model, BL VEGF was an independent prognostic factor (p=0.014); patients with high BL VEGF (>131 pg/ml) had poorer prognosis and a trend towards greater PFS benefit with SOR (SOR vs P, HR=0.48 vs 0.64 for high vs low VEGF, p=0.096). BL sVEGFR2, changes in VEGF or sVEGFR2 at C1D21, and pERK levels in limited diagnostic tumor biopsies were not predictive of SOR response. Conclusion: SOR demonstrated a PFS benefit in advanced RCC, although ITT final OS analysis showed a confounding effect of crossover. Significant OS benefit of SOR was seen in a planned secondary analysis adjusting for crossover. VEGF levels have prognostic importance, and SOR-associated changes in VEGF and sVEGFR2 are consistent with inhibition of VEGF signaling.

No significant financial relationships to disclose.

Phase I Trial of Sorafenib in Combination with Gefitinib in Patients with Refractory or Recurrent Non–Small Cell Lung Cancer

PURPOSE

To evaluate the combination of sorafenib and gefitinib in patients with advanced non-small cell lung cancer.

EXPERIMENTAL DESIGN

In this dose-escalation trial, patients received oral sorafenib (200-400 mg) twice daily with gefitinib (250 mg orally) once daily to identify the recommended dose for phase II trials (RDP; part A). The pharmacokinetics of the RDP were characterized further in additional patients (part B) receiving single-agent gefitinib or sorafenib for 21 days followed by a 7-day washout with crossover to the other agent for an additional 21 days. Patients then received the combination of sorafenib plus gefitinib in 28-day cycles. Safety, pharmacokinetics, and antitumor efficacy were evaluated. Potential drug-drug interactions and the relationship between pharmacokinetics and toxicity were also assessed.

RESULTS

Thirty-one patients were treated (n=12, part A; n=19, part B). Most adverse events were grade 1/2. The most frequent grade 3/4 events included diarrhea and elevated alanine aminotransferase (both 9.7%). One dose-limiting toxicity occurred (part A: elevated alanine aminotransferase at 400 mg twice daily). Gefitinib had no effect on sorafenib pharmacokinetics. However, gefitinib C(max) (26%) and area under the curve (38%) were reduced by concomitant sorafenib. One patient had a partial response; 20 (65%; n=8, part A; n=12, part B) had stable disease >or=4 months. The RDP was sorafenib 400 mg twice daily with gefitinib 250 mg once daily.

CONCLUSIONS

Sorafenib combined with gefitinib is well tolerated, with promising efficacy in patients with advanced non-small cell lung cancer. Studies to further investigate the significance of the reduction in gefitinib exposure by sorafenib are warranted.

Sorafenib in advanced clear-cell renal-cell carcinoma

BACKGROUND

We conducted a phase 3, randomized, double-blind, placebo-controlled trial of sorafenib, a multikinase inhibitor of tumor-cell proliferation and angiogenesis, in patients with advanced clear-cell renal-cell carcinoma.

METHODS

From November 2003 to March 2005, we randomly assigned 903 patients with renal-cell carcinoma that was resistant to standard therapy to receive either continuous treatment with oral sorafenib (at a dose of 400 mg twice daily) or placebo; 451 patients received sorafenib and 452 received placebo. The primary end point was overall survival. A single planned analysis of progression-free survival in January 2005 showed a statistically significant benefit of sorafenib over placebo. Consequently, crossover was permitted from placebo to sorafenib, beginning in May 2005.

RESULTS

At the January 2005 cutoff, the median progression-free survival was 5.5 months in the sorafenib group and 2.8 months in the placebo group (hazard ratio for disease progression in the sorafenib group, 0.44; 95% confidence interval [CI], 0.35 to 0.55; P<0.01). The first interim analysis of overall survival in May 2005 showed that sorafenib reduced the risk of death, as compared with placebo (hazard ratio, 0.72; 95% CI, 0.54 to 0.94; P=0.02), although this benefit was not statistically significant according to the O'Brien-Fleming threshold. Partial responses were reported as the best response in 10% of patients receiving sorafenib and in 2% of those receiving placebo (P<0.001). Diarrhea, rash, fatigue, and hand-foot skin reactions were the most common adverse events associated with sorafenib. Hypertension and cardiac ischemia were rare serious adverse events that were more common in patients receiving sorafenib than in those receiving placebo.

CONCLUSIONS

As compared with placebo, treatment with sorafenib prolongs progression-free survival in patients with advanced clear-cell renal-cell carcinoma in whom previous therapy has failed; however, treatment is associated with increased toxic effects. (ClinicalTrials.gov number, NCT00073307 [ClinicalTrials.gov].).

Discovery and development of sorafenib: a multikinase inhibitor for treating cancer

Since the molecular revolution of the 1980s, knowledge of the aetiology of cancer has increased considerably, which has led to the discovery and development of targeted therapies tailored to inhibit cancer-specific pathways. The introduction and refinement of rapid, high-throughput screening technologies over the past decade has greatly facilitated this targeted discovery and development process. Here, we describe the discovery and continuing development of sorafenib (previously known as BAY 43-9006), the first oral multikinase inhibitor that targets Raf and affects tumour signalling and the tumour vasculature. The discovery cycle of sorafenib (Nexavar; Bayer Pharmaceuticals) - from initial screening for a lead compound to FDA approval for the treatment of advanced renal cell carcinoma in December 2005 - was completed in just 11 years, with approval being received approximately 5 years after the initiation of the first Phase I trial.

Neprilysin Inhibits Angiogenesis via Proteolysis of Fibroblast Growth Factor-2

Neprilysin is a cell surface peptidase that catalytically inactivates neuropeptide substrates and functions as a tumor suppressor via its enzymatic function and multiple protein-protein interactions. We investigated whether neutral endopeptidase could inhibit angiogenesis in vivo utilizing a murine corneal pocket angiogenesis model and found that it reduced fibroblast growth factor-2-induced angiogenesis by 85% (p < 0.01) but had no effect on that of vascular endothelial growth factor. Treatment with recombinant neprilysin, but not enzymatically inactive neprilysin, resulted in a slight increase in basic fibroblast growth factor electrophoretic mobility from proteolytic cleavage between amino acids Leu-135 and Gly-136, which was inhibited by the neutral endopeptidase inhibitor CGS24592 and heparin. Cleavage kinetics were rapid, comparable with that of other known neprilysin substrates. Functional studies involving neprilysin-expressing vascular endothelial cells demonstrated that neutral endopeptidase inhibition significantly enhanced fibroblast growth factor-mediated endothelial cell growth, capillary array formation, and signaling, whereas exogenous recombinant neprilysin inhibited signaling. Recombinant constructs confirmed that cleavage products neither promoted capillary array formation nor induced signaling. Moreover, mutation of the cleavage site resulted in concomitant loss of cleavage and increased the potency of fibroblast growth factor-2 to induce capillary array formation. These data indicate that neprilysin proteolytically inactivates fibroblast growth factor-2, resulting in negative regulation of angiogenesis.

Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis

The effects of sorafenib – an oral multikinase inhibitor targeting the tumour and tumour vasculature – were evaluated in patients with advanced melanoma enrolled in a large multidisease Phase II randomised discontinuation trial (RDT). Enrolled patients received a 12-week run-in of sorafenib 400 mg twice daily (b.i.d.). Patients with changes in bi-dimensional tumour measurements <25% from baseline were then randomised to sorafenib or placebo for a further 12 weeks (ie to week 24). Patients with ⩾25% tumour shrinkage after the run-in continued on open-label sorafenib, whereas those with ⩾25% tumour growth discontinued treatment. This analysis focussed on secondary RDT end points: changes in bi-dimensional tumour measurements from baseline after 12 weeks and overall tumour responses (WHO criteria) at week 24, progression-free survival (PFS), safety and biomarkers (BRAF, KRAS and NRAS mutational status). Of 37 melanoma patients treated during the run-in phase, 34 were evaluable for response: one had ⩾25% tumour shrinkage and remained on open-label sorafenib; six (16%) had <25% tumour growth and were randomised (placebo, n=3; sorafenib, n=3); and 27 had ⩾25% tumour growth and discontinued. All three randomised sorafenib patients progressed by week 24; one remained on sorafenib for symptomatic relief. All three placebo patients progressed by week-24 and were re-started on sorafenib; one experienced disease re-stabilisation. Overall, the confirmed best responses for each of the 37 melanoma patients who received sorafenib were 19% stable disease (SD) (ie n=1 open-label; n=6 randomised), 62% (n=23) progressive disease (PD) and 19% (n=7) unevaluable. The overall median PFS was 11 weeks. The six randomised patients with SD had overall PFS values ranging from 16 to 34 weeks. The most common drug-related adverse events were dermatological (eg rash/desquamation, 51%; hand-foot skin reaction, 35%). There was no relationship between V600E BRAF status and disease stability. DNA was extracted from the biopsies of 17/22 patients. Six had V600E-positive tumours (n=4 had PD; n=1 had SD; n=1 unevaluable for response), and 11 had tumours containing wild-type BRAF (n=9 PD; n=1 SD; n=1 unevaluable for response). In conclusion, sorafenib is well tolerated but has little or no antitumour activity in advanced melanoma patients as a single agent at the dose evaluated (400 mg b.i.d.). Ongoing trials in advanced melanoma are evaluating sorafenib combination therapies.

Randomized phase III trial of sorafenib in advanced renal cell carcinoma (RCC): Impact of crossover on survival

4524

Background: Sorafenib was approved for advanced RCC in the USA December 2005. A Phase III randomized double-blind, placebo-controlled trial demonstrated an estimated 39% improvement in survival for patients receiving sorafenib versus placebo (HR= 0.72, p = 0.018) (ECCO 2005). These data supported independently reviewed doubling of PFS to 24 weeks in RCC patients receiving sorafenib compared with placebo (12 weeks) (p < 0.000001) (ASCO 2005). Based on the statistical significance and magnitude of PFS benefit, patients were unblinded and placebo patients allowed to crossover to sorafenib in April 2005. A prospectively planned interim OS analysis reflecting impact of crossover of placebo patients is presented. Methods: OS data up to November 30, 2005, were analyzed in this interim analysis using a stratified log-rank test comparing the two treatment groups. In order to examine the effect of crossover on OS, a secondary analysis was performed censoring data from patients randomized to placebo at June 30, 2005. Results: A total of 903 patients were randomized (451 to sorafenib, 452 to placebo) and >200 placebo patients crossed over to sorafenib. Baseline characteristics were similar between treatment arms. There were 367 deaths. The median OS was 19.3 months for sorafenib versus 15.9 months for placebo (HR = 0.77; 95% CI 0.63, 0.95; p = 0.015); although this did not attain the level of significance specified for the interim analysis (α = 0.009), a continued favorable trend in survival benefit was observed. With censoring of crossover data, the median OS was 19.3 months for sorafenib versus 14.3 months for placebo (HR = 0.74, 95% CI 0.58, 0.93; p = 0.010). Conclusion: Sorafenib is the first novel, oral approved treatment for advanced RCC in more than a decade. Previous information on the effect of crossover on OS in randomized oncology studies is limited. The lower HR observed after censoring placebo patients crossed over to sorafenib suggests a continued beneficial effect of sorafenib. Final results await more mature data.

[Table: see text]

Health-related quality of life measures in advanced non-small cell lung cancer patients receiving sorafenib

17085

Background: A multicenter, international, single-arm Phase II study evaluated the efficacy, safety, and tolerability of sorafenib in patients with advanced non-small-cell lung cancer (NSCLC). In addition, patients’ health-related quality of life (HRQL) and symptoms were assessed. Methods: HRQL was measured by the Functional Assessment of Cancer Therapy-Lung (FACT-L) questionnaire that was self-administered at baseline, at every other cycle during the study treatment period, and at the end-of-treatment (EOT) visit. Patients responded to each item on a five-point Likert-type scale ranging from 0 (not at all) to 4 (very much). Five subscale scores and an overall function score were calculated, with higher scores reflecting better function and symptom response. A change of two points, the minimum important difference (MID), in each of the five domains (physical well-being [PWB], emotional well-being [EWB], social well-being [SWB], lung cancer symptoms [LCS], and functional well-being [FWB]) was determined to be clinically meaningful. The total score of the treatment outcome index (TOI) was also assessed. Results: A total of 52 patients were evaluated. Data were collected at baseline, Cycle 2, Cycle 4, and EOT for 50/52 (96%), 42/52 (81%), 21/52 (40%), and 20/52 (38%) of patients, respectively. The mean total FACT-L scores were 99.3, 106.5, and 83.7 at Cycles 2, 4, and EOT, respectively. The mean changes from baseline in the total FACT-L score were -4.6, -0.2, and -14.6 at Cycles 2, 4, and EOT, respectively. The mean change from baseline in the each subscale scores were: -0.6, -1.0, -5.8 for PWB; -0.4, -0.8, -0.6 for SWB; -0.0, 2.1, -1.1 for EWB; -0.7, 0.9, -3.9 for FWB; -0.5, -1.0, -3.6 for LCS; and -2.6, -1.0, -13.2 for TOI, at Cycles 2, 4, and EOT, respectively. An improvement greater than the MID was observed in EWB at Cycle 4. Decreases below MID were observed for EWB at Cycle 2 and EOT, and all other subscales of the FACT-L at Cycles 2, 4, and EOT. Conclusions: These findings are encouraging and suggest that sorafenib did not adversely impact patient-reported outcomes in function and symptom response during the treatment period. As there is no comparator arm, interpretation of results is limited.

[Table: see text]

Phase II trial of single-agent sorafenib in patients with advanced non-small cell lung carcinoma

7002

Background: Sorafenib, an oral multi-kinase inhibitor, targets the Raf/MEK/ERK pathway at the level of Raf kinase and receptor tyrosine kinases, and has shown efficacy against several tumor types in phase I/II trials. Non-small-cell lung cancer (NSCLC) is associated with mutations in k-ras, upstream of Raf/MEK/ERK. Methods: This multi-center, uncontrolled, phase II trial evaluated efficacy (every 8 weeks using RECIST) and safety of sorafenib (400 mg bid, continuous) in patients with relapsed or refractory advanced NSCLC. Plasma for proteomic biomarker analysis (ELISA [n=44]; mass-spectrometry [n=43]) was taken at screening, Day 21 of Cycle 1, and Day 1 of Cycle 3. Results: Fifty-two of 54 patients enrolled received sorafenib. Most (49/52) patients who received sorafenib had stage IV NSCLC. Thirty patients (59%) out of 51 evaluable for efficacy had SD. Although there were no confirmed PRs, tumor shrinkage was observed in 15 (29%) patients (four had ≥30% shrinkage). Patients with SD had a median progression-free survival (PFS) of 23.7 weeks, while all evaluable patients (n=51) had a median PFS of 11.9 weeks and median overall survival of 29.3 weeks. The most frequent drug-related adverse events observed in 52 patients were diarrhea (21 [40%] patients), hand-foot skin reaction (HFS; 19 [37%]), fatigue (14 [27%]), and nausea (13 [25%]). Frequent drug-related adverse events ≥ grade 3 included HFS (n=5 [10%]) and hypertension (n=2 [4%]). Three patients discontinued due to adverse events (HFS, elevated lipase, and myocardial infarction). There were nine deaths within 30 days of discontinuation of sorafenib (n=5 PD; n=2 cardiopulmonary arrest; n=1 hemoptysis; and n=1 unknown cause). The levels of five proteins measured by ELISA, either at screening or change over treatment duration, correlated significantly with time to progression (TTP) or maximum tumor shrinkage. Levels of five additional proteins, identified by mass-spectrometry, also correlated with TTP. Conclusions: Identified biomarkers may help assess efficacy of sorafenib in NSCLC patients. Sorafenib 400 mg bid is generally well tolerated and shows promising efficacy in patients with advanced, progressive NSCLC, with approximately 60% of pts achieving disease stabilization.

[Table: see text]

Phase II Placebo-Controlled Randomized Discontinuation Trial of Sorafenib in Patients With Metastatic Renal Cell Carcinoma

Purpose

This phase II randomized discontinuation trial evaluated the effects of sorafenib (BAY 43-9006), an oral multikinase inhibitor targeting the tumor and vasculature, on tumor growth in patients with metastatic renal cell carcinoma.

Patients and Methods

Patients initially received oral sorafenib 400 mg twice daily during the initial run-in period. After 12 weeks, patients with changes in bidimensional tumor measurements that were less than 25% from baseline were randomly assigned to sorafenib or placebo for an additional 12 weeks; patients with ≥ 25% tumor shrinkage continued open-label sorafenib; patients with ≥ 25% tumor growth discontinued treatment. The primary end point was the percentage of randomly assigned patients remaining progression free at 24 weeks after the initiation of sorafenib.

Results

Of 202 patients treated during the run-in period, 73 patients had tumor shrinkage of ≥ 25%. Sixty-five patients with stable disease at 12 weeks were randomly assigned to sorafenib (n = 32) or placebo (n = 33). At 24 weeks, 50% of the sorafenib-treated patients were progression free versus 18% of the placebo-treated patients (P = .0077). Median progression-free survival (PFS) from randomization was significantly longer with sorafenib (24 weeks) than placebo (6 weeks; P = .0087). Median overall PFS was 29 weeks for the entire renal cell carcinoma population (n = 202). Sorafenib was readministered in 28 patients whose disease progressed on placebo; these patients continued on sorafenib until further progression, for a median of 24 weeks. Common adverse events were skin rash/desquamation, hand-foot skin reaction, and fatigue; 9% of patients discontinued therapy, and no patients died from toxicity.

Conclusion

Sorafenib has significant disease-stabilizing activity in metastatic renal cell carcinoma and is tolerable with chronic daily therapy.

The antiangiogenic effect of thrombospondin-2 is mediated by CD36 and modulated by histidine-rich glycoprotein

Thrombospondins-1 and -2 (TSP-1, TSP-2) are matricellular glycoproteins with potent antiangiogenic activity. We have previously shown that the antiangiogenic activity of TSP-1 is mediated by the interaction of the type I repeats (TSR) with the receptor CD36, although other domains of TSP-1 have also been implicated. We now show that the antiangiogenic activity of TSP-2, which contains three TSRs but, unlike TSP-1, lacks the capacity to activate TGF-beta, is similarly dependent on CD36. Using the corneal pocket assay we found that TSP-2 did not inhibit bFGF-induced angiogenesis in CD36 null mice. We then demonstrated that (125)[I]-TSP-2 bound to murine macrophages and that binding was diminished by 70% by anti-CD36 antibody or by using cells from CD36 null animals. Solid-phase binding studies revealed that (125)[I]-TSP-2 bound to CD36/glutathione-S-transferase (GST) fusion proteins encoding the region spanning amino acids 93-120, but not amino acids 298-439. This 93-120 amino acid region, previously identified as the TSP-1 binding site, is homologous to domains on other TSP binding proteins, such as LIMP-2 and histidine-rich glycoprotein (HRGP). Finally, we showed with an immunoabsorbent binding assay that TSP-2 bound HRGP with high affinity and that HRGP blocked the antiangiogenic activity of TSP-2, acting like a "decoy" receptor. These data suggest that modulation of the TSR/CD36 system may play an important role in the regulation of the angiogenic "switch," and may provide a target for therapeutic interventions.

Annexin II regulates fibrin homeostasis and neoangiogenesis in vivo

A central tenet of fibrinolysis is that tissue plasminogen activator-dependent (t-PA- dependent) conversion of plasminogen to active plasmin requires the presence of the cofactor/substrate fibrin. However, previous in vitro studies have suggested that the endothelial cell surface protein annexin II can stimulate t-PA-mediated plasminogen activation in the complete absence of fibrin. Here, homozygous annexin II-null mice displayed deposition of fibrin in the microvasculature and incomplete clearance of injury-induced arterial thrombi. While these animals demonstrated normal lysis of a fibrin-containing plasma clot, t-PA-dependent plasmin generation at the endothelial cell surface was markedly deficient. Directed migration of annexin II-null endothelial cells through fibrin and collagen lattices in vitro was also reduced, and an annexin II peptide mimicking sequences necessary for t-PA binding blocked endothelial cell invasion of Matrigel implants in wild-type mice. In addition, annexin II-deficient mice displayed markedly diminished neovascularization of fibroblast growth factor-stimulated cornea and of oxygen-primed neonatal retina. Capillary sprouting from annexin II-deficient aortic ring explants was markedly reduced in association with severe impairment of activation of metalloproteinase-9 and -13. These data establish annexin II as a regulator of cell surface plasmin generation and reveal that impaired endothelial cell fibrinolytic activity constitutes a barrier to effective neoangiogenesis.

Annexin II regulates fibrin homeostasis and neoangiogenesis in vivo

A central tenet of fibrinolysis is that tissue plasminogen activator-dependent (t-PA- dependent) conversion of plasminogen to active plasmin requires the presence of the cofactor/substrate fibrin. However, previous in vitro studies have suggested that the endothelial cell surface protein annexin II can stimulate t-PA-mediated plasminogen activation in the complete absence of fibrin. Here, homozygous annexin II-null mice displayed deposition of fibrin in the microvasculature and incomplete clearance of injury-induced arterial thrombi. While these animals demonstrated normal lysis of a fibrin-containing plasma clot, t-PA-dependent plasmin generation at the endothelial cell surface was markedly deficient. Directed migration of annexin II-null endothelial cells through fibrin and collagen lattices in vitro was also reduced, and an annexin II peptide mimicking sequences necessary for t-PA binding blocked endothelial cell invasion of Matrigel implants in wild-type mice. In addition, annexin II-deficient mice displayed markedly diminished neovascularization of fibroblast growth factor-stimulated cornea and of oxygen-primed neonatal retina. Capillary sprouting from annexin II-deficient aortic ring explants was markedly reduced in association with severe impairment of activation of metalloproteinase-9 and -13. These data establish annexin II as a regulator of cell surface plasmin generation and reveal that impaired endothelial cell fibrinolytic activity constitutes a barrier to effective neoangiogenesis.

Genomic absence of the gene encoding T cell receptor Vbeta7.2 is linked to the presence of autoantibodies in Sjögren's syndrome

OBJECTIVE

It is not yet known whether the absence of certain T cell receptor V(beta) (TCRBV) genes (e.g., due to genomic deletion) has functional significance. We examined this question in relation to a known 21.6-kb insertion/deletion-related polymorphism (IDRP) in the human BV locus.

METHODS

New polymerase chain reaction (PCR) genotyping methods were used. Monoclonal antibodies to TCRBV gene products were used to confirm the absence of the relevant proteins. Patients with Sjögren's syndrome (SS) or systemic lupus erythematosus (SLE) were compared with normal controls with regard to TCR genotypes and serologic profiles.

RESULTS

There are 3 known haplotypes (I, D1, D2) and 6 possible genotypes related to the 21.6-kb IDRP. Novel PCR-based methods were used to define these genotypes. In subjects with deleted/deleted (D/D) genotypes, T cells could not express V(beta)7.2 TCRs, as assayed with a new antibody specific for V(beta)7.2. This was the sole significant difference between subjects without the insertion and those with either 1 or 2 copies. Surprisingly, we found that the D/D genotype was associated with primary SS, but only when pathogenic autoantibodies were present.

CONCLUSION

These results suggest that T cells expressing TCRs with V(beta)7.2 are protective against a pathogenic immune response in SS. Thus, genomic polymorphism of TCR genes (along with the correct HLA alleles) determines whether T cells can direct a pathogenic autoimmune response.

Prevalence and correlates of accelerated atherosclerosis in systemic lupus erythematosus

BACKGROUND

Although systemic lupus erythematosus is associated with premature myocardial infarction, the prevalence of underlying atherosclerosis and its relation to traditional risk factors for cardiovascular disease and lupus-related factors have not been examined in a case-control study.

METHODS

In 197 patients with lupus and 197 matched controls, we performed carotid ultrasonography, echocardiography, and an assessment for risk factors for cardiovascular disease. The patients were also evaluated with respect to their clinical and serologic features, inflammatory mediators, and disease treatment.

RESULTS

The risk factors for cardiovascular disease were similar among patients and controls. Atherosclerosis (carotid plaque) was more prevalent among patients than the controls (37.1 percent vs. 15.2 percent, P<0.001). In multivariate analysis, only older age, the presence of systemic lupus erythematosus (odds ratio, 4.8; 95 percent confidence interval, 2.6 to 8.7), and a higher serum cholesterol level were independently related to the presence of plaque. As compared with patients without plaque, patients with plaque were older, had a longer duration of disease and more disease-related damage, and were less likely to have multiple autoantibodies or to have been treated with prednisone, cyclophosphamide, or hydroxychloroquine. In multivariate analyses including patients with lupus, independent predictors of plaque were a longer duration of disease, a higher damage-index score, a lower incidence of the use of cyclophosphamide, and the absence of anti-Smith antibodies.

CONCLUSIONS

Atherosclerosis occurs prematurely in patients with systemic lupus erythematosus and is independent of traditional risk factors for cardiovascular disease. The clinical profile of patients with lupus and atherosclerosis suggests a role for disease-related factors in atherogenesis and underscores the need for trials of more focused and effective antiinflammatory therapy.

CD36: a critical anti-angiogenic receptor

Thrombospondin-1 (TSP-1) is a potent inhibitor of angiogenesis in vivo and of microvascular endothelial cell responses to angiogenic factors in vitro. CD36 is the cellular receptor for TSP-1 on microvascular endothelium and is necessary for its anti-angiogenic activity. The anti-angiogenic activity of TSP-1 is contained in a structural domain known as the TSP type I repeat (TSR-1). TSR-1 domains occur in many other proteins, some of which have also been shown to have anti-angiogenic activity. Structure-function analyses have determined that binding of TSP-1 to CD36 is mediated by interaction of the TSR-1 domain of TSP with a conserved domain called CLESH-1 in CD36. Histidine rich glycoprotein, a plasma and cellular protein that blocks the binding of thrombospndin-1 to CD36, inhibits the antiangiogenic response to thrombospondin and may serve to modulate the thrombospondin/CD36 anti-angiogenic pathway. Several in vivo models support the role of the TSP/CD36 system in angiogenesis and tumor growth and provide evidence that the CD36 antiangiogenic pathway offers attractive therapeutic targets.

Mitochondrial voltage-dependent anion channel is involved in dopamine-induced apoptosis

Neuronal NMB cells were used to determine changes in gene expression upon treatment with dopamine. Twelve differentially expressed cDNAs were identified and cloned, one of them having 99.4% sequence homology with isoform 2 of a voltage-dependent anion channel (VDAC-2). The known role of VDAC, a mitochondrial outer-membrane protein, in transport of anions, pore formation, and release of cytochrome C prompted us to investigate the possible role of VDAC gene family in dopamine-induced apoptosis. Semi-quantitative PCR analysis indicated that expression of the three VDAC isoforms was reduced by dopamine. Immunoblotting with anti-VDAC antibodies detected two VDAC protein bands of 33 and 34 kDa. Dopamine decreased differentially the immunoreactivity of the 34 kDa protein. Whether the decrease in VDAC expression influence the mitochondrial membrane potential (Delta(Psi)(m)) was determined with the dye Rhodamine-123. Dopamine indeed decreased the mitochondrial Delta(Psi)(m), but the maximum effect was observed within 3 h, prior to the decrease in VDAC mRNA or protein levels. Cyclosporin A, a blocker of the mitochondrial pore complex, prevented the decrease in Delta(Psi)(m), but did not rescue the cells from dopamine toxicity. To elucidate possible involvement of protease caspases in dopamine-induced apoptosis, the effect of the caspase inhibitor z-Val-Ala-Asp(Ome)-FMK (zVAD) was determined. zVAD decreased dopamine toxicity, yet it did not rescue the mitochondrial Delta(Psi)(m) drop. Dopamine also decreased ATP levels. Finally, transfection of NMB cells with pcDNA-VDAC decreased the cytotoxic effect of dopamine. These findings are in agreement with the notion that the mitochondria, and VDAC, are important participants in dopamine-induced apoptosis.

Dopamine induces phenotypic differentiation or apoptosis in a dose-dependent fashion: involvement of the dopamine transporter and p53

The effect of dopamine on the growth, phenotypes (morphological and biochemical) and programmed cell death (apoptosis) of the human neuronal NMB cell line was examined. Exposure to 20-50 microM of dopamine decreased cell growth, induced an apparent differentiated cell morphology and increased (3)H-dopamine uptake. At higher concentrations (100-300 microM) dopamine was neurotoxic and induced apoptosis, as reported previously. The observed effects of both low and high doses of dopamine were blocked by cocaine, which suggested involvement of dopamine transporters. Indeed, several experiments demonstrated the relationship between dopamine uptake of cells and their vulnerability to the toxic effect of dopamine. High concentrations of dopamine, which induced apoptosis, also increased p53 levels, detected by RT-PCR analysis and immunoblotting, whereas lower dopamine concentrations, which induced a differentiated phenotype, did not increase p53 immunoblotting. Dibutyryl-cAMP and dimethyl sulfoxide, which induced differentiation but not apoptosis of the NMB cells, did not increase p53 expression. These findings provide an insight into the role of dopamine, dopamine transporters and p53 in the differentiation and apoptosis of dopaminergic neurons, which will further our understanding of neuronal development and neurodegenerative diseases.

Allelic variation of serotonin transporter expression is associated with depression in Parkinson's disease

Idiopathic Parkinson's disease (PD) is a common neurodegenerative disorder with prominent motor symptoms. However, depression is common in PD, affecting about 40% of PD patients. Since there is extensive evidence of degeneration of serotonin (5HT) neurons and loss of the 5HT transporter (5HTT) in PD, we assessed whether a functional polymorphism in the promoter of the 5HTT gene (5HTT gene-linked polymorphic region, 5HTTLPR), which determines high or low 5HT uptake, is associated with depressive symptomatology in PD patients. We found that patients with the short allele of the 5HTTLPR had significantly higher scores on the Hamilton Depression Scale. A functional promoter polymorphism of the monoamine oxidase A (MAOA) gene showed no association. Thus, the 5HTTLPR but not the MAOA gene promoter-associated polymorphism may be a risk factor for depression in PD patients, while neither polymorphism increases the risk for development of Parkinson's disease itself.

Plasticity in serotonin uptake in primary neuronal cultures of serotonin transporter knockout mice

The cross talk between dopaminergic and serotonergic systems in the brain has multiple neurophysiological and behavioral implications. Primary neuronal cultures of embryonic wild type (+/+) and serotonin transporter knockout (-/-) mice were used as a model to elucidate the possibility of plasticity at the level of serotonin uptake. Serotonergic neurons were identified in midbrain-hindbrain cultures of both wild type and knockout mice, using polyclonal anti-serotonin antibodies. Adding serotonin (10 microM) to wild type midbrain-hindbrain cultures increased the intensity of serotonin immunostaining, but did not change the number of serotonergic neurons. This increased intensity of serotonin staining was blocked by the serotonin transporter inhibitors fluoxetine and imipramine, but not with the dopamine transporter inhibitor nomifensine. In serotonin transporter knockout cultures, however, serotonin increased both the intensity of serotonin immunostaining and the number of serotonin positive neurons, and nomifensine decreased the number of serotonin-labeled neurons. Uptake of [3H]serotonin to wild type midbrain-hindbrain cultures was completely blocked by 1 microM fluoxetine, whereas nomifensine had a very small effect. In contrast, [3H]serotonin uptake to serotonin transporter knockout cultures, although very weak, was better inhibited by nomifensine than fluoxetine. The results imply that midbrain-hindbrain neuronal cultures of knockout mice, that do not express serotonin transporters, acquire the capacity to take up serotonin, apparently via dopamine transporters.

Histidine-rich glycoprotein inhibits the antiangiogenic effect of thrombospondin-1

Angiogenesis is critical for the growth and proliferation of tumors as well as for normal development. We now describe a novel role for histidine-rich glycoprotein (HRGP) in the modulation of angiogenesis. HRGP is a plasma protein that circulates in relatively high concentrations (1.5 microM), but has no known function in vivo. We have shown previously that HRGP binds with high affinity to thrombospondin-1 (TSP-1), a homotrimeric glycoprotein that is a potent inhibitor of angiogenesis. The antiangiogenic activity of TSP-1 is mediated by the binding of properdin-like type I repeats to the receptor CD36. We found that binding of HRGP to TSP-1 was similarly mediated by TSP type I repeats. HRGP colocalized with TSP-1 in the stroma of human breast cancer specimens, and this interaction masked the antiangiogenic epitope of TSP-1. In assays performed in vitro of endothelial cell migration and tube formation, and in vivo corneal angiogenesis assays, HRGP inhibited the antiangiogenic effect of TSP-1. These studies suggest that HRGP can modulate the antiangiogenic activity of TSP-1, and identify a potential mechanism of resistance to the antiangiogenic effect of TSP-1.

Differential regulation of adenosine A(1) and A(2A) receptors in serotonin transporter and monoamine oxidase A-deficient mice

The serotonin (5HT) transporter (5HTT) removes 5HT from the synaptic cleft and is thus critical to the control of serotonergic neurotransmission. Mice with a targeted inactivation of the 5HTT represent a novel and unique tool to study serotonergic system functioning. Because the release of 5HT is regulated by adenosine, we investigated 5HTT-deficient mice for possible adaptive changes of adenosine A(1) and A(2A) receptors. A(1) and A(2A) receptors were studied by means of quantitative autoradiography using the radioligands [3H]8-cyclopentyl-1,3-dipropylxanthine and [3H]CGS 21680, respectively. A comparison of 5HTT knockout versus control mice revealed upregulation of A(1) receptors in the dorsal raphe nucleus (DRN, +21%), but not in any of the serotonergic projection areas, and downregulation of A(2A) receptors in basal ganglia. The adaptive changes of A(1) and A(2A) receptors in 5HTT-deficient mice are likely to represent a compensatory neuroprotective effect mediated by the adenosinergic modulatory system. For comparison, these receptors were also studied in monoamine oxidase A (MAOA) knockout mice and in 5HTT/MAOA double knockout mice. 5HTT/MAOA double knockout mice showed adaptive changes of adenosine A(1) and A(2A) receptors similar to 5HTT knockout mice, while investigation of MAOA-deficient mice revealed an upregulation of A(2A) receptors, which may relate to a role of both MAOA and adenosine A(2A) receptors in anxiety.

High affinity binding of beta 2-glycoprotein I to human endothelial cells is mediated by annexin II

Beta(2)-glycoprotein I (beta(2)GPI) is an abundant plasma phospholipid-binding protein and an autoantigen in the antiphospholipid antibody syndrome. Binding of beta(2)GPI to endothelial cells targets them for activation by anti-beta(2)GPI antibodies, which circulate and are associated with thrombosis in patients with the antiphospholipid antibody syndrome. However, the binding of beta(2)GPI to endothelial cells has not been characterized and is assumed to result from association of beta(2)GPI with membrane phospholipid. Here, we characterize the binding of beta(2)GPI to endothelial cells and identify the beta(2)GPI binding site. (125)I-beta(2)GPI bound with high affinity (K(d) approximately 18 nm) to human umbilical vein endothelial cells (HUVECs). Using affinity purification, we isolated beta(2)GPI-binding proteins of approximately 78 and approximately 36 kDa from HUVECs and EAHY.926 cells. Amino acid sequences of tryptic peptides from each of these were identical to sequences within annexin II. A role for annexin II in binding of beta(2)GPI to cells was confirmed by the observations that annexin II-transfected HEK 293 cells bound approximately 10-fold more (125)I-beta(2)GPI than control cells and that anti-annexin II antibodies inhibited the binding of (125)I-beta(2)GPI to HUVECs by approximately 90%. Finally, surface plasmon resonance studies revealed high affinity binding between annexin II and beta(2)GPI. These results demonstrate that annexin II mediates the binding of beta(2)GPI to endothelial cells.

Bcl-2 and p53: role in dopamine-induced apoptosis and differentiation

The fate of a neuron in the developing brain to multiply, differentiate, or die in an apoptotic manner depends on the expression of genes that are involved in regulating the cell cycle. Recent studies determined the involvement of several genes, including cyclin A and B2, in dopamine-induced apoptosis in cultured chick sympathetic neurons. Another gene that plays a role in apoptosis and differentiation of neurons, oligodendrocytes and PC12 cells is p53. It is also known that DNA damage increases p53 levels, triggering repair or apoptosis in response to moderate or severe damage, respectively. NMB cells express active and inducible forms of p53, thus being particularly suitable to analyze the role of this gene in dopamine-induced apoptosis and differentiation. The main observation of this work is that low concentrations of dopamine induce differentiation while high concentrations induce apoptosis, and that concentrations of dopamine that induce apoptosis increased p53 levels. There peak increase in p53 was within 3-6 h, before cell death. Thus, treatment with a high dopamine concentration may result in oxidation products and/or free radicals that heavily damage DNA, thus increasing p53 levels and initiating a cascade of events leading to apoptosis. Lower concentrations of dopamine apparently have a milder damaging effect on the DNA and induce growth arrest and differentiation. In various systems Bcl-2 inhibits cell death, being apoptotic or necrotic. Bcl-2, and other members of the family, such as Bax, are located downstream to p53 in the apoptotic pathway, and they contain negative or positive p53 response elements. Bcl-2 also protects cells by acting as antioxidant. Neuronal differentiation may be accompanied with an increase in Bcl-2, though it was suggested that the role of Bcl-2 in differentiation is less critical than in apoptosis. Herein, Bcl-2 was found to inhibit dopamine neurotoxicity. Whether the expression of Bcl-2 is regulated by different dopamine concentrations, or by dibutyryl-cAMP and DMSO, remains to be determined.

Pharmacokinetics of intraperitoneal piperacillin/tazobactam in patients on peritoneal dialysis with and without pseudomonas peritonitis

OBJECTIVE

The objective of this study was to assess the pharmacokinetics of intraperitoneal (IP) administration of the antibiotic combination piperacillin/tazobactam (PIP/TAZ) to patients on chronic ambulatory peritoneal dialysis (CAPD) with and without pseudomonas peritonitis.

DESIGN

Open-labeled study.

SETTING

The study was carried out in the CAPD unit of Assaf Harofeh Medical Center, Zerifin, Israel.

PATIENTS AND METHODS

Six patients participated in the study, 4 had pseudomonas peritonitis, all were given an IP loading dose of 4 g/0.5 g PIP/TAZ. Twenty-four hours after the initial dose, a maintenance dose of 0.5 g/0.0625 g PIP/TAZ was administered with each dialysate exchange for a period of 1 week. The patients without peritonitis received only the loading dose. High performance liquid chromatography was used to determine the concentrations of PIPITAZ in plasma obtained at 0, 30, 60, 90, 120, 360, 480, 600, 720, and 1440 minutes after administration. Samples of the dialysate fluid for determination of PIP/TAZ concentration were collected at 6,10,14, 24, and 72, 120, and 168 hours.

RESULTS

After the loading dose, the highest plasma PIP concentration (Cmax) was 51.6 t 21.25 Lig/mL and appeared at 1.5 = 0.45 hours (t,,a). During the maintenance period plasma PIP concentration was 5.2 t 4.75 Lg/mL. Tazobactam was detected in the plasma of 1 patient only. The concentration of TAZ in the dialysate fluid during the maintenance period was 2.3 t 0.5 ig/mL.

CONCLUSIONS

Piperacillin administered IP at 4 g reached plasma concentrations comparable to intravenous administration and considered therapeutic (above the MIC90 for Pseudomonas aeruginosa) in CAPD patients with or without peritonitis. The maintenance dose, however, should be augmented. Tazobactam could not be detected in the plasma of most patients and the therapeutic implications of IP administration of TAZ cannot be directly correlated to intravenous administration.

Conversion of recent onset paroxysmal atrial fibrillation to normal sinus rhythm: the effect of no treatment and high-dose amiodarone. A randomized, placebo-controlled study

BACKGROUND

Spontaneous conversion of recent onset paroxysmal atrial fibrillation to normal sinus rhythm occurs commonly and is not affected by low-dose amiodarone treatment.

METHODS

In a randomized, placebo-controlled trial of 100 patients with paroxysmal atrial fibrillation of recent onset (<48 h) we compared the effects of treatment with continuous intravenous amiodarone 125 mg per hour (total 3 g) and intravenous placebo. Patients in the placebo group who did not convert to normal sinus rhythm within 24 h were started on amiodarone therapy.

RESULTS

Conversion to normal sinus rhythm occurred within 24 h in 32 of 50 patients (64%) in the placebo group, most of whom converted within 8 h. Lower conversion rates were observed in patients with hypertension, ischaemic heart disease or congestive heart failure and in patients with echocardiographic findings of left atrial diameter above 45 mm, ejection fraction below 45% or significant mitral regurgitation. However, in most patients these clinical or echocardiographic risk factors of decreases in conversion rate were not present. In such patients the spontaneous conversion rate was approximately 90%. The conversion rate during 24 h of treatment in the amiodarone group was 92% (P=0.0017, compared to the placebo group). In this group, the conversion rate was largely unaffected by baseline characteristics. Of the 18 patients who did not convert with placebo, 15 (85%) converted after being crossed over to amiodarone. All patients not responding to high-dose amiodarone were in chronic atrial fibrillation within 1 month. In patients still in atrial fibrillation after 8 h of treatment, the pulse rate decreased significantly more in the amiodarone as compared to the placebo group (83+/-15 vs 114+/-20 beats. min(-1), P=0.0014).

CONCLUSION

The spontaneous conversion of recent onset paroxysmal atrial fibrillation is high and approaches 90% in specific clinical and echocardiographically defined subgroups. Intravenous high-dose amiodarone safely facilitates conversion of paroxysmal atrial fibrillation. However, such treatment should be reserved for patients with unfavourable risk factor profiles, not converting during 8 h of observation or requiring rate control.

Antisense knockdown of glutamate transporters alters the subfield selectivity of kainate-induced cell death in rat hippocampal slice cultures

Organotypic rat hippocampal slice cultures were used to study the role of excitatory amino acid transporters (EAATs) in kainate-induced cell death. Expression of the neuronal (EAAT3) or glial (EAAT2) transporters was inhibited with antisense phosphothioate oligonucleotides, and cytotoxicity was assessed with propidium iodide uptake. In control cultures, a concentration of 10 microM kainate was more cytotoxic in CA3 than in CA1. Treatment for 24 h with EAAT3 antisense oligonucleotide decreased kainate toxicity in CA1 but had an opposite effect in CA3. Neither antisense oligonucleotide to EAAT2 nor mismatch oligonucleotide to EAAT3 decreased kainate toxicity in CA1. Immunoblotting with affinity-purified antibodies showed that EAAT3 antisense oligonucleotide decreased selectively EAAT3 but not EAAT2 protein levels, and vice versa. NMDA was more cytotoxic in CA1 than in CA3, and antisense oligonucleotides to either EAAT3 or EAAT2 did not decrease the NMDA effect in CA1 or CA3. Dihydrokainate and DL-threo-beta-hydroxyaspartic acid were more cytotoxic in CA1 than in CA3, suggesting that the higher vulnerability of CA3 to kainate was not the result of its activity as transporter blocker. We conclude that glutamate transporters differentially regulate excitotoxicity in different hippocampal subfields.

Genetic background determines the extent of atherosclerosis in ApoE-deficient mice

Two strains of ApoE-deficient mice were found to have markedly different plasma lipoprotein profiles and susceptibility to atherosclerosis when fed either a low-fat chow or a high-fat Western-type diet. FVB/NJ ApoE-deficient (FVB E0) mice had higher total cholesterol, HDL cholesterol, ApoA1, and ApoA2 levels when compared with C57BL/6J ApoE-deficient (C57 E0) mice. At 16 weeks of age, mean aortic root atherosclerotic lesion area was 7- to 9-fold higher in chow diet-fed C57 E0 mice and 3.5-fold higher in Western diet-fed C57 E0 mice compared with FVB E0 mice fed similar diets. Lesion area in chow diet-fed first-generation mice from a strain intercross was intermediate in size compared with parental values. The distribution of the lesion area in 150 chow diet-fed second-generation progeny spanned the range of the lesion area in both parental strains. There were no correlations between total cholesterol, non-HDL cholesterol, HDL cholesterol, ApoA1, ApoA2, ApoJ, or anti-cardiolipin antibodies and lesion area in the second-generation progeny. Thus, a genomic approach may succeed in identifying the genes responsible for the variation in atherosclerosis susceptibility in these 2 strains of ApoE-deficient mice, which could not be explained by measured plasma parameters.

Changes in expression of neuronal and glial glutamate transporters in rat hippocampus following kainate-induced seizure activity

The expression of excitatory amino acid transporters (EAATs) in rat hippocampus was studied following kainic acid-induced seizure activity in vivo and in hippocampal slice cultures. Protein and mRNA levels of the glial (EAAT2) and neuronal (EAAT3) transporters were determined with affinity-purified antibodies and oligonucleotide probes, respectively. Kainate treatment decreased EAAT3 immunoreactivity in stratum lacunosum moleculare within 4 h of seizure onset. Upon pyramidal cell death (5 days after kainate treatment), EAAT3 immunoreactivity in stratum pyramidale of CA1 and in stratum lacunosum moleculare was almost completely eliminated. The rapid effect of kainate on EAAT3 expression was confirmed by in situ hybridization; EAAT3 mRNA levels were decreased in CA1 and CA3 regions within 4-8 h of seizure onset. Kainate treatment had an opposite effect on levels and expression of EAAT2. Developmental studies indicated that the rapid regulation of transporter expression was not observed in rats younger than 21 days, an observation congruent with previous reports regarding the resistance of young rats to kainate. In hippocampal organotypic cultures, which lack a major excitatory input from the entorhinal cortex, kainate produced a slow decrease in [3H]d-aspartate uptake. This study indicates that an early effect of kainate treatment consists of down-regulation of the neuronal transporter EAAT3 in restricted hippocampal regions, together with a modest increase in the expression of the glial transporter EAAT2. Differential regulation of neuronal and glial glutamate transporters may thus play a role in kainate-induced seizure, neurotoxicity and neuronal plasticity.

Effect of low-dose treatment with selegiline on dopamine transporter (DAT) expression and amphetamine-induced dopamine release in vivo

1. Chronic treatment with low doses of the selective monoamine oxidase (MAO) type B inhibitors selegiline [(-)-deprenyl] and rasagiline, causes elevation in extracellular level of 3,4-dihydroxyphenylethylamine (dopamine) in the rat striatum in vivo (Lamensdorf et al., 1996). The present study was carried out to determine whether this effect of selegiline could be the result of an inhibition of the high-affinity dopamine neuronal transport process. 2. Changes in activity of the dopamine transporter (DAT) in vivo following selegiline treatment were evaluated indirectly by microdialysis technique in the rat, from the change in striatal dopamine extracellular concentration following systemic amphetamine administration (4 mg kg(-1), i.p.). Striatal levels of the DAT molecule were determined by immunoblotting. Uptake of [3H]-dopamine was determined in synaptosomes from selegiline-treated animals. 3. Amphetamine-induced increase in striatal extracellular dopamine level was attenuated by one day and by chronic (21 days) treatment with selegiline (0.25 mg kg(-1), s.c.). 4. Striatal levels of DAT were elevated after 1 and 21 days treatment with selegiline, but were not affected by clorgyline, rasagiline, nomifensine or amphetamine. 5. The increase in DAT expression, and attenuation of amphetamine-induced dopamine release, were not accompanied by a change in [3H]-dopamine uptake in synaptosomes of selegiline-treated animals. 6. The results suggest that a reversible inhibition of dopamine uptake occurs following chronic low dose selegiline treatment in vivo which may be mediated by an increase in endogenous MAO-B substrates such as 2-phenylethylamine, rather than by the inhibitor molecule or its metabolites. Increased DAT expression appears to be a special property of the selegiline molecule, since it occurs after one low dose of selegiline, and is not seen with other inhibitors of MAO-A or MAO-B. The new DAT molecules formed following selegiline treatment appear not to be functionally active.

Thrombosis and malignancy: pathogenesis and prevention

An increased incidence of thrombosis has been observed in cancer patients for over a century. The hypercoagulable state of malignancy results from multiple mechanisms including activation of the coagulation cascade and alterations of cellular blood components and endothelial cells by tumor cells. Studies have been done to determine the role of prophylactic anticoagulation therapy in cancer patients, and have shown to reduce safely the incidence of thrombosis in patients receiving treatment for metastatic breast cancer and in patients with implanted upper extremity venous catheters. Further studies are needed to determine the contribution of newly described genetic risk factors for thrombosis in order to stratify the risk for thrombosis in patients with cancer.