Two Phase 3 Trials of Adalimumab for Hidradenitis Suppurativa

BACKGROUND

Hidradenitis suppurativa is a painful, chronic inflammatory skin disease with few options for effective treatment. In a phase 2 trial, adalimumab, an antibody against tumor necrosis factor α, showed efficacy against hidradenitis suppurativa.

METHODS

PIONEER I and II were similarly designed, phase 3 multicenter trials of adalimumab for hidradenitis suppurativa, with two double-blind, placebo-controlled periods. In period 1, patients were randomly assigned in a 1:1 ratio to 40 mg of adalimumab weekly or matching placebo for 12 weeks. In period 2, patients were reassigned to adalimumab at a weekly or every-other-week dose or to placebo for 24 weeks. The primary end point was a clinical response, defined as at least a 50% reduction from baseline in the abscess and inflammatory-nodule count, with no increase in abscess or draining-fistula counts, at week 12.

RESULTS

We enrolled 307 patients in PIONEER I and 326 in PIONEER II. Clinical response rates at week 12 were significantly higher for the groups receiving adalimumab weekly than for the placebo groups: 41.8% versus 26.0% in PIONEER I (P=0.003) and 58.9% versus 27.6% in PIONEER II (P<0.001). Patients receiving adalimumab had significantly greater improvement than the placebo groups in rank-ordered secondary outcomes (lesions, pain, and the modified Sartorius score for disease severity) at week 12 in PIONEER II only. Serious adverse events in period 1 (excluding worsening of underlying disease) occurred in 1.3% of patients receiving adalimumab and 1.3% of those receiving placebo in PIONEER I and in 1.8% and 3.7% of patients, respectively, in PIONEER II. In period 2, the rates of serious adverse events were 4.6% or less in all the groups in both studies, with no significant between-group differences.

CONCLUSIONS

Treatment with adalimumab (40 mg weekly), as compared with placebo, resulted in significantly higher clinical response rates in both trials at 12 weeks; rates of serious adverse events were similar in the study groups. (Funded by AbbVie; ClinicalTrials.gov numbers, NCT01468207 and NCT01468233 for PIONEER I and PIONEER II, respectively.).

Randomized phase II study of carboplatin and paclitaxel with either linifanib or placebo for advanced nonsquamous non-small-cell lung cancer

PURPOSE

Linifanib, a potent, selective inhibitor of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) receptors, has single-agent activity in non-small-cell lung cancer (NSCLC). We evaluated linifanib with carboplatin and paclitaxel as first-line therapy of advanced nonsquamous NSCLC.

PATIENTS AND METHODS

Patients with stage IIIB/IV nonsquamous NSCLC were randomly assigned to 3-week cycles of carboplatin (area under the curve 6) and paclitaxel (200 mg/m(2)) with daily placebo (arm A), linifanib 7.5 mg (arm B), or linifanib 12.5 mg (arm C). The primary end point was progression-free survival (PFS); secondary efficacy end points included overall survival (OS) and objective response rate.

RESULTS

One hundred thirty-eight patients were randomly assigned (median age, 61 years; 57% men; 84% smokers). Median PFS times were 5.4 months (95% CI, 4.2 to 5.7 months) in arm A (n = 47), 8.3 months (95% CI, 4.2 to 10.8 months) in arm B (n = 44), and 7.3 months (95% CI, 4.6 to 10.8 months) in arm C (n = 47). Hazard ratios (HRs) for PFS were 0.51 for arm B versus A (P = .022) and 0.64 for arm C versus A (P = .118). Median OS times were 11.3, 11.4, and 13.0 months in arms A, B, and C, respectively. HRs for OS were 1.08 for arm B versus A (P = .779) and 0.88 for arm C versus A (P = .650). Both linifanib doses were associated with increased toxicity, including a higher incidence of adverse events known to be associated with VEGF/PDGF inhibition. Baseline plasma carcinoembryonic antigen/cytokeratin 19 fragments biomarker signature was associated with PFS improvement and a trend toward OS improvement with linifanib 12.5 mg.

CONCLUSION

Addition of linifanib to chemotherapy significantly improved PFS (arm B), with a modest trend for survival benefit (arm C) and increased toxicity reflective of known VEGF/PDGF inhibitory effects.

Linifanib versus Sorafenib in patients with advanced hepatocellular carcinoma: results of a randomized phase III trial

PURPOSE

This open-label phase III trial evaluated efficacy and tolerability of linifanib versus sorafenib in patients with advanced hepatocellular carcinoma (HCC) without prior systemic therapy.

PATIENTS AND METHODS

Patients were randomly assigned in a 1:1 ratio to linifanib 17.5 mg once daily or sorafenib 400 mg twice daily. Patients were stratified by region (Outside Asia, Japan, and rest of Asia), Eastern Cooperative Oncology Group performance score (ECOG PS; 0 or 1), vascular invasion or extrahepatic spread (yes or no), and hepatitis B virus (HBV) infection (yes or no). The primary end point of the study was overall survival (OS). Secondary end points were time to progression (TTP) and objective response rate (ORR) per RECIST v1.1.

RESULTS

We randomly assigned 1,035 patients (median age, 60 years; Asian, 66.6%; ECOG PS 0, 65.2%; HBV, 49.1%; vascular invasion or extrahepatic spread, 70.1%). Median OS was 9.1 months on the linifanib arm (95% CI, 8.1 to 10.2) and 9.8 months on the sorafenib arm (95% CI, 8.3 to 11.0; hazard ratio [HR], 1.046; 95% CI, 0.896 to 1.221). For prespecified stratification subgroups, OS HRs ranged from 0.793 to 1.119 and the 95% CI contained 1.0. Median TTP was 5.4 months on the linifanib arm (95% CI, 4.2 to 5.6) and 4.0 months on the sorafenib arm (95% CI, 2.8 to 4.2; HR, 0.759; 95% CI, 0.643 to 0.895; P = .001). Best response rate was 13.0% on the linifanib arm versus 6.9% on the sorafenib arm. Grade 3/4 adverse events (AEs); serious AEs; and AEs leading to discontinuation, dose interruption, and reduction were more frequent with linifanib (all P < .001).

CONCLUSION

Linifanib and sorafenib had similar OS in advanced HCC. Predefined superiority and noninferiority OS boundaries were not met for linifanib and the study failed to meet the primary end point. TTP and ORR favored linifanib; safety results favored sorafenib.

Randomized phase II open-label study of mFOLFOX6 in combination with linifanib or bevacizumab for metastatic colorectal cancer

BACKGROUND

Although CRC is the third most commonly diagnosed cancer in the United States, second-line CRC treatment is limited. In this trial we examined the efficacy and safety of linifanib, an oral, potent, selective tyrosine kinase inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor families, with mFOLFOX6, compared with bevacizumab and mFOLFOX6, in previously treated metastatic CRC.

PATIENTS AND METHODS

One hundred forty-eight patients with advanced CRC previously treated with fluoropyrimidine or irinotecan received bevacizumab (10 mg/kg, intravenous), low-dose linifanib (7.5 mg), or high-dose linifanib (12.5 mg), with mFOLFOX6. The primary end point was progression-free survival (PFS). Secondary objectives included overall survival (OS), objective response rate (ORR), and safety.

RESULTS

No statistically significant differences in PFS occurred between bevacizumab and linifanib doses (low, hazard ratio [HR], 1.453 [95% confidence interval [CI], 0.830-2.539]; high, HR, 1.257 [95% CI, 0.672-2.351]). Median OS values were similar for bevacizumab and high-dose linifanib (bevacizumab, 16.5 months [95% CI, 13.0-not available]; high-dose linifanib, 16.4 months [95% CI, 11.9-21.7]; low-dose linifanib, 12.0 months [95% CI, 10.1-13.0]). ORRs were similar (bevacizumab, 34.7% [95% CI, 21.7-49.6]; low-dose linifanib, 24.0% [95% CI, 13.1-38.2]; high-dose linifanib, 22.4% [95% CI, 11.8-36.6]). Median cycles of 5-fluorouracil were reduced in the linifanib arms, versus the bevacizumab arm. Grade 3/4 adverse event occurrences were more frequent with linifanib. Palmar-plantar erythrodysesthesia, hypothyroidism, and thrombocytopenia were more common with high-dose linifanib than bevacizumab.

CONCLUSION

Combining linifanib with mFOLFOX6 as a second-line treatment for metastatic CRC did not improve PFS, radiographic findings, or duration of response versus bevacizumab and mFOLFOX6.

A phase 1 study of linifanib in combination with carboplatin/paclitaxel as first-line treatment of Japanese patients with advanced or metastatic non-small cell lung cancer (NSCLC)

INTRODUCTION

Linifanib is a potent, orally active, and selective inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor kinase activities with clinical efficacy in non-small cell lung cancer (NSCLC). This phase 1 dose-escalation study evaluated the pharmacokinetics, safety, and efficacy of linifanib in combination with carboplatin/paclitaxel in Japanese patients with advanced NSCLC.

METHODS

Carboplatin (AUC = 6 mg/mL/min) and paclitaxel (200 mg/m²) were administered on day 1 of each 21-day cycle up to a maximum of six cycles. Oral linifanib (7.5 mg) was given to six patients once daily throughout all cycles and escalated to 12.5 mg/day in a second cohort of six patients.

RESULTS

Twelve patients received at least one dose of linifanib. The most common adverse events were hematologic and consistent with expected toxicities with carboplatin/paclitaxel. With 12.5 mg linifanib, grade 3/4 neutropenia, leukopenia, and thrombocytopenia occurred in 100, 83, and 83 % of patients, respectively. Dose-limiting grade 4 thrombocytopenia occurred in one patient at each dose level. Linifanib pharmacokinetics was similar to that in non-Japanese patients. At 12.5 mg, linifanib Cmax was 0.32 μg/mL and AUC₂₄ was 4.29 μg h/mL. Linifanib Cmax occurred at 2-3 h with both doses and when given alone or in combination with carboplatin/paclitaxel. Exposure to linifanib appeared to be increased by carboplatin/paclitaxel, and exposure to paclitaxel appeared to be increased by linifanib. Partial responses were observed in nine patients.

CONCLUSIONS

Linifanib added to carboplatin/paclitaxel is well tolerated in Japanese patients with advanced/metastatic NSCLC. The recommended dose of linifanib with carboplatin/paclitaxel is 12.5 mg, same as for US patients.

Effects of fenofibric acid on carotid intima-media thickness in patients with mixed dyslipidemia on atorvastatin therapy: randomized, placebo-controlled study (FIRST)

OBJECTIVE

To assess whether adding a fibrate to statin therapy reduces residual cardiovascular risk associated with elevated triglycerides and low high-density lipoprotein cholesterol, The Evaluation of Choline Fenofibrate (ABT-335) on Carotid Intima-Media Thickness (cIMT) in Subjects with Type IIb Dyslipidemia with Residual Risk in Addition to Atorvastatin Therapy (FIRST) trial evaluated the effects of fenofibric acid (FA) treatment on cIMT in patients with mixed dyslipidemia on atorvastatin.

APPROACH AND RESULTS

This multicenter, double-blind, placebo-controlled study was performed in patients with mixed dyslipidemia (fasting triglycerides, ≥150 mg/dL; high-density lipoprotein cholesterol, ≤45 [men] or 55 mg/dL [women]; low-density lipoprotein cholesterol, ≤100 mg/dL once and averaging ≤105 mg/dL) and a history of coronary heart disease or risk equivalent. Patients on background atorvastatin (continued on starting dose or titrated to 40 mg, if needed) were randomized to FA 135 mg or placebo. The primary end point was rate of change from baseline through week 104 of the mean posterior-wall cIMT, measured by ultrasound. In patients with controlled low-density lipoprotein cholesterol while on atorvastatin background therapy, rate of change in posterior-wall cIMT was similar with FA plus atorvastatin (-0.006 mm/y) versus atorvastatin monotherapy (0.000 mm/y; P=0.22). FA plus atorvastatin was favored (P<0.05) in 5 of 24 prespecified subgroups: age ≥60 years, history of coronary artery disease, cIMT >0.795 mm, triglycerides 170 to 235 mg/dL, and statin use at entry. Adverse events were consistent with the known safety profiles of both drugs; however, FA plus atorvastatin was associated with a greater incidence of renal-related adverse events compared with atorvastatin monotherapy (6.5% versus 0.9%).

CONCLUSIONS

Compared with atorvastatin monotherapy, FA plus atorvastatin did not further decrease cIMT progression in high-risk patients with mixed dyslipidemia.

Results of a phase I, open-label, randomized, crossover study evaluating the effects of linifanib on QTc intervals in patients with solid tumors

PURPOSE

Linifanib is a selective inhibitor of the vascular endothelial growth factor and platelet-derived growth factor family of tyrosine kinase inhibitors. The purpose of this high-precision QT study was to evaluate the effects of linifanib on cardiac repolarization in patients with advanced metastatic tumors.

METHODS

Enrolled patients (n = 24) had measurable disease refractory to standard therapies, ECOG performance status of 0-1, and adequate organ function. Patients were randomized in a 2-sequence, 2-period crossover design. Serial ECG measurements and pharmacokinetic samples were collected for each crossover period. An intersection-union test was performed for time-matched baseline-adjusted QTcF intervals. An exposure-response analysis was explored to correlate the plasma concentration and QTcF.

RESULTS

The maximum 95 % upper confidence bound for the baseline-adjusted QTcF was 4.3 ms at hour 3 at the maximum tolerated linifanib dose of 0.25 mg/kg. Linifanib did not meet the regulatory threshold (10 ms) for QT prolongation. Exposure-response modeling showed that the QTcF change was not significant at the maximum plasma concentration.

CONCLUSIONS

Linifanib does not significantly affect cardiac repolarization in patients with advanced solid tumors.

Exposure-response (safety) analysis to identify linifanib dose for a Phase III study in patients with hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths and the fifth most common cancer globally. Hepatocellular carcinoma produces highly vascular tumors that overexpress vascular endothelial growth factor (VEGF), thus making VEGF a promising therapeutic target. The competitive inhibitor linifanib (ABT-869) has selectivity for VEGF and platelet-derived growth factor (PDGF) receptors and minimal activity against unrelated tyrosine and serine and threonine kinases. However, the optimal dosing regimen for linifanib in HCC patients is not yet known.

OBJECTIVE

This study attempts to identify a linifanib dose or dosing regimen with an acceptable safety profile for a Phase III study in HCC patients.

METHODS

The pharmacokinetic (PK) properties of linifanib were characterized from 2 Phase I and 3 Phase II clinical trials. Of the 266 patients evaluated, the median weight was 68 kg (range, 35-177 kg), 64% were male, and 87.6% of patients received an oral solution of linifanib, whereas 12.4% received a tablet formulation. Approximately 95% of patients received drug based on weight, with the remaining on a fixed-dosing regimen. A population PK analysis was conducted to characterize the linifanib exposure for each patient. Linifanib Cmax and AUC derived from the population PK properties were correlated with the rates of adverse events (AEs).

RESULTS

Linifanib PK properties are dose proportional for the 0.10-mg/kg to 0.25-mg/kg once daily dose range and are time independent after repeated oral dosing. The Tmax of linifanib is approximately 3 hours, and the t½ is approximately 1 day. The most common AEs related to linifanib PK were hypertension (P = 0.02 for Cmax and P = 0.01 for AUC), diarrhea (P = 0.001 for Cmax and P = 0.0012 for AUC), proteinuria (P = 0.001 for Cmax and P = 0.002 for AUC), and asthenia (P = 0.03 for AUC). Weight and sex were identified as covariates for Cmax, and sex was identified as a covariate for AUC. The predicted AE range for females was slightly higher compared with males; however, the AE range is tighter for the weight range for fixed dosing compared with weight-based dosing, regardless of sex.

CONCLUSIONS

The PK properties of linifanib support a one-compartment model with first-order absorption and elimination. Comparison of weight-based and fixed dosing revealed predicted AE rates to be similar, with a tighter AE range for fixed dosing. The safety profile of linifanib, therefore, supports a 17.5 mg fixed starting dose for Phase III clinical studies.

Phase III trial of linifanib versus sorafenib in patients with advanced hepatocellular carcinoma (HCC)

249

Background: Linifanib (ABT-869; Lin) is a potent and selective inhibitor of the vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) receptor tyrosine kinase families. In a phase II trial in patients (pts) with advanced HCC, Lin showed clinical activity (objective response rate [ORR] 10.5% in Child-Pugh A [CPA] pts). This open-label, global phase 3 trial evaluated Lin versus sorafenib (Sor) as first-line therapy in pts with advanced CPA HCC (NCT01009593). Methods: Pts were randomized 1:1 to Lin 17.5 mg QD or Sor 400 mg BID and stratified by region (non-Asia/Japan/rest of Asia), ECOG performance status (0/1), vascular invasion or extrahepatic spread (yes/no) and HBV infection (yes/no). The primary efficacy endpoint was overall survival (OS); both non-inferiority (margin 1.0491) and superiority hypotheses were to be tested. Secondary efficacy endpoints included time to progression (TTP) and ORR, using RECIST v1.1. AE severity was graded using NCI-CTCAE v4.0. Results: 1035 pts (median age 60 y, 68% Asian, 65% ECOG 0, 49% HBV, 70% vascular invasion or extrahepatic spread) were randomized at 149 sites in 26 countries. Hazard ratio (HR) for OS was 1.046 (95% CI: 0.896, 1.221). Median OS (95% CI) was 9.1 months (m) (8.1, 10.2) on Lin and 9.8 m (8.3, 11.0) on Sor. For all pre-specifed subgroup analyses, OS HRs ranged from 0.793-1.119, and the 95% CI contained 1.0. TTP HR was 0.759 (95% CI: 0.643, 0.895; p=0.001) favoring Lin. Median TTP (95% CI) was 5.4 m (4.2, 5.6) on Lin and 4.0 m (2.8. 4.2) on Sor. ORR was 13.0% on Lin and 6.9% on Sor. Grade 3/4 AEs, serious AEs and AEs leading to discontinuations, dose interruptions and reductions were more frequent on Lin versus Sor (all p<0.001). Conclusions: Lin and Sor resulted in similar OS in advanced HCC. Predefined superiority and non-inferiority OS boundaries were not met for Lin. Secondary endpoints (TTP and ORR) favored Lin while safety results favored Sor. Clinical trial information: NCT01009593.

Study design, rationale, and baseline characteristics: evaluation of fenofibric acid on carotid intima-media thickness in patients with type IIb dyslipidemia with residual risk in addition to atorvastatin therapy (FIRST) trial

PURPOSE

Elevated triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C) levels contribute to cardiovascular disease risk and can be effectively treated with fenofibric acid. A trial is under way to evaluate the effect of once-daily fenofibric acid or placebo on carotid intima-media thickness (CIMT) progression in patients with controlled low-density lipoprotein cholesterol (LDL-C) levels achieved through atorvastatin treatment, but with high TG and low HDL-C levels.

METHODS

In this multicenter, double-blind study, 682 patients were randomized to once-daily delayed-release capsules of choline fenofibrate 135 mg (fenofibric acid [Trilipix(®); Abbott, North Chicago, IL]) or placebo plus atorvastatin treatment after a 2- to 10-week diet and atorvastatin run-in period. Key inclusion criteria included age ≥45 years; posterior-wall common CIMT ≥0.7 mm on at least one side at baseline; fasting results of TG ≥150 mg/dL, and HDL-C ≤45 mg/dL for men or HDL-C ≤55 mg/dL for women at screening while receiving atorvastatin; controlled LDL-C; and known coronary heart disease (CHD) or a CHD risk equivalent. The primary efficacy variable is the rate of change from baseline through week 104 in the mean posterior-wall intima-media thickness of the common carotid arteries (composite value of left and right sides).

CONCLUSIONS

This trial is the first to examine the effect of fenofibric acid on CIMT and the first CIMT trial to select patients with controlled LDL-C and elevated TG and low HDL-C as inclusion criteria. Also, this trial will prospectively evaluate the effect of treatment on LDL particles and address shortcomings of previous CIMT trials.

Phase 2 trial of linifanib (ABT-869) in patients with unresectable or metastatic hepatocellular carcinoma

BACKGROUND

The efficacy and safety of linifanib (ABT-869), a selective inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor tyrosine kinases, were assessed in this phase 2, single-arm, open-label, multicenter trial.

METHODS

Eligible patients had unresectable or metastatic hepatocellular carcinoma and had received ≤ 1 prior systemic therapy. Patients received oral linifanib at a fasting dose of 0.25 mg/kg,. The primary endpoint was the progression-free rate at 16 weeks. Tumor response was assessed every 8 weeks. Secondary endpoints included the time to disease progression, overall survival, and objective response rate. Safety was also assessed.

RESULTS

Of the 44 patients enrolled, the majority were Asian (89%), had received no prior systemic therapy (82%), had Child-Pugh class A hepatic function (86%), and had hepatitis B virus infection (61%). The estimated progression-free rate at 16 weeks was 31.8% (34.2% for patients with Child-Pugh class A hepatic function), the estimated objective response rate was 9.1% (10.5% for patients with Child-Pugh class A hepatic function), the median time to disease progression was 3.7 months (3.7 months for patients with Child-Pugh class A hepatic function), and the median overall survival was 9.7 months (10.4 months for patients with Child-Pugh class A hepatic function). The most common linifanib-related adverse events were diarrhea (55%) and fatigue (52%). The most common linifanib-related grade 3/4 adverse events were hypertension (25%) and fatigue (14%). Serum levels of biomarkers cancer antigen (CA) 125, cytokeratin fragment (CYFRA)21.1, and protein induced by vitamin K absence or antagonist II (PIVKA) demonstrated potential as prognostic indicators of patient response or outcome.

CONCLUSIONS

Single-agent linifanib was found to be clinically active in patients with advanced hepatocellular carcinoma, with an acceptable safety profile.

Randomized phase II open-label study of mFOLFOX6 in combination with linifanib or bevacizumab for metastatic colorectal cancer

3532

Background: Linifanib is a potent and selective inhibitor of VEGF/PDGF receptors. This trial assessed the efficacy and safety of mFOLFOX6 in combination with linifanib or bevacizumab as second-line treatment for metastatic colorectal cancer (mCRC). Methods: Patients (pts) with measurable mCRC refractory to 1 prior regimen and ECOG PS 0–1, stratified by prior bevacizumab treatment and radiotherapy, were randomized to receive mFOLFOX6 with bevacizumab 10 mg/kg on day (d) 1 of 14-d cycle (Arm A), mFOLFOX6 with daily linifanib 7.5 mg (Arm B), or mFOLFOX6 with daily linifanib 12.5 mg (Arm C). The primary endpoint was progression-free survival (PFS). Severity of adverse events (AEs) was graded using NCI-CTCAE v3.0. Results: 148 pts were randomized at 45 sites in 14 countries. 32 pts (21.6%) had received prior bevacizumab. PFS and response data are shown below (Table). Median survival (OS) was not reached at median follow up 7.6 months. Palmar-plantar erythrodysesthesia (PPE) was the only Grade 3/4 AE significantly higher on linifanib (high dose, 16.3%) vs. bevacizumab (0%). Rate of any Grade 3+ AE was significantly higher on linifanib vs. bevacizumab.Hypertension rates were 41.7% (Arm A), 40.0% (Arm B), and 36.7% (Arm C). AEs dose-related to linifanib were constipation, proctalgia, stomatitis, fatigue, weight decrease, decreased appetite, and PPE. Conclusions: The addition of linifanib to mFOLFOX6, compared to mFOLFOX6 + bevacizumab, did not provide a PFS advantage for mCRC. OS results will be updated for conference presentation. [Table: see text]

Randomized phase II study of carboplatin and paclitaxel with either linifanib or placebo for advanced nonsquamous NSCLC

7512

Background: Linifanib is a potent and selective inhibitor of VEGF and PDGF receptors with modest single-agent activity in NSCLC. We evaluated the combination of linifanib with carboplatin (C) and paclitaxel (P) for first-line therapy of advanced non-squamous NSCLC. Methods: Patients (pts) with stage IIIB/IV, non-squamous NSCLC, stratified by ECOG PS and gender, were randomized to receive up to six 3-wk cycles of C (AUC 6 mg/ml/min) and P (200 mg/m2) with daily placebo (Arm A), linifanib 7.5 mg (Arm B), or linifanib 12.5 mg (Arm C). The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), 12 m survival rate, and objective response rate (ORR). Safety was assessed by NCI-CTCAE v3.0. Results: 138 pts were randomized at 37 sites in 6 countries. Baseline characteristics were: median age, 61 y; men, 57%; smoker, 84%. Efficacy results are shown in the table. Thrombocytopenia was the only Grade 3/4 AE significantly higher on linifanib (Arm B: 16.7%; Arm C: 29.8%) vs. placebo (2.1%). Other adverse events (AEs) related to the dose of linifanib were diarrhea, thrombocytopenia, hypertension, weight loss, palmar-plantar erythrodysaesthesia syndrome, and hypothyroidism. Analysis of samples for predictive biomarkers including serum VEGF and placental growth factor are underway. Conclusions: The addition of linifanib to chemotherapy was tolerable at the doses tested and resulted in a significant improvement in PFS, with a modest survival improvement for Arm C in first-line therapy of advanced non-squamous NSCLC. [Table: see text]

Association of baseline plasma biomarker signature with survival in advanced NSCLC patients on linifanib

e13583

Background: Linifanib is a potent and selective VEGF and PDGF receptor inhibitor that has activity in unselected, advanced NSCLC patients (pts) both as monotherapy in the relapsed setting and with carboplatin (C) and paclitaxel (P) in the first-line setting. A baseline plasma biomarker signature identifying NSCLC pts most sensitive to linifanib is needed. Methods: An exploratory retrospective analysis of four randomized clinical trials including linifanib or other treatments in relapsed NSCLC was conducted. Evaluable baseline plasma samples were obtained from 116 pts who received linifanib and 71 pts on other treatments. A signature combining established tumor markers (carcinoembryonic antigen [CEA] and fragments of cytokeratin 19 [CYFRA 21-1]) was derived using a sequential BATTing approach. The signature was then tested across a randomized trial of CP + placebo, linifanib 7.5 mg, or linifanib 12.5 mg in first-line advanced, non-squamous NSCLC. Results: In 2/3L NSCLC, the signature was associated with improvement in survival on linifanib monotherapy (HR=0.51 vs. signature negative; P=0.0017), but no improvement in survival on other treatments (P=0.87). In the first-line setting with CP, the signature was associated with significant PFS improvement with linifanib and a trend towards significant overall survival improvement at high dose (Table). Conclusions: A baseline plasma biomarker signature is associated with improved survival in advanced NSCLC patients on linifanib. Incorporation of this signature should be considered in any further investigation of linifanib in NSCLC. [Table: see text]

An open-label, phase 1 study evaluating safety, tolerability, and pharmacokinetics of linifanib (ABT-869) in Japanese patients with solid tumors

Purpose

This phase 1 study assessed the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of linifanib in Japanese patients with advanced solid tumors.

Methods

Patients were assigned to one of four sequential cohorts (0.05, 0.10, 0.20, or 0.25 mg/kg) of oral, once-daily linifanib on a 21-day cycle. Adverse events (AEs) were assessed per common terminology criteria for adverse events v3.0; tumor responses were assessed by response evaluation criteria in solid tumors.

Results

Eighteen patients were enrolled. Eleven (61%) received ≥3 prior therapies. Dose-limiting toxicities were Grade 3 ALT increase (0.10 mg/kg linifanib) and Grade 1 T-wave inversion (0.25 mg/kg linifanib) requiring dose interruption for >7 days and discontinuation on day 29. The most common linifanib-related AE was hypertension. Other significant treatment-related AEs included proteinuria, fatigue, and palmar-plantar erythrodysaesthesia. Linifanib pharmacokinetics were dose-proportional across 0.10–0.25 mg/kg. Two patients (11.1%) had confirmed partial responses, 12 had a best response of stable disease (11 had stable disease for ≥12 weeks), and four patients were not evaluable due to incomplete data. Four patients (lung cancer, breast cancer, thymic cancer, sarcoma) have continued linifanib for ≥48 weeks (range, 48–96+ weeks).

Conclusion

Linifanib was well tolerated with promising preliminary clinical activity in Japanese patients. Later-phase global studies examining linifanib efficacy will include Japanese patients.

Phase 1 trial of linifanib (ABT-869) in patients with refractory or relapsed acute myeloid leukemia

Linifanib, a potent oral inhibitor of fms-like tyrosine kinase 3 (FLT3) and vascular endothelial growth factor receptor tyrosine kinases, has demonstrated promising preclinical single-agent and synergistic anti-leukemic activity in combination with cytarabine. In this phase 1, multicenter, open-label, dose-escalation study, 45 adults with relapsed/refractory acute myeloid leukemia (AML) received linifanib alone in arm A (n = 29) and linifanib plus intermediate-dose cytarabine in arm B (n = 16). Median treatment duration was 21 days (range 5-110). Linifanib was well tolerated overall. The most common grade 3/4 events were fatigue (arm A) and febrile neutropenia (arm B). The recommended phase 2 dose was 15 mg (alone), and 10 mg (with cytarabine). Evidence of on-target kinase inhibition in patients with FLT3-mutant and wild-type AML was seen. Decreased phosphorylated FLT3 was seen in 3/3 patients with FLT3-internal tandem duplication (ITD) with peripheral blast reductions and in 8/24 (33%) patients with wild-type, D835 or unknown FLT3 mutation. Eight/29 (28%) patients had decreased phosphorylated extracellular signal-regulated kinase (ERK).

Phase 2 trial of linifanib (ABT-869) in patients with advanced renal cell cancer after sunitinib failure

PURPOSE

This study assessed the efficacy and safety of linifanib in patients with advanced renal cell carcinoma (RCC) who were previously treated with sunitinib.

MATERIALS AND METHODS

This open-label, multicentre, phase 2 trial of oral linifanib 0.25 mg/kg/day enrolled patients who had prior nephrectomy and adequate organ function. The primary end-point was objective response rate (ORR) per response evaluation criteria in solid tumors (RECIST) by central imaging. Secondary end-points were progression-free survival (PFS), overall survival (OS) and time to progression (TTP). Safety was also assessed.

RESULTS

Fifty-three patients, median age 61 years (range 40-80) were enrolled (August 2007 to October 2008) across 12 North-American centres. Median number of prior therapies was 2 (range 1-4); 43 patients (81%) had clear-cell histology. ORR was 13.2%, median PFS was 5.4 months (95% Confidence Interval (CI): 3.6, 6.0) and TTP was the same; median OS was 14.5 months (95% CI: 10.8, 24.1). The most common treatment-related adverse events (AEs) were diarrhoea (74%), fatigue (74%) and hypertension (66%), and the most common treatment-related Grade 3/4 AE was hypertension (40%).

CONCLUSIONS

Linifanib demonstrated clinically meaningful activity in patients with advanced RCC after sunitinib failure. At 0.25 mg/kg/day, significant dose modifications were required. An alternative, fixed-dosing strategy is being evaluated in other trials.

Achievement of lipid targets with the combination of rosuvastatin and fenofibric Acid in patients with type 2 diabetes mellitus

Objective

The objective of this study was to assess the proportion of patients with type 2 diabetes mellitus (T2DM) attaining individual and combined targets of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), non-HDL-C, and apolipoprotein B (ApoB) after treatment with rosuvastatin (R) + fenofibric acid (FA) compared with corresponding-dose R monotherapy.

Methods

This post hoc analysis evaluated data from the T2DM subset of patients with mixed dyslipidemia (LDL-C ≥130 mg/dL, HDL-C <40/50 mg/dL in men/women, and TG ≥150 mg/dL) from 2 randomized studies. Patients included in the analysis (N = 456) were treated with R (5, 10, or 20 mg), FA 135 mg, or R (5, 10, or 20 mg) + FA 135 mg for 12 weeks. Attainment of LDL-C <100 mg/dL, HDL-C >40/50 mg/dL in men/women, TG <150 mg/dL, non-HDL-C <130 mg/dL, ApoB <90 mg/dL, and the combined targets of these parameters was assessed.

Results

Treatment with R + FA resulted in a significantly higher proportion of patients achieving optimal levels of HDL-C (46.8% vs. 20.8%, P = 0.009 for R 10 mg + FA), TG (60.0% vs. 34.0%, P = 0.02 for R 10 mg + FA; 54.0% vs. 26.4%, P = 0.005 for R 20 mg + FA), non-HDL-C (55.1% vs. 36.4%, P = 0.04 for R 5 mg + FA), ApoB (58.0% vs. 36.4%, P = 0.02 for R 5 mg + FA); and the combined targets of LDL-C, HDL-C, and TG (28.3% vs. 8.3%, P = 0.02 for R 10 mg + FA) and all 5 parameters (26.1% vs. 8.3%, P = 0.03 for R 10 mg + FA) than corresponding-dose R monotherapies.

Conclusions

A significantly greater proportion of T2DM patients achieved individual and combined lipid targets when treated with the combination of R + FA than corresponding-dose R monotherapies.

Efficacy and safety of rosuvastatin 5 mg in combination with fenofibric acid 135 mg in patients with mixed dyslipidemia - a phase 3 study

BACKGROUND

Patients with mixed dyslipidemia characterized by elevated low-density lipoprotein cholesterol (LDL-C), elevated triglycerides (TG), and reduced high-density lipoprotein cholesterol (HDL-C) often require combination therapy to improve multiple lipid and nonlipid parameters. This phase 3, multicenter, randomized, double-blind study evaluated the efficacy and safety of rosuvastatin 5 mg coadministered with fenofibric acid 135 mg in patients with mixed dyslipidemia.

METHODS

A total of 760 patients with TG ≥ 150 mg/dL, HDL-C <40 mg/dL (<50 mg/dL for women), and LDL-C ≥ 130 mg/dL were randomized for a 12-week treatment period to rosuvastatin 5 mg, fenofibric acid 135 mg, or rosuvastatin 5 mg + fenofibric acid 135 mg. The primary efficacy comparisons were mean percentage changes in HDL-C and TG (rosuvastatin + fenofibric acid vs. rosuvastatin monotherapy), and LDL-C (rosuvastatin + fenofibric acid vs. fenofibric acid monotherapy).

RESULTS

Treatment with rosuvastatin + fenofibric acid resulted in statistically significant greater improvements in HDL-C (23.0% vs. 12.4%; P < 0.001) and TG (-40.3% vs. -17.5%; P < 0.001), compared with rosuvastatin monotherapy; and LDL-C (-28.7% vs. -4.1%; P < 0.001), compared with fenofibric acid monotherapy. All secondary efficacy variables improved with combination therapy. Combination therapy was generally well tolerated with a safety profile consistent with individual monotherapies. No unexpected muscle, hepatic, or renal safety signals were identified with combination therapy versus individual monotherapies.

CONCLUSION

In conclusion, rosuvastatin 5 mg + fenofibric acid 135 mg resulted in comprehensive improvements in the lipid profile of patients with mixed dyslipidemia without unanticipated adverse events.

Abstract 1277: Modeling the correlation of linifanib (ABT-869) pharmacokinetic (PK) exposure and DCE-MRI response in patients with advanced or metastatic solid tumors

Background: Vascular endothelial growth factor (VEFG) has a pivotal role in tumor angiogenesis, which is required for the growth of most solid tumors and progression to metastases. Linifanib is a novel orally active, potent and selective inhibitor of VEGF and platelet derived growth factor (PDGF) receptor tyrosine kinases. DCE-MRI is a non-invasive functional imaging technique that permits indirect measurement of tumor hemodynamics, therefore, suitable for monitoring VEGF inhibition response in tumor vasculature. This population PK-PD modeling analysis was to assess the correlation between linifanib PK exposures and DCE-MRI response in patients with advanced or metastatic solid tumors.

Methods: DCE-MRI variables including Ktrans were available from one phase 1 clinical trial (N=17) on Day 0, Day 3 and Day 15 and three phase 2 clinical trials (N=122) on Day 0 and Day 15. Linifanib exposures were obtained by estimating AUC at steady-state (AUCss) using a population PK model (Previously established). PK-PD modeling was performed by using NONMEM (Version VII) to fit the available data to an inhibitory maximum effect (Emax) model with time component. The percentage of change from baseline in Ktrans was the response variable and AUCss was the PK-exposure variable. The mixture function of NONMEM was used by examining the decrease function of individual Ktrans data fit over time to allow separation between responding patients (with decrease function) and non-responding patients (with non-decrease function). This model was defined as base model and was used for identification of covariates that influence the PK-PD relationship. Covariates were tested using an iterative forward addition (p&lt;0.01) and backward elimination (p&lt;0.001) procedure. The final model was defined as the model containing only the most significant covariate relations. Goodness-of-fit plots were used to assess the adequacy of the final model. Robustness of the parameter estimates from the final model was also assessed using bootstrap validation.

Results: An inhibitory maximum effect (Emax) model with time component described the data well. Two populations, responders (88.5%) and non-responders (11.5%), were characterized using the mixture model approach. Following model selection criteria, the final model included baseline Ktrans and baseline ECOG as covariates on EC50 (EAUCss50). The estimated median EAUCss50 from the final model was approximately 6 μg·hr/mL, which corresponded to a dose of 17.5 mg QD, the maximum tolerated dose (MTD) identified for linifanib as a single-agent.

Conclusions: The PK-PD relationship between PK exposure (AUCss) and biologic response (percentage of change from baseline in Ktrans) shows that the linifanib dose of 17.5 mg QD, implemented in the phase 3 monotherapy trial in patients with hepatocellular carcinoma, is biologically effective.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1277. doi:10.1158/1538-7445.AM2011-1277

Combination rosuvastatin plus fenofibric acid in a cohort of patients 65 years or older with mixed dyslipidemia: subanalysis of two randomized, controlled studies

BACKGROUND

Coronary heart disease risk increases with advancing age and is further increased in patients with mixed dyslipidemia, characterized by elevated low-density lipoprotein cholesterol (LDL-C), low high-density lipoprotein cholesterol (HDL-C), and high triglycerides (TG). Combination lipid therapy is an option; however, efficacy and safety data among elderly patients are lacking.

HYPOTHESIS

The combination of rosuvastatin and fenofibric acid (R + FA) results in more comprehensive lipid improvements than corresponding-dose monotherapies, without additional safety concerns, in elderly patients with mixed dyslipidemia.

METHODS

This post-hoc analysis evaluated data from patients age ≥ 65 years (n = 401) with mixed dyslipidemia (LDL-C ≥ 130 mg/dL, HDL-C < 40 mg/dL [men] or < 50 mg/dL [women], and TG ≥ 150 mg/dL) in 2 randomized studies. Patients included in this analysis received either monotherapy (as R 5, 10, or 20 mg or FA 135 mg), or combination therapy with R (5, 10, or 20 mg) + FA 135 mg, for 12 weeks. Data were pooled and analyzed, and mean/median percent changes in multiple lipid parameters and biomarkers were compared.

RESULTS

Combination therapy decreased LDL-C by 31.8%-47.2% vs 10.6% with FA monotherapy (P < 0.001). Combination therapy also increased HDL-C by 21.9%-27.0% vs 5.9%-9.9% with R monotherapy (P < 0.001), and decreased TG by 48.3%-53.5% vs 20.7%-32.8% with R monotherapy (P < 0.001). In general, safety profiles were consistent between combination therapy and individual monotherapies.

CONCLUSIONS

In these elderly patients with mixed dyslipidemia, R 5, 10, or 20 mg in combination with FA 135 mg improved the overall lipid profile, without new or unexpected safety issues.

Efficacy and safety of rosuvastatin and fenofibric acid combination therapy versus simvastatin monotherapy in patients with hypercholesterolemia and hypertriglyceridemia: a randomized, double-blind study

OBJECTIVES

To evaluate the efficacy and safety of fixed-dose combinations of rosuvastatin and fenofibric acid (rosuvastatin/fenofibric acid) compared with simvastatin in patients with high levels of low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG).

BACKGROUND

Combination therapy with a statin and a fibrate is one of the treatment options to manage multiple lipid abnormalities in patients with hypercholesterolemia and elevated TGs.

METHODS

In this randomized, double-blind study, patients (n = 474) with LDL-C > or =160 mg/dL and < or =240 mg/dL and TG > or =150 mg/dL and <400 mg/dL were treated for 8 weeks with simvastatin 40 mg, rosuvastatin/fenofibric acid 5 mg/135 mg, rosuvastatin/fenofibric acid 10 mg/135 mg, or rosuvastatin/fenofibric acid 20 mg/135 mg. Primary and secondary variables were mean percent changes in LDL-C comparing rosuvastatin/fenofibric acid 20 mg/135 mg with simvastatin 40 mg and rosuvastatin/fenofibric acid 10 mg/135 mg and rosuvastatin/fenofibric acid 5 mg/135 mg with simvastatin 40 mg, respectively. Additional efficacy variables included non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein (Apo) B, HDL-C, TG, and high-sensitivity C-reactive protein (hsCRP). Safety was evaluated based on data collected for adverse events (AEs), physical and electrocardiographic examinations, vital sign measurements, and clinical laboratory tests.

RESULTS

Significantly greater reductions in LDL-C levels from baseline values were observed with the combination of rosuvastatin/fenofibric acid 20 mg/135 mg (-47.2%, p < 0.001), rosuvastatin/fenofibric acid 10 mg/135 mg (-46.0%, p < 0.001), and rosuvastatin/fenofibric acid 5 mg/135 mg (-38.9%, p = 0.007) than with simvastatin 40 mg (-32.8%). Significant (p < or = 0.04 for all comparisons) improvements in non-HDL-C, ApoB, HDL-C, TG, and hsCRP levels were also observed with each of the rosuvastatin/fenofibric acid doses as compared with simvastatin 40 mg. Treatment-related AEs and discontinuations due to AEs were similar across groups. The incidence of serious AEs was 0% with simvastatin 40 mg, 3.4% with rosuvastatin/fenofibric acid 5 mg/135 mg, 0.8% with rosuvastatin/fenofibric acid 10 mg/135 mg, and 2.5% with rosuvastatin/fenofibric acid 20 mg/135 mg. No cases of rhabdomyolysis or drug-related myopathy were reported.

CONCLUSION

In patients with high LDL-C and TG levels, combination treatment with rosuvastatin/fenofibric acid was well tolerated, and each of the rosuvastatin/fenofibric acid doses produced greater reductions in LDL-C and improvements in other efficacy parameters, compared with simvastatin 40 mg. [Clinical trial is registered at www.clinicaltrials.gov NCT00812955.].

Targeting the unmet medical need: the Abbott Laboratories oncology approach

While significant advances in the treatment of cancer occured during the last half of the twentieth century, parallel decreases in overall cancer death rates were not observed. Cancer therapy remains an area of significant unmet medical need. Abbott's oncology research programs are focused on pioneering trageted, less toxic therapies, aimed at different aspects of tumor growth and development. Oncology drugs in development at Abbott target several mechanisms of cancer progression by interfering with multiple processes necessary for tumor growth: recruitment of a blood supply, cell proliferation, and the development of metastases. They include a selective endothelin A-receptor antagonist (atrasentan/Xinlay), 3 angiogenesis inhibitors (ABT 510, a thrombospondin mimetic: ABT-869, a multitargeted receptor tyrosine kinase inhibitor; and ABT 828, recombinant human plasminogen kringle 5), a cell proliferation inhibitor (ABT-751, an antimitotic agent), an apoptosis inducer (ABT 737, a Bcl-2 family inhibitor), and a poly(ADP-ribose)polymerase inhibitor.

A corpus-linguistic investigation of dental English

This article begins by presenting corpus linguistics and explaining how the corpus approach to language analysis can be used to investigate the language of dentistry. It then reports findings from an analysis that was carried out with readily available software and a corpus of 1,400 dental research abstracts. Included is information about word frequency in dental abstracts and also about how certain words tend to co-occur in sentences and form regular patterns. The article concludes with a discussion of ways that corpus-based findings can be applied to the teaching of English to non-native speakers of the language, many of whom will need English skills for their future careers in dentistry.

Expression, regulation, and function of the SPR family of proteins. A review

The small, proline-rich (SPR) genes consist of three subclasses closely linked on human chromosome 1, a region referred to as the epidermal differentiation complex. SPR genes consist of two exons, with the second exon containing the entire open reading frame. SPRs are expressed in all squamous tissues of the skin, scalp, footpad, vaginal epithelia, and most of the epithelial lining of the digestive tract, including the lip, tongue, esophagus, and forestomach. Although SPR1 is absent in normal mucociliary epithelium of the respiratory tract, epithelia that undergo squamous differentiation in response to vitamin-A deficiency or to injury owing to exposure to environmental toxicants express SPR1. High levels of SPR1 are detected in various diseases and cancers of the skin or respiratory epithelia and in nonkeratinizing papillary adenocarcinomas. SPR expression can be regulated by transcriptional factors, by posttranscriptional factors, or by factors that affect SPR1 mRNA translation or protein turnover. Furthermore, regulation can be affected by the state of cell proliferation. The presence of SPR1 in most of these epithelia, and the absence of SPR3 in normal skin, suggest that these subclasses have distinct functions. Various approaches to the study of the cross-linked envelope (CE) components in identifying SPR1 and SPR2 and in suggesting that SPRs are one of the precursor proteins of the CE. However, expression of SPR1 in nonsquamous tissues and cell lines indicates a function not associated with squamous differentiation. Several studies have demonstrated that SPR1 antibodies react with nuclear proteins and that SPR1 is expressed in cells before entering the G0 phase of the cell cycle. Future studies should clarify the role of SPRs by modifying their contents in CE, and should identify SPR-associated proteins to clarify the cell growth-related role of SPR1.

Induction of p34cdc2 in mouse parotid glands upon activation of beta1-adrenergic receptors

Dramatic morphological, biochemical and cytological changes occur in parotid glands of rats and mice which have been treated with the beta-adrenergic receptor agonist isoproterenol (Ipr). Changes include glandular hypertrophy, induction of tissue-specific proline-rich proteins (PRPs), increases in cAMP, and occurrence of polyploidy. Similar changes also occur after feeding mice polyphenolic compounds commonly referred to as tannins. Data are presented which show that changes in cell cycle proteins are due to stimulation of the beta-adrenergic receptor by either isoproterenol or tannin treatment of mice. Both p34cdc2 mRNA and protein levels were elevated dramatically after mice were treated. Induction of p34cdc2 occurred within 24 hrs. and was transient during treatment. The beta1-adrenergic receptor antagonist atenolol blocked both tissue-specific expression of proline-rich proteins and induction of p34cdc2. Coincident with the increase in p34cdc2, cyclin-dependent kinase complexes containing cyclins A and B increased forty- and ten-fold, respectively. These results show that in mouse parotid glands activation of the beta1-adrenergic receptor by either the administration of isoproterenol or ingestion of dietary tannins induces synthesis of p34cdc2 and most likely contributes to the occurrence of polyploidy.

Cyclic AMP regulation of mouse proline-rich protein gene expression: isoproterenol induction of AP-1 transcription factors in parotid glands

Proline-rich protein mRNAs are increased dramatically in the salivary glands of rats, mice, and hamsters upon treatment with the beta-agonist isoproterenol. Sequence comparisons between mice and hamster proline-rich protein genes identified conserved regions upstream from the transcription start site. Reporter plasmids containing these 5'-flanking sequences from a mouse proline-rich protein gene, MP2, were constructed and tested for transcriptional regulation by cAMP. Transient transfection experiments in mouse L-M cells showed that the upstream region -702 to -322 bp relative to the transcription start site is sufficient to confer cAMP induction on a heterologous promoter. Multiple copies of the AP-1 sequence elements within this region (-625 to -551) mediate the cAMP transcriptional response of reporter gene expression in L-M cells. L-M cell nuclear proteins and purified human c-jun protein bind to these upstream elements as determined by DNase I footprint analysis. Nuclear proteins isolated from mouse parotid glands protected the consensus AP-1 binding site 5'-TGAGTCA-3' (-592 to -586). The nuclear proteins interacting at this site were increased about sixfold in glands isolated from isoproterenol-treated mice when compared with glands from untreated mice. These results suggest that induction of AP-1 transcription factors in the parotid gland control the upregulation of some mouse salivary proline-rich proteins.

Cell cycle-specific expression of G(0)SPR1 in Chinese hamster ovary cells

A family of small proline-rich proteins (SPR1s) is induced in cells undergoing squamous differentiation. Because SPR1 mRNA is detected in mesenchymal nasal cells of rats exposed to cigarette smoke, expression of this mRNA in other nonsquamous cells and tissues was investigated. Using PCR, low levels of SPR1 mRNA were identified in a number of nondifferentiating cell lines and in nonsquamous tissues. G(0)SPR1 mRNA, the hamster homologue of SPR1 mRNA, was increased 10-fold in Chinese hamster ovary (CHO) cells when the culture reached 80-90% confluence and was downregulated after cells ceased growing at 100% confluence. The deduced amino acid sequence of G(0)SPR1 showed a high homology to the family of SPR1 from different species. Affinity-purified antibodies to SPR1 reacted to about 50% of the CHO cell population, indicating that the protein is expressed at specific stages of the cell cycle. CHO cells that were switched to low-serum medium when they were at 60% confluence showed an increase in G(0)SPR1 levels before the cells entered G0, indicating that G(0)SPR1 may b a signal to cells entering G0. Because expression of the SPR1 family of proteins is associated with squamous differentiation, the observations in the nondifferentiating CHO cells indicate that these proteins may play a role in mediating the withdrawal from the cell cycle prior to the commitment to differentiation.

Expression of the spr1 gene in cultured tracheal epithelial cells and its regulation by retinoids before and after confluence

The absence of vitamin A or vitamin A derivatives in culture media promotes squamous cell differentiation of tracheobronchial epithelial cells. This is especially true for the expression of a small proline-rich protein (20K; 98 amino acids) in pig trachea epithelial cells. Multigene families encode different small proline-rich proteins in different species, and these proteins are possible markers for squamous cell differentiation. 20K mRNA and 20K protein were detected in cells within 4 and 5 days in culture, respectively, when cells reached about 50% confluence, and expression increase 12-fold during cell proliferation until cells reached 100% confluence. Arotinoid (10(-9)M), a synthetic retinoid, essentially totally inhibited expression of 20K mRNA in proliferating tracheobronchial cells within 3 days of treatment while 20K protein levels were only decreased 4-fold after 5 days. However, if cells were exposed to arotinoid 3 days after reaching confluent growth, the levels of either 20K mRNA or 20K protein were unchanged. Cells exposed to arotinoid from the onset of culturing, and then removal of the retinoid from proliferating cells resulted in the expression of 20K mRNA and protein after 4 and 5 days as observed previously. 20K mRNA was not detected in cells that had been continuously exposed to arotinoid from the start of culture until 3 days post confluence, even 10 days following removal of arotinoid. Our results strongly suggest that the growth phase and state of cell differentiation greatly affect the response of these epithelial cells to vitamin A derivatives.

Two nuclear proteins in tracheal epithelial cells are recognized by antibodies specific to a squamous differentiation marker, sprI

In cell-free translations of RNA from primary cultures of pig trachea surface epithelial cells we observed that a mRNA encoding a 20 kDa proline-rich protein (sPRP) was dramatically induced during culturing (Tesfaigzi et al., 1990, Biochem. Biophys. Res. Commun., 172:M1304-1309). This mRNA was not detected in tracheal tissue or in epithelial cells prior to culturing. Antisera were raised to synthetic peptide sequences corresponding to 23 amino acids on the C-terminus (C23-antiserum) and 29 amino acids on the N-terminus (N29 antiserum) of sPRP. On Western blot analysis, C23 antiserum reacted with a 20 kDa protein in cytosolic extracts from pig tracheal cells maintained in culture for 4 days. The reaction with the 20 kDa protein was inhibited by adding C23 peptide. Two nuclear proteins (66 and 70 kDa) obtained by micrococcal nuclease treatment of tracheal cell nuclei were detected on Western blots with C23 antiserum. These proteins were present in cells both before and after culturing. Sucrose gradient fractionation indicated that these nuclear proteins are associated with chromatin. Small amounts of the 66 and 70 kDa proteins were obtained from nuclear matrix fractions. These nuclear proteins also reacted with N29 antiserum. Since these proteins share similar epitopes with the N- and C-termini of sPRP, it is likely that the 20 kDa protein (sPRP) is part of these proteins. However, purification of the nuclear proteins followed by an amino acid sequence analysis is necessary to clarify whether sPRP is part of these proteins.

Palatal muscle electromyogram activity in obstructive sleep apnea

Eight subjects (5 men, 3 women, ages 27 to 55) with obstructive sleep apnea syndrome (OSAS) were studied to quantify and compare electromyographic (EMG) activity of levator veli palatini (LVP) and palatoglossus (PG), two velopharyngeal muscles, and genioglossus (GG) during obstructive apnea cycles in non-rapid eye movement (NREM) sleep. EMG activity of three successive preapneic breaths, first and last apneic efforts, and three successive postapneic breaths was quantified for each muscle as peak phasic inspiratory EMG normalized as percent activity of the last preapneic breath. In all subjects, apnea onset coincided with simultaneous inspiratory EMG nadir of all three muscles (LVP = 63 +/- 40%, PG = 74 +/- 53%. GG = 83 +/- 48%. mean +/- SD activity of last preapneic breath). Apnea resolution did not occur until inspiratory EMG of all three muscles simultaneously reached maximal activity, at levels significantly greater than preapneic activity as well as activity of the last preapneic effort (LVP = 215 +/- 205%, PG = 227 +/- 240+, GG = 235 +/- 202%, mean +/- SD activity of last preapneic breath, p < 0.05, Fisher's partial least-squares difference [PLSD] test for each muscle). The presence or absence of electroencephalographic arousal at apnea resolution did not influence these patterns of EMG activity. Inspiratory recruitment of velopharyngeal as well as oropharyngeal muscles appears to be associated with upper airway patency during sleep in patients with OSAS.

Characterization of vitellogenin from white sturgeon, Acipenser transmontanus

Sturgeon are an ancient family (Acipenseridae) of fishes that lie close to the divergence of fish that eventually evolved into terrestrial animals and those that evolved into modern teleost species. Therefore, white sturgeon vitellogenin sequences fill a gap in the current understanding of the functional domains of this protein family. Vitellogenin cDNA was sequenced and used to investigate gene expression in white sturgeon, Acipenser transmontanus. Estrogen-induced vitellogenin mRNA was detected in the livers of both males and females and was also detected in undifferentiated gonads of estrogen-treated fish. Low levels of vitellogenin mRNA were also detected in the testis of both control and estrogen-treated males. The cDNA encoded a 186-kDa protein that was missing only six to seven of the amino-terminal amino acids. Comparisons to silver lamprey, Xenopus, and chicken vitellogenin sequences indicate that the overall structure of the yolk protein domains were highly conserved. There was considerable homology in three regions of the lipovitellin I domain. These conserved sequences are likely to be involved in vitellogenin receptor binding. The phosvitin domain of white sturgeon vitellogenin contained fewer and shorter serine repeats as predicted from yolk protein phosphate content of fish compared to Xenopus and chicken. However, the vitellogenin of white sturgeon had a lower serine content as compared with silver lamprey, indicating that an increased serine content is not strictly a function of evolutionary age.

cDNA cloning and characterization of rat salivary glycoproteins. Novel members of the proline-rich-protein multigene families

The cDNAs for two glycoproteins, the 158-kDa submandibular glycoprotein (SGP158) and the 200-kDa parotid glycoprotein (PGP200), have been cloned from rat submandibular and parotid glands, respectively. Both cDNAs encode for identical proteins with repeating peptides -Asp-Gln-Gly-(Asn)-Gln-Thr-Gln-Pro-Arg-Pro-Pro-His-Pro-. A full-length cDNA encoding SGP158 was obtained using the strategy of anchor-PCR, and a full-length cDNA of PGP200 was prepared using RNA-PCR. Sequence analysis of the cDNAs revealed that SGP158 and PGP200 are identical proteins with 23 repeating peptides. Twenty-one peptides contain potential N-glycosylation sites and these two glycoproteins differ only in their glycosylation patterns. Southern-blot analysis showed that a single-copy gene encodes both mRNAs. PGP200 is constitutively expressed, but the synthesis of SGP158 is totally dependent upon treatment of animals with the beta-agonist isoproterenol. The first 106-nucleotide sequence of cDNAs for PGP200 and SGP158, which corresponds to the 5'-untranslated region and sequence encoding the signal peptide, is highly conserved when compared with proline-rich protein and glutamine-rich protein gene sequences. Based on the nucleotide sequences of exon I, a phylogenetic tree was constructed for 35 members of these multigene families. The tree fits with the generally recognized phylogeny of mammalian orders. We propose that exon I sequences of the proline-rich protein and glutamine-rich protein multigene families are relatively new and are possibly generated through exon shuffling during evolution.

Gene expression following direct injection of DNA into liver

The liver is an attractive target tissue for gene therapy. Current approaches for hepatic gene delivery include retroviral and adenoviral vectors, liposome/DNA, and peptide/DNA complexes. This study describes a technique for direct injection of DNA into liver that led to significant gene expression. Gene expression was characterized in both rats and cats following injection of plasmid DNA encoding several different proteins. Luciferase activity was measured after injection of plasmid DNA encoding the luciferase gene (pCMVL), beta-galactosidase (beta-Gal) activity was evaluated in situ using plasmid DNA encoding Lac Z (pCMV beta), and serum concentration of secreted human alpha-1-antitrypsin was measured following injection of plasmid DNA encoding this protein (pRC/CMV-sHAT). Several variables, including injection technique, DNA dose, and DNA diluent, were investigated. Direct injection of pCMVL resulted in maximal luciferase expression at 24-48 hr. beta-Gal staining demonstrated that the majority of transfected hepatocytes were located near the injection site. Significant concentrations of human alpha-1-antitrypsin were detected in the serum of animals injected with pRC/CMV-sHAT. These findings demonstrate the general principle that direct injection of plasmid DNA into liver can lead to significant gene expression.

Dexamethasone enhancement of gene expression after direct hepatic DNA injection

The critical physiological functions of the liver make hepatocytes important targets for therapeutic gene delivery. This study reports significant gene expression following direct injection of plasmid DNA into the livers of rats and cats. Transfection was characterized using luciferase and Lac Z expression from plasmids with the cytomegalovirus immediate early promoter/enhancer (CMV IE) or the Rous sarcoma virus long terminal repeat (RSV LTR). Dexamethasone treatment enhanced and prolonged transfected gene expression, possibly by activating gene expression. Southern analysis of total DNA extracted from liver at various times following injection detected persistent unintegrated plasmid DNA which maintained a prokaryotic methylation pattern. This study demonstrates the feasibility of direct DNA injection in the experimental analysis of hepatic gene expression in vivo.

Acoustically induced cortical arousal increases phasic pharyngeal muscle and diaphragmatic EMG in NREM sleep

Six healthy subjects (3 males, 3 females) were studied to assess phasic inspiratory responses of upper airway (UA) and diaphragm muscles to electrocortical arousal independent of other potential respiratory stimulation. Transient electroencephalographic (EEG) arousal (abrupt EEG frequency shift > or = 3 s without awakening) was induced during supine stage 2 non-rapid-eye-movement (NREM) sleep with binaural tone bursts (0.5 s, 4 kHz, 25-95 dB). Electromyograms (EMG) of levator veli palatini (EMGlvp) and genioglossus (EMGgg) were obtained with intramuscular electrodes, and EMG of diaphragm (EMGdi) was obtained with esophageal electrodes. EMG signals were processed as moving time-averaged inspiratory activity over 100-ms windows. For each arousal, each of five consecutive postarousal breaths (R1-R5) was scored for peak inspiratory phasic EMG and normalized as percent averaged EMG of the three prearousal breaths for all muscles. After arousal, EMGlvp was increased for R1-R5 and EMGgg and EMGdi were increased for R1-R4. The increase in EMGlvp was greater than those of EMGgg and EMGdi for all response breaths. There was a significant increase in EMGlvp in all subjects, and EMGgg and EMGdi were significantly increased in three and two subjects, respectively. These data indicate that isolated transient electrocortical arousal is generally associated with phasic inspiratory recruitment of UA and diaphragm muscles in normal humans during NREM sleep; velopharyngeal muscle recruitment appears to be more consistent and of greater magnitude and duration than that of oropharyngeal muscle or diaphragm. We speculate that transient arousal from sleep may contribute to UA patency independent of chemical and mechanical respiratory stimuli.

Expression of a squamous cell marker, the spr1 gene, is posttranscriptionally down-regulated by retinol in airway epithelium

Vitamin A (retinol) is required for the normal mucociliary differentiation of respiratory epithelium. A depletion of vitamin A promotes squamous cell metaplasia. To understand how vitamin A suppresses squamous cell differentiation, the expression of a squamous cell differentiation marker, the small proline-rich protein gene (spr1), was studied in cultured monkey tracheobronchial epithelial (TBE) cells. The expression of the spr1 gene was inhibited about 40 fold by retinol. The mRNA levels of the spr1 gene started to decline within 6 h of retinol treatment and reached a minimum level after 7 days. The inhibition by retinol was concentration dependent and did not require concurrent protein synthesis. The inhibition of the spr1 mRNA by retinol was not due to a decrease in the transcription rate of its gene but due to a decrease in its stability, as determined by nuclear run-on assays and mRNA half-life measurement, respectively. This result was further supported by a DNA transfection study using a chimeric construct containing the spr1 promoter region and the chloramphenicol acetyltransferase (CAT) reporter gene. The CAT activity in transfected cells was not inhibited by retinol. These results suggest that spr1 gene expression is posttranscriptionally down-regulated by retinol.

A small proline-rich protein regulated by vitamin A in tracheal epithelial cells is induced in lung tumors

In cell-free translations of RNA from primary cultures of pig trachea surface epithelial cells, we observed that a 20 kD proline-rich protein (sPRP) is induced during culturing (Biochem. Biophys. Res. Commun. 1990; 172:1304-1309). Subsequently, a cDNA encoding sPRP has been cloned from pig tracheal cell mRNA and sequenced. This cDNA shows a high similarity to cDNAs cloned from monkey tracheal cells cultured in vitamin A-free medium and from UV-irradiated human epidermal keratinocytes. Amino acid sequences from these cDNAs are exceptionally rich in proline, glutamine, cysteine, and lysine but contain no aromatic amino acids. Two repeats of 12 amino acids on the N-terminus are followed by multiple 8 amino acid repeats. When compared with monkey trachea and human keratinocyte cDNAs, the sPRP cDNA from pig trachea has an additional 24 bp nucleotide repeat. Antiserum raised to a synthetic peptide (23 amino acids) on the C-terminus of sPRP (C23-antiserum) reacted with the 20 kD sPRP in immunoprecipitations from cell-free translations. On Northern blot analysis, sPRP cDNA hybridized to RNAs of similar sizes in tracheal cells from cat, rabbit, and lamb. sPRP was not detected in tracheal cells that were cultured with 10(-9) M arotinoid. Since sPRP is considered a putative squamous cell differentiation marker, experiments using lung tumors were performed. sPRP mRNA levels were dramatically increased in squamous lung tumors that were induced by injecting hamsters with 4-(methylnitrosamino)- 1-(3-pyridyl)-1-butanone, a tobacco-specific nitrosamine. In situ hybridization with tissue sections prepared from these lung tumors revealed that cells around the keratin pearls contained high levels of sPRP mRNA.

Salivary proline-rich proteins: biochemistry, molecular biology, and regulation of expression

The proline-rich proteins (PRPs) in mammalian salivary glands are encoded by tissue-specific multigene families whose members have diverged with respect to structure and regulation of expression. PRPs are expressed constitutively in humans, and comprise about [70%] of the total salivary proteins. Families of similar proteins are dramatically increased or induced in parotid and submandibular glands of rats, mice and hamsters by treatment with the [beta-] agonist isoproterenol. Feeding tannins to rats and mice mimics the effects of isoproterenol on the parotid glands. Salivary PRPs may constitute a defense mechanism against tannins and other polyhydroxylated phenols ingested. Putative transcriptional regulatory sequences have been identified in mouse PRP genes.