Potential Therapeutic Value of Urotensin II Receptor Antagonist in Chronic Kidney Disease and Associated Comorbidities.

Chronic kidney disease (CKD) remains a common disorder, leading to growing health and economic burden without curative treatment. In diabetic patients, CKD may result from a combination of metabolic and nonmetabolic-related factors, with mortality mainly driven by cardiovascular events. The marked overactivity of the urotensinergic system in diabetic patients implicates this vasoactive peptide as a possible contributor to the pathogenesis of renal as well as heart failure. Previous preclinical studies with urotensin II (UII) antagonists in chronic kidney disease were based on simple end points that did not reflect the complex etiology of the disease. Given this, our studies revisited the therapeutic value of UII antagonism in CKD and extensively characterized 1-({[6-{4-chloro-3-[3-(dimethylamino)propoxy]phenyl}-5-(2-methylphenyl)pyridin-2-yl]carbonyl}amino) cyclohexanecarboxylic acid hydrochloride (SAR101099), a potent, selective, and orally long-acting UII receptor competitive antagonist, inhibiting not only UII but also urotensin-related peptide activities. SR101099 treatment more than halved proteinurea and albumin/creatinine ratio in spontaneously hypertensive stroke-prone (SHR-SP) rats fed with salt/fat diet and Dahl-salt-sensitive rats, respectively, and it halved albuminuria in streptozotocin-induced diabetes rats. Importantly, these effects were accompanied by a decrease in mortality of 50% in SHR-SP and of 35% in the Dahl salt-sensitive rats. SAR101099 was also active on CKD-related cardiovascular pathologies and partly preserved contractile reserve in models of heart failure induced by myocardial infarction or ischemia/reperfusion in rats and pigs, respectively. SAR101099 exhibited a good safety/tolerability profile at all tested doses in clinical phase-I studies. Together, these data suggest that CKD patient selection considering comorbidities together with new stratification modalities should unveil the urotensin antagonists' therapeutic potential. SIGNIFICANCE STATEMENT: Chronic kidney disease (CKD) is a pathology with growing health and economic burden, without curative treatment. For years, the impact of urotensin II receptor (UT) antagonism to treat CKD may have been compromised by available tools or models to deeper characterize the urotensinergic system. New potent, selective, orally long-acting cross-species UT antagonist such as SAR101099 exerting reno- and cardioprotective effects could offer novel therapeutic opportunities. Its preclinical and clinical results suggest that UT antagonism remains an attractive target in CKD on top of current standard of care.

Phase I studies of AVE9633, an anti-CD33 antibody-maytansinoid conjugate, in adult patients with relapsed/refractory acute myeloid leukemia.

The efficacy of anti-CD33 immunoconjugates had been previously demonstrated for gemtuzumab-ozogamicin. AVE9633 is an anti-CD33-maytansine conjugate created by ImmunoGen Inc. Phase I trials of AVE9633 were performed in patients with AML to evaluate tolerability, pharmacokinetics and pharmacodynamics. Three phase I studies of AVE9633 were performed in 54 patients with refractory/relapsed AML, evaluating drug infusion on day 1 of a 21-day cycle (Day 1 study), day 1 and 8 (Day 1/8 study) and day 1, 4 and 7 (Day 1/4/7 study) of a 28-day cycle. Toxicity was mainly allergic reaction during infusion (3 grade 3 bronchospasms). DLT was reached for the D1-D7 schedule at 150 mg/sqm (1 keratitis, 1 liver toxicity), and the MTD was set at 130 mg/sqm for this schedule. In the two other phases I, the DLT was not reached. In the Day 1/8 study, CD33 on peripheral blasts was saturated and down-modulated for doses of 75 mg/m(2) × 2 or higher, which was correlated with WBC kinetics and plasma levels of AVE9633. Decrease of DM4/CD33 ratio on the blasts surface between day 1 and 8 was the rational for evaluating day 1/4/7 schedule. This induced relatively constant DM4/CD33 levels over the first 8 days, however no activity was noted. One CRp, one PR and biological activity in five other patients were observed in this study. The Day 1 and Day 1/4/7 studies were early discontinued because of drug inactivity at doses significantly higher than CD33 -saturating doses. No myelossuppression was observed at any trial of AVE9633. The pharmacokinetics/pharmacodynamics data obtained in these studies will provide very useful information for the design of the next generation of immunoconjugates.

Albumin binding Nanofitins, a new scaffold to extend half-life of biologics - a case study with exenatide peptide.

A new strategy of peptide half-life extension has been evaluated. We investigated libraries of a small and very stable protein scaffold called Nanofitin, capable of high affinity for protein targets. We have identified Nanofitins targeting Human and mouse Serum Albumin, which could significantly improve the pharmacokinetics of an active associated peptide, mobilizing the patient's own albumin without external source. To demonstrate the impact of this approach on half-life extension, a genetic fusion of an Exenatide peptide with an Albumin Binding Nanofitin (ABNF) was performed. Specific activity of Exenatide-ABNF was measured and unaffected by the fusion. In vivo mice results provided convincing data (t½ of 8 min for Exenatide peptide compared to 20 h for Exenatide-ABNF) with sustained pharmacological activity over 3 days. This study constitutes a proof-of-concept of in vivo half-life extension of a biologic using an ABNF. Besides, the absence of cysteine in the Nanofitin scaffold, which is therefore devoid of structuring disulfide bonds, allows manufacturing in microbial cost effective systems.

Reversion of cardiac dysfunction by a novel orally available calcium/calmodulin-dependent protein kinase II inhibitor, RA306, in a genetic model of dilated cardiomyopathy.

AIMS: Despite improvements in patient identification and management, heart failure (HF) remains a major public health burden and an important clinical challenge. A variety of animal and human studies have provided evidence suggesting a central role of calcium/calmodulin-dependent protein kinase II (CaMKII) in the development of pathological cardiac remodelling and HF. Here, we describe a new potent, selective, and orally available CaMKII inhibitor. METHODS AND RESULTS: Chemical optimization led to the identification of RA306 as a selective CaMKII inhibitor. This compound was found potent on the cardiac CaMKII isoforms delta and gamma (IC50 in the 10 nM range), with pharmacokinetic properties allowing oral administration in animal models of HF. RA306 was administered to diseased mice carrying a mutation in alpha-actin that is responsible for dilated cardiomyopathy (DCM) in humans. In two separate studies, RA306 was orally administered at 30 mg/kg either for 2 weeks (twice a day) or for 2 months (once a day). Echocardiography monitoring showed that RA306 significantly improved cardiac function (ejection fraction and cardiac output) as compared to vehicle. These disease modifying effects of RA306 were associated with inhibition of cardiac phosphorylation of phospholamban (PLN) at threonine-17, indicating reduced cardiac CaMKII activity. CONCLUSION: This work supports the feasibility of identifying potent orally available CaMKII inhibitors suitable for clinical use to treat heart disease.

The oral Ca/calmodulin-dependent kinase II inhibitor RA608 improves contractile function and prevents arrhythmias in heart failure.

AIMS: Excessive activation of Ca/calmodulin-dependent kinase II (CaMKII) is of critical importance in heart failure (HF) and atrial fibrillation. Unfortunately, lack of selectivity, specificity, and bioavailability have slowed down development of inhibitors for clinical use. We investigated a novel CaMKIIδ/CaMKIIÉ£-selective, ATP-competitive, orally available CaMKII inhibitor (RA608) on right atrial biopsies of 119 patients undergoing heart surgery. Furthermore, we evaluated its oral efficacy to prevent deterioration of HF in mice after transverse aortic constriction (TAC). METHODS AND RESULTS: In human atrial cardiomyocytes and trabeculae, respectively, RA608 significantly reduced sarcoplasmic reticulum Ca leak, reduced diastolic tension, and increased sarcoplasmic reticulum Ca content. Patch-clamp recordings confirmed the safety of RA608 in human cardiomyocytes. C57BL6/J mice were subjected to TAC, and left ventricular function was monitored by echocardiography. Two weeks after TAC, RA608 was administered by oral gavage for 7 days. Oral RA608 treatment prevented deterioration of ejection fraction. At 3 weeks after TAC, ejection fraction was 46.1 ± 3.7% (RA608) vs. 34.9 ± 2.6% (vehicle), n = 9 vs. n = 12, P < 0.05, ANOVA, which correlated with significantly less CaMKII autophosphorylation at threonine 287. Moreover, a single oral dose significantly reduced inducibility of atrial and ventricular arrhythmias in CaMKIIδ transgenic mice 4 h after administration. Atrial fibrillation was induced in 6/6 mice for vehicle vs. 1/7 for RA608, P < 0.05, 'n - 1' χ2 test. Ventricular tachycardia was induced in 6/7 for vehicle vs. 2/7 for RA608, P < 0.05, 'n - 1' χ2 test. CONCLUSIONS: RA608 is the first orally administrable CaMKII inhibitor with potent efficacy in human myocytes. Moreover, oral administration potently inhibits arrhythmogenesis and attenuates HF development in mice in vivo.

Idiopathic Pulmonary Fibrosis: Prospective, Case-Controlled Study of Natural History and Circulating Biomarkers.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with 3 to 5 years' survival. Although FVC is used to assess disease progression and treatment response, identifying predictive circulating blood biomarkers could help identify specific biologic pathways for treatment. An international, prospective, noninterventional, case-controlled, 52-week study was therefore conducted to identify a clinical and biomarker baseline profile predictive of longitudinal disease behavior. METHODS: Patients with IPF and control subjects had lung function tests and blood sampling for biomarker quantification (control subjects at baseline only). The primary end point was disease progression rate (composite end point: decrease ≥ 10% from baseline in FVC % predicted, decrease ≥ 15% from baseline in diffusing capacity of the lung for carbon monoxide % predicted, lung transplantation, death) at week 52 and its relationship to selected biomarkers at baseline. RESULTS: Altogether, 211 subjects (154 patients with IPF and 57 control subjects) were enrolled; one-third of patients (n = 47) with IPF had progressed by week 52. Biomarkers CC-chemokine ligand 18 (CCL18), intercellular adhesion molecule 1, Krebs von den Lungen-6, surfactant protein (SP)-A, SP-D, matrix metallopeptidase 7, urokinase-type plasminogen activator receptor, and two novel biomarkers, human epididymis protein-4 (HE4) and prostasin, discriminated patients with IPF vs control subjects. There was no difference in baseline CCL18 concentration between progressors and nonprogressors at week 52 (area under the receiver operating characteristic curve, 0.62; corrected P = .161). No biomarkers were predictive for disease progression. CONCLUSIONS: Several biomarkers, including CCL18, were associated with IPF, but none predicted disease progression. Two novel biomarkers, HE4 and prostasin, were identified and warrant further investigation.

Pharmacokinetics and pharmacodynamics of the vasopeptidase inhibitor AVE7688 in humans.

OBJECTIVE: Our objective was to define the pharmacodynamic profile of the new dual neutral endopeptidase (NEP)/angiotensin-converting enzyme (ACE) inhibitor AVE7688. METHODS: We compared the effects of single oral doses of AVE7688 (5 and 25 mg) with those of 10 mg ramipril (R10), a selective ACE inhibitor, in a placebo-controlled crossover study in sodium-depleted normotensive subjects. We also compared the effects of 25 mg AVE7688 with those of a renin-angiotensin system (RAS) blockade induced by a high dose of an angiotensin II receptor antagonist (300 mg irbesartan) and a dual blockade of the RAS (150 mg irbesartan plus 10 mg ramipril) in sodium-replete normotensive subjects by use of the same study design. The in vivo inhibition of ACE and NEP was monitored by measuring the urinary excretion of N-acetyl-Ser-Asp-Lys-Pro (AcSDKP) and atrial natriuretic peptide (ANP), respectively. The intensity of RAS blockade was assessed by the increase in plasma active renin concentration. RESULTS: The 24-hour urine AcSDKP cumulative excretion increased significantly more after 25 mg AVE7688 (919 nmol [95% confidence interval (CI), 803-1052 nmol], P < .05) than after 5 mg AVE7688 (706 nmol [95% CI, 612-813 nmol]) or 10 mg ramipril (511 nmol [95% CI, 440-593 nmol]). The 25-mg dose of AVE7866 significantly and transiently (4 to 8 hours after drug intake) increased urinary ANP (2.02 +/- 1.05 ng/h, P < .05), whereas 5 mg AVE7688 (1.14 +/- 0.77 ng/h) and 10 mg ramipril (0.93 +/- 0.65 ng/h) had no effect compared with placebo (0.80 +/- 0.37 ng/h). In the low-salt panel the rise in plasma active renin concentration achieved 24 hours after dosing by 25 mg AVE7688 (247 pg/mL [95% CI, 157-389 pg/mL], P < .05) was significantly higher than that achieved by 5 mg AVE7688 (129 pg/mL [95% CI, 75-221 pg/mL]) or 10 mg ramipril (113 pg/mL [95% CI, 67-193 pg/mL]), which did not differ. In the high-salt panel group the effects of 25 mg AVE7688 on renin release did not significantly differ from those after administration of the combination of 150 mg irbesartan plus 10 mg ramipril or 300 mg irbesartan alone. All of these active drugs similarly decreased blood pressure compared with placebo. CONCLUSION: AVE7688 at a dose of 25 mg has a favorable pharmacodynamic profile compared with other RAS blockers. These results support further clinical studies of its long-term effects in essential or resistant hypertension, chronic proteinuric nephropathy, and chronic heart failure.

Anticoagulant and anti-platelet effects are maintained following coadministration of otamixaban, a direct factor Xa inhibitor, and acetylsalicylic acid.

The pharmacokinetics, pharmacodynamics and safety of the direct factor Xa inhibitor, otamixaban, with and without concomitant acetylsalicylic acid (ASA) were investigated in healthy volunteers. The study was a double-blind, placebo-controlled 3-way crossover study. Sixty-eight male volunteers in total were randomised to otamixaban, ASA, or otamixaban with ASA. ASA (300 mg once a day) was started 2 days before and continued on the day of the otamixaban 6-hour IV infusion (0.3 and 0.5 mg/kg). Pharmacokinetic and pharmacodynamic parameters (coagulation markers, platelet function tests and skin bleeding time) were determined. Drug interaction was assessed by the ratios of geometric means and 90% confidence intervals (90% CI)of the parameter estimates. Pharmacokinetic parameters of otamixaban remained unchanged with ASA. Ratios of geometric means (90% CI) were for Ceoi 96.54 (91.21-102.19) and 95.04 (90.10-100.24) and for AUC 98.0 (93.92-102.25) and 95.90 (92.61-99.31), for 0.3 and 0.5 mg/kg, respectively. No drug interaction was observed between otamixaban and ASA on the coagulation and platelet function parameters. Neither otamixaban nor ASA had an effect on skin bleeding time; their co-administration led to a slight prolongation of skin bleeding time above the normal range without any clinically relevant bleeding. This study demonstrated that the desired effects of otamixaban and ASA, namely anticoagulation and platelet inhibition, respectively, are maintained during co-administration of both drugs.

Pharmacokinetic/pharmacodynamic relationships for otamixaban, a direct factor Xa inhibitor, in healthy subjects.

Direct pharmacokinetic/pharmacodynamic relationships for otamixaban were investigated after rising doses in healthy subjects using mixed-effect modeling. Activated partial thromboplastin time, prothrombin time, dilute prothrombin time, and Russell's viper venom-induced clotting time (RVVT) related linearly, whereas Heptest clotting time (HCT) followed a sigmoidal E(max) model. The pharmacokinetic/pharmacodynamic response (slope) and their corresponding interindividual variability (seconds per ng/mL, [% coefficient of variation]) were 0.263 (29%) for Russell's viper venom-induced clotting time, 0.117 (10%) for dilute prothrombin time, 0.058 (19%) for activated partial thromboplastin time, and 0.021 (11%) for prothrombin time. For Heptest clotting time, the parameter estimates with their corresponding interindividual variability (% coefficient of variation) were 71 ng/mL (30%) for EC(50), 186 seconds (64%) for E(max), and 17 seconds (16%) for E(0). The model predicted otamixaban plasma concentrations to double the clotting times that were close to those observed. These pharmacokinetic/pharmacodynamic relationships, together with the predictable pharmacokinetics, allowed the anticoagulant effect at given doses of otamixaban to be foreseen in healthy subjects.

How validated receptor occupancy flow cytometry assays can impact decisions and support drug development.

Because of the pressure of significant attrition in drug development, demonstration of target engagement after drug administration enables dose and regimen optimization, patient selection, and stratification from the earliest stages of drug development. The determination of receptor occupancy (RO) can support these efforts. Flow cytometry is one of the preferred technologies to be used based on the important advances in the technology over the last years enabling the simultaneous determination on target cells, of multi intra or surface cell parameters with adequate precision in a regulated environment. Nevertheless, compared to other platforms using the same antigen-antibody binding concept, the flow cytometry approach has faced several challenges, not only due to the technology per se and the diversity of receptor occupancy approaches, but also related to the nature of the matrix where the determination is performed. To illustrate these points, three case studies (antibody-drug conjugate and naked antibody) are provided here to highlight the importance of the choice of the right antibody pair to measure both receptor density (RD) and occupancy by the drug on cancer cells in blood and in bone marrow and the possibility to circumvent the lack of a critical reagent with an innovative approach. In addition, the use of RO data to determine the minimum anticipated biological effect level (MABEL) with translational data from preclinical to human studies, selection of starting dose for the first in man study will be discussed.

Correction: Identification of microRNAs in Macaca fascicularis (Cynomolgus Monkey) by Homology Search and Experimental Validation by Small RNA-Seq and RT-qPCR Using Kidney Cortex Tissues.

[This corrects the article DOI: 10.1371/journal.pone.0142708.].

Pharmacodynamic markers in the early clinical assessment of otamixaban, a direct factor Xa inhibitor.

This manuscript reports the assessment of pharmacodynamic (PD) markers of anti-coagulation in the first-in-man study with the novel direct Factor Xa (FXa) inhibitor, otamixaban, with a brief description of safety and pharmacokinetic (PK) findings. The study comprised ten consecutive parallel groups of healthy male subjects (6 active, 2 placebo per group). Eight groups received escalating intravenous doses of otamixaban as 6-hour infusions (1.7 to 183 microg/kg/h) and two groups received a bolus dose (30 or 120 microg/kg) with a 6-hour infusion (60 or 140 microg/ kg/h, respectively). PD markers included anti-FXa activity and clotting time measurements, i.e. activated Thromboplastin Time (aPTT), Prothrombin Time (PT), Heptest Clotting Time (HCT), and Russell's Viper Venom-induced clotting Time (RVVT). In addition, Endogenous Thrombin Potential (ETP) was assessed in the bolus-plus-infusion dose groups. Otamixaban was well tolerated. Otamixaban plasma concentrations increased with escalating dose, were maximal at the end-of-infusion (C(eoi)), and decreased rapidly as the infusion was stopped. Anti-FXa activity coincided with otamixaban plasma concentrations and clotting time measurements followed the same pattern. Maximal changes from baseline at C(eoi) were 1.9 +/- 0.2 for aPTT, 2.0 +/- 0.2 for PT, 5.1 +/- 0.6 for HCT, and 4.5 +/- 1.2 for RVVT. Otamixaban inhibited thrombin generation (24% decrease in ETP) and a delay in thrombin generation was noticed in vitro at high concentrations.

Identification of microRNAs in Macaca fascicularis (Cynomolgus Monkey) by Homology Search and Experimental Validation by Small RNA-Seq and RT-qPCR Using Kidney Cortex Tissues.

MicroRNAs (miRNAs) present in tissues and biofluids are emerging as sensitive and specific safety biomarkers. MiRNAs have not been thoroughly described in M. fascicularis, an animal model used in pharmaceutical industry especially in drug safety evaluation. Here we investigated the miRNAs in M. fascicularis. For Macaca mulatta, a closely related species of M. fascicularis, 619 stem-loop precursor miRNAs (pre-miRNAs) and 914 mature miRNAs are available in miRBase version 21. Using M. mulatta miRNAs as a reference list and homology search tools, we identified 604 pre-miRNAs and 913 mature miRNAs in the genome of M. fascicularis. In order to validate the miRNAs identified by homology search we attempted to sequence miRNAs expressed in kidney cortex from M. fascicularis. MiRNAs expressed in kidney cortex may indeed be released in urine upon kidney cortex damage and be potentially used to monitor drug induced kidney injury. Hence small RNA sequencing libraries were prepared using kidney cortex tissues obtained from three naive M. fascicularis and sequenced. Analysis of sequencing data indicated that 432 out of 913 mature miRNAs were expressed in kidney cortex tissues. Assigning these 432 miRNAs to pre-miRNAs revealed that 273 were expressed from both the -5p and -3p arms of 150 pre-miRNAs and 159 miRNAs expressed from either the -5p or -3p arm of 176 pre-miRNAs. Mapping sequencing reads to pre-miRNAs also facilitated the detection of twenty-two new miRNAs. To substantiate miRNAs identified by small RNA sequencing, 313 miRNAs were examined by RT-qPCR. Expression of 262 miRNAs in kidney cortex tissues ware confirmed by TaqMan microRNA RT-qPCR assays. Analysis of kidney cortex miRNA targeted genes suggested that they play important role in kidney development and function. Data presented in this study may serve as a valuable resource to assess the renal safety biomarker potential of miRNAs in Cynomolgus monkeys.

The pharmacokinetics and pharmacodynamics of enoxaparin in obese volunteers.

OBJECTIVES: The objective of this study was to compare the pharmacokinetics of the low-molecular-weight heparin enoxaparin in obese and nonobese volunteers, by means of two administration regimens. METHODS: Enoxaparin was administered subcutaneously (1.5 mg/kg once daily for 4 days) and in a single 6-hour infusion (1.5 mg/kg) to 24 obese volunteers and 24 age-, sex-, and height-matched nonobese volunteers in a randomized, open-label, 2-way crossover design. Blood plasma was assessed for anti-Xa and anti-IIa activity and activated partial thromboplastin time. RESULTS: After subcutaneous administration, steady-state exposure was achieved after the second dose in nonobese volunteers and after the third dose in obese volunteers. Time to maximum anti-Xa activity was 1 hour longer in obese volunteers, but maximum anti-Xa activity was similar in both groups. For anti-Xa activity, exposure at steady-state was 16% higher in obese volunteers than in nonobese volunteers (90% confidence interval, 108%-125%). After intravenous infusion, total body clearance and volume of distribution at steady state were higher in obese volunteers than in nonobese volunteers, but when adjusted for weight, these values were about 10% lower in obese volunteers. Anti-IIa activity after subcutaneous administration did not differ significantly between obese and nonobese volunteers. Pharmacodynamic analysis of activated partial thromboplastin time showed similar results in obese and nonobese volunteers after both intravenous and subcutaneous administration. No deaths or serious adverse events occurred during the study. CONCLUSIONS: Enoxaparin was well tolerated when administered subcutaneously or intravenously, and there appears to be no need to modify the currently recommended dose for obese volunteers.

Pharmacokinetics and pharmacodynamics of the prophylactic dose of enoxaparin once daily over 4 days in patients with renal impairment.

The pharmacokinetics of the low-molecular-weight heparin enoxaparin were evaluated in 12 healthy volunteers and 36 patients with mild, moderate or severe renal impairment. Enoxaparin was administered once daily by subcutaneous injections at a dose of 40 mg for 4 days and venous blood samples were taken over a 5-day period to determine antifactor Xa and antifactor IIa activity and the activated partial thromboplastin time. Adverse events were also recorded. The results for anti-Xa activity showed that the rate of absorption of enoxaparin was similar across the four groups of study participants. The elimination half-life increased with the degree of renal impairment, and this relationship was more evident after repeated dosing. Anti-Xa exposure was not significantly different between healthy volunteers and patients with mild or moderate renal impairment, but was significantly increased in patients with severe renal impairment (creatinine clearance < or =30 ml/min). Anti-Xa clearance decreased with the degree of renal impairment after repeated dosing, but only the difference between patients with severe renal impairment and healthy volunteers was statistically significant, the clearance on Day 4 being 39% lower in patients with severe renal impairment than in healthy volunteers (P=.0001). Anti-IIa activity was low in all study participants, and the activated partial thromboplastin time was not significantly different between the study groups. In conclusion, the clearance of enoxaparin is reduced in patients with severe renal impairment. Dose adjustment of enoxaparin may need to be recommended in these patients, but no recommendation can be made in patients with mild or moderate renal impairment.

Validation of an immunoassay to selectively quantify the naked antibody of a new Antibody Drug Conjugate--SAR566658--for pharmacokinetic interpretation improvement.

Given the nature of the ADCs (Antibody Drug Conjugates) as antibodies carrying cytotoxic drugs, two types of immunoassays are usually implemented to perform the analysis of preclinical and clinical study samples during the development phase. The first assay measures the conjugated antibody defined as the ADC carrying at least 1 drug molecule (i.e. drug/antibody ratio greater than or equal to 1). The other measures the total antibody, defined as the ADC irrespective of the drug load (i.e., drug/antibody ratio greater than or equal to 0). One analytical limitation of the total antibody assay is the difficulty to adequately calibrate the assay due to the lack of a representative standard reference for the different circulating entities which change in proportion with time following ADC administration. A new analytical approach that gets round the above highlighted limitation is presented with the development and the validation of a method to quantify selectively naked antibody to support the development of SAR566658 (huDS6-SPDB-DM4). Assessed on 6 separate occasions, the accuracy ranged from -4.3% to 8.9% of nominal values and the precision is 13% at most. The current assay was successfully validated for the quantitation of huDS6 in human LiHe plasma even in the presence of SAR566658 up to 2.00 µg/mL as demonstrated using in vitro spike in quality controls and in actual clinical samples. This innovative assay provides a new tool to document in vivo plasma stability of ADCs and potentially to optimize dose and regimen selection for ADC development.

A dose finding, safety and pharmacokinetic study of AVE1642, an anti-insulin-like growth factor-1 receptor (IGF-1R/CD221) monoclonal antibody, administered as a single agent and in combination with docetaxel in patients with advanced solid tumours.

PURPOSE: AVE1642, a humanised mAb, binds the human IGF-1R specifically and with high affinity. This study aimed to select the dose of AVE1642 alone and then combined with docetaxel 75mg/m(2) (D). MATERIAL AND METHODS: AVE1642 was administered alone at cycle (cy) 1 and then combined with D from cy2, q3w. RESULTS: A total of 27 patients received a median number of 5 cy (range, 1-10). The most common tumour types were sarcoma (18.5%), osseous tumours (11.1%) and colon cancer (11.1%). Two DLTs were reported in cy1 at dose level (DL) 18mg/kg and dose escalation was stopped. No major safety issue was observed. No anti-drug antibodies were detected. The Maximal Tolerated Dose of AVE1642 was 12mg/kg. The dose selected for further combinations is 6mg/kg, based on PK/PD data. Three objective responses, (two in sarcoma and one breast cancer) were observed but only one was confirmed. Eleven patients appeared to benefit from treatment with prolonged disease stabilisation ⩾4months. CONCLUSION: AVE1642 is well tolerated as a single agent and combined with D. The selected dose of AVE1642 combined with D is 6mg/kg. Promising activity was seen in sarcoma and breast cancer patients.

Reliable anticoagulation with enoxaparin in patients undergoing percutaneous coronary intervention: The pharmacokinetics of enoxaparin in PCI (PEPCI) study.

The objective of this study was to evaluate the pharmacokinetic response to intravenous (IV) enoxaparin given 8-12 hr after subcutaneous (SC) dosing in patients undergoing percutaneous coronary intervention (PCI). Fifty-five patients received SC enoxaparin (1 mg/kg every 12 hr) followed by an IV bolus (0.3 mg/kg) 8-12 hr after the last SC dose, at the start of PCI or during catheterization. Anti-Xa levels were within the target range in 98% of patients 2-8 hr after the last SC dose, in 96% of patients following the IV bolus, and in 91% of patients for a further 2 hr. Subcutaneous enoxaparin (1 mg/kg every 12 hr) provides sufficient anti-Xa levels for PCI 2-8 hr after the last dose. An additional 0.3 mg/kg enoxaparin dose given IV 8-12 hr after the last SC dose reliably maintains anti-Xa levels within the target for at least 2 additional hr.