Reinhard Schinzel vasopharm GmbH Würzburg

Einfluss natürlicher Schwankungen bei einer Phase I

Studie am Beispiel renaler Parameter

First-in-Man Study VAS203

VAS203 Phase I

-  NOAEL Cynomolgus: 200 mg/kg b.w. -  FIM: 6 h infusion of VAS203 in healthy male volunteers

-  Unexpected finding in man:

Kidney target organ Higher Cmax

- Lower NOAEL Man: 10 mg/kg b.w.

Repeated Dose - Renale Parameter

Creatine Clearance (12h) Serum: - sCrea (bedside, every 2 h to 4 h) - Cystatin C (every 12 h) Urine: -  Proteins: Albumin, α1-Microglobulin, ß2-Microglobulin, N-Acetylglucosaminidase -  Sediment

-  Urine volume (12 h Urine)

Phase I – Renal

Verlauf sCREA – 3 x 12 h Infusion

3x 12 h Infusion von 5 mg/kg/Tag VAS203 (durch Striche gekennzeichnet, t= 0 : Start der ersten Infusion), Schattierung zeigt Tage an.

VAS203 Phase I

Verlauf sCREA – Mean Verum vs. Placebo

3x 12 h Infusion von 5 mg/kg/Tag VAS203 Mean verum vs Placebo

Phase I

Cystatin C

3x 12 h Infusion von 5 mg/kg/Tag VAS203 (durch Striche gekennzeichnet, t =0: Start der ersten Infusion), Schattierung zeigt Tage an; Rot: Placebo (Subject 14)

1. Infusion 2. Infusion 3. Infusion

Phase I

Sonstige Renale Parameter

- Albuminurie: Alle Proben unter Nachweisgrenze - α1-Microglobulin: Alle Proben unter Nachweisgrenze

- ß2-Microglobulin: Alle Proben im Normalbereich

- N-Acetylglucosaminidase: Alle Proben im Normalbereich

- Sediment: Alle Proben ohne pathologische Befunde

- Urinvolumen: im Normalbereich, aber ausgeprägte Tag/Nacht-Schwankungen

VAS203 Phase I – Renal

Serum creatinine - problems

General: -  Knowledge about sCrea in healthy subjects limited!

-  Measurements over days, months or weeks but not hours

-  Knowledge about effects on basal levels but not on variation

-  Some knowledge on effects of exercise

-  Variation high at low (normal) sCrea levels

Lamb-E British Renal Association 2005

Serum creatinine - problems

Analytical problems: •  Non-specificity (ketones, ascorbic acid etc) -> Unlikely •  Spectral interferences (icterus/lipaemia/haemolysis) -> No •  No international standardization -> Time course Non-renal influences: •  gender, ethnicity and age -> No •  drugs -> Unlikely •  muscle mass -> Time course •  nutrition/diet -> Possible!

Lamb-E British Renal Association 2005

sCREA – 3 x 12 h Infusion

3x 12 h Infusion von 5 mg/kg/Tag VAS203 (durch Striche gekennzeichnet, t= 0 : Start der ersten Infusion), Pfeile zeigen Hauptmahlzeiten, Schattierung zeigt Tage an.

Phase I

sCREA – Diet

Creatinine

A: 300 g raw beef B: 300 g cooked beef C: 300 g boiled beef D: 300 g Goulash E: 250 g pork stew Jacobsen et al. BMJ 1979 1050

hrs

Phase I sCREA – Verlauf nach Mahlzeit

Phase I

Hours after Lunch

sCREA – Diet

Creatinine

Creatine supplementation minimally impacts creatinine concentrations and renal function in young healthy adults. Creatinine concentrations may increase after long periods of creatine supplementation Pline and Smith. The effect of creatine intake on renal function. Ann Pharmacother. 2005 39:1093-6.

sCREA – Tagesverlauf bei Gesunden

Vergleich sCrea Verlauf Mittelwert Verum Tag 1 mit Werten von Pasternack und Kuhlbäck (Scand J Clin Lab Invest. 1971 27:1-7)

Serum Creatinine

GFR measured

3x 12 h Infusion von 5 mg/kg/Tag VAS203 Rot: Placebo (Subject 14)

Phase I

0

50

100

150

200

250

´-24to -12h

, -12to -0h

0 to12h

12 to24h

0 to12h

12 to24h

0 to12h

12 to24h

24 to36h

36 to48h

Day -1

Day -1

Day 1 Day 1 Day 2 Day 2 Day 3 Day 3 Day 4 Day 4

GFR

[mL/

min

]

910111213141516

GFR

As the relationship between GFR and creatinine or cystatin C is exponential, this fact will still be a limitation factor for the estimation of GFR in normal range ( > 60 ml/min/1.73 m 2 ) with both creatinine- and cystatin C-based equations

Comparison eGFR and iGFR in patients +/- renal disease

circle = CKD, square = kidney donors from Poggio et al. JASN 2005

Creatinine

The CKD-EPI equation

CKD-EPI equation expressed as a single equation: GFR = 141 × min(SCr/κ, 1)α × max(SCr/κ, 1)-1.209 × 0.993Age × 1.018 [if female] × 1.159 [if black] where SCr is serum creatinine, κ is 0.7 for females and 0.9 for males, α is -0.329 for females and -0.411 for males, min indicates the minimum of SCr/κ or 1, and max indicates the maximum of SCr/κ or 1. Stevens et al. AJKD 2010 56:486

Cystatin C – Proband mit ungewöhnlich niedrigen Werten

Cystatin C

0,000,100,200,300,400,500,600,700,800,90

-24 -12 0 12 24 36 48 60

t [h]

Cys

C [m

g/L]

001002003004005006007008

Cystatin C

The relative effects of fat versus muscle mass on cystatin C and estimates of renal function in healthy young men Janice S C Chew-Harris1, Christopher M Florkowski2, Peter M George2, Jane L Elmslie2 and Zoltan H Endre3 1Biochemistry Department, Medlab South Ltd, PO Box 25-091, Christchurch 8013; 2Clinical Biochemistry Unit, Canterbury Health Laboratories, Corner of Tuam Street and Hagley Avenue, PO Box 151; 3Department of Medicine, Christchurch School of Medicine, University of Otago, PO Box 4345, Christchurch 8014, New Zealand Corresponding author: Christopher M Florkowski. Email: chris.florkowski@cdhb.govt.nz Abstract Background: It is well known that plasma creatinine concentration is affected by muscle mass, while some studies have suggested cystatin C is affected by body mass index (BMI). Our aim was to assess the effects of lean versus fat mass on cystatin C and creatinine derivative equations in estimating glomerular filtration rate (GFR) in healthy young men. Methods: Three groups of participants were studied: those classified as normal (BMI 18–25 kg/m2 with body fat ,30%); muscular subjects (BMI .30 kg/m2 and body fat ,20%); and obese subjects (BMI .30 kg/m2 and body fat .30%). All underwent diethylenetriamine pentaacetic acid GFR, bio-electrical impedance and dual-energy X-ray absorptiometry body composition analysis, measurement of plasma cystatin C, creatinine and high-sensitivity C-reactive protein and completed a diet record. Results: Cystatin C was highest in the obese group (0.77 mg/L; 95% confidence intervals [CI] 0.69–0.77) and creatinine was highest in the muscular group (90.1 mmol/L; 95% CI 84.3–96.0). On multivariate analysis, body fat and GFR (P ¼ 0.003) were significant determinants of cystatin C; muscle mass and age affected creatinine significantly (P ¼ 0.02). Using cystatin C equations, Le Bricon and Hoek showed significantly lower estimated GFR in the obese group but performed reasonably well within 50%, 30% and 20% of GFR. Creatinine equations showed significant underestimations of GFR for the muscular group. Conclusions: Body fat is a significant determinant of cystatin C while creatinine concentration is highly affected by muscle mass and age. Body composition plays an important role in the interpretation of renal function. Cystatin C equations are still accurate in predicting GFR in our healthy male group without chronic kidney disease.

The relative effects of fat versus muscle mass on cystatin C and estimates of renal function in healthy young men Chew-Harris et al. 2012 Ann Clin Chem. in press Cystatin C was highest in the obese group (0.77 mg/L; 95% confidence intervals [CI] 0.69–0.77) and creatinine was highest in the muscular group (90.1 mmol/L; 95% CI 84.3–96.0). On multivariate analysis, body fat and GFR (p < 0.003) were significant determinants of cystatin C; muscle mass and age affected creatinine significantly (P < 0.02). Creatinine equations showed significant underestimations of GFR for the muscular group. Body fat is a significant determinant of cystatin C while creatinine concentration is highly affected by muscle mass and age. Body composition plays an important role in the interpretation of renal function.

Kidney function in healthy subjects

Zusammenfassung: -  Wissen über sCrea in Gesunden limitiert

-  sCrea wird aber Methode der Wahl bleiben

-  Andere Parameter wenig charakterisiert -  Leichte Meßbarkeit -  Standardisierte Messung möglich -  Verbesserte GFR Formeln für Gesunde