Assessment of the renal toxicity of novel anti-inflammatory compounds using  cynomolgus monkey and human kidney cells.
PF1, an anti-inflammatory drug candidate, was nephrotoxic in cynomolgus monkeys in a manner that was qualitatively comparable to that observed with the two previous exploratory drug candidates (PF2and PF3). Based on the severity of nephrotoxicity, PF1 ranked between the other two compounds, withPF2 inducing mortality at all doses and PF3 eliciting only mild nephrotoxicity. To further characterize nephrotoxicity in monkeys and enable direct comparisons with humans, primary cultures of proximal tubular (PT) cells from monkey and human kidneys were used as in vitro tools, using lactate dehydrogenase release as the biomarker of cytotoxicity. In both human and monkey PT cells, PF2was by far the most cytotoxic compound of the three drugs. PF1 exhibited modest cytotoxicity at the highest concentration tested in human PT cells but none in monkey kidney cells whereas PF3 exhibited the reverse pattern.Because these drugs are organic anions, mechanistic studies using human organic anion transporters 1 and 3 (hOAT1 andhOAT3) transfected cell lines were pursued to evaluate the potential of these compounds to interact with these transporters. All three drugs exhibited high affinity for hOAT3 (PF1 exhibited the lowest IC50 of 6M) but only weakly interacted with hOAT1 (with no interaction found for PF2). PF2 was a strong hOAT3 (not hOAT1) substrate, whereas PF1 and PF3 were substrates for both hOAT1 and hOAT3.Upon pretreatment of monkeys with the OAT substrate probenecid, PF3 systemic exposure (AUC) and half-life (t1/2) increased approximately 2-fold whereas clearance (CL) and volume of distribution (Vdss) decreased, as compared to naïve monkeys. This indicated that PF3 competed with probenecid for hOAT1 and/or hOAT3mediated elimination of PF3. Thus, hOAT1 and/or hOAT3 may be responsible for the uptake of this series of drugs in renal PT cells, which may directly or indirectly lead to the observed nephrotoxicity in vivo.
Department of Pharmacokinetics, Dynamics and Metabolism, Pfizer Global Research and Development (PGRD), 2800 Plymouth Road, Ann Arbor, MI 48105, United States. hongliang.cai@pfizer.com
Hongliang
H
Cai
Arun K
AK
Agrawal
David A
DA
Putt
Muhammed
M
Hashim
Anita
A
Reddy
Joanne
J
Brodfuehrer
Narayanan
N
Surendran
Lawrence H
LH
Lash
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical / Q000379:methods; D015507:Drugs, Investigational / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008252:Macaca fascicularis; D027362:Organic Anion Transport Protein 1 / Q000235:genetics / Q000502:physiology; D029362:Organic Anion Transporters, Sodium-Independent / Q000235:genetics / Q000502:physiology; D011237:Predictive Value of Tests; D014162:Transfection
D000893:Anti-Inflammatory Agents; D015507:Drugs, Investigational; D027362:Organic Anion Transport Protein 1; D029362:Organic Anion Transporters, Sodium-Independent; C114338:organic anion transport protein 3