title: Changes in serum creatinine in patients with active rheumatoid arthritis treated with tofacitinib: results from clinical trials.
abstract: BACKGROUND
  Small increases in mean serum creatinine (SCr) were observed in studies of rheumatoid arthritis patients during tofacitinib treatment. These SCr changes were investigated and potential mechanisms explored.
  
  
  METHODS
  SCr values and renal adverse event data were pooled from five Phase 3 and two long-term extension (LTE) studies. Dose-response relationships and association with inflammation (C-reactive protein (CRP)) were explored using Phase 2 data and confirmed with Phase 3 data.
  
  
  RESULTS
  In Phase 3, least squares mean SCr differences from placebo at Month 3 were 0.02 and 0.04 mg/dl for tofacitinib 5 and 10 mg twice daily (BID) (P <0.05), respectively. During Months 0 to 3, confirmed SCr ≥33% increases over baseline were reported in 17 (1.4%; 5 mg BID) and 23 (1.9%; 10 mg BID) patients. Generally, elevations plateaued and remained within normal limits throughout Phase 3 and LTE studies. Exposure-response modeling demonstrated small, reversible effects of tofacitinib on mean SCr, and significant (P <0.05) effects of CRP on model parameters. Phase 3 data confirmed that patients with higher baseline CRP or greater CRP decreases following tofacitinib treatment had the largest increases in SCr. Across Phase 3 and LTE studies, 22 tofacitinib-treated patients had clinical acute renal failure (ARF), predominantly in the setting of concurrent serious illness.
  
  
  CONCLUSIONS
  Tofacitinib treatment was associated with small, reversible mean increases in SCr that plateaued early. The mechanism behind these SCr changes remains unknown, but may involve effects of tofacitinib on inflammation. ARF occurred infrequently, was associated with concurrent serious illness, and was unrelated to prior SCr increases.
authors: John D
authors: JD
authors: Isaacs
authors: Andrea
authors: A
authors: Zuckerman
authors: Sriram
authors: S
authors: Krishnaswami
authors: Chudy
authors: C
authors: Nduaka
authors: Shuping
authors: S
authors: Lan
authors: Matthew M
authors: MM
authors: Hutmacher
authors: Mary G
authors: MG
authors: Boy
authors: Ken
authors: K
authors: Kowalski
authors: Sujatha
authors: S
authors: Menon
authors: Richard
authors: R
authors: Riese
mesh_terms: D018501:Antirheumatic Agents / Q000009:adverse effects*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D002097:C-Reactive Protein / Q000378:metabolism; D003404:Creatinine / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000009:adverse effects*; D047428:Protein Kinase Inhibitors / Q000009:adverse effects*; D011743:Pyrimidines / Q000009:adverse effects*; D011758:Pyrroles / Q000009:adverse effects*
chemical_list: D018501:Antirheumatic Agents; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; C479163:tofacitinib; D002097:C-Reactive Protein; D003404:Creatinine