Phase 1 dose-escalation study of CP-690 550 in stable renal allograft recipients: Preliminary findings of safety, tolerability, effects on lymphocyte subsets and pharmacokinetics

Academic Article


  • CP-690 550 inhibits Janus kinase 3 with nanomolar potency. In this dose-escalation study, we assessed the safety, tolerability, effects on lymphocyte subsets, and pharmacokinetics of CP-690 550 when coadministered with mycophenolate mofetil in stable renal allograft recipients for 28 days. Twenty-eight patients were enrolled. Six patients received CP-690 550 5 mg twice daily (BID), 6 patients received 15 mg BID, 10 patients received 30 mg BID, and 6 patients received placebo. The most frequent adverse events were infections and gastrointestinal (abdominal pain, diarrhea, dyspepsia, and vomiting). CP-690 550 15 mg BID and 30 mg BID were associated with a mean decrease in hemoglobin from baseline of 11% and a mean decrease in absolute natural killer cell counts of 50%. CP-690 550 30 mg BID was also associated with a mean increase in absolute CD19+ B-lymphocytes of 130%. There were no changes in the number of neutrophils, total lymphocytes, platelets, or CD4+ or CD8+ T cells; clinical chemistry; vital signs; or electrocardiograms from the pretreatment baseline. Administration of CP-690 550 without a concomitant calcineurin inhibitor resulted in CP-690 550 exposures consistent with previous studies in nontransplant subjects. Additional dose-ranging studies are warranted to evaluate the safety and efficacy of CP-690 550 in renal transplant recipients over longer treatment duration. © 2008 The Authors.
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    Author List

  • Van Gurp E; Weimar W; Gaston R; Brennan D; Mendez R; Pirsch J; Swan S; Pescovitz MD; Ni G; Wang C
  • Start Page

  • 1711
  • End Page

  • 1718
  • Volume

  • 8
  • Issue

  • 8