A phase I trial of the selective oral cyclin-dependent kinase inhibitor seliciclib (CYC202; R-Roscovitine), administered twice daily for 7 days every 21 days

Br J Cancer. 2007 Jan 15;96(1):29-37. doi: 10.1038/sj.bjc.6603509. Epub 2006 Dec 19.


Seliciclib (CYC202; R-roscovitine) is the first selective, orally bioavailable inhibitor of cyclin-dependent kinases 1, 2, 7 and 9 to enter clinical trial. Preclinical studies showed antitumour activity in a broad range of human tumour xenografts. A phase I trial was performed with a 7-day b.i.d. p.o. schedule. Twenty-one patients (median age 62 years, range: 39-73 years) were treated with doses of 100, 200 and 800 b.i.d. Dose-limiting toxicities were seen at 800 mg b.i.d.; grade 3 fatigue, grade 3 skin rash, grade 3 hyponatraemia and grade 4 hypokalaemia. Other toxicities included reversible raised creatinine (grade 2), reversible grade 3 abnormal liver function and grade 2 emesis. An 800 mg portion was investigated further in 12 patients, three of whom had MAG3 renograms. One patient with a rapid increase in creatinine on day 3 had a reversible fall in renal perfusion, with full recovery by day 14, and no changes suggestive of renal tubular damage. Further dose escalation was precluded by hypokalaemia. Seliciclib reached peak plasma concentrations between 1 and 4 h and elimination half-life was 2-5 h. Inhibition of retinoblastoma protein phosphorylation was not demonstrated in peripheral blood mononuclear cells. No objective tumour responses were noted, but disease stabilisation was recorded in eight patients; this lasted for a total of six courses (18 weeks) in a patient with ovarian cancer.

Publication types

  • Clinical Trial, Phase I
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Antineoplastic Agents / administration & dosage*
  • Antineoplastic Agents / adverse effects
  • Cyclin-Dependent Kinases / antagonists & inhibitors
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Enzyme Inhibitors / administration & dosage*
  • Enzyme Inhibitors / adverse effects
  • Female
  • Humans
  • Hyperglycemia / chemically induced
  • Male
  • Maximum Tolerated Dose
  • Middle Aged
  • Neoplasm Staging
  • Neoplasms / drug therapy*
  • Purines / administration & dosage*
  • Purines / adverse effects
  • Roscovitine
  • Treatment Outcome


  • Antineoplastic Agents
  • Enzyme Inhibitors
  • Purines
  • Roscovitine
  • Cyclin-Dependent Kinases