title: A window of opportunity phase II study of enzastaurin in chemonaive patients with asymptomatic metastatic colorectal cancer.
abstract: BACKGROUND
  Preclinically, protein kinase C and AKT activation can be inhibited by enzastaurin and reduce tumor growth of colorectal cancer cells. In asymptomatic patients with metastatic colorectal cancer (mCRC), enzastaurin activity was evaluated by measuring the 6-month progression-free survival (PFS) rate in a window study design.
  
  
  METHODS
  Chemonaive patients with asymptomatic mCRC who did not require immediate chemotherapy-induced tumor reduction received a 400-mg thrice daily loading dose of enzastaurin on day 1 of cycle 1, followed by 500 mg once daily for the remaining 28-day cycles. Progression was assessed on the basis of radiographic imaging, rise in carcinoembryonic antigen or lactate dehydrogenase (LDH) levels or by appearance of clinical symptoms.
  
  
  RESULTS
  Twenty-eight patients received daily enzastaurin. The 6-month PFS rate was 28% [95% confidence interval (CI) 13%-45%] and median PFS was 1.9 months (95% CI 1.8-4.5 months). Twelve (43%) patients had stable disease with a median duration of 6.1 months. The survival rate at 20 months was 77% (95% CI 47%-92%). No grade 4 toxicity was reported and grade 3 toxic effects were observed in three patients with one patient showing probable drug-related elevation of liver transaminases.
  
  
  CONCLUSIONS
  The window design in asymptomatic patients with mCRC can be safely applied to assess the activity and safety of novel cytostatic agents like enzastaurin.
authors.affiliation: Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Uppsala, Sweden. bengt.glimelius@onkologi.uu.se
authors.forename: B
authors.initials: B
authors.lastname: Glimelius
authors.forename: M
authors.initials: M
authors.lastname: Lahn
authors.forename: S
authors.initials: S
authors.lastname: Gawande
authors.forename: A
authors.initials: A
authors.lastname: Cleverly
authors.forename: C
authors.initials: C
authors.lastname: Darstein
authors.forename: L
authors.initials: L
authors.lastname: Musib
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: K L
authors.initials: KL
authors.lastname: Spindler
authors.forename: J-E
authors.initials: JE
authors.lastname: Frödin
authors.forename: A
authors.initials: A
authors.lastname: Berglund
authors.forename: P
authors.initials: P
authors.lastname: Byström
authors.forename: C
authors.initials: C
authors.lastname: Qvortrup
authors.forename: A
authors.initials: A
authors.lastname: Jakobsen
authors.forename: P
authors.initials: P
authors.lastname: Pfeiffer
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011379:Prognosis; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D064546:Protein Kinase C beta; D014018:Tissue Distribution
chemical_list: D002272:Carcinoembryonic Antigen; D007211:Indoles; D007770:L-Lactate Dehydrogenase; D011493:Protein Kinase C; D064546:Protein Kinase C beta; C504878:enzastaurin