A phase II trial of imatinib mesylate in patients with prostate specific antigen progression after local therapy for prostate cancer

Prostate. 2005 Feb 1;62(2):115-22. doi: 10.1002/pros.20130.


Purpose: To test the hypothesis that progression of androgen sensitive prostate cancer is dependent on growth factors, such as platelet derived growth factor (PDGF), and inhibition of PDGF receptor (PDGF-R) with imatinib will induce anti-tumor activity.

Patients and methods: This phase II study evaluated imatinib in patients with androgen sensitive prostate cancer and prostate specific antigen (PSA) progression after local therapy. Patients received 400 mg of imatinib orally twice a day for 24 weeks (six cycles). Patients were monitored every 4 weeks for an effect on PSA and toxicity. Immunohistochemistry (IHC) for PDGF-R was performed in available tumor specimens.

Results: Twenty-one patients were enrolled on this trial with a median age of 64 years. A total of 72 cycles of therapy were administered. Sixteen patients were evaluable for a response. Nine of the 16 patients demonstrated a stable PSA. Seven patients demonstrated PSA progression. Grade 3 and 4 toxicity included rash (4.1%), hematuria (1.4%), diarrhea (1.4%), and neutropenia (2.7%). Testosterone levels did not change during therapy. Four patients with available tumor demonstrated PDGF-R alpha and beta by IHC.

Conclusions: This first study evaluated the efficacy and safety of imatinib in patients with early androgen sensitive prostate cancer following local therapy. As a single agent at this dosing, imatinib had limited biochemical activity.

Publication types

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

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / administration & dosage*
  • Antineoplastic Agents / adverse effects
  • Benzamides
  • Humans
  • Imatinib Mesylate
  • Male
  • Middle Aged
  • Piperazines / administration & dosage*
  • Piperazines / adverse effects
  • Prostate-Specific Antigen / metabolism*
  • Prostatic Neoplasms / drug therapy*
  • Pyrimidines / administration & dosage*
  • Pyrimidines / adverse effects
  • Receptors, Platelet-Derived Growth Factor / antagonists & inhibitors
  • Receptors, Platelet-Derived Growth Factor / metabolism
  • Treatment Failure


  • Antineoplastic Agents
  • Benzamides
  • Piperazines
  • Pyrimidines
  • Imatinib Mesylate
  • Receptors, Platelet-Derived Growth Factor
  • Prostate-Specific Antigen