Abstract | PURPOSE: EXPERIMENTAL DESIGN: Eligible patients received figitumumab 20 mg/kg intravenously every 3 weeks for 3 cycles followed by prostatectomy. The primary endpoint was IGF-IR expression inhibition as assessed by immunohistochemistry. RESULTS: Sixteen patients were accrued. Median age was 63 years, median prostate-specific antigen (PSA) was 7.2 μg/L (range, 2.5-35), clinical stage was T1 in four patients and T2 in 12 patients, Gleason score ≤ 7 or >7 in 15 and one patients. Two patients received only 1 cycle (patient choice and grade III hyperglycemia). A PSA decline from baseline of ≥ 25% and ≥ 50% occurred in 15 (94%) and 5 (31%) of patients. Mean figitumumab concentration was 350.4 μg/mL (range, 26.3-492.8) in plasma and 51.3 μg/g (range, 27.4-79.6) in prostate tissue. Compared with pretreatment biopsies, IGF-IR expression decreased in the prostatectomy specimens in 14 of 16 patients. The mean IGF-IR immunohistochemistry visual score was 2.1 (SD = 0.6) in biopsy and 1.1 (SD = 0.5) in prostatectomy specimens (P < 0.0001). Androgen receptor expression was also decreased and there was a trend for a decrease in downstream IGF-IR signaling components. CONCLUSIONS:
Figitumumab is biologically active in prostate cancer. PSA declines in treatment-naive patients were observed, potentially mediated by IGF-IR effects on androgen receptor expression. These results support the clinical relevance of IGF-IR signaling in prostate cancer and justify further clinical trials.
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Authors | Kim N Chi, Martin E Gleave, Ladan Fazli, S Larry Goldenberg, Alan So, Christian Kollmannsberger, Nevin Murray, Anna Tinker, Michael Pollak |
Journal | Clinical cancer research : an official journal of the American Association for Cancer Research
(Clin Cancer Res)
Vol. 18
Issue 12
Pg. 3407-13
(Jun 15 2012)
ISSN: 1557-3265 [Electronic] United States |
PMID | 22553344
(Publication Type: Clinical Trial, Phase II, Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | ©2012 AACR. |
Chemical References |
- Antibodies, Monoclonal
- Immunoglobulins, Intravenous
- Receptor, IGF Type 1
- Prostate-Specific Antigen
- figitumumab
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Topics |
- Aged
- Antibodies, Monoclonal
- Combined Modality Therapy
- Disease Progression
- Humans
- Immunoglobulins, Intravenous
(pharmacology, therapeutic use)
- Male
- Middle Aged
- Neoplasm Staging
- Prostate-Specific Antigen
(blood)
- Prostatectomy
- Prostatic Neoplasms
(drug therapy, metabolism, pathology, surgery)
- Receptor, IGF Type 1
(antagonists & inhibitors, blood, immunology)
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