Prostate-specific antigen kinetics as a measure of the biologic effect of granulocyte-macrophage colony-stimulating factor in patients with serologic progression of prostate cancer.
OBJECTIVE
To determine the biologic effect of granulocyte-macrophage colony-stimulating factor (sangramostim, GM-CSF; Immunex Corporation, Seattle, WA) as measured by prostate-specific antigen (PSA) kinetics in patients with serologic progression of prostate cancer after definitive local therapy.


METHODS
Patients with prostate cancer who had undergone previous definitive surgical or radiation therapy with nonmetastatic, recurrent disease as manifested by a rising PSA between 0.4 ng/mL and 6.0 ng/mL were enrolled on this phase II trial. Patients received 250 micro g/m(2)/day of subcutaneous GM-CSF on days 1 through 14 of a 28-day cycle. PSA was measured at day 1 of each cycle.


RESULTS
Thirty patients with serologic progression of prostate cancer were treated. The median pretreatment PSA was 2.9 ng/mL. Of the 29 evaluable patients, three patients (10%; 95% confidence interval, 2% to 27%) achieved a 50% reduction in PSA. For the patients (n = 26) in whom the on-treatment PSA doubling time could be calculated, the median PSA doubling time increased from 8.4 months to 15 months (P =.001), and the median slope of the PSA versus time curve decreased with treatment (P =.004). Therapy was well tolerated by all patients, with an average treatment duration of 16.5 cycles (range, 5 to 33).


CONCLUSIONS
GM-CSF has a biologic effect in patients with serologic progression of prostate cancer after definitive local therapy, as measured by PSA declines and modulation of PSA kinetics.
Rini
Brian I
BI
University of California San Francisco Comprehensive Cancer Center, San Francisco, CA 94115, USA. brini@medicine.ucsf.edu
Weinberg
Vivian
V
Bok
Robert
R
Small
Eric J
EJ
D000230:Adenocarcinoma / Q000097:blood* / Q000188:drug therapy*; D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D017430:Prostate-Specific Antigen / Q000097:blood / Q000187:drug effects*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000188:drug therapy*; D018709:Statistics, Nonparametric
D000970:Antineoplastic Agents; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D017430:Prostate-Specific Antigen