Higher-dose and less frequent dendritic cell infusions with PSMA peptides in hormone-refractory metastatic prostate cancer patients.
BACKGROUND
Infusion of dendritic cells (DCs) pulsed with PSMA peptides was considered possible in hormone-refractory metastatic prostate cancer patients both with or without prior treatment with a greater number of DCs and for lesser infusions than previously administered.


METHODS
DCs + PSMA peptides in patients undergoing leukapheresis were administered monthly 1-4 times, at rates greater than 20 million DCs in 17 patients not previously treated, and in 11 patients previously treated.


RESULTS
Three partial responders and one complete responder were noted in the 17 previously untreated persons. DCs + PSMA peptides averaged 28.5 million cells (range in millions, 21.0-42.3). All responders received 3 or 4 infusions of greater than 22 million cells (3-4 times). In the previously treated group of 11 patients, DCs infused averaged 29.3 million cells (range in millions, 20-40.5). One new responder (bone scan) was noted. Two prior responders continued. Observation times were similar. Toxicity was minimal.


CONCLUSIONS
These results suggest that DCs + PSMA peptide infusions can be given with greater numbers of DCs with a lesser number of infusions (1-4 monthly) with no loss of response rates compared to those noted previously, and without increased side effects. In previously treated patients (both relapsing and nonrelapsing), adverse effects were not noted, and new responses can be anticipated to be without harmful side effects. However, the follow-up time, and number of patients in this group, were small.
Murphy
G P
GP
Pacific Northwest Cancer Foundation, Seattle, Washington 98125, USA.
Tjoa
B A
BA
Simmons
S J
SJ
Rogers
M K
MK
Kenny
G M
GM
Jarisch
J
J
D000954:Antigens, Surface; D002268:Carboxypeptidases / Q000627:therapeutic use*; D003713:Dendritic Cells / Q000637:transplantation*; D004351:Drug Resistance; D043425:Glutamate Carboxypeptidase II; D006728:Hormones / Q000627:therapeutic use; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000627:therapeutic use*; D011471:Prostatic Neoplasms / Q000556:secondary* / Q000628:therapy*; D019233:Retreatment; D016896:Treatment Outcome
D000954:Antigens, Surface; D006728:Hormones; D010446:Peptide Fragments; D002268:Carboxypeptidases; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II