PS-341 and gemcitabine in patients with metastatic pancreatic adenocarcinoma: a North Central Cancer Treatment Group (NCCTG) randomized phase II study.
BACKGROUND
PS-341 is a proteasome inhibitor with preclinical activity in pancreatic cancer tumor models and synergistic activity with gemcitabine. This randomized phase II study determined the tumor response rate (RR) for PS-341 alone and the 6-month survival and RR for the combination of gemcitabine and PS-341 in patients with metastatic pancreatic adenocarcinoma.


METHODS
Patients were randomized to receive 3-week cycles of either arm A: PS-341 1.5 mg/m(2) i.v. bolus (over 3--5 s) on days 1, 4, 8 and 11 or arm B: PS-341 1.0 mg/m(2) (same as arm A otherwise) plus gemcitabine 1,000 mg/m(2) i.v. on days 1 and 8. Patients progressing on arm A were allowed to receive arm B treatment.


RESULTS
Arm A: 42 evaluable patients were enrolled with a confirmed RR of 0% (95% CI 0% to 8%), median survival of 2.5 months (95% CI 2.0-3.3), and median time to progression (TTP) of 1.2 months (95% CI 1.1--1.3). Twelve of 43 evaluable patients (28%) experienced at least one grade 4+ AE. Arm B: 39 evaluable patients yielded a 6-month survival rate of 41% (16/39, 95% CI 29.8% to 67.0%), median survival of 4.8 months (95% CI 2.4--7.4), median TTP of 2.4 months (95% CI 1.5--3.1), and confirmed RR of 10% (4 partial responses/0 complete responses, 95% CI 3% to 24%). Eleven of 43 evaluable patients (26%) experienced at least one grade 4+ AE. One patient had grade 5 hypotension.


CONCLUSIONS
The use of PS-341 alone or in combination with gemcitabine did not result in an overall survival and RR better than that expected for gemcitabine alone. Based on the lack of efficacy and the toxicity seen in our trial, there does not appear to be a role for PS-341 in pancreatic adenocarcinoma with either of the schedules used in this trial.
Alberts
S R
SR
Mayo Clinic and Mayo Foundation, Rochester, MN 55905. alberts.steven@mayo.edu
Foster
N R
NR
Morton
R F
RF
Kugler
J
J
Schaefer
P
P
Wiesenfeld
M
M
Fitch
T R
TR
Steen
P
P
Kim
G P
GP
Gill
S
S
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001897:Boronic Acids / Q000008:administration & dosage / Q000627:therapeutic use*; D000069286:Bortezomib; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D018450:Disease Progression; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011719:Pyrazines / Q000008:administration & dosage / Q000627:therapeutic use*; D016019:Survival Analysis; D016896:Treatment Outcome; D000093542:Gemcitabine
D000970:Antineoplastic Agents; D001897:Boronic Acids; D011719:Pyrazines; D003841:Deoxycytidine; D000069286:Bortezomib; D000093542:Gemcitabine