A phase I study of imexon plus gemcitabine as first-line therapy for advanced pancreatic cancer.
OBJECTIVE
Imexon is an aziridine-derived iminopyrrolidone which has synergy with gemcitabine in pancreatic cancer cell lines. Gemcitabine is a standard therapy for pancreatic cancer. We performed a phase I trial of imexon and gemcitabine to evaluate safety, dose-limiting toxicity (DLT), and maximum tolerated dose (MTD) in patients with advanced pancreatic cancer.


METHODS
Patients with untreated locally advanced or metastatic pancreatic adenocarcinoma received therapy in sequential cohorts on regimen A (n = 19; imexon 200 or 280 mg/m(2) intravenously (IV) over 30 min days 1-5, 15-19 and gemcitabine 800 or 1,000 mg/m(2) IV over 30 min on days 1,8,15 every 28 days) or regimen B (n = 86; imexon 280-1,300 mg/m(2) IV over 30-60 min days 1, 8, and 15 and gemcitabine 1,000 mg/m(2) IV over 30 min on days 1, 8, and 15 every 28 days).


RESULTS
One hundred five patients received 340 treatment cycles (median 2, range 1-16).


METHODS
median age 63, 61% male, ECOG PS 0/1 50%/50%, 93% metastatic. DLT was abdominal cramping and pain, often with transient, acute diarrhea. Best response was confirmed partial response (PR) in 11.4%, 8.9% unconfirmed PR, and 48.1% with stable disease. There was a dose proportional increase in imexon AUC across the doses tested with terminal half life 69 min at the MTD and no alteration of gemcitabine pharmacokinetics.


CONCLUSIONS
The recommended phase II dose of imexon is 875 mg/m(2) with gemcitabine 1,000 mg/m(2). DLT was acute abdominal pain and cramping. Encouraging antitumor responses support further evaluation of this combination in advanced pancreatic cancer.
Department of Medical Oncology, Fox Chase Cancer Center, 333 Cottman Avenue, Room C307, Philadelphia, PA 19111-2497, USA. S_Cohen@fccc.edu
Steven J
SJ
Cohen
Mark M
MM
Zalupski
Manuel R
MR
Modiano
Paul
P
Conkling
Yehuda Z
YZ
Patt
Peg
P
Davis
Robert T
RT
Dorr
Michelle L
ML
Boytim
Evan M
EM
Hersh
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D019540:Area Under Curve; D015331:Cohort Studies; D003553:Cystine / Q000097:blood; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D004305:Dose-Response Relationship, Drug; D005260:Female; D006207:Half-Life; D006588:Hexanones / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D013438:Sulfhydryl Compounds / Q000378:metabolism; D014057:Tomography, X-Ray Computed; D000093542:Gemcitabine
D000964:Antimetabolites, Antineoplastic; D006588:Hexanones; D013438:Sulfhydryl Compounds; D003841:Deoxycytidine; D003553:Cystine; C014919:4-imino-1,3-diazabicyclo(3.1.0)hexan-2-one; D000093542:Gemcitabine