A phase I/II dose-escalation study of exisulind and docetaxel in patients with hormone-refractory prostate cancer.
OBJECTIVE
To determine the safety and efficacy, in a dose-escalation study, of exisulind (an oral sulphone metabolite of sulindac thought to induce apoptosis in malignant cells by inhibiting cGMP-phosphodiesterase) combined with docetaxel in men with hormone-refractory prostate cancer (HRPC), as pre-clinical studies suggested activity against prostate cancer and synergy with cytotoxic agents.


METHODS
Thirty-four patients with HRPC were treated with oral exisulind twice daily for 21-day cycles and intravenous docetaxel given for 1 h on the first day of each cycle. Three dose levels were assessed, combining exisulind 150 and 250 mg twice daily with docetaxel at 60 or 75 mg/m2. Toxicity was then evaluated using standard criteria.


RESULTS
The recommended phase II dose was determined to be exisulind 250 mg and docetaxel 60 mg/m2, with escalation to 75 mg/m2 after cycle 1, as tolerated. The most common grade 3-4 toxicities among all patients were neutropenia (56%), infection (24%) and hyperglycaemia (18%). Twelve of 32 evaluable patients (38%, 95% confidence interval, CI, 23-55%) had a decline in PSA by at least half. Only four of 17 evaluable patients (95% CI, 1-47%) treated at the phase II dose level had such a decline in PSA. The median (95% CI) overall survival of all patients was 16 (12.9-19.7) months and median progression-free survival 4.7 (2.7-5.2) months.


CONCLUSIONS
The combination of exisulind and docetaxel was tolerable in patients with HRPC. The PSA response rates do not suggest an improvement over historical data with single-agent docetaxel in this population.
Ryan
Christopher W
CW
Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR 97239-3098, USA. ryanc@ohsu.edu
Stadler
Walter M
WM
Vogelzang
Nicholas J
NJ
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D018572:Disease-Free Survival; D000077143:Docetaxel; D019008:Drug Resistance, Neoplasm; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D013467:Sulindac / Q000008:administration & dosage / Q000031:analogs & derivatives*; D043823:Taxoids / Q000008:administration & dosage
D043823:Taxoids; D000077143:Docetaxel; D013467:Sulindac; C025463:sulindac sulfone