Dose escalation of imatinib after failure of standard dose in Korean patients with metastatic or unresectable gastrointestinal stromal tumor.
OBJECTIVE
We evaluated the results of imatinib dose escalation in patients with advanced gastrointestinal stromal tumors (GISTs) after disease progression on standard-dose imatinib.


METHODS
Clinical data from patients with metastatic or unresectable GISTs whose dose of imatinib was increased after disease progression on imatinib 400 mg/day were retrospectively reviewed.


RESULTS
The 24 patients studied had a median age of 52 years. Imatinib dosing was escalated to 600 mg/day in 12 patients, then to 800 mg/day in four patients. The other 12 patients had dose escalation directly to 800 mg/day. Two patients (8.3%) achieved a partial response, and seven (29.2%) had stable disease. Six-month progression-free and overall survival rates were 33.3 and 70.7%, respectively. Dose escalation to 600 or 800 mg/day was generally well tolerated.


CONCLUSIONS
Imatinib dose escalation is feasible and well tolerated in patients with advanced GIST who progress on standard-dose therapy, producing clinical benefit in approximately 37% of patients.
Park
Inkeun
I
Division of Oncology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-2dong, Songpa-gu, Seoul 138-736, Republic of Korea.
Ryu
Min-Hee
MH
Sym
Sun Jin
SJ
Lee
Sung Sook
SS
Jang
Geundoo
G
Kim
Tae Won
TW
Chang
Heung Moon
HM
Lee
Jae-Lyun
JL
Lee
Hyoungnam
H
Kang
Yoon-Koo
YK
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000633:toxicity; D044466:Asian People; D001549:Benzamides; D004252:DNA Mutational Analysis; D018450:Disease Progression; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000401:mortality; D006801:Humans; D000068877:Imatinib Mesylate; D007723:Korea; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010879:Piperazines / Q000008:administration & dosage* / Q000633:toxicity; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D011743:Pyrimidines / Q000008:administration & dosage* / Q000633:toxicity; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics; D012189:Retrospective Studies; D015996:Survival Rate; D017211:Treatment Failure
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha