Superiority of prolonged low-dose azanucleoside administration? Results of 5-aza-2'-deoxycytidine retreatment in high-risk myelodysplasia patients.
BACKGROUND
The optimal treatment duration with decitabine (DAC) in patients with myelodysplastic syndromes (MDS) remains a matter of debate. Although at least 2 consolidating courses after best response usually are performed, the response to treatment after disease recurrence has not been systematically studied to date.


METHODS
In the current study, the authors report on 22 of 108 patients with MDS (20%) treated with low-dose DAC in 3 Phase II trials who received DAC as retreatment at the time of disease recurrence.


RESULTS
According to the International Prognostic Scoring System (IPSS) at the time of initial treatment, 5 of 22 patients (23%) had a score of intermediate-1 (Int-1), 4 patients (18%) had a score of Int-2, and 13 patients (59%) were scored as high-risk. Patients initially received a median of 6 courses of DAC (range, 2 courses-6 courses), which resulted in a complete remission (complete response [CR]) in 12 of the 22 patients (55%). Retreatment with DAC at the time of disease recurrence was initiated at a median of 11 months (range, 3 mos-27 mos) after the last course of initial treatment. With regard to DAC retreatment, patients received a median of 3 courses (range, 1 courses-6 courses), with 10 of 22 patients (45%) responding (1 with a CR and 2 with partial remissions [partial response (PR)]; all 3 patients achieved a CR at the time of initial treatment) and 7 patients demonstrating a hematologic improvement (HI) (at the time of initial treatment there were 2 CRs, 4 PRs, and 1 HI). Twelve of the 22 patients (55%) did not demonstrate any objective responses to retreatment, including 4 patients with primary resistance to the first course of retreatment. The median survival of all patients from the initiation of the first DAC course was 27.5 months (range, 15 mos-50+ mos). The median survival of 43 patients who also had achieved a response to the initial treatment with DAC but who received best supportive care (n = 33 patients) or induction chemotherapy (n = 10 patients) was 18 months (range, 5 mos-72 mos). Second responders to DAC retreatment were found less frequently in the IPSS high-risk group compared with nonresponders (40% vs. 83%). Age, French-American-British classification subtype, serum lactate dehydrogenase level at retreatment, and previous response to DAC were not found to strongly differ between the groups; however, the subgroups were too small to perform a statistical analysis.


CONCLUSIONS
Retreatment with DAC was found to result in objective responses in 45% of previously DAC-responsive patients. However, the quality and duration of the second disease remissions were found to be inferior. Therefore, DAC-responsive patients might derive more clinical benefit from continuation of the initial treatment.
Rüter
Björn
B
Division of Hematology/Oncology, Department of Internal Medicine I, Albert-Ludwigs-University Freiburg, Freiburg, Germany.
Wijermans
Pierre W
PW
Lübbert
Michael
M
D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage*; D001374:Azacitidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000077209:Decitabine; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000188:drug therapy* / Q000401:mortality; D012008:Recurrence; D019233:Retreatment; D012307:Risk Factors; D015996:Survival Rate
D000964:Antimetabolites, Antineoplastic; D000077209:Decitabine; D001374:Azacitidine