Phase I to II multicenter study of oblimersen sodium, a Bcl-2 antisense oligonucleotide, in patients with advanced chronic lymphocytic leukemia.
OBJECTIVE
To determine the maximum-tolerated dose (MTD), efficacy, safety, and pharmacokinetics of oblimersen sodium in patients with advanced chronic lymphocytic leukemia (CLL).


METHODS
Eligible patients had relapsed or refractory CLL after treatment with fludarabine. Oblimersen was administered at doses ranging from 3 to 7 mg/kg/d as a 5-day continuous intravenous infusion in cycle 1 and as a 7-day continuous intravenous infusion in subsequent cycles every 3 weeks in stable or responding patients.


RESULTS
Forty patients were enrolled and treated (14 patients in phase I and 26 patients in phase II). Dose-limiting reactions in phase I included hypotension and fever, and the MTD for phase II dosing was established at 3 mg/kg/d. Two (8%) of 26 assessable patients achieved a partial response. Other evidence of antitumor activity included > or = 50% reduction in splenomegaly (seven of 17 patients; 41%), complete disappearance of hepatomegaly (two of seven patients; 29%), > or = 50% reduction of lymphadenopathy (seven of 22 patients; 32%), and > or = 50% reduction in circulating lymphocyte counts (11 of 22 patients; 50%). Adverse events included transient hypotension, fever, fatigue, night sweats, diarrhea, nausea, vomiting, hypokalemia, and cough. Plasma concentrations of oblimersen (parent drug) and its major metabolites were variable. Renal clearance represented only a small portion of total parent drug clearance.


CONCLUSIONS
Dosing with oblimersen sodium in patients with CLL is limited by development of a cytokine release syndrome that is characterized by fever, hypotension, and back pain. Oblimersen sodium has modest single-agent activity in heavily pretreated patients with advanced CLL, and further evaluation of its activity in combination with cytotoxic drugs is warranted.
O'Brien
Susan M
SM
M.D. Anderson Cancer Center, 1515 Holcombe Blvd, Box 428, Houston, TX 77030-7305, USA. sobrien@mdanderson.org
Cunningham
Charles C
CC
Golenkov
Anatoliy K
AK
Turkina
Anna G
AG
Novick
Steven C
SC
Rai
Kanti R
KR
D000328:Adult; D000368:Aged; D004305:Dose-Response Relationship, Drug; D005260:Female; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy* / Q000235:genetics; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D016376:Oligonucleotides, Antisense / Q000493:pharmacokinetics* / Q000627:therapeutic use; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012074:Remission Induction; D015996:Survival Rate; D013873:Thionucleotides / Q000493:pharmacokinetics* / Q000627:therapeutic use
D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D013873:Thionucleotides; C408162:oblimersen