A single weekly dose of imatinib is sufficient to induce and maintain remission of chronic eosinophilic leukaemia in FIP1L1-PDGFRA-expressing patients.
Hypereosinophilic syndrome (HES) is defined as chronic, unexplained hypereosinophilia with organ involvement. A subset of HES patients presents an interstitial deletion in chromosome 4q12, which leads to the expression of an imatinib-responsive fusion gene, FIP1L1-PDGFRA. These patients are diagnosed as chronic eosinophilic leukaemia (CEL). We treated seven CEL and HES patients, six of which expressed FIP1L1-PDGFRA, with imatinib using initial daily doses ranging from 100 to 400 mg. In a remission maintenance phase, the patients were treated with imatinib once weekly. All imatinib-treated patients achieved a complete haematological remission (CHR), and five of the six patients with FIP1L1-PDGFRA expression exhibited molecular remission. The decreased imatinib doses were as follows: 200 mg/week in three patients, 100 mg/week in two patients and 100 mg/d in the remaining two patients. For remission maintenance, imatinib doses were set at 100 mg/week in five patients and 200 mg/week in two patients. At a median follow-up of 30 months all patients remained in CHR and FIP1L1-PDGFRA expression was undetectable in five of the six FIP1L1-PDGFRA-expressing patients. These data suggest that a single weekly dose of imatinib is sufficient to maintain remission in FIP1L1-PDGFRA- positive CEL patients.
Helbig
Grzegorz
G
Department of Haematology and Bone Marrow Transplantation, Silesian Medical University, Katowice, Poland. ghelbig@o2.pl
Stella-Hołowiecka
Beata
B
Majewski
Mirosław
M
Całbecka
Małgorzata
M
Gajkowska
Jolanta
J
Klimkiewicz
Ryszard
R
Moskwa
Andrzej
A
Grzegorczyk
Janina
J
Lewandowska
Monika
M
Hołowiecki
Jerzy
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001549:Benzamides; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000097:blood / Q000188:drug therapy*; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000097:blood*; D010879:Piperazines / Q000008:administration & dosage* / Q000627:therapeutic use; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000008:administration & dosage* / Q000627:therapeutic use; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000097:blood*; D012074:Remission Induction; D016896:Treatment Outcome; D039221:mRNA Cleavage and Polyadenylation Factors / Q000097:blood*
D001549:Benzamides; D015415:Biomarkers; D015514:Oncogene Proteins, Fusion; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D039221:mRNA Cleavage and Polyadenylation Factors; D000068877:Imatinib Mesylate; C479819:FIP1L1-PDGFRA fusion protein, human; D011505:Protein-Tyrosine Kinases; D020796:Receptor, Platelet-Derived Growth Factor alpha