Treatment of rheumatoid arthritis with imatinib mesylate: clinical improvement in three refractory cases.
BACKGROUND
Imatinib mesylate is an inhibitor of a few tyrosine kinases including KIT, which is an important growth factor receptor of mast cells.


OBJECTIVE
To study the efficacy and safety of imatinib in the treatment of rheumatoid arthritis.


METHODS
Three patients with severe rheumatoid were treated with imatinib for 12 weeks. The number of tender and swollen joints, patient-assessed disease activity and pain as assessed by a visual analogue scale, a health assessment questionnaire (HAQ) score, serum C-reactive protein (CRP) and blood erythrocyte sedimentation rate (ESR) were used as the primary outcome measures.


RESULTS
All outcome measures improved. The swollen joint count decreased in all patients, and the tender joint count in two of the three patients. The patients reported less pain and disease activity, and the HAQ scores improved. Serum CRP and blood ESR improved in two patients. One patient interrupted therapy due to a rash.


CONCLUSIONS
Imatinib mesylate may have considerable anti-rheumatic efficacy. The mechanism of action is not known, but one possible target for the action of imatinib is inhibition of the KIT receptor on mast cells.
Eklund
Kari K
KK
Department of Internal Medicine, Division of Rheumatology, Helsinki University Central Hospital, Helsinki, Finland. kari.eklund@HUS.fi
Joensuu
Heikki
H
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy*; D001549:Benzamides; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008407:Mast Cells / Q000502:physiology; D008875:Middle Aged; D010147:Pain Measurement; D010879:Piperazines / Q000627:therapeutic use*; D011446:Prospective Studies; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D011743:Pyrimidines / Q000627:therapeutic use*; D016896:Treatment Outcome
D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D002097:C-Reactive Protein; D011505:Protein-Tyrosine Kinases