Treatment for systemic sclerosis–associated active interstitial lung disease with a relatively high dose of imatinib can be effective, but it carries many side effects, judging from findings of a 20-person study.
The study subjects met the American College of Rheumatology criteria for systemic sclerosis (SSc). The mean disease duration was less than 10 years, their mean forced vital capacity (FVC) was less than 85% of predicted, their dyspnea on exertion was at least grade 2 on the magnitude of task component of the Mahler Baseline Dyspnea Index, and high-resolution computed tomography showed the presence of ground-glass opacifications.
Patients with SSc received oral therapy with imatinib up to 600 mg/day for a period of 1 year. The researchers recorded adverse events and tested pulmonary function. In addition, the modified Rodnan skin thickness score (MRSS) was assessed every 3 months, according to Dr. Dinesh Khanna of the University of California at Los Angeles.
Imatinib treatment increased FVC by 1.74%, though this was not statistically significant. In addition, the MRSS increased by 3.9 units. The total lung capacity increased by 4.17% over predicted and the diffusing capacity for carbon monoxide increased improved by 1.46% versus predicted, according to the investigators (Arthritis Rheum. 2011;63:3540-6 [doi 10.1002/art.30548]).
Of the 20 who participated, 5 did not complete the study due to adverse events that were caused by the treatment itself. A further two dropped out due to adverse events caused by SSc, and one was lost due to follow-up. The rest completed the study.
Some of the common adverse events the participants experienced were fatigue, edema of the face and/or lower extremities, nausea and vomiting, diarrhea, generalized rash, and new-onset proteinuria.
Because of its efficacy, the authors suggest further research with smaller doses of imatinib, so as to reduce AEs while maintaining the positive effects.
The researchers reported no relevant financial disclosures. Novartis Pharmaceuticals provided the study drug and partial support for the study.