FROM BLOOD
For patients with chronic primary immune thrombocytopenia, a three-drug regimen was associated with a high response rate and relapse-free survival, according to the results of a single-arm, phase IIb trial published online in Blood.
Twenty patients with primary immune thrombocytopenia (ITP) received an investigative triple therapy of oral dexamethasone 40 mg (days 1-4), oral cyclosporine 2.5-3.0 mg/kg daily (days 1-28), and intravenous rituximab 100 mg (day 7, 14, 21, and 28), and of this group, 12 patients responded. The median time to response was 7.4 days, and all patients maintained their response for at least 7 months, Dr. Philip Young-Ill Choi, of St. George Clinical School, University of New South Wales, Kogarah, Australia, and his colleagues reported (Blood 2015;126[4]:500-3).
Complete response was 30% at 6 months, and only two patients relapsed during a median follow-up period of 17.5 months (range, 7-47 months). Among patients who responded, relapse-free survival at 12 and 24 months was 92% and 76%, respectively (95% confidence intervals, 53%-98% and 30%-93%, respectively).
Peripheral T cells declined for all patients, irrespective of response, but responders had lower CD4+ T cells than did nonresponders for 6 months after treatment (median, 0.62 vs. 0.91 x 109/L; P less than .0001). Peripheral CD19+ B cells became undetectable for all patients by day 28, but recovery was earlier for patients younger than 50 years (median, 6.5 months vs. not reached; P = .0105).
The regimen was generally well tolerated, without any deaths, treatment-related serious adverse events, serum sickness, interruptions, or delays caused by toxicity.
A major advantage of this regimen is its short duration of therapy, and yet 12 of 20 patients enjoyed a prolonged remission of 7 months or longer without needing further treatment. However, interpretation of the data was limited by the small sample size, the investigators noted.
“Although our study shows encouraging results, the incremental benefit of cyclosporine to rituximab and dexamethasone remains unresolved, and randomized controlled trials are required,” they wrote.
No funding source for the study was given. One author reported receiving speaker’s fees from Roche, and another is on the speakers bureau and receives research funding from GlaxoSmithKline and Amgen. The remaining authors declared no competing financial interests.
