TPO ‐ RA s in pITP : description of a case series and analysis of predictive factors for response

Objective To report our experience concerning sustained response ( SR ) after TPO ‐ RA discontinuation in adult pITP patients and to identify possible predictive factors for outcome. Methods Thirty‐nine pITP patients who received a TPO ‐ RA were evaluated. Response (R) was defined as a platelet count ≥30 × 10 9 /L and at least a twofold increase in the baseline count and complete response ( CR ) as a platelet count ≥100 × 10 9 /L, in the absence of bleeding. Durable response ( DR ) was defined as a R/ CR persisting ≥4 wk with a stable dose of TPO ‐ RA , and SR as the first assessed platelet count ≥30 × 10 9 /L, available at more than 4 wk after discontinuation of TPO ‐ RA , in the absence of other concomitant or rescue therapies. Results Twenty‐nine/39 (74%) were responders: 18 (46%) reached a CR and 11 (28%) a R. A DR was observed in 16/29 (55%) responders. Seven SR (18%) were reached: five of seven patients achieved a SR from a prior DR . CR was statistically associated with the achievement of a subsequent DR : 13/18 (72%) CR patients obtained a DR , while only three of 11 (27%) R ones did ( P = 0.027). Conclusions CR was a significant prognostic factor for the achievement of a DR . Moreover, we observed a trend for DR patients to obtain a subsequent SR .