Hematological response
The hematological response was evaluated at 3 months, 6 months and 12 months after IST and at the last follow-up in both groups. In the eltrombopag group, the CR and OR rates were 30.3% and 63.6% at 3 months after IST, respectively, versus 8.2% and 49.0% in the control group, respectively. There was a significant difference in CR between the two groups at 3 months (P=0.004). There was no significant difference in OR between the two groups at 3 months (P=0.074). At 6 months, the CR and OR rates were 50.0% and 71.2% in the eltrombopag group, respectively. From 3 to 6 months, 3 NR cases achieved CR, 3 NR cases were converted to PR, 10 PR cases were converted to CR, one PR relapsed, and 18 cases maintained NR. In the control group, the CR and OR rates were 10.2% and 57.1% at 6 months after IST. From 3 to 6 months, one NR case was converted to CR, 9 NR cases were converted to PR, and 16 cases maintained NR. There was a significant difference in CR between the two groups at 6 months (P<0.001). There was no significant difference in OR between the two groups (P=0.117).
At 12 months after IST, the CR and OR rates were 51.5% and 71.2%, respectively, in the eltrombopag group. From 6 to 12 months, 3 NR cases achieved CR, one NR case was converted to PR, 3 PR cases were converted to CR, one PR and one CR cases relapsed, and 18 cases retained NR. In the control group at 12 months after IST, the CR and OR rates were 42.9% and 65.3%, respectively. From 6 to 12 months, 16 PR cases were converted to CR, one PR case relapsed, and 17 cases retained NR. There were no significant differences in CR (P=0.358) and OR (0.499) between the two groups.
The clinical data were analyzed retrospectively to definite response times in both groups. The median response time was 71 days (interquartile range, 56 to 91 days) in the eltrombopag group. In the control group, the median response time was 90 days (interquartile range, 60 to 135 days). There was a significant difference in response time between the eltrombopag and control groups (P=0.007). The median times to CR in the eltrombopag and control groups were 98 days (interquartile range, 65 to 158 days) and 360 days (interquartile range, 180 to 435 days), respectively, indicating a significant difference between the two groups (p<0.001). We also compared the times to factor-CSF, red blood cells and platelets between the two groups. There were significant differences between the two groups in these variables (Table 3).
Long term prognosis
We evaluated long-term prognosis by comparing OS, relapse, clone evolution and EFS in both groups, as well as factors influencing prognosis. It should be noted that the median follow-up time were 34 months in the eltrombopag group and 71 months in the control group. Unfortunately, 10 patients were lost at the end of follow-up in the control group.