Table 2.
Caplacizumab-related features and clinical endpoints.
| Variables | N = 26 |
|---|---|
| Time to receive the first dose of caplacizumab after TPE start, (d) median (IQR)a | 1 (0-8) |
| Length of caplacizumab treatment after the end of daily TPE, (d) median (IQR)b,i | 26 (18-30) |
| Time to first normalization of platelet count after caplacizumab start, (d) median (IQR)b | 4 (3-4) |
| Time to clinical response after caplacizumab start, (d) median (IQR) | 6 (5-7) |
| Total no. of TPE procedures to achieve clinical response, median (IQR) | 7 (6-14) |
| Total days of TPE to achieve clinical response, median (IQR)b | 8 (6-14.8) |
| Total length of hospital stay, (d) median (IQR)c | 18 (9-29) |
| ICU admission, n (%) | 5 (19.2) |
| ICU stay, (d) median (IQR) | 13 (8-15) |
| Clinical response, n (%) | 26 (100) |
| Acute clinical exacerbation after caplacizumab start, n (%)d,j | 1 (4.3) |
| Clinical remission, n (%) | 26 (100) |
| Partial ADAMTS-13 remission in total observational time, n (%)e | 22 (91.7) |
| Total ADAMTS-13 remission in total observational time, n (%)e | 19 (79.2) |
| Partial ADAMTS-13 remission within 30 d after caplacizumab stop, n (%)f | 17 (81.0) |
| Total ADAMTS-13 remission within 30 d after caplacizumab stop, n (%)f | 13 (56.5) |
| ADAMTS-13 activity level at caplacizumab stopf | |
| <20 IU/dL, n (%)g | 6 (27.3) |
| 20 IU/dL<ADAMTS-13<45 IU/dL, n (%) | 7 (31.8) |
| ≥45 IU/dL, n (%) | 9 (40.9) |
| Caplacizumab-related adverse events leading to drug discontinuation | 2 (7.7) |
| Caplacizumab-related major bleeding episodesh | 2 (7.7) |
For the patient treated with a TPE-free approach, the time to receive the first dose of caplacizumab has been considered since episode onset. For patients admitted also to ICU, as total length of hospital stay we considered the total number of days (both in ICU and not in ICU).
ICU, intensive care unit; TPE, therapeutic plasma exchange.
Available in 25 patients;
available in 22 patients;
available in 21 patients;
available in 23 patients;
available in 24 patients;
these proportions became 77% (partial) and 57% (total) in the 15 patients treated with caplacizumab upfront;
undetectable in 3 patients (8 IU/dL, 10 IU/dL and 11 IU/dL);
defined based on the ISTH criteria employed for non-surgical patients; more details are reported in the Supporting information.
The ADAMTS13 response allowed to discontinue caplacizumab before 30 days after the end of daily TPE in about 70% of cases. Adverse drug reactions and drug cost-related issues may explain the early discontinuation in the other cases.
The patient who exacerbated had started caplacizumab 59 days after TPE initiation for a refractory disease and, at caplacizumab stop, ADAMTS13 activity was still undetectable.