Nanobody can help treat acquired TTP

However, the investigators said they could not rule out a possible effect of PE therapy on LDH, creatinine, and troponin levels.

Need for PE

Results showed that caplacizumab could reduce the need for PE, at least while patients continued to receive the drug.

Patients in the caplacizumab arm required fewer PEs during the daily PE treatment period and the overall treatment period. But this benefit was lost during the 1-month follow-up period, which is reflective of the increased number of relapses, according to the investigators.

During the daily PE treatment period, the mean number of PE days was 5.9 in the caplacizumab arm and 7.9 in the placebo arm. During the overall treatment period, it was 7.7 and 11.7 days, respectively. And during the overall treatment and follow-up period, it was 10.2 and 11.7 days, respectively.

Adverse events

The investigators said caplacizumab increased the risk of bleeding events, but these were readily managed.

Treatment-emergent adverse events (AEs) occurred in 97% of patients in the caplacizumab arm and 100% of patients in the placebo arm. Eight percent of caplacizumab-treated patients discontinued treatment due to AEs, but none of the controls did.

Fifty-four percent of patients in the caplacizumab arm had a bleeding event, as did 38% of patients in the placebo arm. Eighty percent of the bleeding events in the caplacizumab arm were mild. Three patients required drug treatment. None required von Willebrand factor or factor VIII substitution.

Serious AEs occurred in 57% of caplacizumab-treated patients and 51% of controls. Serious bleeding events occurred in 6% and 5%, respectively.