1.1 Caplacizumab with plasma exchange and immunosuppression is recommended, within its marketing authorisation, as an option for treating an acute episode of acquired thrombotic thrombocytopenic purpura (TTP) in adults, and in young people aged 12 years and over who weigh at least 40 kg. Treatment should be started and supervised by physicians experienced in managing thrombotic microangiopathies. It is recommended only if the company provides caplacizumab according to the commercial arrangement.
Why the committee made these recommendations
Standard care for an acute episode of acquired TTP includes plasma exchange and immunosuppressant medicines. Trial results show that, compared with standard care alone, caplacizumab plus standard care reduces:
the time it takes to bring platelet levels back to normal
the number of plasma exchange treatments needed
time in hospital and intensive care.
Adding caplacizumab likely reduces the long-term complications of acquired TTP and risk of death around the time of an acute episode, but it is unclear by how much. This is because the trial results do not address whether adding caplacizumab improves either length or quality of life in the long term after people stop taking the drug. Also, there are limited reported data on the long-term complications of acquired TTP after an acute episode.
However, the assumptions in the economic modelling are plausible. Also, there are potential benefits with caplacizumab that are not included in the cost-effectiveness estimates. Overall, the estimates are within the range normally considered a cost-effective use of NHS resources. So, caplacizumab is recommended for treating acute acquired TTP.