Caplacizumab in paediatric immune thrombotic thrombocytopenic purpura (iTTP): the UK TTP Registry experience.

Paediatric thrombotic thrombocytopenic purpura (TTP) is an ultra-rare disease. Immune TTP (iTTP) is driven by anti-ADAMTS13 autoantibodies causing an imbalanced VWF:ADAMTS13 axis, and rarer still in children, but potentially life-threatening. Caplacizumab is licensed for iTTP treatment in adults and adolescents aged 12 years and older who weigh 40kg plus. There is a need to clarify whether caplacizumab can be used in younger children. We retrospectively describe caplacizumab use in 16 patients under 18 years of age from the UK TTP Registry, including 4 children aged less than 12 years. For patients weighing less than 40kg (n=3), caplacizumab was dosed at 5mg od. The youngest patient was 33 months old at diagnosis. Plasma exchange (PEX) was used in 15 patients, with a median of 5 exchanges required before platelet count normalisation (range 2-9). One patient was managed without plasma exchange. All patients achieved normalisation of platelet count (median 5.5 days, range 3-28) and ADAMTS13 activity (median 35 days, range 8 to 149), with a median hospital admission of 11 days (range 5 to 26). There were no refractory patients. One patient relapsed at 9 months post presentation. Bleeding requiring VWF supplementation and reduction of caplacizumab use occurred in one patient with severe epistaxis, with no significant intracranial or gastrointestinal bleeding. We demonstrate the efficacy and safety of caplacizumab in the paediatric population, synonymous with the adult trial data: primarily, reduction of PEX compared with the pre-caplacizumab era. This has implications for intensification and duration of admission, particularly relevant in paediatric care.

Fifteen-minute consultation: Initial management of suspected acute leukaemia by non-specialists.

Leukaemia is the most common cancer of childhood. Most children with a new diagnosis of leukaemia are clinically stable at initial presentation. However, there are a number of life-threatening complications that have to be considered and monitored for. These complications include sepsis, tumour lysis syndrome, mediastinal masses, bleeding and pain. The aim of this article is to equip the general paediatrician with a framework for managing children with suspected leukaemia, prior to transfer to the primary treatment centre. The presentation, diagnosis and definitive treatment of acute leukaemia is not in the remit of this article.

Double Relapsed and/or Refractory Multiple Myeloma: Clinical Outcomes and Real World Healthcare Costs.

Double relapsed and/or refractory multiple myeloma (DRMM), MM that is relapsed and/or refractory to bortezomib and lenalidomide, carries a poor prognosis. The healthcare costs of DRMM have not previously been reported. We analyzed detailed medical resource utilization (MRU) costs, drug costs and outcomes for 39 UK patients receiving standard DRMM therapy. Median OS in this cohort was 5.6 months. The mean cost of DRMM treatment plus MRU until death was £23,472 [range: £1,411-£90,262], split between drug costs £11,191 and other resource use costs £12,281. The cost per assumed quality-adjusted life year (QALY) during DRMM was £66,983. These data provide a standard of care comparison when evaluating the cost-effectiveness of new drugs in DRMM.

Isolated extraocular muscle infiltration with plasmacytoma treated with localized injection of dexamethasone.

Plasmacytoma of the orbit secondary to multiple myeloma is rare and has not previously been reported limited to an extraocular muscle. Conventional treatment is either localized radiotherapy or systemic chemotherapy. We report a case of plasmacytoma within the medial rectus muscle, which regressed completely with localized infiltration of dexamethasone.