Secondary prophylaxis therapy: what are the benefits, limitations and unknowns?

Prophylaxis is widely recommended for the management of severe haemophilia A. Adoption of this approach has varied from country to country, and notably in the US prophylaxis is currently administered in fewer than one-half of severe cases. One implication is that a substantial segment of the severe haemophilia. A population will only be able to reap the potential benefits of prophylaxis if administered in the form of secondary prophylaxis. This therapeutic alternative has been less extensively investigated than primary prophylaxis, but nevertheless sufficient evidence has been reported to allow an assessment of the benefits and limitations of secondary prophylaxis. This evidence addresses the use of secondary prophylaxis in three contexts: (i). early secondary prophylaxis; (ii). delayed secondary prophylaxis and (iii). secondary prophylaxis in adults. In patients receiving early secondary prophylaxis studies in Sweden, the Netherlands, the UK and the US have demonstrated a reduction in the frequency of bleeding episodes and a subsequent low incidence of arthropathy. Additional reported benefits consist of reduced emergency room visits and hospitalizations. However, secondary prophylaxis is associated with an increased risk of the eventual development of arthropathy compared with primary prophylaxis. When delayed until school age or adolescence or until the development of frequent bleeding episodes under on-demand treatment, secondary prophylaxis generally appears to be unable to reverse all existing or developing joint damage. Nevertheless, multiple studies have shown that this therapy can retard further joint deterioration, reduce the frequency of haemorrhage, hospitalization and missed school days, improve physical function and capacity for self care, lessen restrictions on activities, reduce pain and enhance quality of life. Secondary prophylaxis in adults has been shown effective in reducing bleeding episodes. Adults under secondary prophylaxis can also experience improvements in joint condition, functional capacity and quality of life and a reduction in pain. Irrespective of age at initiation, long-term secondary prophylaxis appears to reduce the frequency of bleeding episodes even in patients with existing target joints whose bleeding diathesis persists during the early phases of secondary prophylactic therapy. In light of its potential benefits for substantial numbers of patients with severe haemophilia A, secondary prophylaxis should be considered to as a therapeutic option for patients not receiving primary prophylaxis.