The Malmö-Klaipeda WFH twinning programme: a comparative description of the haemophilia cohorts

Current challenges of pharmacovigilance in bleeding disorders: converting the burden to benefit

SUMMARY

Safety surveillance studies have proven essential in research and development of new biological therapies for bleeding disorders as well as other diseases. Although product safety regarding HIV, hepatitis, and other blood-borne infections is currently excellent, potential new infectious agents require continued vigilant monitoring. Inhibitor development is the most common serious side effect of haemophilia replacement therapy. Several aetiological factors associated with inhibitors have been identified, but their true impact is still largely unknown. Moreover, whether plasma-derived and recombinant factor products differ in their immunogenic profiles is an unresolved issue. Coagulation factor products under development and those currently on the market require uniform, long-term surveillance. The European Haemophilia Safety Surveillance (EUHASS) project was recently established to meet these goals. The pharmaceutical industry and clinicians face common challenges complying with these requirements. In rare diseases like haemophilia, obtaining adequate patient numbers poses a challenge. Another challenge is a lack of methods for assessing disease severity, a surprising deficiency in the era of modern medical and laboratory technology. National and international registries can be used to gather required safety surveillance information. Simultaneously, clinicians benefit from well-organized registry data in their daily practice and harmonize the quality of comprehensive haemophilia care by homogeneous follow-up platforms. Experience with such registries comes, for example, from Europe (PEDNET), the USA (CDC/UDC), the UK (UKHCDO), and Sweden (Malmö). It is important to commit to future pharmacovigilance efforts, aiming at high-quality safety surveillance programmes at both the pharmaceutical research community and clinical levels.

Should prophylaxis be used in adolescent and adult patients with severe haemophilia? An European survey of practice and outcome data

A survey of 21 haemophilia doctors, throughout Europe, who care for a total of approximately 5000 patients with bleeding disorders addressing practice and opinions regarding prophylaxis in patients aged 16-24 years and adults aged over 50 years, is presented. The outcome of adolescent patients who reduced or stopped prophylaxis was recorded. Eighteen of 19 respondents would consider modification of established prophylaxis in the adolescent age group, principal considerations being avoidance of risks of further concentrate exposure, predicted poor compliance and treatment costs. The preferred age for modification was 16-20 years, but there was very little consensus on the particular prophylactic regime recommended. Approximately, half of a cohort of 218 patients with severe haemophilia successfully reduced or stopped prophylaxis when they reached adolescence. Only 26 of 92 (28%) of the patient cohort who stopped prophylaxis, required reintroduction of a prophylactic regime and 12 of 59 (20%) of those who reduced the intensity of prophylaxis had to reintroduce a more intensive regime. A majority of respondents would consider starting prophylaxis in those over 50 years. There was no consensus as to indications for this practice or the nature of the prophylaxis protocol. We conclude that there is an absence of consensus on the management of patients with severe haemophilia, as they pass through adolescence and young adulthood, and reach the age of 50. Aggregate outcome data suggest a significant proportion of patients in the 18-22 years age range may be able to reduce or stop prophylaxis. A substantial number of older patients are on prophylaxis.

The risk associated with indwelling catheters in children with haemophilia

Infections are the most frequent complications associated with the use of central venous lines (CVLs) in children with haemophilia. Several retrospective studies that include data from a substantial number of patients have reported approximately 0.2-0.3 infections per 1000 catheter-days (mainly Port-A-Cath). Some studies have shown a much higher frequency of infections, 1-2/1000 catheter-days. The most plausible explanations, for the difference seen in frequency of infections with Port-A-Caths, are probably related to the protocol used for the device care and the quality of education and the compliance of the users, whether these are parents or health-care professionals. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not performed in most of these series. In studies, where this has been performed, a high frequency of abnormalities (>50%) on venograms have been seen in some series but not in others. Despite obvious potential risks with CVLs, they are useful in many cases and facilitate the treatment of a serious disorder. With careful guidelines and surveillance protocols, the risk of complications should be reduced in the future.

Towards achieving global haemophilia care--World Federation of Hemophilia programmes

The overall purpose of the 'Decade Plan' published in 1992 was to do everything possible to make effective treatment available to people with haemophilia throughout the world. In 1990 it was estimated that there were 350,000 individuals with haemophilia worldwide, with 80% or 280,000 without treatment. By the year 2020 this may have reached the figure 440,000, or the population of Jerusalem. Earlier this century Carroll Birch reported a series of 113 patients where 82 died before their 15th year, and only six survived beyond 40. Thus as Jones has pointed out for the developing world this is a paediatric problem for the WFH to face now. The examples described in this paper illustrating the WFH programmes and the commitment of many people from the 88 member organisations worldwide as well as the doctors and scientists shows what can be done through cooperation. There is no doubt that these achievements are capitalising from the unique quality of WFH from the beginning, that is a membership which includes both those with haemophilia and their families, and those with an interest in treating haemophilia.