Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, with reference to commissioning criterion 6b of NHS England’s Criteria for the Prescribing of Enhanced Half-Life Blood Factors, published in September 2016; for what reason a maximum conversion ratio from Standard Half Life to EHL products was set; and whether a patient that achieved higher trough levels than before from a narrower conversion ratio would be switched back to their previous regimen.

The maximum conversion ratios were provided by clinical experts based on their experience of managing the clinical needs of most patients. Clinicians manage individual patients to achieve bleed control in line with the British Society of Haematology for trough levels, and bleed levels.

The maximum conversion ratios apply only when switching from standard half-life (SHL) Factor IX (FIX) to and enhanced half-life (EHL) FIX. They do not apply when switching from an EHL FIX to an SHL FIX.

Depending on individual patient need, it is possible that a patient could be switched to a previous or alternative regimen to achieve a target trough level greater than 1%.