This report details a case study for assessing the benefit-risk balance of efalizumab (Raptiva) for the treatment of moderate to severe plaque psoriasis in patients who have failed to respond to, or who have a contraindication to, or are intolerant to other systemic therapies including cyclosporine, methotrexate and PUVA. The comparison is made against placebo and the perspective used is the Regulator's one.

The drug was approved in EU in September 2004; the license was suspended by CHMP in February 2009 because of a negative benefit-risk balance following the accrual of serious side-effects emerging in post-marketing period. The last risk reported before Market Authorisation suspension was an emerging risk of PML (Progressive Multifocal Leukoencephalopathy) a rare but potentially fatal neurological disorder.

The evolving trade-off between a modest efficacy of this monoclonal antibody in a non-fatal disease, and the post-marketing emergence of serious side effects, made this example a useful case study for the testing of Benefit-Risk models.

The key question addressed was: are there in January 2009 any risk minimisation measures which could be rapidly implemented, this maintaining the B-R balance of the drug as positive. If not, shouldthe Marketing Authorisation be suspended/revoked?

The following pages provide a summary of the methodologies tested, lessons learnt and key messages from this case study.

The full Efalizumab Case Study report can be downloaded from here.