UK drug giant GlaxoSmithKline and US partner Genmab received a boost on Friday after advisors to the European Medicines Agency recommended approval of Arzerra for leukaemia.

Shares in Genmab were on the rise after the Committee for Medicinal Products for Human Use gave its backing to the conditional approval of Arzerra (ofatumumab) for the treatment of refractory chronic lymphocytic leukaemia, but only in the 25% or so of patients do not respond to the standard therapies fludarabine and alemtuzumab.

Conditional marketing authorisation can be assigned to drugs with positive benefit/risk profiles that address an unmet medical need when the benefits of their immediate availability outweigh the risks of insufficient data for full approval. Consequently, under the associated conditions for such approval, GSK will be required to submit further data for Arzerra to the EMEA.

Arzerra is a monoclonal antibody that triggers the body’s immune system to fight against normal and cancerous B-cells. It has a unique mode of action, attaching itself to the small and large loop epitopes on a molecule called CD20, which is found on the surface of B-cells, the type of cell which becomes cancerous in CLL, and was approved by regulators across the Atlantic in October last year.

GSK purchased the global rights to Arzerra back in December 2006 in a deal valued at over $2 billion, and analysts expect the drug to pull in annual sales of around $465 million by 2013, according to Reuters.