It held out the tantalising promise of being the first marketed gene therapy product in the west, but the failure of Ark Therapeutics' product for malignant glioma, Cerepro, to gain approval from the European regulator has once again highlighted the difficulties inherent in developing these novel therapies (Ark sinking after EU rejection, December 18, 2009).

Cerepro had been the great white hope of the space and its knock back is likely to have dented confidence of an approval for a gene therapy product anytime soon. An analysis from EP Vantage shows that while there is definitely interest in the space with an impressive 133 products either in the clinic or listed as research projects, this is more than counterbalanced by the high failure rate of treatments (see table below).