Two more attempts were made to get Glybera passed, both of which were rejected.

FORBES: Europe Takes The Lead Toward Approval Of First Gene Therapy Drug

But getting to this stage has been a challenging journey for Glybera as gene therapy has struggled to get traction among drug regulators.

FORBES: Europe Takes The Lead Toward Approval Of First Gene Therapy Drug

Last month, the European Union approved Glybera for treatment of a rare genetic disease, making it the first gene-therapy medicine approved in the Western world.

WSJ: The Future of Medicine Is Now: Medical Innovations

Winning approval for Glybera proved particularly challenging because the company was only able to test it on 27 patients in clinical trials, due to the rarity of the condition.

MSN: European regulators back first gene therapy drug

This month, a committee from the European Medicines Agency recommended the approval of a gene therapy drug, named Glybera (alipogene tiparvovec), for the treatment of a rare inherited genetic disorder.

FORBES: Europe Takes The Lead Toward Approval Of First Gene Therapy Drug

"Our established ways of assessing the benefits and risks of Glybera were challenged by the extreme rarity of the condition and also by uncertainties associated with data provided, " he said.

MSN: European regulators back first gene therapy drug

Glybera is used to treat lipoprotein lipase deficiency.

BBC: Gene therapy: Glybera approved by European Commission

Tomas Salmonson, acting chairman of the EMA's Committee for Medicinal Products for Human Use, said evaluating Glybera had not been easy and experts had decided it should be recommended only for those patients with the greatest need for treatment.

MSN: European regulators back first gene therapy drug