FDA panel backs wider use of Vertex cystic fibrosis drug

More cystic fibrosis patients in the US should be eligible for treatment with Vertex Pharma's Kalydeco therapy, according to an FDA advisory committee.

Yesterday the expert panel voted 13 to two in favour of extending the indications of Kalydeco (ivacaftor) to include patients aged six and older with a mutation in the R117H gene, who number around 500 in the US.

The positive recommendation came despite Kalydeco missing its primary endpoint in a clinical trial involving CF patients with R117H mutations, failing to show a significant improvement in lung function, although the drug did show efficacy in a subgroup of adults with CF in the trial.

Panellists recognised that there is a critical unmet medical need for CF treatments, according to analysts, which said this bodes well for Vertex efforts to expand use of the drug in future.

"Today's recommendation is a positive and important step toward making ivacaftor available for people ages six and older with the R117H mutation," said the company's chief medical officer Jeffrey Chodakewitz.

Kalydeco has been on the US market since early 2012 for patients with several other CF mutations, with Vertex estimating that these cover a patient population of around 2,600 across North America, Europe and Australia.

With an annual price tag of around $300,000 the drug has quickly become a major earner for the US company, bringing in more than $210m in the first six months of this year, and analysts have suggested the new indication could add another $160m to peak sales.

Vertex's strategy with the drug is to progressively expand its use into other forms of CF, and the company is currently conducting a trial in CF children aged two to five as well as exploring longer-term treatment.

It is also developing a combination of Kalydeco and lumacaftor (VX-809) and has a follow-up corrector compound called VX-661 coming through the pipeline which is being tested in a phase II trial.

In June the company reported positive data from two phase III trials (TRAFFIC and TRANSPORT) of the Kalydeco/lumacaftor combination in patients with two copies of the F508del mutation, the most common form of CF, and is expecting to file for approval before the end of the year.

The combination could eclipse Kalydeco as a monotherapy because the F508del mutation affects more than 28,000 people worldwide. ISI Group analyst Mark Schoenebaum said recently Vertex's CF franchise could boost the company's sales to $5.5bn by 2020.