Vertex shares slide as analysts query final data on PhII CF trial

Vertex ($VRTX) today opened the door on a key part of final results for a mid-stage combo study of its two cystic fibrosis drugs, mapping out its late-stage strategy on a program that has built up hopes for a potentially blockbuster pioneering treatment.

Investigators for the company say they've assembled some impressive data in Phase II. Adding to the interim picture presented last month, the combination of VX-809 and Kalydeco in a 600 mg dose delivered a 6.7% improvement in lung function when compared to the placebo results. In the drug treatment group, the improvement was 3.4%. Both figures are statistically significant. In the placebo group patients experienced a 3.3% decline in lung function. 

Given the snafu over the interim data, when the company unexpectedly had to go back and revise outcomes, the numbers are also likely to be rock solid. But analysts swiftly began to query the data, puzzled that the company wasn't offering a strictly comparable look at the interim and final data.

"This non apples-to-apples disclosure has created investor doubt that the data are 'real,'" noted ISI's Mark Schoenebaum, according to a Reuters story. And Vertex shares took a nasty hit on those doubts, sliding more than 10% this morning.

That 600 mg dose is the highest dose in the study. The data on the other two doses were not discussed, raising some eyebrows among the Twitter crowd. But Vertex is looking to advance a breakthrough treatment for the most common genetic defect that triggers CF, and a clear success in a mid-stage study dominated the analysis of today's results. Vertex did report, though, that the results for the other two doses did come in as statistically significant.

"We are focused on developing additional medicines to treat the underlying cause of cystic fibrosis, and these data represent exciting progress toward that goal," said Chris Wright, Vertex's senior vice president, global medicines development. "The data announced today show that the addition of Kalydeco to VX-809 resulted in improvements in lung function and support our plans to start a pivotal program in people with cystic fibrosis who have two copies of the most common CFTR mutation in early 2013."

- read the press release
- here's the Reuters story
- get the story from TheStreet

Related Articles:
Vertex stock sales questioned after CF data gaffe
Bungled analysis forces Vertex to revise cystic fibrosis drug data
Vertex finds key support for cystic fibrosis drug in Europe

Suggested Articles

Fifteen of the 22 patients in a gene therapy trial no longer needed transfusions, while the remainder needed fewer transfusions.

Argos Therapeutics is ending its kidney cancer trial and mulling options, including a merger or sale, to stay alive.

CNS Pharma says berubicin is the first anthracycline drug to cross the blood-brain barrier and could transform treatment of the highly invasive brain tumor.