Theravance shares tank on troubling study results for Relovair

by Suzanne Elvidge and John Carroll

Shares of GlaxoSmithKline ($GSK) caught a chill this morning after investigators released mixed late-stage data and flagged troubling safety concerns for its COPD and asthma therapy Relovair. Shares of the pharma giant slipped a bit as analysts raised concerns about pneumonia-related deaths in a study. But its biotech partner Theravance ($THRX) suffered a much more painful slide as the news wiped out more than a third of its stock value in a matter of minutes.

Officially, GlaxoSmithKline and Theravance maintained an upbeat tone today, noting that the study results warrant the treatment's submission to regulators for an approval. Relovair is their crucial next-gen drug for their blockbuster treatment Advair. But investors were much less sanguine, possibly because they began to discount the persistent rumors that Glaxo would likely buy Theravance in the wake of a successful clinical program.

In both studies for COPD, Relovair reduced the annual rate of worsening of disease (exacerbations) compared with vilanterol alone--however, in one study, the reduction for the highest dose wasn't statistically significant. GlaxoSmithKline is also looking at drug safety after reports of fatal pneumonia at the highest dose. For both COPD and asthma, at the lowest dose, Relovair didn't meet the threshold for demonstrating superiority over Seretide (fluticasone propionate/salmeterol).

Relovair is in development as part of a collaboration between GlaxoSmithKline and Theravance, and the two companies "believe that it is appropriate to request that regulatory authorities review the totality of the exacerbation data, including the effects seen across both studies for the 100/25mcg dose," according to GlaxoSmithKline's press release.

The company plans submissions for COPD for the US and Europe for mid-2012. The expectation for asthma is to submit an application in Europe in mid-2012, followed up with a submission in the USA after discussions with the FDA.

- here's the GSK release