Why Is Gastrointestinal Healthcare Focused Ironwood Pharmaceuticals Stock Sinking On Thursday?

Ironwood Pharmaceuticals Inc IRWD released topline results from its pivotal Phase 3 STARS trial of once-weekly subcutaneous apraglutide in reducing parenteral support (PS) (drugs given by routes other than the digestive tract) dependency in adult patients with short bowel syndrome with intestinal failure (SBS-IF). 

SBS-IF, a rare and severe organ failure condition in which patients are dependent on PS, affects an estimated 18,000 adult patients in the U.S., Europe, and Japan. 

The trial met its primary endpoint of relative change from baseline in actual weekly PS volume at week 24, comparing apraglutide versus placebo (-25.5% vs. -12.5%).

In addition, there were four key secondary endpoints evaluated in statistical hierarchy. 

Apraglutide demonstrated statistical significance for the first two key secondary endpoints, with more patients in the combined population achieving at least one day/week off PS relative to baseline at week 24 versus placebo (43.0% vs. 27.5%; p=0.040) and more patients treated with apraglutide versus placebo demonstrating improvement in relative change from baseline in actual weekly PS volume at week 24 in the stoma population (-25.6% vs. -7.8%; p<0.001). 

The third and fourth key secondary endpoints were specific to colon-in-continuity patients in assessing at least one day/week off PS versus baseline and reaching enteral autonomy at week 48, which were not achieved. 

Probably, shares tanked because of this endpoint miss.

Apraglutide was numerically favorable but not statistically significant relative to placebo for improving days off PS (51.8% versus 44.4%) and reaching enteral autonomy in seven out of 56 (12.5%) patients versus two out of 27 (7.4%) patients on placebo. Apraglutide was generally well-tolerated.

Ironwood Pharmaceuticals added apraglutide to its portfolio when it acquired VectivBio for $17.00 per share in an all-cash transaction with an estimated aggregate consideration of approximately $1 billion, net of VectivBio cash and debt.

Ironwood plans to submit a new drug application and other regulatory filings for apraglutide for use in adult patients with SBS who are dependent on PS. 

Ironwood looks forward to presenting additional data from the STARS study at upcoming medical conferences later this year.

Price Action: IRWD shares are down 39.50% at $9.15 on the last check Thursday.

Photo by hans-reniers for Unsplash