Insmed shares routed on head-to-head antibiotic Phase III results

Bright and early this morning Insmed ($INSM) announced that its inhaled antibiotic Arikace hit its primary endpoint in a Phase III study and was awarded fast-track status at the FDA. But investors weren't in a party mood after they picked through the data.

Instead, Insmed's shares were routed today, swiftly plunging more than 25% as investors concluded that its once-daily Arikace didn't quite compare so favorably to twice-daily Tobi from Novartis ($NVS) when it came to treating Pseudomonas aeruginosa in cystic fibrosis patients.

A set of slides comparing the data from the study made it clear that Arikace patients did a little worse than those in the Tobi arm. And there were more serious adverse events for the Arikace group as well. So even though the treatment was statistically equivalent, Insmed also just helped prove Tobi's (slight) superiority.

Insmed shifted focus to concentrate most of its resources on this Phase III study, which is crucial to the company's future. And investors were quick to pick up on the implications after they took a closer look at the head-to-head data.

Insmed's release, though, trumpeted a number of bullish remarks indicating that the treatment should be on its way to a potential approval.

"The study achieved its primary endpoint and suggests that once-daily Arikace treatment was comparable to twice-daily Tobi treatment, the current gold standard of care for cystic fibrosis patients with Pseudomonas aeruginosa lung infections," said Felix Ratjen, a professor at the University of Toronto Hospital for Sick Children and co-chair of the study steering committee. "These results provide hope that an inhaled aminoglycoside that requires only once-daily dosing may be added to the toolbox of available therapies for physicians to treat cystic fibrosis patients who suffer from chronic Pseudomonas aeruginosa lung infections." 

- here's the press release
- here are the data slides
- here's the report from TheStreet

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.