Enteromedics' Prospects Worsen With FDA Panel Documents' Release

Jun.13.14 | About: EnteroMedics Inc. (ETRM)


Enteromedics' FDA meeting materials on Maestro approval published.

New info: Pivotal trial showed no significant difference from sham on any co-morbidity measure.

Argument to approve despite failing all efficacy endpoints heavily undermined.

Enteromedics (NASDAQ:ETRM) awaits an FDA review on Tuesday June 17th for its obesity device; the broadest characterization to-date for the therapy came out overnight in the briefing materials for that advisory committee panel to consider closely. Several noteworthy new aspects of the therapy's performance have come to light.

The most salient should probably be that the therapy failed to distinguish itself at all from the sham control with regards to co-morbidity, the set of disease states closely associated with obesity and which any obesity therapy looks to have significant impact on.

ETRM's Maestro/VBLOC system came in from the ReCharge study having failed all the primary efficacy endpoints, and this was reiterated in the briefing materials. The main measure of the device's efficacy - difference in %EWL (excess weight loss) treated vs. sham control - came in clearly below target, at only 8.5% more EWL than control, where the FDA-desired goal had been at least 10% more than control. This 8.5%EWL corresponds to 3.1%TBL (total body-weight loss)

Traditionally, the FDA had been looking to see at least 5%TBL over control for weight loss therapies, largely because it is around those levels that significant correlations with significant reduction in co-morbidities begin to occur. But with the ReCharge having failed badly to reach those weight loss levels in the two Phase III trials of Maestro, the argument to approve changed to accepting the lesser efficacy anyway because it was still "clinically meaningful", a characterization which assumes crucially that the clinical goal of reducing those co-morbidities is still in play.

The ReCharge co-morbidity data quantifies four measures - systolic and diastolic blood pressure; HbA1c, a measure important in treatment of diabetes; fasting glucose - and none was able to show any significant difference vs. sham control. All the differences were quite small, perhaps the most damning number was the 0.0% difference in HbA1c. To quote the FDA document cited below:

"As seen in Table 10.9, there were small improvements of various parameters in both the VBLOC group and the sham group from baseline to 12 months, but the change in the VBLOC group was never statistically significantly different from the change in the sham group."

In essence, there seems to be little reason to expect any meaningful clinical efficacy form this device - even less now, than what little was expected from the very poor weight loss numbers of the first two Phase III trials of 0.04%TBL over sham (Empower study, also reviewed in the briefing doc) and 3.1%TBL over sham.

For the full briefing materials, see here.

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