UPDATED: Rockwell's dialysis drug wins an FDA OK, despite lingering doubts

Rockwell Medical has overcome some hard questions and lingering doubts about its iron-replacement drug for dialysis patients, winning a long-sought FDA approval for Triferic and providing the biotech a green light to begin its marketing campaign.

The Triferic application raised some troubling issues at the FDA, which were flagged in a critical internal review of the therapy. The drug hit its primary endpoints for raising hemoglobin and serum iron in CKD patients. But remarkably, fewer than one in 5 of the patients in those Phase III studies actually reached the 48-week finish line for therapy. Close to half of them didn't get to 20 weeks, with a large concentration of the dropouts needing to treat anemia with erythropoiesis-stimulating agents (ESAs)--even though Rockwell wanted to market the drug based on its ability to forego ESAs.

The missing data caused fretful regulators inside the FDA to question whether Rockwell had the results needed to make its case. But a majority of outside experts voted 8 to 3 in favor of the drug, and the FDA officially agreed.

Doubts about the drug's market potential have cascaded into lower projections of the drug's peak sales potential. FBR Capital's Andrew Berens recently noted that without a chance to tout the drug's ability to reduce the use of ESAs, the top annual take was likely only about $202 million, lowering an earlier target of $364 million. That's on the low end of a range of estimates that stretch from $200 million to $250 million, which are all well below Rockwell's projection of $300 million to $600 million in the U.S. and more than $1 billion worldwide, as cited by Reuters.

Shares of Rockwell Medical shot up about 18% in morning trading, but the company couldn't hold on to the gains for very long. By the end of the day, Rockwell's shares were slightly in the red.

Rockwell CEO Robert Chioini

"It is the first drug approved to replace ongoing iron losses and to maintain hemoglobin levels in hemodialysis patients," said Rockwell CEO Robert Chioini in a statement. "Triferic's unique ability to be delivered via dialysate and to deliver iron without increasing iron stores strengthens its potential to become the market-leading iron therapy treatment for hemodialysis patients. We view today's FDA decision as a major development both for Rockwell and for the entire hemodialysis patient population who now have a significantly better treatment option for addressing their iron losses. We are highly confident in executing a successful commercial launch and penetrating the market."

- here's the release