Daiichi clot-fighter aces study, but can it compete with Pradaxa, Xarelto and Eliquis?

The good news for Daiichi Sankyo: Its new anticoagulant drug matched the old standard-issue drug warfarin at preventing stroke and blood clots. And as far as safety goes, edoxaban beat warfarin by a significant stretch. That's an entree into the warfarin-alternative market, expected to grow to $10 billion over the next several years.

But the not-so-good fact is that the Daiichi's drug, which it plans to submit for FDA approval early next year, would face some well-established rivals in that very market. First to launch, Boehringer Ingelheim's Pradaxa has been racking up sales in stroke and clot prevention for years now, and it passed the blockbuster threshold last year. Hot on its heels is Bayer and Johnson & Johnson's ($JNJ) Xarelto. And then there's Pfizer ($PFE) and Bristol-Myers Squibb's ($BMY) Eliquis, which had a faltering start but is picking up steam on the strength of an advertising-and-marketing push.

Still, in announcing the results of the Engage AF study at the American Heart Association meeting, lead researcher Robert Giugliano, a cardiologist at Brigham and Women's Hospital in Boston, said he figures edoxaban will catch on. "Personally, I think it will be used," Giugliano said (as quoted by Reuters). "We know this drug is safer than warfarin."

The key question, however is whether it's safer than Pradaxa, Xarelto and Eliquis--and whether it works as well as or better than they do. Yes, even doctors who weren't involved in the Engage study have praised its design and results. But the data supporting Eliquis was widely praised as well. The Xarelto studies? Not so much--FDA reviewers had some pointed questions about that data, in fact--but now that the drug is on the market, that hasn't interfered with J&J and Bayer's ability to gain market share.

Meanwhile, Boehringer has been rolling out new analyses of its RE-LY research, with long-term data supporting safety and efficacy, in an attempt to answer some safety questions that have arisen as the drug rolled out to millions of patients in the real world. Some of that newly released data stretches back as far as 6 years.

Lining up the Engage data against studies supporting the other three drugs may reveal some advantages for one drug or another, under one measure or another. But there are no head-to-head studies pitting these warfarin-alternative products against one another. Distinguishing their individual advantages can be tough for doctors and patients--and for that reason, selling these drugs is a marketing game, Reuters notes. The only truly obvious difference among them is that Xarelto and edoxaban are once-daily pills, while Pradaxa and Eliquis are taken twice daily.

"We see an uphill battle for edoxaban and do not expect the product to meaningfully change market dynamics in the atrial fibrillation space," JPMorgan analyst Chris Schott said (as quoted by Reuters).

Doctors have worried about bleeding and deaths from bleeding in patients on these warfarin alternative drugs because unlike the older drug, they currently have no proven, quick-acting antidotes. Companies are working to develop agents that can counteract bleeding if it occurs; in fact, Boehringer unveiled some Phase I data on its in-development antidote showing that it worked immediately after a 5 minute-infusion. The small study also showed that the antidote completely reversed Pradaxa's anticoagulant effect in all patients given a 4g dose and 7 of 9 patients given a 2g dose.

And in any case, Giugliano told Reuters, the new generation of drugs has plenty of advantages: "They're safer, more convenient to use and there's no need for monitoring," he said. "These drugs dramatically reduce bleeding in the brain. They are saving lives."

- see the Reuters story
- get the release from Boehringer

Special Report: Top 15 Drug Launch Superstars - Xarelto | Top 10 Generics Makers by 2012 Revenue - Daiichi Sankyo

Editor's note: This article was revised to show that Xarelto is a once-a-day pill, rather than twice daily, while Eliquis is taken twice a day, rather than once daily, as previously stated.