Running a large, expensive cardiovascular study is no easy feat for a small biotech. That’s why the $24.3 million Armetheon raised in a Series B round last week is likely a harbinger of things to come.
Armetheon may seek $30 million to $40 million more to run the 3,000-patient Phase 3 trial it’s kicking off for its prospective anticoagulant drug, tecarfarin, according to M. (Ken) Kengatharan, the president and COO of Menlo Park, CA, based Armetheon. Where might that money come from? Probably not venture capital, the source of the round Armetheon closed this week, Kengatharan says.
“[VCs] are one avenue, but I think we may have passed them already because we’re not a start up anymore,” he says, noting that pharma partnerships, an IPO, and private equity backers are “all being considered right now.”
Tecarfarin has been on this stage before. It failed a clinical trial in 2009 when it couldn’t beat warfarin—an anticoagulant drug that’s been around for decades—head to head. That led its original owner, ARYx Therapeutics, into a tailspin it never recovered from, closing down for good in 2011.
ARYx’s executives, however, didn’t give up. Founder Peter Milner took the drug over to a new company, Armetheon, in 2011. And the startup has found a new way to breathe life into tecarfarin by targeting a specific group of patients that don’t respond well to warfarin.
Anticoagulants are given to patients to prevent blood clots that can be caused by heart rhythm disorders, mechanical heart valves, and a variety of other conditions. While warfarin is a staple treatment, it has its flaws. It doesn’t react well with some other drugs. Warfarin can be difficult to control because of the unpredictability of the enzyme that metabolizes it — a so-called CYP enzyme that also metabolizes many other drugs — and its use can lead to severe bleeding or stroke, Kengatharan says.
Tecarfarin, a vitamin-K antagonist like warfarin, is designed to avoid this problem because it is doesn’t use the CYP enzyme, he says.
Armetheon’s new Phase 3 test will once again pit tecarfarin against warfarin. Armetheon and the FDA have negotiated a “special protocol assessment” for the study—an agreement up front about the key elements of a clinical trial, like the main goal and the statistical analysis plan. Armetheon’s task: prove tecarfarin is safer and more effective than warfarin in patients who have the worst response to warfarin.
“All we have to do is follow that SPA very closely, and If the data holds, then the approval should come through,” Kengatharan says.
Succeeding would help differentiate Armetheon’s drug from the pack, in particular for specific types of patients, such as those with prosthetic heart valves. Kengatharan notes that the two most recently approved anticoagulant drugs, the Factor Xa inhibitors rivaroxaban (Xarelto, approved in 2011) and apixaban (Eliquis, approved in 2012), are not recommended for heart valve patients. With warfarin as the only other option for patients, tecarfarin could feed demand from those who need a blood thinner and respond poorly to warfarin.
Kengatharan has bigger plans for tecarfarin than just patients with prosthetic valves, which account for about just 15 percent of the anticoagulant users in the U.S. Armetheon wants to see the drug approved for any patient needing an anticoagulant; he says that tecarfarin can be “complementary” to the Factor Xa inhibitors and warfarin.
But first thing’s first: beating warfarin head to head, the way ARYx couldn’t. Kengatharan is optimistic that the drug will finally find a niche.
“Whether it’s those new agent drugs or warfarin, there’s a whole population that need anticoagulants,” he says. “Anyone with a heart valve has to take an anticoagulant for the rest of their lives, every day. They only have warfarin.”
The $24.3 million of new funding was led by Hercules Bioventure Partners and Capital TEN II. Other investors included China Development Industrial Bank Healthcare, CDIB & Partners, iD SoftCapital Group and AmKey Ventures, as well as individuals Larry Hsu and Stefan Roever. Hsu is a general partner at Hercules and Capital TEN.
