What's Happening at the FDA with Rivaroxaban?

Last month, the FDA panel (which included clinical experts) voted 15 to 2 in favor of rivaroxaban (which may get marketed as Xarelto by Bayer and J&J if it receives FDA approval). What's going on at the FDA this month?

Speaking of new anticoagulants, Pradaxa or dabigatran etexilate is another agent that may be nearing approval. This drug is made by Boehringer Ingelheim and has received maketing approval by the European Commission. Unlike rivaroxaban (which is an oral factor Xa inhbitor), dabigatran is an oral direct thrombin inhibitor (DTI). Both are oral pills and both may someday replace warfarin (Coumadin) if they receive FDA approval for anticoagulation.

There's always a bleeding risk associated with an any anticoagulant drug, so the big question is whether the risks outweigh the benefits. Let's hope that these drugs don't follow the same fate as ximelegatran (Exanta).

Rivaroxaban to be Reviewed by the FDA Panel on March 19

March 19 is match day for 4th year medical students. It's also the day when the FDA Panel is supposed to review the anticoagulant rivaroxaban (also known as BAY 59-7939 or Xarelto). It is an oral, direct Factor Xa inhibitor (I don't think I'll ever forget that coagulation cascade diagram that I learned in medical school). If approved, this drug could shut down all those coumadin (warfarin) clinics out there that monitor blood INR in people taking this vitamin K antagonist. Rivaroxaban would not require any blood monitoring. Plus, all those home INR tests manufacturers would need to look for something new to do.

I think everyone is wondering how the FDA will react to this new medication. If approved by the FDA, rivaroxaban will be sold in the US for short-term use as a prophylactic anticoagulant for patients undergoing knee- and hip-replacement surgeries. I'm sure the drug manufacturers will go for additional indications later on. Rivaroxaban is manufactured by Bayer and will be marketed by Ortho-McNeil Pharmaceutical which is a Johnson & Johnson group.

Are the Days of Coumadin Over?

I know someone on a personal basis (not a patient) who used to take Coumadin for recurrent DVTs. His INR used to go all over the place because he would alter his diet and start new medications that often interacted with Vitamin K. Back in those days, physicians used to dream about a magic pill that didn't require any INR monitoring and that would provide optimal anticoagulation to prevent DVTs. Many people are now wondering, "Is rivaroxaban/BAY 59-7939/Xarelto the first pill that will replace Coumadin and eliminate routine INR monitoring?" I'm very eager to see how other oral factor Xa inhibitors will compare. Is factor Xa inhibition the ideal mechanism? What about factor IIa? Direct thrombin inhibitor? The world of pharmacology is changing so rapidly that it's impossible to keep up with all these changes.