Sometimes clinical trials don't go as planned. The National Institutes of Health announced Tuesday that it's discontinuing the low-dose rivaroxaban arm of its ongoing Phase 3 CAPTIVA stroke prevention trial. The decision came after an independent safety review spotted increased safety events and, perhaps worse, a signal suggesting the drug wasn't likely to deliver any real benefit.
The CAPTIVA trial is designed to figure out whether experimental treatment arms using rivaroxaban, ticagrelor, or a combination of both can outperform the control arm using clopidogrel when it comes to reducing the one-year rate of ischemic stroke, intracerebral hemorrhage, or vascular death. It's the kind of study that could reshape how doctors approach stroke prevention, assuming any of the experimental therapies actually work better than what's already out there.
Safety Board Says Stop
The decision to halt the rivaroxaban group wasn't made lightly. It followed a routine evaluation by the study's Data Safety and Monitoring Board, an independent panel whose entire job is watching out for participant safety. After their review, they recommended pulling the plug, and NIH's National Institute of Neurological Disorders and Stroke, which funds the trial, agreed. The rivaroxaban arm hit both safety concerns and a pre-specified futility threshold, meaning it wasn't just potentially dangerous but also unlikely to succeed.
Rivaroxaban is marketed as Xarelto by Bayer AG (BAYRY) and Johnson & Johnson (JNJ). It's already an FDA-approved anticoagulant used to treat or prevent blood clots, so this wasn't some experimental compound. But testing it in a new context for stroke prevention apparently didn't pan out.
What Happens to the Trial Now?
Study sites with participants assigned to the discontinued arm have been instructed to stop administering rivaroxaban. Anyone who already completed their evaluation in that arm will be contacted by their study site. NIH emphasized that participant safety remains the top priority, which is reassuring given the circumstances.
The good news is the trial itself continues. CAPTIVA is designed to determine whether either of two newer treatment strategies is more effective than current standard therapy in preventing recurrent stroke. Up to 1,683 participants are being enrolled across more than 100 sites over four years as part of NIH's StrokeNet network, so there's still plenty of data to collect from the remaining arms.
The Other Contenders
So what treatments are still in the running? The trial continues with these arms:
AstraZeneca Plc's (AZN) Brilinta (ticagrelor) at a 180 mg loading dose, then 90 mg twice daily, plus aspirin at 81 mg daily.
Sanofi SA's (SNY) Plavix (clopidogrel) at a 600 mg loading dose, then 75 mg daily, plus aspirin at 81 mg daily.
The study won't directly pit the two newer therapies against each other. Instead, it's focused on determining whether either offers an advantage over current treatment while generating additional safety and efficacy data. That's a smart design because it answers the question doctors actually care about: is there something better than what we're already using?
The National Institute of Neurological Disorders and Stroke funds both CAPTIVA and the broader StrokeNet initiative, which coordinates stroke research across the country.
Stock Movement: Johnson & Johnson (JNJ) shares were up 1.09% at $240.95 at the time of publication on Wednesday, hitting a new 52-week high according to market data. Apparently investors aren't too concerned about one trial arm getting discontinued, which makes sense given Xarelto is already approved and marketed for other uses.
