Bayer/J&J's Xarelto matches warfarin in Phase III ROCKET-AF, but full results at AHA
This article was originally published in Scrip
Bayer has frustrated investors by providing "preliminary" ROCKET-AF information on its factor Xa inhibitor in development with Johnson & Johnson – specifically, that rivaroxaban (Xarelto) has been shown to be non-inferior to standard therapy, warfarin, in preventing strokes in patients with atrial fibrillation.
Full results from the key Phase III study will not be presented until 15 November at the American Heart Association (AHA).
Investors are anxious for more details – now that Boehringer Ingelheim has beaten all rivals with the first warfarin replacement, Pradaxa (dabigatran). Late last month, Pradaxa gained FDA approval for stroke prevention in patients with AF, and has been shown to be superior to warfarin (scripintelligence.com, 25 October 2010).
In a very brief announcement, Bayer stated, "Rivaroxaban has met its primary efficacy endpoint vs dose-adjusted warfarin. The rates of the composite of major and non-major clinically relevant bleeding were comparable".
ROCKET-AF randomised more than 14,000 patients with non-valvular AF to either rivaroxaban or warfarin. The goal of the study was to establish the non-inferiority of rivaroxaban to warfarin. The primary efficacy endpoint was a composite of all-cause stroke and non-CNS systemic embolism. The primary safety endpoint was the composite of major and non-major clinically relevant bleeding events.
Leerink Swann analysts have commented that the announcement that the trial established non-inferiority may suggest that rivaroxaban was not superior to warfarin and that "this will be viewed as a relative disappointment" by investors. Clearly, with the scant information so far presented, the AHA late breaker session on 15 November when more data will be revealed will be eagerly followed by analysts and investors alike.
Until more data are revealed, the exact competitive positioning of rivaroxaban will remain unclear.
Another Factor Xa inhibitor that is being watched closely is apixaban, under joint development by Bristol-Myers Squibb and Pfizer.
The partners have filed a rolling submission for its Factor Xa inhibitor apixaban based on Phase III data showing the product was superior to aspirin for prevention of stroke in patients with AF who are unable to take warfarin (scripintelligence.com, 1 November 2010). Previously, it was not known how quickly the FDA submission could be, or whether BMS would wait for additional pivotal trial results. Patients with AF face a risk of clots as blood collects in the upper chambers. Physicians currently rely on aspirin and warfarin.
Prevention of strokes in patients with AF is by far the bigger opportunity for the new anticoagulants.
But rivaroxaban was shown to be non-inferior to standard therapy with Sanofi-Aventis's Lovenox (enoxaparin) and warfarin in a Phase III trial, EINSTEIN-DVT, testing it as a treatment for deep vein thrombosis (scripintelligence.com, 6 August 2010).
Rivaroxaban and dabigatran have already been approved in the EU for the prevention of venous thromboembolism (VTE) in patients who have had elective total hip or knee replacement surgery. Rivaroxaban was rejected for the same indication in the US last year. The FDA reportedly did not ask for new clinical or non-clinical studies to evaluate efficacy or safety, but did request additional data from completed and ongoing studies of the drug (scripintelligence.com, 15 July 2009). Bayer will be responding to the FDA later this year.
You may also be interested in...
ChemoCentryx has successfully completed its initial public offering on Nasdaq, raising $45 million to help support its multiple R&D programmes. It sold 4.5 million shares at $10, a somewhat less ambitious debut than it had originally planned in January when it wanted to sell four million shares at $14-$16. The reduced offer is a sign of the challenging nature of the IPO market, but ChemoCentryx's assessment of its own worth was at least closer to the market’s assessment that Cempra which got its IPO away on 6 February at valuation that was less than two-thirds of that implied by its initial prospectus (scripintelligence.com, 7 February 2012).
Ampio Pharmaceuticals, a development-stage company, initially raised $15 million which was boosted to $16.9 million by the exercise of overallotments by brokers. The shares were offered at $3.25, an 8.5% discount to the closing price of $3.66 on 12 July. The market pushed them down slightly further to 3.21 on 13 July.
Verastem, a cancer stem cells startup, has moved quickly to build its pipeline just five months after an initial public offering. Management at the Cambridge, Massachusetts firm believes that recent moves have accelerated Verastem's clinical development plans by a year.