Xarelto backed for ACS ahead of FDA advisory panel

Documents released by the FDA ahead of an upcoming advisory committee meeting indicate that the agency supports extending the indications of Johnson & Johnson/Bayer's Xarelto to include patients with acute coronary syndrome (ACS).

J&J and Bayer submitted Xarelto (rivaroxaban) for approval late last year for use in combination with standard antiplatelet therapy to reduce the risk of secondary cardiovascular events in patients with ACS.

At the time, the companies said the drug was the first oral anticoagulant to be filed for use alongside aspirin and clopidogrel - so-called dual antiplatelet therapy - in ACS patients.  If approved in ACS, Xarelto would tap into a new market estimated as being worth up to $1bn a year.

Xarelto's application in ACS is based on the results of the 15,000-patient ATLAS ACS 2 TIMI 51 trial, which showed that the drug reduced the risk of both all-cause and cardiovascular mortality by 16 per cent compared to placebo but also increased the risk of bleeding and intracranial haemorrhage.

A briefing document posted on the FDA's website indicates that the agency reviewer supports approval but has requested advice on a number of issues relating to the trial, including "substantial missing data" relating to patient follow-up and other issues.

The reviewer notes that "poor follow-up, predominantly attributed to withdrawal of consent, has been a distressing trend in recent cardiovascular outcomes trials."

However, the reviewer determines that the trial's sponsors had "made a reasonable effort to obtain vital status information on these subjects."

Issues for discussion noted the document include an inconsistency in clinical findings between doses of Xarelto - which raise questions about the biologic plausibility of the study results.

Specifically, the reviewer points out that the efficacy of the lower 2.5mg dose accounted for by a reduction in cardiovascular death, while the higher 5mg dose was attributed mainly to lower rates of myocardial infarction.

The document also suggests that the data is not sufficiently strong to support a mortality claim on Xarelto's labelling, although this will be voted on by the panel.

The FDA's Cardiovascular and Renal Drugs Advisory Committee (CRDAC) is scheduled to discuss the application on Wednesday May 23, 2012.

Two other anticoagulants in the same Factor Xa inhibitor class, Bristol-Myers Squibb/Pfizer's Eliquis (apixaban), and Astellas' darexaban, have been blocked from securing approval in ACS because of bleeding complications.