Before many drugs are reviewed by the Food and Drug Administration, they face the scrutiny of a panel of experts, industry representatives and patient representatives. While the outcome of the meeting is not the final say in a drug's approval, the advisory meeting is a good chance for a company to state its case and gives investors some insight into expert opinion. That will be the case next week when Chelsea Therapeutics (UNKNOWN:CHTP.DL), Merck (NYSE:MRK), and Johnson & Johnson (NYSE:JNJ) appear before the Cardiovascular and Renal Drugs Advisory Committee.
Will Chelsea Therapeutics get a head rush?
On Jan 14., Chelsea Therapeutics will present the case for its drug Northera to be approved for the treatment of orthostatic hypotension in patients with primary autonomic failure. When healthy individuals stand up after sitting or lying down, tightly controlled neuronal signals make sure that blood doesn't rush to the feet causing lightheadedness. In some patients with diseases like Parkinson's, those signals can't do their job and patients experience a dangerous drop in blood pressure.
Since its first go-around with the FDA in 2012, Chelsea has another phase 3 trial under its belt showing a significant improvement in dizziness versus placebo after one week. That consistency should help Chelsea's case, but there will be a few points the panel could harp on. The first is a statistical quirk arising from a disproportionate number of trial dropouts from the Northera arm of the study. The second is the lack of a long term study of prolonged improvements to dizziness. In its first rejection, the FDA requested a longer two to three-month study, but has since signaled that the additional shorter trial might be sufficient. It is possible that the FDA panel could recommend approval but request post-marketing long-term trials.
Chelsea's stock popped a head rush-inducing 400% in 2013. For that rise to be sustainable, Chelsea has to come through next week in defense of Northera.
Merck's murky trial data
Vorapaxar is designed to reduce the risk of cardiovascular events in patients with a history of heart attack or stroke by blocking the thrombin receptor, a key component of clot formation. Once a blockbuster hope, excitement over vorapaxar has diminished since the artery clearing drug showed an increase in bleeding risk. As is the case with all blood thinners, bleeding risk is a serious safety consideration, and Merck will have its hands full arguing that the benefits of the drug outweigh the risks.
To make its case easier, Merck's application only includes approval for use in patients with a history of heart attack and no stroke. In a prespecified secondary analysis of its huge phase 3 trial TRA 2P, Merck examined the efficacy and safety of this patient subpopulation. In those patients, the drug was still effective at reducing cardiovascular risk and was associated with an increased risk of bleeding, but not intracranial bleeding. That distinction could make the difference in front of an FDA panel, but also limits the approved population should vorapaxar hit the market.
More blood thinners
If panel members didn't get their fill of blood thinners the day before, on Thursday, Jan. 16, they'll hear from Johnson & Johnson's Janssen division, which hopes to expand the label for oral blood thinner Xarelto. Xarelto, marketed overseas by Bayer (OTC:BAYRY), is already approved in the U.S. for indications including stroke and heart attack prevention in patients with atrial fibrillation, deep vein thrombosis, or following hip and knee replacements.
Now, Johnson & Johnson is seeking to include approval for the prevention of thrombotic events in patients with acute coronary syndrome, a much larger population. Johnson & Johnson has had a hard time getting Xarelto approved in this patient population after two FDA rejections. As with vorapaxar, safety is the real issue and will be the main focus of the meeting.
Label expansion could be great news for Johnson & Johnson and Bayer. Xarelto already exists in a crowded market with competitors like generic warfarin, Bristol-Myers Squibb's Eliquis, and Boehringer Engelheim's Pradaxa. An ACS indication would make the drug available to more than 1 million additional patients.