Cardiome shares drop on heart drug test data

TORONTO--Cardiome Pharma Corp.'s shares dipped more than 10 percent on Wednesday after reporting mixed phase 2a results for a treatment for abnormal heartbeats, which fell short of investor expectations.

The study of the investigational drug RSD1235 for the conversion of atrial fibrillation showed that 61 percent of patients in the 300 mg dose completed the study with a normal heart rhythm, compared with 43 percent of all patients receiving a placebo.

Patients in the 600 mg dosing group also showed a 61 percent occurrence of normal heart rhythm compared with 43 percent of patients receiving a placebo, but fell short of expectations on a key comparison.

The data was in line with similar preliminary data Cardiome reported in late July, which sent the stock soaring almost 35 percent in one day after the numbers were released.

Cardiome shares were down C$1.67, or 11.2 percent, at C$13.27 on the Toronto Stock Exchange at midday on a volume of 429,000 shares. On Nasdaq, the shares were off $1.50, or 11.3 percent, at $11.81.

Analysts said investors were looking for improved results above the reported 61 percent in the 600 mg range, from the latest tests.
"This is a continuation of the interim results. I just think that the market got overly enthusiastic with the interim results and we were looking for something much better," said John Maletic, an analyst at Scotia Capital in Toronto.

The Vancouver, British Columbia-based company said 171 patients were successfully cardioverted after the initial three days of dosing and continued in the study, of which 159 either completed the dosing or relapsed to atrial fibrillation.

The remainder of the patients were discontinued from the study for reasons unrelated to atrial fibrillation.

The company said the safety data for both dosing groups suggests that RSD1235 appeared well-tolerated within the target population.

The company also said there were no cases of drug-related "Torsades de Pointes", a well-characterized arrhythmia which is an occasional side effect of some current anti-arrhythmic drugs.

Karl Keegan, an analyst at Canaccord Adams, said the market overreacted to the news.



So what happened? First of all, atrial fibrillation is the rapid, sometimes uncontrolled beating of the upper chambers of the heart. These rapid beats are related to electrical malfunctions in the heart. [I personally have these all the time from a related syndrome termed WPW]. Most anti-arrhythmic drugs are beta-blockers, which bind to beta adrenergic receptors in the heart and control calcium channel release. RSD1235 works in a similar way but blocks potassium channels in the upper chambers of the heart (atria).

The side effect mentioned of Torsades de Pointes is a drug side effect that affects the ventricles of the heart along with the atria, thus causing ventricular tachycardia which is not good. This tells me that RSD1235 is very specific for its target receptor.

As far as the market overreacting to the news from July trials, how often have we seen that? The drug not meeting efficacy to a significant number happens all the time and should have been factored into the stock price before this.