Continuing a lengthening saga to win U.S. approval for its cryoablation system in the treatment of atrial flutter (AFL), CryoCor (San Diego) yesterday reported that the FDA will now convene an advisory panel meeting to review the company's premarket approval application (PMA).

The FDA's decision is the latest turn in a series of developments stretching back to early last year, and must come as a bit of a blow to the company, considering that the agency told it in February that it did not believe it would need to convene an advisory panel meeting for the company's PMA for this application.

The company has developed a cryoablation system designed to treat cardiac arrhythmias through the use of cryoenergy, or extreme cold, to destroy targeted cardiac tissue.

It received a "not approvable" letter from the FDA in February 2006 (Medical Device Daily, Feb. 6, 2006) for its AFL PMA, because, according to the agency, the data presented did not meet "chronic efficacy" criteria, the criteria the company used in its trial supporting the application.

At the time of the "not approvable" letter, CEO Greg Ayers, indicated that the primary reason for the agency's decision was based on the "subjective" method required for interpreting chronic efficacy.

"The process requires complex interpretation of clinical data and can result in different interpretations as to the results," Ayers said.

"We provided analysis of our chronic data, based on what we feel were appropriate classifications of the patients and measures of effectiveness of our ablation procedure, based on clinical experience with similar patients treated with our systems outside the U.S. and with our clinical interpretation of the patients in this trial and their post-procedure clinical course."

This turn of events caused the company to amend its PMA filing for the device which is already approved in Europe for the treatment of atrial fibrillation and AFL, which are the two most common forms of heart arrhythmias.

The company said it expects the panel meeting to be held in June or July, with a decision from the FDA on the application expected in August.

The company did not return calls for additional comment.

Before the FDA told the company it might not need a panel meeting, it had been scheduled to go before the agency this month, which could have moved up its approval timeline.

The company probably needs this submission to work if it is going to continue on with any real traction, since at the end of March it disclosed that its annual report contained a "going concern" qualification. The company said it had sufficient working capital to fund its operations until December 2007 and to pay off its existing debt.

Additional capital would be needed to fund operations in 2008, the company said in a statement.

Helen Barold, MD, chief medical officer of CryoCor, said in a statement, "The FDA has stated that, as cryoablation is a new medical technology for the treatment of atrial flutter, it intends to convene an advisory panel to advise on our chronic effectiveness results. We look forward to presenting all of our data to the advisory panel." He added that the company "strongly believe[s] that our clinical data demonstrate a reasonable assurance of safety and effectiveness, and believe our device has an important role in the clinical arena for physician's use in treating patients."

CryoCor reported that the chronic effectiveness of its cryoablation system, based upon a strict expert core lab analysis completed by an independent electrophysiologist, was statistically computed to be above 80%. An additional analysis performed utilizing a clinical assessment that the company believes is comparable to the analysis from published literature demonstrates a chronic effectiveness above 90%. CryoCor believes the use of an expert core lab to determine the chronic effectiveness is a more rigorous evaluation than has been completed in other clinical trials for the treatment of AFL.

Gregory Feld, MD, the principal investigator for CryoCor's AFL pivotal trial said in a statement that he is excited to participate in the presentation of clinical data on behalf of CryoCor at the upcoming advisory panel meeting. "I believe it is important to make this new medical technology available as an alternative to existing treatments, as there are specific atrial flutter patients that would benefit from cryoablation therapy."

CryoCor is also conducting a pivotal trial in the U.S. to evaluate the safety and efficacy of the cryoablation system for the treatment of atrial fibrillation.