CDU Washington Editor

FDA last month issued a formal guidance on clinical studies and trials for neurothrombectomy devices, but the guidance may simply be a formal statement of long-standing informal agency policy.

The guidance states that eight hours is still the expected window for the onset of treatment after the ischemic stroke event, and recommends that manufacturers should establish “whether your device causes the formation of smaller clots, either during or after its use.”

FDA stated that it is “aware of the difficulty in recruiting subjects for stroke treatment studies” and will “consider various study designs if they are scientifically sound” and include “randomized comparisons to other legally marketed devices or therapies, or concurrent controls” who get the current standard of care.

Follow-up assessment recommendations include the use of angiography immediately following the procedure “to assess the extent of restoration of flow.” The guidance also details the agency’s expectations regarding other neurological imaging assessments as well as evaluations of neurological function, which would come immediately following the procedure, 24 hours after the procedure, seven to 10 days following discharge, and at 30 and 90 days.

Andrew Weiss, president/CEO of CoAxia (Minneapolis), told Cardiovascular Device Update that he was not sure “what prompted [FDA] to issue this guidance,” but that the document reaffirms the agency’s interest in randomized, controlled trials as well as some of the “rational, intelligent things” that devices should be tested for, including “whether flow has been re-established.”

Weiss said “I think this is quite a complete statement,” but “from our standpoint, this is nothing really new.”

He added that one could argue that “they should have done this a few years ago, and my guess is that they’ve got a lot of input from their advisers” thus prompting the formal statement.

The guidance doesn’t change anything at CoAxia, Weiss said. “This is essentially what we’ve been doing the past few years.”

Cook’s Resten-MP trial a new challenge to DES?

The best way to fight instent restenosis is to paint a little bit of drug on your stent — right?

Well, maybe not. How about implanting a bare-metal stent and then following it with a drug.

That could work just as well — or even better, given the recent problems of DES technology — according to a new study just unveiled by Cook Medical (Bloomington, Indiana), indicating BMS first, drug application afterwards can do the job.

Results of Cook’s APPRAISAL trial have shown the positive effects of Resten-MP delivered to a patient following stent placement may be just as effective, or more so, than a drug attached to and eluting from a stent device. Phase II of the trials were held in Germany and France and enrolled about 52 patients taking part in the six-month-study.

The patients suffered from symptomatic ischemic heart disease and the stenotic lesion of native coronary arteries. About 80% of the patients in the study were type B2, C-lesions — some of the more serious cases in cardiovascular illnesses.

In the study, clinicians administered Resten-MP within 60 minutes of successful stent placement in the coronary artery, and again 24 hours later via slow-push intravenous administration.

Resten-MP (AVI-4126) was developed by AVI BioPharma (Portland, Oregon) and licensed by Cook. It is a third-generation antisense agent that targets the key regulatory gene involved in cardiovascular restenosis.

“We’re putting in a bare stent [rather than a DES],” Joe Horn president of Global Therapeutics, a subsidiary of Cook Medical, told Cardiovascular Device Update. “The delivery system is through microparticles or microbubbles. The bare stent bonds with the tissue.”

Besides impacting the current range of first-generation of DES devices, the finding for Resten-MP may cast a shadow over the prospects of second-generation DES devices poised to come online.

“The latest clinical trial results are really promising. We believe that the Resten-MP delivery system eliminates the potential long-term problems associated with the current drug-eluting stent systems available to physicians and patients,” said Stefan Sack, MD, principal investigator at the University Of Essen in Germany (Duisburg, Germany), the study’s main investigative center.

Horn told CDU that if the initial positive result “plays out [in future trials] it would be a monumental change in treating cardiovascular problems.

“We are currently planning for European CE Mark approval.”