SAN FRANCISCO – Mitraclip from Abbott Park, Ill.-based Abbott Laboratories, has long been the only minimally invasive mitral valve repair device that's approved by the FDA. Edwards Lifesciences Corp., of Irvine, Calif., aims to challenge that dominance with its Pascal. This week at the Transcatheter Cardiovascular Therapeutics (TCT) conference, positive one-year data from the small CLASP study on Pascal were presented, offering a further glimpse of data for comparison.
Basis for contrast
The presenter cautioned that any contrast between Mitraclip and Pascal is premature ahead of results from head-to-head studies. Edwards is conducting a pair of noninferiority studies, CLASP IID and CLASP IIF, pitting Pascal against Mitraclip in degenerative mitral regurgitation (DMR) and functional mitral regurgitation (FMR), respectively. The former is currently enrolling, while the latter is slated to start enrolling later this year. CLASP IID is expected to complete enrollment by year end, with data reporting by late 2020.
Queried on the relative advantages of Pascal vs. Mitraclip in specific kinds of patients, Saibal Kar of Cedars-Sinai Medical Center responded jokingly, "The truth is: it all depends on who brought the breakfast in the morning," in reference to medical sales people who use this practice to court physicians.
He went on to add, "It's very difficult. Both these technologies, especially to compare the new generation Mitraclip, are amazing systems. They both have shown data clearly that they treat MR (mitral regurgitation) very effectively. The only way to answer that question is to complete the randomized trial."
He subsequently did note a couple of differences between Pascal and Mitraclip based on his own experience. Kar said that with more than one device, it can be easier to reposition Pascal. Then he noted that when there's a lot of chordal crowding, with Pascal it can be difficult to get the clasp in between two chords. Chords extend from the free edge of the leaflet to the papillary muscles and from the ventricular surface.
The one-year data were in 30 of the original 62 CLASP patients, but that was a bit better than the six-month data that only included 28 of those patients. The data were largely consistent with those previously reported six-month results.
One patient died due to stroke, putting one-year survival at 93.5% with 86% of patients remaining free of heart failure. Mitraclip recently received an expanded FDA approval specifically for heart failure patients who also have moderate to severe mitral regurgitation.
Importantly, all the CLASP patients at one-year had a mitral regurgitation score of 2+, which indicates mild to moderate disease, while 74% had an MR score of 1+ or less, which indicates mild disease.
Larry Biegelsen of Wells Fargo contrasted that favorably against Mitraclip data: "If we look at the Mitraclip post-approval study in Europe, ACCESS-EU, we see that the rate of 2+ or less was 79% of patients and the rate of 1+ or less was 31%."
Secondary endpoints, including functional status and exercise capacity, remained consistent at one-year, as compared to 30-day results. On the safety front, Biegelsen was concerned with a high rate of bleeding reported, he noted, "There was a relatively high rate of severe bleeding at one year (16.7%), however, our earlier conversations with physicians suggest there is no reason for the rate of bleeding to be higher with Pascal compared to Mitraclip."
Still, Biegelsen remained quite optimistic on the prospects for Pascal in head-to-head clinical testing, concluding, "Based on the data from the CLASP trial, we believe Edwards may be able to demonstrate superior efficacy with Pascal over Mitraclip."
He was a bit more cautious in another note that followed a meeting with Abbott management on Thursday: "Regarding the efficacy of Pascal, Abbott believes it's too early to tell if one device is superior to the other, but it doesn't expect an efficacy difference between the two. Abbott believes Mitraclip has advantages over Pascal because Mitraclip is a smaller device and this could have important implications longer term."
"Regarding Pascal's share in Europe, Abbott indicated it's too early to measure," the note continued. "Abbott has seen some trialing of Pascal in Europe but believes its share is still in excess of 80%." Pascal received a CE mark in February.