The open-label phase of the DEXTERITY-AFP trial investigating the Bullfrog microinfusion device—which involves the perivenous injection of the anti-inflammatory drug dexamethasone to improve patency and post-thrombotic syndrome (PTS) six months after thrombus removal in symptomatic deep vein thrombosis (DVT) patients—has shown positive results.
That’s according to late-breaking data revealed during The VEINS 2023 meeting (Oct. 28–30) in Las Vegas by David J. Dexter, co-principal investigator and a vascular surgeon at Sentara Healthcare in Norfolk, Virginia.
From a trend standpoint, Dexter told attendees, the 20-patient cohort, fully enrolled with six months of follow-up, showed a 5% rate of any PTS and currently no patients through 12 months with moderate-to-severe PTS.
The femoropopliteal segment study is moving in its second phase during which 60 patients will be enrolled 1:1 in a dual-blinded randomized controlled trial (RCT), and is considered the first known to investigate local drug delivery intended to reduce venous inflammation associated with DVT.
Of the total 21 patients initially enrolled in the first phase, one withdrew after one-month follow-up. In terms of safety, there were no device or drug-related serious adverse events observed. The primary efficacy endpoint—clinically relevant loss of primary patency—will be examined as combined with the RCT phase, the investigators revealed. Of the 21 patients followed at one month, 19 (90.5%) had fully compressible and two had partially compressible common femoral veins. Other key secondary endpoint data for the 20 participants with in-window, six-month follow-up included reduction from baseline to six months in average Villalta score (7.3 to 1.6) and 10-point pain score (3.2 to 0.5).
“Iliofemoral DVT continues to have poor outcomes,” Dexter told The VEINS 2023. “Femoropopliteal DVT has been neglected because we have really poor therapeutic outcomes yet they compromise more than half of DVT cases we see. Inflammation appears to be linked to vein wall scarring and PTS. Dexamethasone appears to show really promising results both in pre-clinical studies as well as in our single-arm, early-phase data. The biomarker work, the compressibility work and the Villalta score all show really favorable early outcomes.”
