Preliminary results from a Phase 3 study suggest an investigational treatment approach may improve the maturation rate for arteriovenous (AV) fistula. At ASN’s Kidney Week 2017 Vascular Therapies Inc. presented preliminary results relating to analysis of the first 18 (open-label) patients from its U.S. Phase 3 study of its collagen-based drug delivery system.

In the clinical trial, surgeons deliver the drug sirolimus to the AV fistula at and around the regions where the vein and artery are surgically connected. The trial is testing whether this treatment approach will increase the proportion of fistulae that become suitable for dialysis use,.

Nationally, between 40% and 60% of AV fistulae are not suitable for dialysis. In the ongoing Vascular Therapies’ trial, 89% (16/18) of the AV fistulae in the open label patients were suitable for dialysis use at six months. Additionally, currently in the U.S., dialysis patients remain on catheters for a median time of 111 days. In the open label patients, this wait time was reduced by about 40% to a median of 64 days.

“These encouraging outcomes from the 18 open label patients are consistent with what was seen in the 30-patient, single arm Phase 2 study,” said Maria DeVita, MD, senior nephrologist at Lenox Hill Hospital in Manhattan and medical monitor for the study. “In the Phase 2 study, the median time to first dialysis was 42 days and 76% of the fistulae were suitable for dialysis at six months.”

Vascular Therapies is currently enrolling patients in its Phase 3 randomized controlled study which is being performed under a Special Protocol Assessment (SPA). Topline results are expected in 2019.

“Improving the proportion of fistulae that are suitable for dialysis and reducing catheter dwell times have remained frustratingly elusive goals,” Nelson Kopyt, MD, Chief of Nephrology at Lehigh Valley Hospital in Allentown, Pa. and a study investigator said. “A positive trial and product approval will be transformational for hemodialysis vascular access management.”