Vascular Therapies, the private group developing a drug-eluting vascular graft for haemodialysis patients, said yesterday that a phase 3 trial of the product had led to “several positive clinical findings”. The main one, unfortunately, was that the Sirogen graft positively did not work. The Access study enrolled 243 end-stage renal disease patients with the aim of proving that Sirogen could be used as an arteriovenous fistula – a connection between an artery and vein in the wrist that can be used to remove and replace the patient’s blood. The graft’s USP is that it releases the antiproliferative sirolimus to help keep the vessel open. After having been in place for six months the graft was found to be unsuitable, missing the trial’s primary endpoint. Vascular Therapies proffered exploratory analyses in patients aged 65-plus that suggested Sirogen had improved suitability for dialysis at 12 months, among other benefits. But the group now has to run another clinical trial “to validate the results”, and is also seeking financing and strategic partnerships. Humacyte, which makes a similar graft from decellularised human tissue, was snapped up by a Spac in February; doubtless Vascular Therapies would jump at the chance of a similar deal.