BTG plc , the specialty pharmaceuticals company, announces the start of the first of three US phase III trials to explore the safety and efficacy of Varisolve polidocanol endovenous microfoam (PEM) as a treatment for varicose veins.

Site initiation has commenced for study VV017, in which Varisolve will be used following endovenous thermal ablation (ETA) to treat those veins of the great saphenous vein (GSV) system not treated by ETA. Two doses of Varisolve PEM will be assessed against a placebo in 105 patients. The primary endpoint will be the improvement in appearance at eight weeks as measured by a patient assessment of appearance instrument (PA-V3) and a physician assessment of appearance instrument (IPR-V3). Patients will be followed up for six months in total.

Two pivotal phase III trials to assess Varisolve as a comprehensive treatment for GSV incompetence and associated visible varicosities are scheduled to commence recruiting patients before the end of 2010. Study VV015 will assess four doses of Varisolve against placebo, with 50 patients in each of the five arms. Study VV016 will assess three doses of Varisolve against placebo, with 60 patients in each of the four arms of the trial. The primary endpoint in both trials is an assessment of symptoms improvement at eight weeks, as measured by a patient symptoms assessment instrument (VVSymQ). Improvement of appearance will be a secondary endpoint, as measured by PA-V3 and IPR-V3. Patients will be followed up for a year in total.

BTG has been discussing studies VV017 and VV015 with the US Food & Drug Administration (FDA) under requests for Special Protocol Assessment (SPA) of the studies. FDA has confirmed that the trial designs and planned statistical analyses are adequate. FDA has also confirmed that to agree SPAs would require completing quantitative validation of PA-V3, IPR-V3 and VVSymQ in advance of starting the studies. In order to commence the phase III trials as soon as practicable, BTG has agreed with the FDA that it will finalise validating these instruments in parallel with the Phase III trials. BTG has therefore decided to withdraw its requests for SPA agreements for these studies and will conduct them under the existing Investigational New Drug application.

Louise Makin, BTG’s CEO commented: “We have now had extensive discussions with the FDA on the whole phase III programme for Varisolve, and based on the detailed guidance we have received we can initiate these trials with confidence. We expect all three trials to be under way by the end of 2010, and we are on track for an NDA submission in 2012 and potential US approval in 2013.”