UK drugmaker Renovo saw its stock plunge 75% on Friday as investors shrank back on news that its leading anti-scarring product Juvista failed miserably in a late-stage trial.

In a huge disappointment for the firm, the first European Phase III trial for Juvista (human recombinant transforming growth factor beta-3) in scar revision surgery failed to meet either its primary or secondary endpoints.  

The double-blind, placebo controlled, 350-patient trial was designed to gage the efficacy of two doses of Juvista (200ng and 500ng/100ul/linear cm of wound margin) on the appearance of scars following scar revision surgery. The primary endpoint for efficacy was a photo-based assessment at 12 months following after surgery by an independent panel of experts using the Global Scar Comparison Scale, while secondary endpoints included an assessment using the same scale by patients and the clinical trial investigator.

Commenting on the failure, Professor Mark Ferguson, Renovo's chief executive, said the firm is "extremely surprised and disappointed" that the trial missed its primary and secondary endpoints. 

Further analysis

The company now plans to conduct further exploratory analysis and determine the future of Juvista and its development programme, and will "consider all options open to it to maximise shareholder value", Ferguson added.

Renovo still has cash reserves of around £44million in its back pockets, and a handful of other candidates in its pipeline, such as Prevascar, currently in Phase II development for reducing scarring, and the preclinical RN1005, for prevention of scarring and enhancement of tissue regeneration.

Fellow UK drugmaker Shire holds rights to sell Juvista in the US, Mexico and Canada, but despite having sunk a significant amount of cash into Renovo on the promise of its drug, the firm was left relatively unscathed by the news, perhaps because its own shares received a boost from a strong set of financial results published last week.