Changed endpoints cannot save Proteon from becoming a shell


The tried and tested biotech strategy of finding a new endpoint to follow after a clinical trial failure has not worked for Proteon Therapeutics. The group's lead project, vonapanitase, has flunked a second phase III trial, leaving the company in a huge hole from which it will be difficult to emerge. The latest disappointment came in the Patency-2 study, which could not show that vonapanitase improved haemodialysis access sites in chronic kidney disease patients; specifically, the trial failed its two co-primary endpoints of arteriovenous fistulae use and secondary patency, the time from fistula creation to its abandonment. Proteon had shifted to these endpoints after the Patency-1 trial hit these secondary endpoints but failed to meet its primary outcome measure of primary unassisted patency. Proteon's shares plunged 86% yesterday on the news of Patency-2's failure, valuing the group at $9.5m, well below its year-end 2018 cash balance of $22m. Proteon has phase I trials under way for vonapanitase in peripheral artery disease, but the the group's future looks uncertain. Perhaps Proteon could provide a shell for another company to reverse into. 

Proteon's last stand? Patency-2 data
Endpoint Vonapanitase Placebo p value
Fistula use for haemodialysis 69.7% 65.1% 0.328
Secondary patency at one year 78% 76% 0.932
Source: Proteon Therapeutics

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