Following failure, Proteon tweaks Phase 3 study
- Waltham, Mass. biotech Proteon Therapeutics has tweaked the ongoing Phase 3 PATENCY-2 study for its chronic kidney disease care drug vonapanitase, expanding enrollment to 500 (expected to complete by the end of 2017) and reordering the endpoints. This follows topline results from the previous PATENCY-1 Phase 3 study, which didn't meet its primary endpoint.
- The company has been in discussion with the Food and Drug Administration since December over the changes to the vonapanitase study, which is in development to improve the patency of patients' fistulas for hemodialysis.
- Provided PATENCY-2 shows statistical significance against placebo when it reports around the end of 2018, Proteon plans to use the data from this, and the previous PATENCY-1 Phase 3 study, to support a biologics license application (BLA) submission in 2019.
The changes to the PATENCY-2 study for vonapanitase follow up the PATENCY-1 Phase 3 topline results announced in December 2016. These showed that the study didn't meet its primary endpoint of improved primary unassisted patency compared with placebo (p=0.254).
The initial analysis did, however, suggest that the drug may improve the secondary endpoint, secondary patency compared with placebo (p=0.048), and unassisted fistula use for hemodialysis (p=0.035) and any use of the fistula (unassisted or assisted) for hemodialysis (p=0.006), one of the tertiary endpoints.
After discussions with the Food and Drug Administration, Proteon Therapeutics reordered the existing endpoints for PATENCY, establishing secondary patency and fistula use for hemodialysis as co-primary endpoints.
"As of February 28, 2017, Proteon had enrolled 315 patients in PATENCY-2 at approximately 40 centers in the U.S. and Canada. Proteon expects to complete enrollment [of 500 patients] in the PATENCY-2 trial during the fourth quarter of 2017 and to report top-line data in the fourth quarter of 2018. If the PATENCY-2 trial is successful, Proteon expects to submit a BLA in 2019," the company said in its full year 2016 earnings statement.
In the U.S., over 660,000 people are being treated for end-stage renal disease (ESRD), and 468,000 undergo hemodialysis or peritoneal dialysis. For patients with chronic kidney disease, getting and keeping access to the blood vessels for hemodialysis can be a challenge.
Surgeons create a fistula by connecting an artery and a vein, but these can fail to develop properly, or become closed off through regrowth of the blood vessel wall, requiring angioplasty. This makes hemodialysis, already a stressful and time-consuming process, even more difficult. Proteon Therapeutics hopes that a single dose of its drug, vonapanitase, can improve outcomes in patients who are having surgery to create an arteriovenous fistula for hemodialysis.
- Proteon Therapeutics Statement
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