Proteon Therapeutics Announces Top-Line Data from Phase 3 PATENCY-1 Clinical Trial of Investigational Vonapanitase in Patients with CKD
- Trial Did Not Meet Primary Efficacy Endpoint -
- Important Secondary and Tertiary Endpoint Data and Enrollment in Second Phase 3 Ongoing -
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PATENCY-1 evaluated the safety and efficacy of a single dose of vonapanitase in patients with chronic kidney disease (CKD) receiving or expecting to receive hemodialysis who underwent surgical creation of a radiocephalic arteriovenous fistula. The multicenter, randomized, double-blind, placebo-controlled clinical trial enrolled 313 patients at 31 medical centers in
The trial's primary endpoint, primary unassisted patency, is the length of time from fistula surgical creation to the first occurrence of a fistula thrombosis or corrective procedure to restore or maintain patency (blood flow). In PATENCY-1, vonapanitase-treated patients had a 17% reduction in the risk of primary unassisted patency loss over one year, compared to placebo (p=0.254). At the end of one year, 42% of patients who received vonapanitase retained primary unassisted patency, compared to 31% of placebo-treated patients.
The Kaplan-Meier curves for primary unassisted patency can be accessed in Figure 1: http://www.globenewswire.com/NewsRoom/AttachmentNg/fae4524b-a782-4332-87fd-550fa9fb87c2
PATENCY-1's secondary endpoint, secondary patency, is the length of time from surgical creation until fistula abandonment (final failure). In PATENCY-1, vonapanitase-treated patients had a 34% reduction in the risk of secondary patency loss over one year, compared to placebo (p=0.048). At the end of one year, 74% of vonapanitase-treated patients maintained secondary patency, compared to 61% of placebo-treated patients.
The Kaplan-Meier curves for secondary patency can be accessed in Figure 2: http://www.globenewswire.com/NewsRoom/AttachmentNg/0e48c0e7-33e4-4053-8ecb-ee40f1dd2248
Top-line results also included the following tertiary endpoint data:
- Use for Hemodialysis. 39.2% of vonapanitase-treated patients achieved unassisted use of their fistula for dialysis, compared to 25.0% of placebo-treated patients (p=0.035). 63.9% of vonapanitase-treated patients used their fistula for dialysis (unassisted or assisted), compared to 44.4% of placebo-treated patients (p=0.006). Use for hemodialysis was defined as continuous use of the fistula for hemodialysis for at least 90 days or, if hemodialysis was not initiated at least 90 days prior to the patient's last visit, for at least 30 days prior to the patient's last visit and in use at the patient's last visit. Unassisted use was defined as use without prior loss of primary unassisted patency.
- Unassisted Maturation. 62.9% of vonapanitase-treated patients reached unassisted maturation, compared to 53.4% of placebo-treated patients (p=0.109). Unassisted maturation by ultrasound criteria, a tertiary endpoint, was defined as achieving a vein diameter ≥4 millimeters and blood flow ≥500 milliliters per minute by three months without loss of primary patency.
- Rate of Procedures to Restore or Maintain Patency. Over one year, vonapanitase-treated patients had 1.10 procedures per patient per year versus placebo-treated patients who had 1.48 procedures per patient per year (p=0.479). Procedures included thrombectomy, angioplasty, stent deployment and surgical revision.
The proportions of patients reporting adverse events (AEs) were comparable between the vonapanitase and placebo arms of the study. The most common AEs were consistent with medical events experienced by CKD patients undergoing radiocephalic fistula surgery and are summarized in the table below.
Proportions of Patients Experiencing Common Adverse Events
|Note: Includes any adverse event that occurred in at least 5% of patients in either treatment group.|
"We are disappointed that the study missed the primary endpoint. However, it appears that vonapanitase had a drug effect and we are encouraged by the secondary patency and fistula use for hemodialysis findings in this trial, both of which we believe are clinically important," said
"We want to thank the clinical investigators and the patients and their families who volunteered to participate in PATENCY-1. We have always recognized that this is an important and complex area of clinical development and Proteon remains committed to the dialysis patient community," stated
Conference Call and Webcast
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About PATENCY-1 and PATENCY-2
PATENCY-1 and PATENCY-2 are Phase 3, multicenter, randomized, double-blind, placebo-controlled clinical trials in patients with chronic kidney disease (CKD) receiving or expecting to receive hemodialysis and undergoing surgical creation of a radiocephalic arteriovenous fistula for hemodialysis. The studies were designed to evaluate, over one year, whether a single administration of 30 micrograms of vonapanitase can improve radiocephalic fistula patency, the period of time during which a fistula remains open with adequate blood flow to enable hemodialysis. Proteon today announced results of PATENCY-1, which enrolled 313 patients at 31 centers in
About Chronic Kidney Disease, Hemodialysis and Vascular Access
In the most severe stage of chronic kidney disease (CKD), also known as kidney failure, the kidneys can no longer function to sustain life. The majority of patients with kidney failure undergo chronic hemodialysis, which requires a high-flow vascular access to repeatedly connect the patient's bloodstream to a hemodialysis machine for this life-saving treatment. The preferred form of vascular access for hemodialysis is a radiocephalic arteriovenous fistula, created when a surgeon connects a vein to an artery in the lower arm, resulting in a substantial increase in blood flow and vein dilation. No
Vonapanitase (formerly PRT-201) is an investigational drug intended to improve arteriovenous fistula patency, the period of time during which a fistula remains open with adequate blood flow to enable hemodialysis. Vonapanitase is applied in a single administration and is currently being studied in a Phase 3 program in patients with chronic kidney disease (CKD) undergoing surgical creation of a radiocephalic arteriovenous fistula for hemodialysis. Vonapanitase has received fast track and orphan drug designations from the
Cautionary Note Regarding Forward-Looking Statements
This press release contains statements that are, or may be deemed to be, "forward-looking statements." In some cases these forward-looking statements can be identified by the use of forward-looking terminology, including the terms "estimates," "anticipates," "expects," "plans," "intends," "may," or "will," in each case, their negatives or other variations thereon or comparable terminology, although not all forward-looking statements contain these words. These statements, including the number of patients to be enrolled in and the timing of enrollment in the PATENCY-2 Phase 3 clinical study of vonapanitase, when the Company expects to report top-line data from the PATENCY-2 Phase 3 clinical study of vonapanitase, the potential treatment of renal and vascular diseases with vonapanitase, the effect or benefit of vonapanitase in patients with CKD, whether vonapanitase improves AVF patency or use, the potential surgical and endovascular applications for vonapanitase, including PAD, the sufficiency of the Company's cash, cash-equivalents and available-for-sale investments to fund the Company's operations into the third quarter of 2018, and those relating to future events or our future financial performance or condition, involve substantial known and unknown risks, uncertainties and other important factors that may cause our actual results, levels of activity, performance or achievements to differ materially from those expressed or implied by these forward-looking statements. These risks, uncertainties and other factors, including whether our cash resources will be sufficient to fund our operating expenses and capital expenditure requirements for the period anticipated; whether data from early nonclinical or clinical studies will be indicative of the data that will be obtained from future clinical trials; whether vonapanitase will advance through the clinical trial process on the anticipated timeline and warrant submission for regulatory approval; whether such a submission would receive approval from the
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