PolyMedix's PMX-60056 Phase 1B/2 dose-ranging clinical study for heparin reversal meets study endpoints

Aug 11 2010

PolyMedix, Inc. (OTC BB: PYMX), an emerging biotechnology company focused on developing new therapeutic drugs to treat acute cardiovascular disorders and infectious diseases, has successfully completed a Phase 1B/2 dose-ranging clinical study with PMX-60056, a synthetic small-molecule designed to reverse heparin and low molecular weight heparin (LMWH) anticoagulants. The data from this study shows that PMX-60056 met the study endpoints regarding both the reversal of varying heparin levels, and allowing re-anticoagulation and re-reversal. PolyMedix intends to use these data to support the development of a Phase 2 clinical trial in surgical patients.

“I am encouraged by the promising results demonstrated with PMX-60056 regarding the reversal of heparin, and subsequent ability to anticoagulate and reverse again soon after”

Key results from the Phase 1B/2 clinical study include:

• PMX-60056 reversed up to 350 U/kg of heparin. Efficacy in this study was measured by ACT (Activated Clotting Time), a standard bedside measurement. Administration of heparin increased ACT to as high as 574 seconds. In this study, ACT readings for all subjects were at or near normal (100 seconds) in less than three minutes after the end of dosing of PMX-60056.
• PMX-60056 did not interfere with a second anticoagulation. Subjects that were re-anticoagulated with 100 U/kg of heparin followed by a second dose of PMX-60056, showed a consistent response time to the initial heparin reversal.
• PMX-60056 was generally well tolerated with no serious adverse events reported during the study. The most common side effect was a brief reduction in blood pressure that was seen only at the end of some reversals when ACT was already nearing baseline, and only after the last dose of PMX-60056.

The Phase 1B/2 study was designed as an open label, dose titration study to evaluate PMX-60056 in the reversal of surgical levels of heparin, and also in allowing for the possibility of re-anticoagulation. Heparin is an anticoagulant that is commonly administered to patients undergoing cardiac and certain other surgical procedures to prevent blood clots from forming, especially if a cardiac bypass pump is being utilized. After surgery, heparin needs to be reversed, to allow the patient's blood to clot normally and prevent bleeding. A patient may sometimes need to be re-anticoagulated soon after heparin reversal to allow for additional surgery.

This study enrolled twelve healthy subjects into two cohorts. Each of the subjects received either 200 U/kg or 350 U/kg of heparin, followed 20 minutes later by an initial ten minute infusion of PMX-60056. Subjects then received additional infusions of PMX-60056 until the remaining heparin was fully reversed. Following the first reversal of heparin, a second dose of 100 U/kg of heparin was administered to achieve re-anticoagulation, which was then also reversed with PMX-60056.

"I am encouraged by the promising results demonstrated with PMX-60056 regarding the reversal of heparin, and subsequent ability to anticoagulate and reverse again soon after," commented Dr. Eric McAllister, Vice President of Clinical Development and Chief Medical Officer at PolyMedix. "We believe the reductions in blood pressure seen in this study are due to an excess of PMX-60056 after the last dose, when most heparin had already been neutralized. This study has provided information that will help us better quantify the dosing of PMX-60056 in our planned Phase 2 clinical trial to reverse heparin in cardiothoracic surgery."

"The need for a safer alternative for managing coagulation after heparin use in surgery is well understood within the medical community," commented Nicholas Landekic, President and CEO of PolyMedix. "We believe these results support further study of the use of PMX-60056 in cardiothoracic and other surgical procedures. We are very proud to have discovered this unique compound for development as an anticoagulant reversing agent, and are looking forward to moving PMX-60056 into more advanced clinical studies."

PolyMedix is planning to initiate a Phase 2 efficacy study in the second half of 2010, subject to regulatory approval. The objective of the study will be to evaluate the safety and efficacy of PMX-60056 in reversing heparin in patients undergoing cardiothoracic surgeries.

Source PolyMedix, Inc.