Back to top

Analyst Blog

Portola Pharmaceuticals, Inc. (PTLA - Snapshot Report) recently announced positive results from a phase II proof-of-concept study evaluating its Factor Xa inhibitor antidote, PRT4445. The candidate aims to reverse the Factor Xa inhibitor’s anticoagulant activity in patients suffering from uncontrolled bleeding or undergoing emergency surgery.

The randomized, placebo-controlled, double-blind, cohort dose-escalation phase II study assessed the pharmacodynamic and safety profile of PRT4445 in healthy volunteers who received Bristol-Myers Squibb Company/Pfizer Inc.’s (BMY - Analyst Report)/(PFE - Analyst Report) Eliquis, a Factor Xa inhibitor. Eliquis is currently used for reducing the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation.

Results from the study showed that the use of intravenous PRT4445 in 420 mg dose resulted in more than 95% reversal of the anticoagulant activity of Eliquis in two minutes. Eliquis’ anticoagulant activity decreased by 80% when the 210 mg dosage of PRT4445 was administered. The candidate was found to be generally safe.

We remind investors that in Nov 2012, Portola entered into an agreement with Bristol-Myers Squibb and Pfizer to evaluate PRT4445 in combination with Eliquis.

Portola is conducting a phase II study evaluating PRT4445 with another Factor Xa inhibitor, Xarelto. The study intends to evaluate the efficacy and safety of PRT4445 in combination with Xarelto across multiple dosages. The study aims to determine the dose of PRT4445 that will be able to reverse the anticoagulant activity of Xarelto in case of an uncontrolled bleeding or other emergency situations. The study is expected to be completed by year end.

We believe PRT4445 has significant revenue potential. Portola retains worldwide development and commercialization rights to PRT4445.

Portola at present carries a Zacks Rank #3 (Neutral). Other stocks such as Jazz Pharmaceuticals (JAZZ - Analyst Report), carrying a Zacks Rank #1 (Strong Buy), currently look more attractive.

Please login to or register to post a comment.

New to Zacks?

Start Here

Zacks Investment Research


Are you a new Zacks Member or a visitor to

Top Zacks Features

My Portfolio Tracker

Is it Time to Sell?

One of the most important steps you can take today is to set up your portfolio tracker on Once you do, you'll be notified of major events affecting your stocks and/or funds with daily email alerts.

More Zacks Resources

Zacks Rank Home - Evaluate your stocks and use the Zacks Rank to eliminate the losers and keep the winners.

Mutual Fund Rank Home - Evaluate your funds with the Mutual Fund Rank for both your personal and retirement funds.

Stock/Mutual Fund Screening - Find better stocks and mutual funds. The ones most likely to beat the market and provide a positive return.

My Portfolio - Track your Portfolio and find out where your stocks/mutual funds stack up with the Zacks Rank.

Zacks #1 Rank Top Movers for Zacks #1 Rank Top Movers

Company Symbol Price %Chg
ERBA DIAGNO… ERB 3.00 +3.09%
SANCHEZ ENE… SN 34.18 +2.67%
THE PANTRY… PTRY 21.02 +2.09%
INTEL CP INTC 35.15 +1.88%
PIPER JAFFR… PJC 54.54 +1.70%