PHILADELPHIA, PA, March 30, 2008 — Data from a Phase III, open label, multi-national study of patients undergoing angioplasty for ST-elevation myocardial infarction (STEMI), showed that treatment with tirofiban (AGGRASTAT®) led to non-inferior ST-segment resolution compared to abciximab (ReoPro®). These findings were reported today at the 57th Annual Scientific Session of the American College of Cardiology and released online by the Journal of the American Medical Association (JAMA) to coincide with the conference. The study will be published in the April 16, 2008 issue of JAMA.

At least 50 percent recovery from ST-elevation occurred in 85.3 percent and 83.6 percent of patients in the tirofiban and abciximab groups, respectively (Relative Risk [RR]: 1.020; 97.5 percent confidence Interval [CI], 0.958 to 1.086; P <0.001 for non-inferiority). At 30 days, ischemic and hemorrhagic outcomes were similar in the tirofiban and abciximab groups, with the incidence of thrombocytopenia being significantly more common with abciximab compared to tirofiban (4.0 versus 0.8 percent, P=0.004). At 8 months, the incidence of major adverse cardiac events (MACE) was approximately 20 percent lower in patients treated with tirofiban compared to abciximab (9.8 percent versus 12.4 percent; P=0.30). The study also evaluated sirolimus-stent implantation versus uncoated stent implantation. While there was no interaction between tirofiban or abciximab and stent types (P=0.60), there was a significant reduction in incidence of MACE at 8months in patients treated with sirolimus-stent implantation versus uncoated stent implantation (7.8 percent versus 14.5 percent, P=0.0039), driven primarily by an increase in target vessel revascularization (3.2 percent versus 10.2 percent; P=0.0002).

"The results of MULTISTRATEGY demonstrate that in STEMI patients undergoing primary angioplasty, treatment with tirofiban results in similar clinical outcomes with improved safety, in terms of lower thrombocytopenia, relative to abxicimab," said Marco Valgimigli, MD, PhD, staff cardiologist at the University of Ferrara, Ferrara, Italy and lead study investigator.

AGGRASTAT is not currently approved for use in STEMI patients or as adjunctive therapy in patients undergoing percutaneous coronary intervention (PCI).

In January of 2008, Iroko acquired all non-US commercial rights to AGGRASTAT® (tirofiban HCl) from Merck & Co., Inc.

"These positive data add to the growing body of evidence illustrating AGGRASTAT’s potential role in the management of high-risk patients," said John Vavricka, President and Chief Executive Officer of Iroko Pharmaceuticals. "We look forward to further data which will reinforce the utility of AGGRASTAT in this patient type."

Multicentre Evaluation of Single High-Dose Bolus Tirofiban versus Abciximab with Sirolimus Eluting Stent or Bare Metal Stent in Acute Myocardial Infarction Study (MULTISTRATEGY)

The open-label trial of 745 patients presenting with STEMI or new left bundle-branch block was conducted in 16 referral centers in Italy, Spain and Argentina from October 2004 to April 2007. Patients were randomly assigned with the use of a 2-by-2 factorial design to one of four interventional strategies: abciximab with an uncoated-stent, abciximab with a sirolimus-eluting stent, tirofiban with an uncoated-stent, or tirofiban with a sirolimus-eluting stent.

The study’s primary end points included evaluating tirofiban’s noninferiority to abciximab for cumulative ST-segment resolution, expressed as the proportion of patients that achieve at least 50 percent recovery within 90 minutes after intervention, as well as whether the sirolimus-stent is superior to uncoated-stent in terms of the composite of death from any cause, reinfarction and clinically-driven target vessel revascularization within the first 8 months. Secondary endpoints included each component of the composite end point, stent thrombosis and bleedings according to the criteria of the Thrombolysis in Myocardial Infarction (TIMI) trials.

Either tirofiban or abciximab was administered at first medical contact, before arterial sheath insertion. Tirofiban was given as a bolus of 25 µg/kg, followed by an 18-24 hour infusion at 0.15 µg/kg/min. Abciximab was administered as a bolus of 0.25 mg/kg, followed by a 12-hour infusion at 0.125 µg/kg/min. Stenting, either sirolimus-eluting or any uncoated-stent, was the default strategy in patients with a reference vessel diameter 2.5 mm at visual estimation. Crossover from a sirolimus-eluting stent to other stent types was allowed only after failure of a sirolimus-stent implantation attempt, or when there were no available stent sizes that matched the coronary reference diameter.