Updated from 9:18 a.m. EST

Shares of

The Medicines Co.

(MDCO) - Get Report

are up 33% in early trading after the company presented strong clinical data Sunday suggesting that its blood-thinning drug, Angiomax, is as effective as heparin but safer and less costly for patients undergoing procedures to remove blockages from coronary arteries.

At present, most cardiologists use Angiomax only on higher-risk heart patients, but the Parsippany, N.J.-based biotech firm intends to use the new data to persuade doctors that Angiomax should be used in a wider swath of patients.

Angiomax is expected to post 2002 sales of about $36 million, its first full year on the market. But if doctors switch to Angiomax in large numbers, the drug's sales could double or possibly triple in 2003, some analysts say.

The Medicines Co. was up $4.25 to $16.95 in early trading Monday.

The data released Sunday are from a highly anticipated, 6,000-patient study referred to as

REPLACE II. The Medicines Co. released results from the study on the opening day of the annual scientific meeting of the American Heart Association, being held in Chicago.

In the trial, half the patients undergoing angioplasty or the insertion of a stent were randomized to get heparin plus one of three drugs known as GP IIb/IIIa inhibitors. This is the current standard of care used by most doctors when performing procedures in heart patients. The other half of patients received Angiomax by itself, although doctors could also use a IIb/IIIa inhibitor if a complication arose during the procedure.

The Medicines Co. says all primary and secondary endpoints of the REPLACE II study were met. Angiomax proved to be equally effective as the heparin-IIb/IIIa inhibitor combination, using a menu of clinical measurements including incidences of death and the need to quickly redo procedures. More important, patients given Angiomax also had significantly fewer bleeding complications, compared with patients given heparin and a IIb/IIIa inhibitor.

Morgan Stanley analyst Steve Harr says interest in the REPLACE II trial was very high; the presentation room at the American Heart Association conference was standing room only. "Angiomax showed significantly lower bleeding and cost; it's more convenient and there is no tradeoff in terms of efficacy. I think these will be compelling arguments in its favor," he says. Harr rates The Medicines Co. overweight and his firm intends to seek banking deals with the company.

A more detailed analysis of the REPLACE II study will be submitted for publication in a major medical journal by the end of the year. The Medicines Co. also said it intends to submit the study's results to the Food and Drug Administration so that the beneficial information can be included on Angiomax's label, although that won't likely occur until 2004.

Based on the REPLACE II results and using wholesale drug costs, The Medicines Co. estimates that cardiology centers can save an average of $448 per patient by using Angiomax alone vs. the combination of heparin and a IIb/IIIa inhibitor. This could be a very important selling point for Angiomax moving forward because cardiology centers are gearing up to pay more for expensive drug-coated stents, so budget-minded hospitals are expected to seek cost savings from the costs of drugs used in catheterization procedures.

Harr belives that Angiomax's superior safety, coupled with its lower costs, will help boost the drug's market share to about 50% to 55% by 2006. He's forecasting 2003 sales of $89 million, 2004 sales of $139 million, reaching $243 million by 2006.

A significant uptick in Angiomax sales could come at the expense of

Millennium Pharmaceuticals

(MLNM)

,

Eli Lilly

(LLY) - Get Report

and

Merck

(MRK) - Get Report

, all of which sell IIb/IIIa inhibitors. Millennium is particularly vulnerable because its IIb/IIIa inhibitor, Integrilin, is the only drug it sells.

Millennium also presented some new data Sunday night, outside the bounds of the American Heart Association conference, that showed a lower in-hospital death rate in high-risk heart patients who were put on Integrilin early. The study, which is actually a review of thousands of past medical records, was designed to encourage doctors to boost adherence to new medical guidelines that call for earlier use of IIb/IIIa inhibitors in some patients.

Shares of Millennium were down 7% to $7.70 in premarket trading Monday.