By Kim Coghill

Washington Editor

Cerus Corp. and its partner, Baxter Healthcare Corp., said Friday late-stage trials of their platelet and plasma transfusion systems have ended successfully.

Concord, Calif.-based Cerus said the Intercept Platelet System Phase III trial showed effectiveness in treating and preventing bleeding during severe thrombocytopenia, a condition characterized by a reduction in platelet levels.

Meanwhile, the Phase IIIb trial of the Intercept Plasma System has resulted in supportive data of safety and therapeutic effectiveness of the system, which protects against transmission of infectious diseases resulting from plasma transfusions.

¿This is a unique situation, being able to announce two successful pivotal Phase III trials in a single day,¿ Stephen Isaacs, Cerus¿ president and CEO, told BioWorld Today. ¿We¿ve seen that the primary endpoints for efficacy were achieved and the safety endpoints we¿ve looked at so far have shown no adverse events.¿

Isaacs said he expects regulatory approval for the platelet system by the end of 2002 and the plasma system approval should be granted in early 2003. The platelet system currently is under regulatory review in Europe.

Intercept products are based on Cerus¿ Helinx technology that inactivates viruses, bacteria and parasites in blood. ¿These systems allow us to decontaminate these blood components for a transfusion to make them safe for transfusion recipients,¿ Isaacs said.

The 671-patient Phase III platelet trial was randomized, controlled and double blind. Platelet transfusions were administered to reduce the risk of bleeding during severe thrombocytopenia and to treat active bleeding. The endpoint was a comparison of the proportion of patients with moderate bleeding following platelet transfusion with either Intercept platelets or platelets that had not been treated with a pathogen inactivation process.

The company said data show that the portion of patients with moderate bleeding between the patients who received Intercept platelets and control groups was statistically equivalent and within 1 percent of each other, achieving the goal of less than 12.5 percent difference between the groups.

The Phase IIIb plasma trial was a multicenter, randomized, controlled, double blind study of 121 patients with acquired defects in coagulation, mostly due to end-stage liver disease. These patients typically need plasma support during surgery. The trial looked at the blood-clotting function of Intercept plasma compared to untreated plasma to determine whether the pathogen inactivation treatment process affected therapeutic performance.

The primary endpoint compared prothrombin and partial thromboplastin responses between Intercept plasma and untreated plasma over seven days. The results were statistically significant. Also, according to the company, the safety data in Intercept plasma patients were comparable to untreated patients.

Several days before the companies released the results, Cerus registered to sell up to $300 million in common stock and debt in a future shelf offering. (See BioWorld Today, Aug. 14, 2001.)

At the end of June, Cerus had 15.6 million shares outstanding and a cash position of $147 million. In mid-May, the company raised $78 million through a placement of 1 million new shares at $52 each with an institutional investor and the sale of 500,000 more at the same price to the pension fund of Baxter. (See BioWorld Today, May 18, 2001.)

The relationship between Cerus and Baxter, of Deerfield, Ill., dates back to 1993. Baxter will be responsible for manufacturing, marketing, distributing and selling their systems.

Cerus¿ stock (NASDAQ:CERS) closed Friday at $57.55, down 90 cents, while Baxter¿s stock (NYSE:BAX) closed at $50.31, down $1.22.