Cerus Corp. said Friday it sold 6 million shares of common stock for gross proceeds of $54.3 million.

Gregory Schafer, chief financial officer of Cerus, said that the funds would go largely to support the company's ongoing research and development work, primarily Phase III trials of its Intercept system in the U.S.

"This signals that the marketplace is opening up, at least for those companies with multiple late-stage products," Schafer said.

Cerus' most advanced programs target systems to enhance the safety of the world's blood supply. Its Intercept Blood System, which is being developed in collaboration with subsidiaries of Baxter International, of Deerfield, Ill., is based on Cerus' Helinx technology and is designed to inactivate viruses, bacteria, other pathogens and white blood cells. The company also is pursuing therapeutic applications of the Helinx technology to prevent and treat diseases.

Including a five-year loan commitment of $50 million from Baxter, the funding gives Cerus upward of $100 million to draw on. The company last year received a $5 million milestone payment from Baxter following European approval of the Intercept system for platelet applications. On March 31, the company reported $96.4 million in cash.

With the new funding, "our [cash] position is very strong," Schafer noted.

The Helinx technology central to the Intercept system is a light-activated inactivation strategy that targets certain pathogens associated with transfusion-transmitted diseases. It works to block infection by preventing the replication of nucleic acid. The company has filed for FDA clearance of the platelet application, and earlier this year company President and CEO Stephen Isaacs said Cerus is in various stages of development and clinical trials for use of the system on plasma and red blood cells.

Schafer reported several modules of the PMA for the platelet application closed, with plans under way for an additional clinical trial. The third of three patient groups for the Phase III plasma application study is being completed "as we speak," Schafer said. And the Phase III study in red cell inactivation is well under way as well, he said.

In January two blood centers, one in Italy, the other in Portugal, reported that they were the first in Europe to implement the Intercept Blood System for platelets. Isaacs projected that in Europe the initial application is a $115 million annual market opportunity. Overall, he put the worldwide blood protection market at $2.5 billion annually, including $400 million in the plasma application and a huge $1.7 billion in red blood cell treatment.

In March, the company unveiled data from a pivotal European Phase III trial (called euroSPRITE) that it said confirms the therapeutic efficacy and safety of the Intercept system for platelets. For specific patient groups in the study the system also was used in place of gamma irradiation to inactivate white blood cells that can cause a fatal reaction in patients with damaged immune systems.

Cerus has said it also is exploring applications of the system for uses in oncology, primarily bone marrow transplants, and in stem cell transplants, with Schafer saying those efforts represent from 10 percent to 20 percent of the company's priorities.

Cerus' stock (NASDAQ:CERS) fell $1.40 Friday, or 13.1 percent, to close at $9.30.