Somatogen's Optro: Phase II Results

Results of two early Phase II trials of Somatogen's recombinant human hemoglobin product Optro (rHb1.1) suggest that it is safe for use as a blood substitute. The data were presented at the International Anesthesia Research Society Meeting in Washington DC, USA, on March 10. Somatogen and its development partner Eli Lilly are now planning to begin an expanded, multicenter Phase II trial of Optro to evaluate further its safety and efficacy.

The first trial, which focused on the intraoperative use of Optro to restore blood volume and oxygen delivery during surgery, was presented at the meeting by Michael Williams of Thomas Jefferson University. A total of 23 patients participated; 16 received Optro at doses ranging from 25g to 100g to replace up to four units of blood, while seven control patients received standard transfusions.

The investigators did not observe any significant treatment-related adverse events, either during treatment or up to seven days postoperatively. Some patients receiving Optro exhibited elevated levels of amylase and lipase beginning at 12-24 hours post-infusion, which returned to normal levels within 48 hours. No clinical signs of pancreatitis were observed.