Another blood substitute trial halted amid doubts on benefits
This article was originally published in Clinica
Baxter has had to stop another trial of its HemAssist artificial blood in a move which could set back the launch of the product well beyond the year 2000.
Baxter stopped the European trial, which was assessing the oxygen-carrying solution for preserving organs and reducing mortality after severe trauma, after it had enrolled just 117 patients. The company said no benefits of using HemAssist had been seen and that it had stopped the trial to assess whether this was because the trial design was wrong.
The setback comes just weeks after Baxter had to end its US trauma trial because of a higher than expected death rate in patients treated with the blood substitute (see Clinica No 803, p 16). In that trial, the company was aiming for a 25% reduction in 28-day mortality, but after just 100 of the 850 patients were enrolled, the mortality rate had actually gone up and was far higher than the control group.
Baxter said that trauma trials were extremely difficult to set up and added that there were doubts as to whether the trial protocols and even the patient selection were suitable. Trauma patients include those in traffic accidents as well as those in shootings and stabbings. HemAssist is administered as soon as possible in those situations to get much-needed oxygen to organs when a great deal of blood has been lost.
Trials of HemAssist in surgery are continuing in the US and Europe. In these trials, the blood substitute, which is made from purified haemoglobin, is being tested to see if it can reduce the need for transfusion. Baxter applied for European approval in surgery last May last year but was told it had to supply data on more patients.
There is a possibility that the European trauma trial could be restarted, but with a number of modifications. "We still believe that it is an efficacious product," said a spokeswoman for Baxter.
Industry observers are doubtful, however. A research note released by US investment firm Deutsche Bank Securities said that trauma was the "most exciting" market because there were no alternatives but that it was now unclear whether blood substitutes would ever play a role in this area.
Baxter has made a huge R&D investment in HemAssist and has built a 100,000 square foot plant in Switzerland to produce it in bulk. It also recently purchased Somatogen, a company which is developing recombinant haemoglobin products, for $189 million (see Clinica No 798, p 11).
A number of other companies are developing blood substitutes including Canadian firm Hemosol which has just completed a Phase II trial of its Hemolink product in hip and knee surgery in Canada.