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Intercept Blood System Gets FDA Nod to Cut Transfusion-Related Infections
The FDA has approved the Intercept Blood System, the first pathogen-reduction system for use by blood establishments in the preparation of plasma to reduce the risk of transfusion-transmitted infections.
According to the product’s manufacturer (Cerus Corporation), the Intercept system inactivates a broad spectrum of enveloped and non-enveloped viruses, as well as Gram-positive and Gram-negative bacteria, spirochetes, and parasites.
The inactivation of potential pathogens in plasma treated using the Intercept system is achieved through a photochemical process involving controlled exposure to ultraviolet light and amotosalen, a chemical that facilitates the inactivation process. The plasma is then purified to remove the chemical and its byproducts.
While current screening tests for a limited number of pathogens can reduce the risks of transfusion-transmitted infections, these tests are reactive approaches, requiring the identification of specific pathogens for which tests can then be developed and implemented, Cerus says. In contrast, pathogen reduction by inactivation is a proactive safety measure –– the process can inactivate susceptible viruses, bacteria, and parasites present in plasma components independently of whether they have been identified as specific blood-supply risks. According to Cerus, this is critical because there is typically a lag between the emergence of new pathogens and the recognition that an additional safety intervention might be needed.
The Intercept system has been used in Europe for more than a decade as a safety option for platelet and plasma components, and was recently made available in the U.S. via two investigational-device exemption (IDE) studies. In the first study, platelets processed with the Intercept system will be used to reduce the risk of transfusion-transmitted dengue and chikungunya viruses, both of which are responsible for current epidemics in the Caribbean region, including Puerto Rico, as well as for cases reported in the southern U.S.
In the second study, the Intercept system is being used to prepare Ebola-convalescent plasma for passive immune transfusion therapy of acutely infected patients, thereby providing an additional layer of safety against pathogens to which these recovered donors may have been exposed because of recent travel in Africa. Plasma from recovered Ebola patients treated with the Intercept process will be used to create a national stockpile for future patients.
Platelets, plasma, and red blood cells do not require functional DNA or RNA for therapeutic efficacy. However, pathogens (i.e., bacteria, viruses, and parasites) and white blood cells do require these nucleic acids in order to replicate. The Intercept system targets this basic biological difference between the therapeutic components of blood, compared with harmful pathogens and donor white blood cells. The system uses a proprietary molecule that, when activated, binds to and blocks the replication of DNA and RNA, thereby preventing nucleic acid replication and rendering the pathogen inactive.
The safety and efficacy of plasma prepared with the Intercept system has been evaluated in six clinical studies involving more than 500 patients. In addition, the routine use of Intercept-processed plasma was monitored in approximately 10,000 patients in an active hemovigilance study conducted in Europe.
Sources: FDA; December 16, 2014; and Cerus Corporation; December 16, 2014.