Periodic Report Summary - PRATH (Preclinical study of Recombinant human Anti-C5 for the Treatment of atypical HUS) Between month 18 and month 24, the only PRATH Beneficiary to perform activities has been ADN-I. According to the Core of the PRATH First Reporting Report, PRATH WP2 (Antibody production in GMP condition) has had significant delay caused by: very low level of antibody produced by CHOS cell line in WAVE bioreactors; aggregation problems after the purification process of the antibody; very low concentration of the antibody in the final form; and internal/administrative problem of the Manufacturing Subcontractor. It became clear to the Coordinator that anti-C5 antibody production procedure needs: the use of a new vector encoding for the human anti-C5. Partner 1 is now evaluating the solution to that problem; the use of different excipients that stabilize the protein in solution; and a new Manufacturing Subcontractor able to successfully complete the pilot-GMP production. With the approval of the PSC, has: requested to the EU a one-year-extension for the PRATH Project, in order to reach all the Project Strategic Objectives; evaluated aspirants for the two different subcontractors profiles (Antibody cell-line provider and GMP producer). The Antibody cell-line provider has been selected, according to FP7 and national/institutional rules for subcontracting, and started its activities in April 2012. Now, ADN-I is in contact with the new GMP producer that will use the new cell line to produce the antibody needed by Partner 3 and Partner 5 to fulfil their activities. At the present moment, due to the lack of sufficient amount of MUBODINA® available for both the Toxicological studies and the Animal model, both Partner 3 and Partner 5 stopped their work. For that reason, they've performed no activities and the RTD Deliverables have not been delivered completely. Moreover, WP4 Leader staff has had problems in breeding the mice to be used in the spontaneous model of aHUS, so now a new model is needed. If the EC will accept the request of one-year-amendment for the PRATH, the PSC will fulfil the Project activities for the end of April 2013.