РЕЗУЛЬТАТЫ ОТКРЫТОГО МНОГОЦЕНТРОВОГО ПРОСПЕКТИВНОГО КЛИНИЧЕСКОГО ИССЛЕДОВАНИЯ ЭФФЕКТИВНОСТИ, БЕЗОПАСНОСТИ И ФАРМАКОКИНЕТИКИ МОРОКТОКОГА АЛЬФА У ДЕТЕЙ В ВОЗРАСТЕ ОТ 6 ДО 12 ЛЕТ С ГЕМОФИЛИЕЙ A

Abstract

Currently, the main method of treatment for hemophilia A is replacement therapy with drugs of blood coagulation factors VIII (FVIII). As a result of the development of new production technologies, recombinant FVIII are increasingly used for the treatment of hemophilia A. The justification for the use of new drugs in pediatric clinical practice requires careful preparation and clinical research studies of their efficacy and safety. The aim of this study was to evaluate the efficacy, safety and pharmacokinetics (PK) of domestic B-domain deleted recombinant factor VIII of Moroctocog alpha (Octofactor, GENERIUM JSC) in a cohort of children with hemophilia A aged 6 to 12 years in the framework of phase III clinical study of moroktocoga alpha in children 2 to 12 years old with hemophilia A. Materials and methods of the research: the age cohort of 6 to 12 years olds of an open multicenter prospective noncomparative study included 27 male children with severe hemophilia A (mean age 8,3±1,9 years). The study was carried out sequentially in 2 stages. Stage I included the study of PK parameters in 22 patients after a single study drug dose of 50 IU/kg. At stage II, the efficacy and safety of the drug was assessed in patients of stage I, as well as in additionally included 5 patients who received the study drug dose of 30±10 IU/kg per day every 2–3 days for 22±1 weeks of treatment. To assess the efficacy, we analyzed the incidence of spontaneous bleeding that occurred within 48–72 h after drug administration; the number of injections and the dose of FVIII used for prophylaxis, as well as for treatment on demand of one episode of bleeding, taking into account its severity; number of patients with severe hemophilia A with residual FVIII activity >/=1% 48–72 h after drug administration; the investigator's overall assessment of response to therapy on the acute hemarthrosis response scale. The main indicators for the analysis of PK properties were the area under the «concentration-time» curve, the half-life, the elimination constant, the increase in activity, and the degree of recovery of activity. To assess safety, the frequency of formation of an inhibitor to FVIII, the dynamics of vital and laboratory parameters, the frequency and characteristics of adverse events (AEs) associated with the administration of the drug were taken into account. Results: the area under the FVIII-time activity curve in the region of 0–48 h (AUC0-48) and with exponential extrapolation to infinity (AUC0-inf) was 731,82±264,94%*h and 756,11±270,16%*h, respectively. The half-life (T1/2) was 10,32±2,27 hours. In the examined age group, 78 bleeding were recorded, of which only 27 (35%) were spontaneous, including 24 (30%) episodes that occurred during 48–72 hours after the administration of drug under investigation. Haemorrhage within 48–72 hours after administration of the Octofactor drug was absent or was observed rarely (1–3 times) against the background of prophylactic treatment in most patients (88%), the median number of bleeding within 48–72 hours after administration of the study drug was 2 episodes per observation period. The proportion of spontaneous bleeding was the smallest in patients receiving a single prophylactic doses of the study drug 2000–3000 IU (7% of all bleeding), the largest proportion of spontaneous bleeding was observed in patients receiving a single prophylactic doses of the study drug 1000–2000 IU (70% of bleeding). The average single dose of Octofactor for preventive treatment was 1290,4±458,6 IU or 39,12±7,79 IU/kg, for on-demand treatment – 1641,7±722,4 IU per single injection. Of the 78 reported bleeding episodes, 68 (87%) required the study drug administration for relief, while the remaining 10 bleedings were selfcontained. On average, to stop bleeding, it took 1,5±0,8 injections of the drug on demand, median doses were 1 [1; 2], and average doses were 2434,3±1501,7 IU. During the study, 37 AEs were recorded in 15 (56%) patients. At the same time, 36 AEs (97%) were not associated with the drug under investigation, and one AE (allergic reaction), according to the researchers, was associated with the use of the drug. Thus, the analysis of data indicates the efficacy and safety of the Octofactor drug both the prophylactic treatment and treatment of on-demand bleeding in 6 to 12 year old patients with severe hemophilia A.