Evaluation of the Safety and Efficacy of Hemophilia B Gene Therapy Drug
Study Details
- Hemophilia B
- Inclusion Criteria of Phase 1/2/3:
- Males ≥ 18 years of age;
- Have hemophilia B with ≤2 IU/dL (≤2 %) endogenous FIX activity levels;
- Have had ≥100 prior exposure days (EDs) to any recombinant and/or plasma-derived FIX protein products based on historical data from the subjects' records/histories;
- Have had bleeding events and/or injected with FIX protein products (including recombination and plasma source) during the last 12 weeks documented in the subjects' medical records;
- Have no prior history of hypersensitivity or anaphylaxis associated with any FIX or IV immunoglobulin administration;
- Agree to use a reliable barrier contraception method from the beginning of signing the informed consent to 52 weeks after administration.
- Exclusion Criteria of Phase 1/2/3:
- Being positive for hepatitis B surface antigen (HBsAg) or hepatitis B virus-DNA (HBV-DNA). Being positive for hepatitis C virus antibody (HCV-Ab) or hepatitis C virus RNA (HCV-RNA). Subjects with medical history of hepatitis B or C can be regarded as negative only when 2 required samplings are conducted at least 3 months apart and both test results of indicators aforementioned are negative, i.e. subjects with natural clearance and anti-viral therapy clearance for hepatitis B or C are eligible;
- Have potential liver diseases, such as previous diagnosis of portal hypertension, splenomegaly, hepatic encephalopathy or liver fibrosis (fibrosis stage ≥ 3); nodules or cysts were found by B ultrasound, or elevated alpha-fetoprotein was detected by laboratory tests. Subjects who are not eligible for the study if the abnormalities are clinically significant regarding to the medical judgement of the investigator;
- HIV positive patients;
- Have participated in a previous gene therapy research trial before screening, or in a clinical study with an investigational drug within 5 half-life of the investigational product, whichever is longer;
- Have alcohol or drug dependence, or cannot stop drinking throughout the study;
- Any concurrent clinically significant major disease or condition that the investigator deems unsuitable for participation in the study.
Protocol Summary
This study is looking at how safe it is to switch from emicizumab to Mim8, in people with haemophilia A. Mim8 is a new medicine that is used to prevent bleeding episodes in people with haemophilia A. Mim8 works by replacing the function of the missing clotting factor VIII (FVIII). Mim8 will be injected under the skin using a pen-injector either once every week, once every two weeks or once every month. The participants will be trained in using the pen injector. The participants can choose themselves, in collaboration with the study doctor how often they get Mim8 in this study. When the participant will get their first Mim8 injection depends on their current treatment with emicizumab. The participants will get their first Mim8 injection at Visit 2. Participants will have between 6 and 27 Mim8 injections. The total number of injections participants will have depends on their dosing frequency. The study will last for about 6-12 months. While taking part in this study, there are some restrictions about what medicine participant can use. The study doctor will tell the participants more about this. In case the participants experience bleeds, these can be treated with additional haemostatic medicine as agreed with the study doctor. Female participants cannot take part if they are pregnant, breast-feeding or plan to get pregnant during the study period.