A Study to Investigate the Safety and Effectiveness of a Coagulation Factor IX Gene Insertion Therapy (REGV131-LNP1265) in Pediatric, Adolescent and Adult Participants With Hemophilia B
Study Details
- Hemophilia B
- Drug: REGV131
- Drug: LNP1265
- Confirmed diagnosis of severe or moderately severe hemophilia B with medical history of FIX functional activity (≤2% or \<0.02 IU/mL) or documented genotype known to produce severe hemophilia B
- Currently taking FIX prophylaxis and previous experience with FIX therapy, as defined in the protocol
- Participation in the lead-in period of this interventional study OR a separate lead-in study (R0000-HEMB-2187 \[NCT05568459\]) for at least 6 months for ABR data while taking FIX prophylaxis, as defined in the protocol
- History of FIX inhibitor (clinical or laboratory-based assessment) on 2 or more occasions
- Bethesda inhibitor titer greater than the upper limit of normal (ULN) at screening
- Detectable pre-existing antibodies to the adeno-associated virus serotype 8 (AAV8) capsid; as measured by enzyme-linked immunosorbent assay (ELISA) at prescreening (or final lead-in visit, if applicable).
- Any significant underlying liver disease such as: cholestatic liver disease, liver cirrhosis, portal hypertension, splenomegaly, hepatic encephalopathy
- Evidence of advanced liver fibrosis, as defined in the protocol
- Evidence of cirrhosis and/or portal hypertension as assessed by abdominal ultrasound at screening or measured within 6 months prior to the screening visit
- History of arterial or venous thrombo-embolic events, as defined in the protocol
- History of hypersensitivity to corticosteroids or known medical condition that requires chronic administration of corticosteroids
- Previously received any AAV gene-based therapy or intends to receive approved or investigational AAV-based gene therapy other than REGV131-LNP1265 during the study period
- NOTE: Other Inclusion/Exclusion Protocol Defined Criteria Apply
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.