Gene Therapy for Haemophilia A.
Study Details
- Hemophilia A
- Biological: AAV2/8-HLP-FVIII-V3
- Inclusion criteria:
- I. Adult males, ≥ 18 years of age; confirmed diagnosis of severe haemophilia A (baseline plasma hFVIII levels of \<1% of normal; assessed by a one-stage clotting or chromogenic assay) II. A severe bleeding phenotype as defined by at least one of the following: (a) On prophylaxis for a history of bleeding or (b) On demand therapy with a current or past history of 4 or more bleeding episodes/year or (c) evidence of chronic haemophilic arthropathy (pain, joint damage, and loss of range of motion) III. Received treatment with hFVIII concentrates with at least \>50 exposure days; IV. Able to give full informed consent and able to comply with all requirements of the trial including 5-year long-term follow-up; V. Willing to practice barrier contraception until at least three consecutive semen samples after vector administration are below the sensitivity of the assay for vector sequences.
- Exclusion criteria:
- VI. Presence of neutralising anti-hFVIII antibodies (inhibitor, determined by the Bethesda inhibitor assay) at the time of enrolment or a previous history of hFVIII inhibitor on at least two occasions that required clinical management ; VII. Use of investigational therapy for haemophilia within 30 days before enrolment; VIII. Subjects with active hepatitis B or C, and HBsAg or hepatitis C RNA viral load positivity, respectively or currently on antiviral therapy for hepatitis B or C. (Negative viral assays in two samples, collected at least six months apart, will be required to be considered negative. Both natural clearers and those who have cleared hepatitis C on antiviral therapy are eligible).
- IX. Serological evidence of HIV; X. Evidence of liver dysfunction (persistently elevated alanine transaminase \>1.5 times upper limit of normal); XI. Uncontrolled glaucoma, diabetes mellitus, or hypertension (systolic BP consistently ≥140 mmHg or diastolic BP consistently ≥90 mmHg); XII. Any disease or condition (including cancer) at the physician's discretion that would prevent the patient from fully complying with the requirements of the study.; XIII. Suspicious lung lesions on CT scan that raise the possibility of cancer or premalignant pathology (based on chest CT scan done at screening or within 6 months prior to the screening visit) XIV. Presence of liver abnormality that is suspicious of malignancy on screening liver ultrasound XV. Patients with uncontrolled cardiac failure or unstable angina; XVI. Detectable neutralising anti-AAV8 antibodies XVII. Received an AAV vector, or any other gene transfer agent in the previous 6 months except for vaccines XVIII. History of active tuberculosis, fungal disease or other chronic infection XIX. Subjects who are unwilling to provide the required semen samples XX. Poor performance status (WHO score \>1) XXI. Patients at high risk of thromboembolic events (high risk patients would include those with a history of arterial or venous thromboembolism (e.g. deep vein thrombosis, pulmonary embolism, non-haemorrhagic stroke, arterial embolus) and those with acquired thrombophilia including conditions such as atrial fibrillation).
- XXII. Patients with a CHA2DS2-VASc score of 2 and above
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.