Gene Therapy Trial for Platelet Derived Factor VIII Production in Hemophilia A
Study Details
- Hemophilia A
- Biological: Auto CD34+PBSC, transduced with a lentiviral vector encoding the B domain deleted from of human coagulation factor VIII
- Study population will include: adult males \>18 years of age with a diagnosis of severe hemophilia A and currently active or a history of FVIII inhibitors (≥0.6 BU). Females will be excluded because hemophilia A is an X-linked disorder that is extremely rare in females.
- Confirmed diagnosis of severe hemophilia A by undetectable plasma factor VIII:C by a one-stage PTT-based assay and coatest chromogenic factor VIII assay. Subjects with currently active or a history of positive FVIII inhibitor titers (≥0.6 BU) irrespective of their titer or current inhibitor status will be included for enrollment.
- Subject may be prescribed prophylactic therapy with factor VIII bypassing agents or factor VIII mimetics prior to referral for inclusion in the study.
- Subjects who are treated on demand using factor VIII bypassing agents must have a history of four or more bleeding episodes requiring treatment in the six-month period prior to referral for inclusion in the study.
- Adequate bone marrow reserve as demonstrated by ANC \>1.5/cu.mm; Hemoglobin \>9g/dL; Platelets \>100,000/microliter.
- Adequate renal function, defined as creatinine clearance\>60 ml/min (Cockroft-Gault formula)
- Adequate liver function, defined as defined as total bilirubin ≤1.5 times the upper limit of normal (ULN) (excluding Gilbert's syndrome), both AST and ALT ≤3 times ULN at the time of screening, and no clinical signs or known laboratory/radiographic evidence consistent with cirrhosis.
- Subject must sign an informed consent after explanation of the study and having questions answered.
- Subject must be willing and able to document type of bleeding episodes and treatment in a paper or electronic diary during the study.
- Subject must be willing to return for regular follow-up visits during the 15-year study.
- A potential subject who meets any of the following exclusion criteria is ineligible to participate in the study.
- Therapy with factor VIII with the intent of immune tolerance induction within 30 days prior to inclusion within the study.
- Enrollment in another interventional clinical trial within 60 days prior to study inclusion.
- Medical contraindication to PBSC cytokine mobilization, use of GCSF, PBSC apheresis procedure or conditioning regimen.
- Medically significant organ dysfunction that would prevent compliance with conditioning or would severely limit the probability of survival based on clinical status.
- Those with a known co-existing clinically significant thrombophilic disorder, or as determined by the presence of any of the below identified on screening laboratory assessments:
- FV Leiden
- Protein S deficiency
- Protein C deficiency
- Prothrombin mutation (G20210A)
- D-dimer \>3 x the upper limit of normal (ULN) at Screening All known patients with the above and any patient with a personal or significant family history of thrombotic events (DVT, PE, arterial clots) as deemed by the principal investigator will be screened for the above disorders.
- Active invasive malignancy (Non-melanoma skin cancers and carcinoma in situ are not excluded).
- Known bone marrow disorders or abnormal bone marrow cytogenetics.
- Fertile males who are unwilling to use contraceptive techniques during and for the twelve months following treatment.
- Life expectancy severely limited by disease(s) other than hemophilia A.
- Patients with HIV, hepatitis B, hepatitis C (with an AST/ALT \> 3 times the upper limit of normal).
- Other active infectious disease that is a contraindicat ion for immunosuppressive therapy.
- Patients who have elective surgery scheduled during the study period.
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.