Trial Condition(s):

Hemophilia A

Study to test the safety and how well patients with severe hemophilia A respond to treatment with BAY 2599023 (DTX 201), a drug therapy that delivers a healthy version of the defective Factor VIII gene into the nucleus of liver cells using an altered, non-infectious virus (AAV) as a “shuttle".

Bayer Identifier:

19429 Identifier:


EudraCT Number:


EU CT Number:


Recruitment Complete

Trial Purpose

In this study researchers want to gather more information about safety and effectiveness of BAY 2599023 (DTX201), a drug therapy that delivers the human factor VIII gene into the human body by use of a viral vector to treat the disease. By replacing the defective gene with a healthy copy the human body may produce clotting factor on its own. Hemophilia A is a bleeding disorder in which the human body does not have enough clotting factor VIII, a protein that controls bleeding. Researcher want to find the optimal dose of BAY 2599023 (DTX201) so that the body may produce enough clotting factor on its own.

Inclusion Criteria
- Males age 18 years or older.
- Confirmed diagnosis of hemophilia A as evidenced by their medical history with plasma FVIII activity levels < 1% of normal or at screening.
- Have >150 exposure days (EDs) to FVIII concentrates (recombinant or plasma-derived). 
If on prophylaxis, are required to be willing to stop prophylactic treatment at specified time points throughout the study or
If on-demand: should have had > 4 bleeding events in the last 52 weeks
- Agree to use reliable barrier contraception.
Exclusion Criteria
- History of allergic reaction to any FVIII product.
- Clinically relevant findings in the physical examination considered critical by the treating physician, including obesity with BMI > 35 kg/m*2
- Current evidence of measurable inhibitor against factor VIII, prior history of inhibitors to FVIII protein or clinical history suggestive of inhibitor.
- Evidence of active hepatitis B or C.
- Currently on antiviral therapy for hepatitis B or C.
- Significant underlying liver disease.
- Serological evidence of HIV-1 or HIV-2 with CD4 counts ≤200/mm*3; HIV+ and stable participants with CD4 count >200/mm*3 and undetectable viral load are eligible to enroll.
- Detectable antibodies reactive with AAVhu37capsid.
- Participant with another bleeding disorder that is different from hemophilia A (e.g., von Willebrand disease, hemophilia B).
- Participated in a gene transfer trial within the last 52 weeks or in a clinical trial with an investigational product within the last 12 weeks.
- Known or suspected hypersensitivity or allergic reaction to trial product(s) or related FVIII products or any component of BAY2599023 (DTX201), or a contraindication to prednisolone

Trial Summary

Enrollment Goal
Trial Dates
Could I receive a placebo?
BAY2599023 (DTX201)
Accepts Healthy Volunteers

Where to Participate


C.S. Mott Children's Hospital

Ann Arbor, United States, 48109


SHATHD Spec. Hospi. for Active Treatm. of Haematol. Dis. EAD

Sofia, Bulgaria, 1756


Arkansas Children's Hospital

Little Rock, United States, 72202-3500


Universitätsklinikum des Saarlandes

Homburg, Germany, 66421


Vivantes Klinikum im Friedrichshain

Berlin, Germany, 10249


Manchester Royal Infirmary

Manchester, United Kingdom, M13 9WL


Academisch Medisch Centrum (AMC)

AMSTERDAM, Netherlands, 1105 AZ


Erasmus Medisch Centrum

ROTTERDAM, Netherlands, 3015 CE


Universitair Medisch Centrum Groningen

GRONINGEN, Netherlands, 9713 GZ


University Medical Center Utrecht

UTRECHT, Netherlands, 3584 CX


Hôpital Pontchaillou

RENNES CEDEX, France, 35033


Hopital Necker les enfants malades - Paris

PARIS, France, 75015


University of Wisconsin - Madison

Madison, United States, 53792

Trial Design