Adeno-associated vector compositions for expression of factor VIII

Abstract

One form of a composition has two types of recombinant adeno-associated virus. The first type encodes a portion of Factor VIII operably linked to an expression control element; and the second type encodes a different portion of Factor VIII operably linked to an expression control element. The first and second nucleotide sequences collectively encode a functional Factor VIII protein. Another form of the composition is a recombinant adeno-associated virus containing a nucleotide sequence encoding functional Factor VIII light or heavy chain operably linked to a tissue-specific promoter.

Description

[0001] This application is a continuation of U.S. Application Ser. No. 09 / 470,618 filed Dec. 22, 1999, which is a continuation-in-part of U.S. Application Ser. No. 09 / 364,862, filed Jul. 30, 1999, which claims benefit under 35 U.S.C. .sctn. 119(e) of U.S. Provisional Application Nos. 60 / 125,974 and 60 / 104,994, filed Mar. 24, 1999 and Oct. 20, 1998, respectively. All of these prior applications are hereby incorporated by reference in their entireties.[0002] The present invention relates to AAV vectors suitable for hemophilia gene therapy. More particularly, these AAV vectors are suitable for delivering nucleic acids encoding Factor VIII into a recipient subject suffering from hemophilia A, such that the subject's blood is able to clot.[0003] Hemophilia is a genetic disease characterized by a blood clotting deficiency. In hemophilia A (classic hemophilia, Factor VIII deficiency), an X-chromosome-linked genetic defect disrupts the gene encoding Factor VIII, a plasma glycoprotein, which...

AI Technical Summary

Benefits of technology

[0072] As defined herein, a "therapeutically effective amount" or "therapeutic effective dose" is an amount or dose of AAV vector or virions capable of producing sufficient amounts of Factor VIII to decrease the time it takes for a subject's blood to clot. Generally, severe hemophiliacs having less than 1% of normal levels of FVIII have a whole blood clotting time of greater than 60 minutes as compared to approximately 10 minutes for non-hemophiliacs.

[0075] Adeno-associated virus (AAV) is a non-pathogenic, replication-defective, helper-dependent parvovirus (or "dependovirus" or "adeno-satellite virus"). There are at least six recognized serotypes, designated as AAV-1, AAV-2, AAV-3, AAV-4, AAV-5, AAV-X7, etc. Culture and serologic evidence indicates that human infection occurs with AAV-2 and AAV-3. Although 85% of the human population is seropositive for AAV-2, the virus has never been associated with disease in humans. Recombinant AAV (rAAV) virions are of interest as vectors for gene therapy because of their broad host range, excellent safety profile, and duration of transgene expression in infected hosts. One remarkable feature of recombinant AAV (rAAV) virions is the prolonged expression achieved after in vivo administration.

Problems solved by technology

Severely affected patients are prone to serious hemorrhages that may dissect through tissue planes, ultimately resulting in death due to compromised vital organs.

A rare, yet often fatal, complication of abdominal hematomas is the perforation and drainage of the hematoma into the colon, resulting in infection and septicemia.

Intracranial and / or extracranial hemorrhage also represent very dangerous bleeding situations.

While subcutaneous hematomas may dissect into muscle, pharyngeal and retropharyngeal hematomas (e.g., complicating bacterial or viral pharyngitis) may enlarge and obstruct the airway, sometimes resulting in a life-threatening situation that requires administration of a sufficient dose of Factor VIII concentrate to normalize the Factor VIII level.

Repeated hemorrhaging into the joints eventually results in extensive destruction of articular cartilage, synovial hyperplasia, and other reactive changes in adjacent tissues and bone.

A major complication of repeated hemarthroses is joint deformity, which is often accompanied by muscle atrophy and soft tissue contractures; osteoporosis and cystic areas in the subchondral bone may also develop, along with progressive loss of joint space.

Bone cysts (pseudotumors) are rare, but dangerous complications of hemophilic bleeding.

Unfortunately, these concentrates transmitted viruses, such as hepatitis B and / or C, and human immunodeficiency virus (HIV).

Currently, the cost of viral-free concentrates and recombinant Factor VIII make it prohibitively expensive to administer the clotting factor prophylactically or on a maintenance basis.

Moreover, even if cost effective preparations of recombinant or virus-free Factor VIII were available, a steady state level of Factor VIII cannot be achieved by its daily administration.

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