AAV9 U7snRNA Gene Therapy to Treat Boys With DMD Exon 2 Duplications.

Duchenne Muscular Dystrophy Clinical Trial

Official title:

Phase I/IIa Systemic Gene Delivery Clinical Trial of scAAV9.U7.ACCA for Exon 2 Duplication-Associated Duchenne Muscular Dystrophy

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT04240314
• Other study ID #: AAV9 Dup2 U7
• Status: Active, not recruiting
• Phase: Phase 1/Phase 2
• Start date: January 15, 2020
• Est. completion date: November 19, 2025

Study information

• Verified date: February 2023
• Source: Nationwide Children's Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Open-label, single dose clinical trial of scAAV9.U7.ACCA via peripheral limb vein injection for Duchenne muscular dystrophy boys who have a duplication of exon 2.

Description:

The proposed clinical trial is a systemic (intravenous) delivery of scAAV9.U7.ACCA for DMD patients with a duplication of exon 2 in the DMD gene. Preclinical data shows that the small nuclear RNA (snRNA) construct delivered by the scAAV9.U7.ACCA vector causes significant skipping of exon 2, resulting in exclusion of the exon from the mature messenger RNA (mRNA) with a high degree of efficiency, leading to mRNA containing only a single exon 2 (wild type [WT] mRNA) or no copies of exon 2 (Del2 mRNA). Translation of the wild-type mRNA results in entirely normal dystrophin protein, whereas translation of the Del2 mRNA via translational initiation of an internal ribosome entry sequence, or IRES) results in a highly functional isoform expressed in patients known to walk into their eighth decade.

The study is designed as an open-label trial to assess safety and obtain preliminary efficacy data. scAAV9.U7.ACCA will be delivered to the systemic circulation via peripheral limb vein.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 3
• Est. completion date: November 19, 2025
• Est. primary completion date: November 19, 2023
• Accepts healthy volunteers: No
• Gender: Male
• Age group: 6 Months to 13 Years

Eligibility

Inclusion Criteria:

• Age greater than 6 months and less than 14 years

• Confirmed duplication of exon 2 in the DMD gene using a clinically accepted technique that completely defines the mutation

• Pre-ambulant (not yet walking) or ambulant (as defined by the ability to walk 10 meters without assistance)

• Males of any ethnic group will be eligible

• Ability to cooperate with muscle testing

• In subjects age 4 and above, stable dose and regimen of corticosteroid therapy (prednisone, deflazacort, or their generic forms) for at least 12 weeks prior to gene transfer.

Exclusion Criteria:

• Active viral infection based on clinical observations

• Symptoms or signs of cardiomyopathy, including:

1. Dyspnea on exertion, pedal edema, shortness of breath upon lying flat, or rales at the base of the lungs

2. Echocardiogram with ejection fraction below 40%

• Serological evidence of HIV infection, or Hepatitis B or C infection

• Diagnosis of (or ongoing treatment for) an autoimmune disease

• Persistent leukopenia or leukocytosis (WBC = 3.5 K/µL or = 20.0 K/µL) or an absolute neutrophil count < 1.5K/µL

• Concomitant illness or requirement for chronic drug treatment that in the opinion of the SI creates unnecessary risks for gene transfer

• AAV9 binding antibody titers = 1:400 as determined by ELISA immunoassay

• Abnormal laboratory values in the clinically significant range as listed in Table 7, based upon normal values in the Nationwide Children's Hospital Laboratory.

Related Conditions & MeSH terms

• Duchenne Muscular Dystrophy
• Muscular Dystrophies
• Muscular Dystrophy, Duchenne

Intervention

Biological:
• scAAV9.U7.ACCA
A single dose of scAAV9.U7.ACCA will be systemically delivered via a peripheral vein injection.

Locations

Country	Name	City	State
United States	Nationwide Children's Hospital	Columbus	Ohio

Sponsors (2)

Lead Sponsor	Collaborator
Megan Waldrop	Audentes Therapeutics

Country where clinical trial is conducted

United States, 

References & Publications (5)

Flanigan KM, Dunn DM, von Niederhausern A, Howard MT, Mendell J, Connolly A, Saunders C, Modrcin A, Dasouki M, Comi GP, Del Bo R, Pickart A, Jacobson R, Finkel R, Medne L, Weiss RB. DMD Trp3X nonsense mutation associated with a founder effect in North American families with mild Becker muscular dystrophy. Neuromuscul Disord. 2009 Nov;19(11):743-8. doi: 10.1016/j.nmd.2009.08.010. Epub 2009 Sep 29. — View Citation

Gurvich OL, Maiti B, Weiss RB, Aggarwal G, Howard MT, Flanigan KM. DMD exon 1 truncating point mutations: amelioration of phenotype by alternative translation initiation in exon 6. Hum Mutat. 2009 Apr;30(4):633-40. doi: 10.1002/humu.20913. — View Citation

Vulin A, Barthelemy I, Goyenvalle A, Thibaud JL, Beley C, Griffith G, Benchaouir R, le Hir M, Unterfinger Y, Lorain S, Dreyfus P, Voit T, Carlier P, Blot S, Garcia L. Muscle function recovery in golden retriever muscular dystrophy after AAV1-U7 exon skipping. Mol Ther. 2012 Nov;20(11):2120-33. doi: 10.1038/mt.2012.181. Epub 2012 Sep 11. — View Citation

Vulin A, Wein N, Simmons TR, Rutherford AM, Findlay AR, Yurkoski JA, Kaminoh Y, Flanigan KM. The first exon duplication mouse model of Duchenne muscular dystrophy: A tool for therapeutic development. Neuromuscul Disord. 2015 Nov;25(11):827-34. doi: 10.1016/j.nmd.2015.08.005. Epub 2015 Aug 11. — View Citation

Wein N, Vulin A, Falzarano MS, Szigyarto CA, Maiti B, Findlay A, Heller KN, Uhlen M, Bakthavachalu B, Messina S, Vita G, Passarelli C, Brioschi S, Bovolenta M, Neri M, Gualandi F, Wilton SD, Rodino-Klapac LR, Yang L, Dunn DM, Schoenberg DR, Weiss RB, Howard MT, Ferlini A, Flanigan KM. Translation from a DMD exon 5 IRES results in a functional dystrophin isoform that attenuates dystrophinopathy in humans and mice. Nat Med. 2014 Sep;20(9):992-1000. doi: 10.1038/nm.3628. Epub 2014 Aug 10. Erratum In: Nat Med. 2015 Apr;21(4):414. Nat Med. 2015 May;21(5):537. Brioschi, Simona [added]; Bovolenta, Matteo [added]; Neri, Marcella [added]. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Monitoring for the development of unacceptable toxicity.	Unacceptable toxicity is defined as the occurrence of two or more unexpected Grade III or higher treatment-related toxicities, as defined by CTCAE 5.0.	2 years
Secondary	Change in dystrophin expression from baseline following treatment with scAAV9.U7.ACCA.	Expression of dystrophin will be measured by immunofluorescent staining in muscle biopsies taken before and after gene therapy.	1 year
Secondary	Change in dystrophin expression from baseline following treatment with scAAV9.U7.ACCA.	Expression of dystrophin will be quantified by western blotting in muscle biopsies taken before and after gene therapy.	1 year
Secondary	Changes in exon 2 inclusion in the dystrophin mRNA transcript.	Exon 2 inclusion will be measured using RT-PCR analysis.	1 year