NCT03061201

A Study of Recombinant AAV2/6 Human Factor 8 Gene Therapy SB-525 (PF-07055480) in Subjects With Severe Hemophilia A

A PHASE 1/2, OPEN-LABEL, ADAPTIVE, DOSE-RANGING STUDY TO ASSESS THE SAFETY AND TOLERABILITY OF SB-525 (PF-07055480) (RECOMBINANT AAV2/6 HUMAN FACTOR 8 GENE THERAPY) IN ADULT SUBJECTS WITH SEVERE HEMOPHILIA A

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 13 (actual)
• Sponsor: Pfizer · Industry
• Sex: Male
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The purpose of the study is to evaluate the safety, tolerability and time-course profile of FVIII activity after dosing with SB-525 (PF-07055480)

Detailed description

The proposed clinical study uses a recombinant adeno-associated virus 2/6 (AAV2/6) vector encoding the cDNA for the B-domain deleted human F8 (hF8). The secreted FVIII has the same amino acid sequence as approved recombinant anti hemophilic factors (Refacto® and Xyntha®). The SB-525 (PF-07055480) vector encodes a liver-specific promotor module and AAV2/6 exhibits liver tropism, thus providing the potential for long-term hepatic production of FVIII in hemophilia A subjects. The constant production of FVIII after a single SB-525 (PF-07055480) administration may provide potential benefit in durable protection against bleeding and the complications thereof without lifelong repetitive IV factor replacement administration.

Conditions

• Hemophilia A

Interventions

Type	Name	Description
BIOLOGICAL	SB-525 (PF-07055480)	Single dose of investigational product SB-525 (PF-07055480)

Timeline

• Start date: 2017-06-21
• Primary completion: 2024-07-16
• Completion: 2024-07-16
• First posted: 2017-02-23
• Last updated: 2025-09-30
• Results posted: 2025-09-30

Locations

22 sites across 1 country: United States

Regulatory

• FDA-regulated drug study