Study to Evaluate the Efficacy and Safety of PF-07055480 in Moderately Severe to Severe Hemophilia A Adults

Phase 3, Open-Label, Single-Arm Study to Evaluate the Efficacy and Safety of PF-07055480 (Recombinant AAV2/6 Human Factor VIII Gene Therapy) in Adult Male Participants With Moderately Severe to Severe Hemophilia A(FVIII:C<=1%) - AFFINE

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2043210021

Enrollment

Registered

2021-05-17

Start date

2021-06-14

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hemophilia A

Interventions

Biological: Recombinant AAV2/6 Human Factor VIII Gene Therapy Single IV infusion Other Name: Gene Therapy

Eligibility

Sex/Gender

Male

Inclusion criteria

Inclusion criteria: Main inclusion Criteria * Males who completed 6 months of routine Factor VIII prophylaxis therapy during the lead in study (C0371004) and have > = 150 documented exposure days to a Factor VIII protein product * Moderately severe to severe hemophilia A (Factor VIII activity < =1%) * Suspension of FVIII prophylaxis therapy post study drug infusion

Exclusion criteria

Exclusion criteria: Main exclusion Criteria * Anti-AAV6 neutralizing antibodies * History of inhibitor to Factor VIII * Laboratory values at screening visit that are abnormal or outside acceptable study limits * Significant and/or unstable liver disease, biliary disease, significant liver fibrosis * Planned surgical procedure requiring Factor VIII surgical prophylactic factor treatment 12 months from screening visit * Active hepatitis B or C * Serological evidence of human immunodeficiency virus HIV-1 or HIV-2 with Cluster of Differentiation 4 positive (CD4+) cell count 20 copies/mL

Design outcomes

Primary

Measure	Time frame
Primary Outcome Measures : 1.Annualized bleeding rate (ABR) [ Time Frame: 12 months ]	—

Secondary

Measure	Time frame
Secondary Outcome Measures : 1.Steady state FVIII activity levels [ Time Frame: 12 months ] 2.Annualized infusion rate (AIR) of exogenous Factor VIII Activity [ Time Frame: 12 months ] 3.Annualized FVIII consumption [ Time Frame: 12 months ] 4.Annualized bleeding rate (ABR) and total ABR of specific type by cause and by location [ Time Frame: 12 months ] 5.Change in joint health using HJHS (Hemophilia Joint Health Score) [ Time Frame: 12 months ] HJHS is a validated outcome tool developed for the assessment of joint health in people with hemophilia. The ordinal joint score assesses 9 items in 6 index joints. 6.Patient Reported Outcome (PRO) instrument - Hemophilia Activities List (HAL) [ Time Frame: 12 months ] HAL is a disease specific measure of the impact of hemophilia on functional abilities in adults. The instrument consists of 42 items across 7 domains, utilizing a past month recall period. Each item is rated on a scale of 0-6 with higher recoded scores indicating more functional limitations. 7.Patient Reported Outcome (PRO) instrument - Haemophilia Quality of Life Questionnaire for Adults (Haem-A-QoL) [ Time Frame: 12 months ] Haem-A-QoL is a disease specific measure of health-related quality of life in patients with hemophilia. Intended for adults, the instrument uses a 4-week recall period to assess health across 10 domains consisting of 46 items. Each item is rated on a scale of 0-6 with lower scores indicating better health-related quality of life. 8.Incidence and severity of AEs [ Time Frame: 5-year study period ]	—

Measure

Time frame

Secondary Outcome Measures : 1.Steady state FVIII activity levels [ Time Frame: 12 months ] 2.Annualized infusion rate (AIR) of exogenous Factor VIII Activity [ Time Frame: 12 months ] 3.Annualized FVIII consumption [ Time Frame: 12 months ] 4.Annualized bleeding rate (ABR) and total ABR of specific type by cause and by location [ Time Frame: 12 months ] 5.Change in joint health using HJHS (Hemophilia Joint Health Score) [ Time Frame: 12 months ] HJHS is a validated outcome tool developed for the assessment of joint health in people with hemophilia. The ordinal joint score assesses 9 items in 6 index joints. 6.Patient Reported Outcome (PRO) instrument - Hemophilia Activities List (HAL) [ Time Frame: 12 months ] HAL is a disease specific measure of the impact of hemophilia on functional abilities in adults. The instrument consists of 42 items across 7 domains, utilizing a past month recall period. Each item is rated on a scale of 0-6 with higher recoded scores indicating more functional limitations. 7.Patient Reported Outcome (PRO) instrument - Haemophilia Quality of Life Questionnaire for Adults (Haem-A-QoL) [ Time Frame: 12 months ] Haem-A-QoL is a disease specific measure of health-related quality of life in patients with hemophilia. Intended for adults, the instrument uses a 4-week recall period to assess health across 10 domains consisting of 46 items. Each item is rated on a scale of 0-6 with lower scores indicating better health-related quality of life. 8.Incidence and severity of AEs [ Time Frame: 5-year study period ]

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Countries

Japan, Korea, Republic of, Taiwan, Turkey, United States

Contacts

Public ContactClinical Trials Information Desk

Pfizer R&D Japan G.K.

clinical-trials@pfizer.com+81-3-5309-7000

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026