Safety and Efficacy Study of PF-06835375 in Primary Immune Thrombocytopenia

Pfizer

Status and phase: Enrolling; Phase 2

Conditions: Primary Immune Thrombocytopenia

Treatments: Biological: PF-06835375

Study type: Interventional

Funder types: Industry

Identifiers

NCT05070845

2021-002897-19 (EudraCT Number)

C1131003

Details and patient eligibility

About

This is a Phase 2, open-label, multicenter, multiple subcutaneous injection, safety and efficacy study of PF-06835375 in adult participants with primary immune thrombocytopenia (ITP). This study will focus on participants with persistent (>3 months and ≤12 months), or chronic (>12 months) ITP

Full description

This study is designed to elucidate the effects of PF-06835375 on platelet counts in participants with moderate to severe primary ITP. Based on the experience with other B-cells depleting agents, it is expected that the platelet counts will increase following a standard treatment. Each participant in cohort 1 will receive 1 subcutaneous injection of dose 1 every month for 3 months during the 12-week treatment period. And each participant in cohort 2 will receive 1 subcutaneous injection of dose 2 every month for 4 months during the 16-week treatment period. This should provide sufficient levels of exposure and depletion of CXCR5 positive cells to sustain the effects of PF-06835375 during the treatment period. Additional depletion of Tfh cells may provide sustained increase in platelet count following the last treatment.

Enrollment: 61 estimated patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Diagnosis of Primary ITP. Ongoing ITP (platelet counts <50 x 109/L) [No severe bleeding within 1 month or during screening] AND Persistent ITP (3 to 12 months) or Chronic ITP >12 months

Exclusion criteria

• Bleeding event according to the WHO grading scale ≥2 occurring ≤4 weeks prior to screen OR a current bleeding event that, in the opinion of the investigator, requires treatment with standard of care therapy OR require blood or blood products during screening
• Splenectomy within 3 months of randomization or planned during the study duration.

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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61 participants in 2 patient groups

Open Label PF-06835375 dose 1 Treatment

Experimental group

Description:

subcutaneous injection once monthly for 3 months

Treatment:

Biological: PF-06835375

Open Label PF-06835375 dose 2 Treatment

Experimental group

Description:

subcutaneous injection once monthly for 4 months

Treatment:

Biological: PF-06835375