Primary Immune Thrombocytopenia
Conditions
Keywords
ITP, platelets
Brief summary
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
Detailed 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 received 1 subcutaneous injection of dose 1 every month for 3 months during the 12-week treatment period. Each participant in cohorts 2, 3, or 4 (will) receive(d) subcutaneous injection(s) of dose 2, 3, or 4 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.
Interventions
BIOLOGICALPF-06835375
CXCR5 inhibitor
Sponsors
Pfizer
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Masking description
open label
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of participants with change from baseline of platelet counts | baseline through 12 and 16 weeks | To evaluate absolute value of platelet count of treated participants |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Treatment Emergent Treatment-Related Adverse Events (AEs) | baseline through end of study (Week 20 for cohort 1 and Week 24 for cohorts 2 and 3) | — |
| Proportion of participants with change from baseline of platelet counts | baseline to Week 20 and Week 24 | — |
| Proportion of participants with change from baseline of circulating cTfh cells | baseline to Week 20 and Week 24 | — |
| proportion of participants with modified overall response (mOR) | baseline through 12 and 16 weeks | To evaluate the modified overall response of platelet count of treated participants |
| proportion of participants with complete response (CR) | baseline through 12 and 16 weeks | To evaluate the complete response of platelet count of treated participants |
| Proportion of participants with change from baseline of circulating B cells | baseline to Week 20 and Week 24 | — |
Countries
Australia, Canada, Czechia, Hungary, Poland, United Kingdom, United States
Contacts
CONTACTPfizer CT.gov Call Center
STUDY_DIRECTORPfizer CT.gov Call Center
Pfizer
Outcome results
None listed