A Phase 2 Open-Label Safety and Efficacy Study of PF-06835375 in adult participants with Immune thrombocytopenia, a disorder in which there is a reduced amount of platelets in the blood stream which are important for blood to clot normally

• Register: EUCTR
• Last refreshed on: 24 June 2024
• Main ID: EUCTR2021-002897-19-HU
• Date of registration: 23/12/2021
• Prospective Registration: Yes
• Primary sponsor: Pfizer Inc.
• Public title: A Phase 2 Open-Label Safety and Efficacy Study of PF-06835375 in adult participants with Immune thrombocytopenia, a disorder in which there is a reduced amount of platelets in the blood stream which are important for blood to clot normally
• Scientific title: AN INTERVENTIONAL PHASE 2, OPEN-LABEL, ONE-ARM, MULTI-CENTER STUDY TO EVALUATE SAFETY AND EFFICACY OF PF-06835375 IN ADULT PARTICIPANTS WITH MODERATE TO SEVERE PRIMARY IMMUNE THROMBOCYTOPENIA - A Phase 2 Open-Label Safety and Efficacy Study of PF-06835375
• Date of first enrolment: 02/03/2022
• Target sample size: 40
• Recruitment status: Not Recruiting
• URL: https://www.clinicaltrialsregister.eu/ctr-search/search?query=eudract_number:2021-002897-19
• Study type: Interventional clinical trial of medicinal product
• Study design: Controlled: no Randomised: yes Open: yes Single blind: no Double blind: no Parallel group: no Cross over: no Other: no If controlled, specify comparator, Other Medicinial Product: no Placebo: no Other: no Number of treatment arms in the trial: 1
• Phase: Human pharmacology (Phase I): no Therapeutic exploratory (Phase II): yes Therapeutic confirmatory - (Phase III): no Therapeutic use (Phase IV): no

Countries of recruitment

Australia, Canada, Czech Republic, Czechia, Hungary, Poland, United States

Contacts

• Name: Clinical Trials.gov Call Centre
• Affiliation: Pfizer Inc.

• Name: Clinical Trials.gov Call Centre
• Affiliation: Pfizer Inc.

Key inclusion & exclusion criteria

Inclusion criteria:
Age and Sex:
1. Participants between the ages of 18 (or the minimum country-specific age of consent if >18) and 70 years, inclusive, at Screening.
Type of Participant and Disease Characteristics:
2. Willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations and other study procedures.
3. Diagnosis of Primary ITP.
ITP must be diagnosed in accordance with established guidelines. 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.
Weight:
4. BMI 17.5 to 40 kg/m2, and minimum weight >40 kg (88 lbs).
Informed Consent:
5. Capable of giving signed informed consent as described in Appendix 1 which includes compliance with the requirements and restrictions listed in the ICD and in this protocol
Are the trial subjects under 18? no
Number of subjects for this age range:
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range 36
F.1.3 Elderly (>=65 years) yes
F.1.3.1 Number of subjects for this age range 4

Exclusion criteria:
Medical Conditions:
1. Bleeding event according to the WHO grading scale 30 =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
2. Splenectomy within 3 months of randomization or planned during the study duration.
3. Have current or recent history of clinically significant, acute or chronic, severe, progressive, or uncontrolled renal, hepatic, gastrointestinal, metabolic, endocrine,
pulmonary, cardiovascular, psychiatric, immunologic/rheumatologic or neurologic disease; or have any other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or study intervention administration, or interfere with the interpretation of study results; or in the opinion of the investigator, the participant is inappropriate for entry into this study.
4. Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator’s judgment, make the participant inappropriate for the study.
15. Current use of any prohibited concomitant medication(s) or those unwilling/unable to use a permitted concomitant medication(s).
16. Any prior treatment with rituximab (or any other B cell depleting agent) must have been completed 12 months prior to first dose of study drug and CD19 count
(>100 cells per microliter) must be normal prior to first dose.
5. Contraindication for the pre and post medication treatments (NSAID, APAP,corticosteroids, antihistamine).
6. Pregnant female participants; breastfeeding female subjects; and female participants of childbearing potential who are unwilling or unable to use one method of
contraception as outlined in this protocol for the duration of the study and for at least 43 days after the last dose of study intervention.
7. Have a history of alcohol or substance abuse within 12 months prior to Day 1 that in the opinion of the investigator will preclude participation in the study or protocol adherence in the study. A positive urine drug screen must be reflective of a clinically appropriate use.
8. Currently active autoimmune disorders or other conditions that compromise or impair the immune system (including but not limited to: CD, RA, scleroderma, vasculitis, SLE, Grave’s disease or asthma) in the opinion of the investigator.
9. Co-existing myelodysplastic disorder. If clinically significant anemia, neutropenia, or pancytopenia exists, documentation of a bone marrow aspirate/biopsy within
24 months prior to the first study dose showing no evidence of myelodysplasia is required.
10. Co-existing thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, coagulopathies or other bleeding disorders.
11. History of immune deficiency or current evidence of total IgG or total IgA deficiency.
12. History of allergic or anaphylactic reaction to any components of the study intervention.
13. Have cancer or a history of cancer within 5 years of screening (other than adequately resected cutaneous basal cell, squamous cell carcinoma, or carcinoma in situ of the uterine cervix with no evidence of recurrence within the previous 3 years).
14. Any psychiatric condition including recent or active suicidal ideation or behavior that meets any of the following crite

Age minimum:
Age maximum:
Gender:
Female: yes
Male: yes

Health Condition(s) or Problem(s) studied

Primary immune thrombocytopenia
MedDRA version: 23.0 Level: LLT Classification code 10083843 Term: Primary immune thrombocytopenia System Organ Class: 100000004851

Therapeutic area: Diseases [C] - Blood and lymphatic diseases [C15]

Intervention(s)

Product Name: PF-06835375
Product Code: PF-06835375
Pharmaceutical Form: Solution for injection
INN or Proposed INN: not available
Current Sponsor code: PF-06835375
Other descriptive name: PF-06835375
Concentration unit: mg/ml milligram(s)/millilitre
Concentration type: equal
Concentration number: 50-

Primary Outcome(s)

Primary end point(s): Log2 (platelet count) at Week 12

Timepoint(s) of evaluation of this end point: Week 12

Main Objective: To evaluate absolute value of platelet count of treated participants at Week 12

Secondary Objective: To evaluate proportion of participants with modified overall response (mOR) at Week 12
To evaluate proportion of participants with complete response (CR) at Week 12
To evaluate safety and tolerability of PF-06835375
To evaluate effect of PF-06835375 treatment on platelet count over time
To evaluate the effect of PF-06835375 on depletion of circulating B cells and cTfh cells over time

Secondary Outcome(s)

Timepoint(s) of evaluation of this end point: Week 12
Week 12
Day 1 through end of study
The secondary endpoints/estimands will include evaluation of expected value (with 90% confidence intervals) for means of log2(Platelet counts) and proportions of mOR and CR responders over time. Censoring of the log2 (Platelet counts), definitions of mOR and CR responses will be similar and methods for the analysis (MMRM and Wald) will be the same as the methods described in the Section 9.3.2 for the key secondary endpoints. The only difference will be that the MMRM model will use the data collected at all available visits rather than the data collected up to and including Week 12 visit.

Secondary end point(s): Modified overall response (mOR) at Week 12
Complete response (CR) at Week 12
Incidence of AEs as characterized by type, frequency, severity, timing,
seriousness, and relationship to study intervention, Day 1 through end of study
Log2 (platelet count)
Modified response (mOR)
Complete response (CR)
Absolute values and change of platelet count from baseline
Absolute values and change from baseline of circulating B and Tfh cell counts

Secondary ID(s)

C1131003

NCT05070845

Source(s) of Monetary Support

Pfizer Inc.

Ethics review

Status: Approved
Approval date: 24/02/2022
Contact: