Immune Thrombocytopenia (ITP)

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by a low platelet count, purpura, and bleeding episodes that derive from antiplatelet autoantibodies.¹ The management of ITP relies on the use of drugs, such as corticosteroids and thrombopoietin receptor agonists (TPO-RAs).² Currently, there are several phase 2 and phase 3 clinical trials focused on investigating the safety and efficacy of these drugs and boosting the clinical development of new therapeutic approaches.

Ongoing Clinical Trials

The long-term safety, tolerability, and efficacy of rozanolixizumab are being investigated in patients with persistent or chronic primary ITP in the phase 3 clinical trial myOpportunITy3 (NCT04596995). The estimated completion date of the study is December 2022.³ Additionally, the long-term safety and efficacy of efgartigimod in patients with primary ITP are currently being studied in the ADVANCE+ trial, an open-label, multicenter, phase 3 clinical trial (NCT04225156). The study has recruited 101 participants and is expected to conclude by November 2025.⁴

The TAPER study (NCT03524612) is a phase 2, open-label, prospective, single-arm clinical trial that has been designed to determine the ability of  Promacta® (eltrombopag) to induce a sustained response off treatment in patients with ITP who have relapsed or did not respond to initial treatment with steroids. The trial has enrolled 105 participants and is expected to conclude by October 2022.⁵

Read more about ITP therapies

Clinical Trials Actively Recruiting

PF-06835375

The safety and efficacy of PF-06835375, a C-X-C chemokine receptor type 5 (CXCR5) inhibitor, will be evaluated in a phase 2, open-label, single-arm, multicenter study led by Pfizer (NCT05070845). This trial is currently recruiting participants and will enroll adult patients with persistent (>3 months and ≤12 months) or chronic (>12 months) ITP who present with moderate to severe bleeding. The effect of PF-06835375 on platelet count will be determined following subcutaneous administration every month over a 3-month period.⁶

Efgartigimod PH20 Subcutaneous

The ADVANCE SC clinical trial is a phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group trial led by Argenx that will evaluate the safety and efficacy of efgartigimod PH20 subcutaneous in adult patients with primary ITP (NCT04687072).⁷ An open-label phase 3 trial, ADVANCE SC+ (NCT04812925), is also recruiting participants and is expected to be completed in October 2026.⁸

Doptelet and Promacta

The safety and efficacy of the TPO-RA medication Doptelet^® (avatrombopag) will be studied in a phase 3b clinical trial sponsored by Sobi, Inc. In this trial, pediatric patients who have had ITP for at least 6 months will be randomized to receive a blinded therapy of avatrombopag or placebo (3:1) for 12 weeks (NCT04516967). Patients who complete this treatment period may be eligible to participate in an open-label extension trial that will last for 2 years.⁹

An investigator-initiated, multicenter, open-label, randomized, two-arm phase 3 trial enrolling participants aged 1 to <18 years who have been newly diagnosed with ITP will evaluate if the proportion of patients with platelet response is significantly greater in patients treated with Promacta® (eltrombopag) than in patients treated with standard front-line management (NCT03939637).¹⁰

Read more about Promacta

Rilzabrutinib

The LUNA3 clinical trial is a randomized, double-blind study of rilzabrutinib in patients with persistent or chronic ITP, sponsored by Principia Biopharma (NCT04562766). In this phase 3 clinical trial, adult and adolescent patients will receive the drug or a placebo at a dose of 400 mg twice per day. The study will be conducted for up to 60 weeks.¹¹

TAK-079

The safety of 3 different doses of the monoclonal anti-CD38 antibody TAK-079 will be determined in a multicenter phase 2 clinical trial sponsored by Takeda Pharmaceuticals (NCT04278924). The biologic activity of TAK-079 will be also evaluated. The trial aims to enroll an estimated 54 participants who will be followed up for at least 8 weeks in a safety follow-up period and then over a 16-week long-term follow-up period after 8 weeks of treatment.¹²

Anti-B-Cell Maturation Antigen Chimeric Antigen Receptor T-Cell Therapy

With the goal of decreasing the burden of disease in relapsing or refractory cases of ITP by increasing platelet count and decreasing the dosage of concomitant medications, the use of autologous anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell therapy will be explored in a prospective, single-center, open-label, single-arm, phase 2 clinical trial (NCT05315778).¹³

Read more about ITP experimental therapies

References

1. Justiz Vaillant AA, Gupta N. ITP-immune thrombocytopenic purpura. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022. Updated July 8, 2022. Accessed October 24, 2022.

2. Kessler CM. Immune thrombocytopenia (ITP) medication. Medscape. Updated January 7, 2021. Accessed October 24, 2022.

3. A study to investigate the long-term safety, tolerability, and efficacy of rozanolixizumab in study participants with persistent or chronic primary immune thrombocytopenia (ITP) (myOpportunITy3). ClinicalTrials.gov. October 22, 2020. Updated October 24, 2022. Accessed October 24, 2022.

4. A long-term study to assess the safety and efficacy of efgartigimod in adult patients with primary immune thrombocytopenia (ITP). (ADVANCE+). ClinicalTrials.gov. January 13, 2020. Updated October 13, 2022. Accessed October 24, 2022.

5. A study to assess the ability of eltrombopag to induce sustained response off treatment in subjects with ITP (TAPER). ClinicalTrials.gov. May 15, 2018. Updated October 5, 2022. Accessed October 24, 2022.

6. Safety and efficacy study of PF-06835375 in primary immune thrombocytopenia. ClinicalTrials.gov. October 7, 2021. Updated October 18, 2022. Accessed October 24, 2022.

7. A study to evaluate the efficacy and safety of efgartigimod PH20 subcutaneous in adult patients with primary immune thrombocytopenia (ADVANCE SC). ClinicalTrials.gov. December 29, 2020. Updated October 13, 2022. Accessed October 24, 2022.

8. A phase 3 study to evaluate the safety and efficacy of efgartigimod PH20 subcutaneous in adult patients with primary immune thrombocytopenia (ADVANCE SC+). ClinicalTrials.gov. March 24, 2021. Updated June 28, 2022. Accessed October 24, 2022.

9. Avatrombopag for the treatment of thrombocytopenia in pediatric subjects with immune thrombocytopenia for ≥6 months. ClinicalTrials.gov. August 18, 2020. Updated July 15, 2022. Accessed October 24, 2022.

10. Eltrombopag vs standard front line management for newly diagnosed immune thrombocytopenia (ITP) in children. ClinicalTrials.gov. May 7, 2019. Updated September 30, 2021. Accessed October 24, 2022.

11. Study to evaluate rilzabrutinib in adults and adolescents with persistent or chronic immune thrombocytopenia (ITP) (LUNA 3). ClinicalTrials.gov. September 24, 2020. Updated September 29, 2022. Accessed October 24, 2022.

12. A study of TAK-079 in adults with persistent/chronic primary immune thrombocytopenia. ClinicalTrials.gov. February 20, 2020. Updated September 8, 2022. Accessed October 24, 2022.

13. Anti-BCMA CAR T-cell therapy for R/R ITP. ClinicalTrials.gov. April 7, 2022. Accessed October 24, 2022.

Reviewed by Hasan Avcu, MD, on 10/30/2022.

---

Diana Diez Gaspar, PharmD, PhD

Diana earned her PhD and PharmD with distinction in the field of Medicinal and Pharmaceutical Chemistry at the Universidade do Porto. She is an accomplished oncology scientist with 10+ years of experience in developing and managing R&D projects and research staff directed to the development of small proteins fit for medical use.