A Phase 1/2, Open-Label, Dose Escalation Study of PRTX-100 in Adult Patients With Persistent/Chronic Immune Thrombocytopenia
Pre-clinical and clinical evaluations show that PRTX- 100 has biological activity that may lead to improved platelet levels where these are decreased due to immunological pathologies and that PRTX-100 has an acceptable safety profile. In vivo treatment with PRTX-100 has been shown to raise platelet counts in a mouse model of immune thrombocytopenia (ITP). The primary objective of the study is to assess the efficacy of PRTX-100 in terms of platelet response in patients with chronic/persistent ITP. Funding Source - FDA OOPD (1R01FD005750-01A1)
• Willing and able to provide written informed consent prior to initiation of any study-related procedures
• Male or female ≥ 18 years of age
• ITP that has persisted for ≥ 3 months. ITP must be diagnosed in accordance The American Society of Hematology 2011 Evidence-based Practice Guideline for Immune Thrombocytopenia (Neunert et al. 2011) or the International Consensus Report on The Investigation and Management of Primary Immune Thrombocytopenia (Provan et al. 2010), as locally applicable.
• Received ≥ 1 typical regime for the treatment of ITP. Splenectomy is considered one standard ITP treatment
• A mean platelet count of \< 30,000/μL, with no individual platelet count \> 35,000/μL; or for those subjects receiving a constant dose of permitted treatments for ITP: a mean platelet count \< 50,000/μL, with no count greater than 55,000/μL. (Note: The mean platelet count must be determined based on 2 platelet counts including one obtained within ≤ 7 days of first PRTX-100 dose and the other within ≤ 30 days of the first dose of PRTX-100.)
• If on corticosteroids, a dose of \< 1 mg/kg prednisone per day or equivalent that has been stable for ≥ 21 days prior to the first dose of PRTX-100. High-dose pulse steroid therapy is NOT allowed within 14 days prior to the first dose of PRTX-100.
• If receiving eltrombopag or romiplostim, the dose must have been stable for ≥ 21 days prior to the first dose of PRTX-100
• If on steroid-sparing adjunctive immunosuppression with cyclosporine, azathioprine, mycophenolate, or 6-mercaptopurine, the dose must have been stable for ≥ 30 days prior to the first dose of PRTX-100 and must be expected to remain stable through study Day 29, unless dose reduction is required due to toxicities. Treatment with other cytotoxic agents (e.g. cyclophosphamide, vincristine) are not allowed within three months prior to the first dose of PRTX- 100.
• Any prior treatment with rituximab or any other anti-CD20 agent must have been \> 6 months prior to the first dose of PRTX-100
⁃ If female, must not be pregnant (pregnancy testing will be performed locally in all female patients of childbearing potential), must not be nursing and must be one of the following:
∙ Surgically sterile (bilateral tubal ligation, hysterectomy)
‣ Postmenopausal with last natural menses \> 24 months prior
‣ Premenopausal and using an acceptable form of birth control. Acceptable forms of birth control include: hormonal contraceptives (implantable, oral, patch) used for ≥ 2 months prior to screening or double barrier methods (any combination of two of the following: intrauterine device \[IUD\], male or female condom with spermicidal gel, diaphragm, sponge, cervical cap). All premenopausal females must have a negative urine or serum pregnancy test at screening and on Day 1 prior to first PRTX-100 treatment.