Study of Efficacy, Safety and Immunogenicity of GP40141 (GEROPHARM, Russia) in Patients With Immune Thrombocytopenia

Inclusion Criteria:

• Signed informed consent to participate in the study.

• male or female

• Age ≥18 years

• Diagnosis of primary immune thrombocytopenia (PIT).

• Duration of PIT at the Screening Visit: for cohort 1: ≥3 months; for cohort 2: ≥6months.

• PIT therapy with glucocorticosteroids (GCS) for cohort 1: duration of continuoustherapy ≥3 months at the Screening Visit or ≥2 courses of pulse therapy during theyear before the Screening Visit;

• TPO-RA therapy: for cohort 1: no history of TPO-RA use; for Cohort 2: Use of TPO-RAfor ≥12 weeks at the Screening Visit;

• No increase in TPO-RA dose during the 4 weeks preceding the end of screening.

• Blood platelet count: for cohort 1: mean platelet count ≤30×109/L, based on thelast two measurements 7±2 days apart, each of which had a platelet count ≤35×109/LOR steroid dependence, defined as the use of prednisolone at a daily dose of >5 mg (or another corticosteroid at an equivalent dose) for ≥2 months before the ScreeningVisit to maintain a platelet count ≥30×109/L OR to prevent bleeding; for cohort 2:platelet count ≥50×109/ml for ≥6 weeks out of the last 8 weeks of follow-up withplatelet counts every 7±2 days and no emergency treatment for severe hemorrhagicsyndrome in the last 12 weeks before the Screening Visit.

• Consent and ability to comply with the procedures of the Protocol, as well as theprohibitions and restrictions provided for by the Research Protocol.

Exclusion Criteria:

• Hypersensitivity to romiplostim.

• History of TPO-RA use: for cohort 1: any TPO-RA; for cohort 2: any TPO-RA, with theexception of romiplostim and eltrombopag.

• Unpromising treatment with romiplostim in the opinion of the Researcher

• Splenectomy <24 weeks prior to the Screening Visit or planned splenectomy during thestudy.

• Treatment with rituximab within the 14 weeks preceding the Screening Visit, orplanned treatment with rituximab during the study.

• Treatment with intravenous immunoglobulin or anti-D immunoglobulin during the 2weeks preceding the Screening Visit, or planned use during the study.

• Therapy with hematopoietic growth factors during the 4 weeks preceding the ScreeningVisit, or their planned use during the study.

• Therapy with alkylating chemotherapy drugs during the 8 weeks preceding theScreening Visit, or their planned use during the study.

• Use of other medicines listed in section 5.3.3. of this study protocol.

• Participation in a clinical trial of an investigational drug or investigationalmedical device within 4 weeks or 5 half-lives (whichever is longer) preceding theScreening Visit.

• Secondary immune thrombocytopenia in the following diseases: autoimmune thyroiditis,systemic lupus erythematosus (SLE), antiphospholipid syndrome (APLS),lymphoproliferative diseases, drug-mediated, viral origin (herpes viruses, HIV,chronic viral hepatitis).

• Hereditary thrombocytopenia.

• Diseases of the hematopoietic system accompanied by thrombocytopenia (for example,acute leukemia, aplastic anemia, myelodysplastic syndrome, lymphoproliferativediseases).

• Metastatic bone marrow lesions.

• Uncontrolled concomitant diseases of internal organs.

• Arterial thrombosis (for example, myocardial infarction, acute cerebrovascularaccident) within 1 year preceding the Screening Visit.

• History of venous thrombosis.

• High risk of venous thrombosis and thromboembolism, defined as the presence of atleast three of the following risk factors:

• diabetes;

• smoking;

• use of combined oral contraceptives or menopausal hormone therapy;

• positive titer of antiphospholipid antibodies;

• hypercholesterolemia (>240 mg/dl or >13 mmol/l);

• hypertriglyceridemia;

• arterial hypertension requiring therapy.

• HIV infection.

• Viral hepatitis B or C.

• Oncological and/or oncohematological disease beyond the stage of complete 5-yearremission at the Screening Visit.

• Major surgery ("major surgery") within 8 weeks preceding the Screening Visit, orincomplete recovery from surgery at the Screening Visit.

• Pregnancy or lactation in women.

• Hospitalization for any reason planned during the patient's participation in thestudy.

• A history of mental disorders that do not allow you to adequately assess yourbehavior and follow the conditions of the study protocol.

• Alcoholism. Alcoholism or consumption of alcohol in quantities exceeding for men: 14units. per week (on average); for women: 7 units. per week (on average).