Clinical trial NCT05694767: A Prospective, One-arm and Open Clinical Study of CM313 in the Treatment of Immune Thrombocytopenia
Official title: A Prospective, One-arm and Open Clinical Study to Assess Safety and Efficacy of Anti-Human CD38 Monoclonal Antibody CM313 in the Treatment of Primary Immune Thrombocytopenia
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Immune Thrombocytopenia
Treatment
Lead sponsor: Institute of Hematology & Blood Diseases Hospital, China
Sponsor class: OTHER
First posted: 2023-01-23
Enrollment: 22
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: To evaluate the safety and efficacy of CM313 in the treatment of immune thrombocytopenia in patients who have not responded adequately or relapsed after first-line treatment and at least one second-line therapy including rituximab and/or TPO-RA.

Detailed description: Immune thrombocytopenia (ITP) is an organ-specific autoimmune disease, which is characterized by decreased platelet count and skin and mucosal bleeding. ITP is a kind of disease with increased platelet destruction and impaired platelet production caused by autoimmunity. Conventional treatment of adult ITP includes first-line glucocorticoid and immunoglobulin therapy, second line TPO and TPO receptor agonist, splenectomy and other immunosuppressive treatments (such as rituximab, vincristine, azathioprine, etc.). ITP is one of the most common hemorrhagic diseases. At present, the treatment response of ITP is not good, and a considerable number of patients need drug maintenance treatment, which seriously affects the quality of life of patients and increases the economic burden of patients. Therefore, there is still a lack of effective treatment for adult ITP, especially for recurrent and refractory ITP patients, which is one of the problems that have attracted more attention and need to be solved urgently.

The main pathogenesis of ITP is the loss of platelet autoantigen immune tolerance, which leads to abnormal activation of humoral and cellular immunity. It is characterized by antibody mediated platelet destruction and insufficient platelet production by megakaryocytes. The residual long-term autoreactive plasma cells may be a source of therapeutic resistance to autoimmune cytopenia. Antiplatelet specific plasma cells have been detected in the spleen of patients with rituximab refractory ITP. Therefore, the strategy of simply eliminating B cells may not work, because LLPC will continue to produce pathogenic antibodies. However, targeting LLPC becomes a new strategy to treat autoimmune diseases.

CM313, a kind of anti-CD38 antibody, is a new type of monoclonal antibody targeting CD38. It targets plasma cells and has carried out some clinical studies in multiple myeloma, with good therapeutic effects. In addition, the clinical trials of similar CD38 monoclonal antibody drugs, such as daratumumab, in the treatment of autoimmune diseases, including membranous nephropathy, systemic lupus erythematosus (SLE) and ITP, are also being carried out simultaneously. We assume that autologous reaction LLPC may be the cause of treatment failure in some ITP patients. Therefore, the use of CD38 monoclonal antibody to clear long-term surviving plasma cells in ITP patients may be a new strategy for treating ITP patients.

Therefore, the investigators designed this clinical trial to evaluate the safety and efficacy of CM313 in the treatment of immune thrombocytopenia in patients who are steroid-refractory or steroid-dependent, and fail to respond to at least one previous second-line therapy, including rituximab and/ or TPO agonist.

Eligibility criteria: Inclusion Criteria:

* Age 18 and above, male or female
* Conform to the diagnostic criteria of immune Thrombocytopenia (ITP)
* Diagnosis of ITP ≥3 months, and with a platelet count of \<30 X 109/L measured within 2 days prior to inclusion
* Failure to achieve response or relapse after corticosteroid therapy, and at least one second-line therapy including rituximab or TPORAs.
* The previous emergency treatment of ITP (e.g. methylprednisolone, platelet transfusion, IVIG transfusion) must be completed at least 2 weeks before the first administration
* Signed and dated written informed consent
* With normal hepatic and renal functions
* ECOG physical state score ≤ 2 points
* Cardiac function of the New York Society of Cardiac Function ≤ 2
* Patients receiving maintenance treatment (including corticosteroids (less than or equal to 0.5mg/kg prednisone), TPO receptor agonists, etc.) must have a stable dose at least 4 weeks before the first administration, and azathioprine, danazol, cyclosporin A, tacrolimus, sirolimus, etc. must be stopped at least 4 weeks before the first administration; The end of rituximab treatment was\>3 months；More than 6 months after splenectomy.

April 10, 2023 After approval by the Ethics Committee on , subjects no longer require platelet glycoprotein autoantibodies positivity upon enrollment.

Exclusion Criteria:

* Received any treatment of anti-CD38 antibody drug
* Uncontrollable primary diseases of important organs, such as malignant tumors, liver failure, heart failure, renal failure and other diseases;
* HIV positive;
* Accompanied by uncontrollable active infection, including hepatitis B, hepatitis C, cytomegalovirus, EB virus and syphilis positive;
* Accompanied by extensive and severe bleeding, such as hemoptysis, upper gastrointestinal hemorrhage, intracranial hemorrhage, etc.;
* At present, there are heart diseases, arrhythmias that need treatment or hypertension that researchers judge is poorly controlled;
* Patients with thrombotic diseases such as pulmonary embolism, thrombosis and atherosclerosis;
* Those who have received allogeneic stem cell transplantation or organ transplantation in the past;
* Patients with mental disorders who cannot normally obtain informed consent and conduct trials and follow-up;
* Patients whose toxic symptoms caused by pre-trial treatment have not disappeared;
* Other serious diseases that may limit the subject's participation in this test (such as diabetes; Severe cardiac insufficiency; Myocardial obstruction or unstable arrhythmia or unstable angina pectoris in recent 6 months; Gastric ulcer, etc.);
* Patients with septicemia or other irregular severe bleeding;
* Patients taking antiplatelet drugs at the same time;
* Pregnant women, suspected pregnancies (positive pregnancy test for human chorionic gonadotropin in urine at screening) and lactating patients.

Primary outcomes:
measure: To evaluate the efficacy after CM313 treatment within 8 weeks
timeFrame: 8 weeks
measure: Safety of CM 313
timeFrame: 24 weeks
Secondary outcomes:
measure: Other efficacy evaluation
timeFrame: 12 weeks
measure: Duration from treatment initiation to platelet count ≥30×10^9/L and ≥50×10^9/L
timeFrame: 12 weeks
measure: Cumulative weeks of platelet ≥30×10^9/L and platelet ≥50×10^9/L
timeFrame: 24 weeks
measure: Number of subjects with clinically significant bleeding as assessed using the world health organization (WHO) bleeding scale
timeFrame: 24 weeks
measure: Measurements of platelet glycoprotein (GP) autoantibodies
timeFrame: 24 weeks
measure: Measurements of immunoglobulin quantification
timeFrame: 24 weeks
measure: Measurements of various subsets of immunocompetent cells
timeFrame: 24 weeks
Other outcomes:
Locations:
city: Tianjin
country: China
facility: Chinese Academy of Medical Science and Blood Disease Hospital
state: Tianjin
Study officials:
affiliation: Chinese Academy of Medical Science and Blood Disease Hospital
name: Lei Zhang, MD
role: PRINCIPAL_INVESTIGATOR
References: