An open-label, single-arm, dose-escalation study designed to determine the potential safety, efficacy, maximum tolerated dose (MTD) or optimal biologic dose (OBD), and recommended phase 2 dose (RP2D) of JSP191 (briquilimab) monotherapy for LR-MDS subjects with documented cytopenia (red blood cell-transfusion dependent, thrombocytopenia, and/or neutropenia).
Age ≥ 18 years MDS with IPSS-R very low, low, or intermediate risk features Symptomatic cytopenias Women of childbearing potential (WOCBP) must agree to use an oral or implanted contraceptive, a double-barrier method of birth control, or an intrauterine device upon enrollment and through 3 months after receiving the last dose of JSP191 Women not of childbearing potential must be post-menopausal (no menstrual period for a minimum of 12 months) or surgically sterilized and have a negative serum pregnancy test upon study entry Male subjects must be surgically sterile or willing to use contraception upon enrollment and through 3 months after receiving the last dose of JSP191 Must be willing and able to provide informed consent
Exclusion Criteria:
Anemia secondary to iron deficiency, vitamin B12 deficiency, or folate deficiency Prior allogeneic or autologous stem cell transplant Known history of human immunodeficiency virus (HIV) (no laboratory testing is required), or active infection with hepatitis B or hepatitis C Pregnant women or women who are nursing and do not wish to discontinue breastfeeding Any other medical condition that, in the opinion of the Investigator, could pose a significant safety risk to the subject or jeopardize the integrity of the study Subjects who, in the opinion of the Investigator, may not be able to comply with the requirements of the study
