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I - MAB BIOPHARMA I - Mab Presents Interim Clinical Data of Lemzoparlimab in Combination with Rituximab in Relapsed and Refractory Non - Hodgkin Lymphoma at ASH 2021 December 14 , 2021 - Positive clinical activity was observed in heavily pretreated patients who had progressed on prior Anti - CD20 therapies SHANGHAI and GAITHERSBURG , Md . , Dec. 14 , 2021 / PRNewswire / -- I - Mab ( the " Company " ) ( Nasdaq : IMAB ) , a clinical stage biopharmaceutical company committed to the discovery , development and commercialization of novel biologics , today reported interim data from an ongoing clinical trial ( NCT03934814 ) of lemzoparlimab in combination with rituximab ( Rituxan® ) in heavily treated patients with relapsed or refractory non - Hodgkin's lymphoma ( NHL ) , at the 63rd American Society of Hematology ( ASH ) Annual Meeting . I - MAB BIOPHARMA Lemzoparlimab is a novel CD47 antibody that blocks CD47 and SIRPa interaction through a epitope designed to confer red blood cell ( RBC ) sparing properties . In all clinical trials conducted so far , lemzoparlimab is administered without a priming dose . " Lemzoparlimab's initial results show it appears to be safe and well - tolerated in combination with rituximab without the need of a priming dose , " said Amitkumar Mehta , MD , Associate Professor and Director of the Lymphoma Program at the University of Alabama at Birmingham and O'Neal Comprehensive Cancer Center at UAB . " This data support further evaluation of lemzoparlimab in combination with rituximab , which is currently ongoing in study in patients with r / r DLBCL and indolent lymphoma . " The preliminary data was generated from nine patients with relapsed and refractory NHL who received at least two prior lines of therapies , with a median of four lines . Lemzoparlimab was safe and well - tolerated at doses of 20 mg / kg and 30 mg / kg weekly , without a priming dose . The maximum tolerated dose ( MTD ) was not reached . Most treatment - related adverse events ( TRAE ) were manageable infusion - related reactions ( n = 4 ) . Among seven efficacy - evaluable patients , four achieved complete response ( CR ) [ 1 transformed FL - DLBCL +3 FL ] , one partial response ( PR ) of FL were observed ( ORR = 71 % ) ; two reported stable disease ( SD ) ; and the disease control rate ( DCR ) is 100 % . Tumor shrinkage was observed in all evaluable patients . The median time to response was 50 days and response lasted from 61 to 236 days . A high level ( 80 % and 90 % ) of intra - tumoral distribution measured by IHC of tumor biopsy was reached at 20 mg / kg and 30mg / kg weekly . " We're encouraged by the interim results reported today . The clinical data of lemzoparlimab further builds our confidence for an innovative therapy that utilizes macrophages against tumors , said Dr. Joan Shen , Chief Executive Officer of I - Mab . " It is very exciting that lemzoparlimab is bringing new hopes to our patients , and we are accelerating its clinical development through international multi - center trials in the U.S. and China . " The ongoing study with 30 mg / kg lemzoparlimab weekly combined with rituximab is being expanded to enroll more patients with relapsed and refractory diffuse large B - cell lymphoma ( DLBCL ) or indolent lymphoma . About CD47 and Lemzoparlimab CD47 is a cell surface protein over - expressed in a wide variety of cancers and can act to protect tumors by delivering a " don't eat me " signal to otherwise tumor - engulfing macrophages . CD47 antibody blocks this signal and enables macrophages to attack tumor cells . However , development of CD47 antibody as a cancer therapy has been hampered by its hematologic side effects , such as severe anemia , caused by natural binding of CD47 antibody to red blood cells . Scientists at I - Mab have discovered a novel CD47 antibody , lemzoparlimab , that is designed to target tumor cells while exerting a minimal untoward effect on red blood cells . Multiple clinical studies are ongoing in both the U.S. and China to explore indications in treating both hematologic maliglencies and solid tumors . Lemzoparlimab is being studied in patients with myelodysplastic syndrome ( MDS ) , acute myelocytic leukemia ( AML ) , and advanced solid tumors in combination with chemotherapy and immune checkpoint inhibitors in the U.S. and China . Combined clinical results from these studies will potentially support registrational trials later in China .