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Updated: Aug 9, 2026
In Vitro Methods for Comparing Target Binding and CDC Induction Between Therapeutic Antibodies: Applications in Biosimilarity Analysis
Published on: May 4, 2017
A DeImmunized chimeric anti-C3b/iC3b monoclonal antibody enhances rituximab-mediated killing in NHL and CLL cells via
Wu Peng1, Xin Zhang, Nehal Mohamed
1Elusys Therapeutics, 25 Riverside Drive, PO Box 102, Pine Brook, NJ 07058, USA. wpeng@elusys.com
Insights
A new antibody, H17, enhances Rituximab (RTX) effectiveness in killing non-Hodgkin's lymphoma (NHL) cells by boosting complement-dependent cytotoxicity (CDC). This approach shows promise for treating NHL and chronic lymphocytic leukemia (CLL).
Area of Science:
- Immunology
- Oncology
- Pharmacology
Background:
- Complement-dependent cytotoxicity (CDC) is a crucial mechanism for Rituximab (RTX) in eliminating non-Hodgkin's lymphoma (NHL) cells.
- Enhancing RTX-mediated CDC could improve treatment outcomes for hematological malignancies.
Purpose of the Study:
- To evaluate the efficacy of a novel antibody, H17, in augmenting RTX-induced CDC against NHL and chronic lymphocytic leukemia (CLL) cells.
- To investigate H17's potential as an adjunctive therapy in combination with RTX.
Main Methods:
- Generation of H17, a de-immunized chimeric monoclonal antibody targeting C3b and iC3b.
- In vitro treatment of NHL cell lines with RTX and H17 in the presence of complement.
- Ex vivo testing of H17 and RTX on primary cells from NHL and CLL patients.
Main Results:
- H17 significantly increased RTX-mediated cell death in NHL cell lines by 40-70% within 1 hour.
- H17 demonstrated enhanced RTX activity in RTX-resistant NHL samples and some CLL samples.
- No significant enhancement was observed when RTX plus complement alone achieved >80% killing.
Conclusions:
- H17 shows therapeutic potential as an adjunctive treatment to RTX for NHL and CLL.
- H17 may broaden the applicability of CDC-mediated therapies for hematological cancers.
- Further research into H17's role in enhancing other therapeutic antibodies is warranted.
Abstract:
Complement-dependent cytotoxicity (CDC) is a key mechanism of Rituximab (RTX) action in killing non-Hodgkin's lymphoma (NHL) cells both in vitro and probably in vivo. A DeImmunized, mouse/human chimeric monoclonal antibody (Mab), H17, specific for cell-associated complement C3 cleavage products, C3b and iC3b, was generated to enhance RTX-mediated killing of target cells by CDC. When NHL cell lines were treated with RTX and H17 in the presence of complement for 1 h, there was 40-70% more cell death than that observed with RTX alone. The enhancing effect of H17 was also seen over longer treatment periods. H17 was tested ex vivo against primary cells from NHL and chronic lymphocytic leukemia (CLL) patients. In RTX-resistant NHL samples, H17 enhanced RTX-mediated killing; in the remaining samples RTX + complement alone promoted more than 80% killing, and no significant enhancement was observed. The H17 antibody also increased RTX-mediated killing in four out of nine CLL samples. H17 may have therapeutic applications in NHL and CLL treatment as an adjunctive therapy to RTX. It might also enhance the activity of other therapeutic antibodies that work through CDC.
