1. MONOCLONAL ANTIBODIES
As therapeutics
As diagnostics
As targeting agents

2. INTRODUCTION Have remarkable specificity
Single specificity -> promising in human therapy
Widely used as diagnostic & research reagents

3. MANUFACTURING OF MONOCLONAL ANTIBODIES
Monoclonal antibodies are traditionally made from mice or rats that have been immunized with the desired antigen

4. CONVENTIONAL METHOD FOR MAKING mAbs

5. Clinical Uses for Monoclonal Antibodies
In vitro diagnostic agents
In vivo imaging agents
Therapeutic agents (MAb works like a drug)
Targeting agents (MAb linked to toxin)

6. Monoclonal Antibodies as in vitro Diagnostic Agents
Detects the presence, absence or relative amount of protein.
MAbs work nicely because they bind very specifically to the protein.
Example: Pregnancy tests. MoAb detects elevated levels of HCG in the urine. High level of HCG is produced by placenta in the early stages of pregnancy.

7. ELISA
Enzyme
produces
Color
Enz

8. Monoclonal Abs on Therapeutics
Suppressing The immune system
Killing Malignant cells
59 MAbs currently in clinical trials
31 for cancer therapy

9. SUPPRESSING THE IMMUNE SYSTEM
Monoclonal antibodies specific to the different receptors of various cells are used to prevent the normal usage of these receptors.

10. SUPPRESSING THE IMMUNE SYSTEM
First MAb on market was OKT3, a murine MAb
used to prevent renal transplant rejection
Orthoclone OKT3  targets T-lymphocytes surface antigen CD3  reversal of acute kidney transplant rejection.

11. Problems with Mouse Ab in Humans
Human immune response to mouse antibodies (HAMA-Human Anti-Mouse Antibodies)
Endanger the patient and enhance the clearance of the Ab and reduce its therapeutic effect.
Mouse antibodies do not activate human complement system or Ab-mediated cytotoxicity

12. To Overcome this Problem
Hybrid monoclonal antibodies have been made by recombinant DNA technology

13. Types of MAbs Mouse Chimeric Humanized Human Blue: Mouse sequences
Red: Human sequences

14. MOUSE CDR
Regions “A”
MOUSE Fv region
Mutagenesis
“ B”

16. SUPPRESSING THE IMMUNE SYSTEM
Zenapax (Daclizumab)  targets Alpha-chain of IL-2 receptor (CD25) of T- lymphocytes.  prevention of acute kidney transplant rejection.
Remicade (Infliximab)  targets tumor necrosis factor-alpha (TNF-α)  treatment of Crohn’s disease & rheumatoid arthritis.
Xolair (Omalizumab)  targets IgE preventing the binding of IgE to mast cells against allergic asthma.

17. Zenapax: Humanized Monoclonal Antibody
Mouse amino acids - Red
Human amino acids - White
Prevents rejection in kidney transplantations

18. Clinical trials with Infliximab…
A chimeric Mab against TNF:
Results showed a significant clinical improvement in all Infliximab doses.
Treatment is usually given together with methotrexate.

19. TO KILL MAGLIGNANT CELLS
Tumors have antigen on the surface that are specific to themselves.
They are also more highly expressed than normal.
Monoclonal antibodies used to target these tumors specific antigen (TSA)

20. TO KILL MAGLIGNANT CELLS

21. TO KILL MAGLIGNANT CELLS
Mabthera/Rituxan (Rituximab)  targets CD20 surface antigen of B-lymphocytes  treatment of non-Hodgkin’s lymphoma.
Herceptin (Trastuzumab)  targets Human epidermal growth factor-like receptor 2 (HER-2)  treatment of metastatic breast cancer over expressing HER-2 protein. The only monoclonal so far that is effective against solid tumors.
MabCampath (Alemtuzumab)  targets B-lymphocytes CD52  treatment of B-cell chronic lymphocytic leukemia. Complete remission up till now.

22. MAbs: Site-directed Targeting Agents
Link a toxic drug, protein or radioisotope to an MAb with a high specific affinity for a tumor-associated antigen.

23. Toxin X X
Toxin
Cancer cell
expressing
tumor antigen

24. CONCLUSION Monoclonal Antibodies used as in vitro Diagnostic Agent
In vivo imaging agents
Therapeutics agents
Supressing immune system
Killing Malignant cells
Targeting Agents (MAb linked to toxin)