IMMUNOMODULATOR

1. IMMUNOMODULATORS Prepared By Ms. Prexita Patel Dept. of Pharmacology Anand Pharmacy College, Anand

2. The Immune Response - why and how ? • Discriminate: Self / Non self • Destroy: • Infectious invaders • Dysregulated self (cancers) • Immunity: • Innate, Natural • Adaptive, Learned

3. Who are involved ? • Innate • Complement • Granulocytes • Monocytes/macrophages • NK cells • Mast cells • Basophils • Adaptive: • B and T lymphocytes • B: antibodies • T : helper, cytolytic, suppressor.

4. Application of Immunomodulator • Hypersensitivity reactions: • It is undesirable reactions produced by the normal immune system and may be damaging, uncomfortable, or occasionally fatal • Type I (immediate ) e.g. Anaphylactic shock, Allergy • Type II: antibody-dependent (or cytotoxic): Self-cells are marked by antibodies for destruction. e.g. cytopenia (low number of blood cells) • Type III: Immune complexes: (antigen-antibody reactions) deposited in various tissues. e.g. Allergy to a medicine • Type IV: Cell-mediated or delayed: these reactions are mediated by T cells, monocytes, and macrophages. e.g. Contact dermatitis

5. B. Autoimmunity: • – Autoimmune diseases arise when the body mounts an immune response against itself as a result of failure to distinguish self tissues and cells from foreign antigens. • E.g. Rheumatoid Arthritis, Systemic lupus erythematosus, Multiple Sclerosis etc. • C. Immunodeficiency Diseases: • – Occur when one or more of the components of the immune system are inactive • Congenital – Severe combined immunodeficiency (SCID) E.g. Adenosine deaminase (ADA) deficiency. Deficiency of this enzyme results in an accumulation of deoxyadenosine, which in turn leads to: •  1- increase in S-adenosylhomocysteine affecting the differentiations of lymphocytes • 2- prevents DNA synthesis, so affecting T and B cells division. • Extrinsic – Cancer and HIV causing AIDS.

6. D. Organ Transplants/Rejections: • Types of Organ Transplants • Autograft: tissue graft from one body site to another (same person) • Isograft: graft received from a genetically identical donor (identical twin) • Allograft: graft received from genetically non-identical donor (same species) • Xenograft: graft received from another species of animal • Transplant rejection: mediated by the immune system (especially T cells, NK, antibodies) • For e.g. Organ transplantation of kidney, liver, Heart etc, Bone marrow etc.

7. E. Cytokines • Cytokines are a category of signaling molecules used extensively in intercellular communication. • They are regulators of host responses to infection, immune responses, inflammation, and trauma • Cytokines can be classified as proteins, peptides, or glycoproteins • Cytokines include • Interleukins / lymphokines • Interferons (IFNs), • Tumor Necrosis Factors (TNFs) (causing the apoptosis), • Transforming Growth Factors (TGFs) • Colony-stimulating factors (CSFs) (causing cells to proliferate and differentiate).

8. Immune Response

9. MAJOR STEPS IN IMMUNE RESPONSES CD8 T cell IL-2 Antigen Cytotoxic T cells 1 4 3 2 Primed CD4 T helper cell IL-1 IL-2 CD4 T helper cell Antigen presenting Cell (macrophage, dendritic cell) 4 Plasma cells IL-2 B cell

10. IMMUNOMODULATORS Immunomodulator are drugs which either suppress the immune system –Immunosuppressant or stimulate the immune system –Immunostimulant Immunosuppressant • Classification :- • Glucocorticoids:- • Prednisolone, Methylprednisolone, Prednisone. • Calcineurin inhibitors :- • Cyclosporine, Tacrolimus, mTOR inhibitors :- Sirolimus and everolimus

11. Antiproliferative / antimetabolic agents :- Azathioprine , Mycophenolate Mofetil. Others – Methotrexate, Cyclophosphamide, Thalidomide and Chlorambucil Biological agents :- (a) TNFα inhibitors: Etanercept, Infliximab, Adalimumab. (b) IL-1 receptor antagonist: Anakinra (c) IL-2 receptor antagonists: Daclizumab, Basiliximab. (d) Anti CD-3 antibody: Muromonab CD3 (e) Polyclonal antibodies: Antithymocyte antibody (ATG), Rho immune globulin. MISCELLANEOUS Campath-1H (Alemtuzumab) , ECULIZUMAB NATALIZUMAB

12. Inhibitors of Immune Response (site of action) Antigen recognition: Immune Globulin IL-1production, cell proliferation: Corticosteroids T cell receptors/surface proteins: Muromonab-CD3 (OKT3), Anti-thymocyte globulin (ATG) IL-2 gene expression (Cyclosporine, Tacrolimus), and IL-2 signal transduction (Sirolimus) T cell proliferation & differentiation: Mycophenolate Azathioprine, Cyclophosphamide (all cell proliferation)

14. SITES OF ACTION OF IMMUNOSUPPRESSIVE DRUGS CD8 T cell 4 Antigen IL-2 X Cytotoxic T cells 1 E X C A X 3 2 X Primed CD4 T helper cell X D D IL-2 IL-1 B antigen presenting cell CD4 T helper cell 4 X Plasma cells IL-2

15. Glucocorticoids Mechanism of Action :- • Induce redistribution of lymphocytes – decrease in peripheral blood lymphocyte counts • Intracellular receptors – regulate gene transcription • Down regulation of IL-1, IL-6 • Inhibition of T cell proliferation • Neutrophils, Monocytes display poor chemotaxis • Broad anti-inflammatory effects on multiple components of cellular immunity

16. Uses :- • Transplant rejection • GVH – BM transplantation • Autoimmune diseases – RA, SLE, Hematological conditions • Psoriasis • Inflammatory Bowel Disease, Eye conditions

17. Toxicity • Hyperglycemia • Hypertension • Growth retardation • Avascular Necrosis of Bone • Risk of Infection • Poor wound healing • Cataract

18. Calcineurin inhibitors • Eg. Cyclosporine, Tacrolimus , Sirolimus. • Most effective immunosuppressive drugs. • Target intracellular signaling pathways. • Blocks Induction of cytokine genes. M/A :- 1. Inhibits calcineurin by binding cyclophilins . This prevents the transcription of genes responsible for the production of Interleukin. 2. Also causes a decrease in expression of Interferon-gamma. Decreased activity and decreased growth of T-Lymphocytes.

19. CYCLOSPORIN TACROLIMUS

20. Cyclosporine • More effective against T-cell dependent immune mechanisms – transplant rejection, autoimmunity • IV, Oral Uses • Organ transplantation: Kidney, Liver, Heart • Rheumatoid arthritis, IBD, uveitis • Psoriasis • Aplastic anemia • Skin Conditions- Atopic dermatitis, Alopecia Areata, Pemphigus vulgaris, Lichen planus, Pyoderma gangrenosum.

21. Toxicity : Cyclosporine • Renal dysfunction • Tremor • Hirsuitism • Gum hyperplasia • Hypertension • Hyperlipidemia • Hyperuricemia – worsens gout • Calcineurin inhibitors + Glucocorticoids = Diabetogenic

22. Drug Interaction :- Cyclosporine • CYP 3A4 Inhibitors: CCB, Antifungals, Antibiotics, HIV PI, Grape juice inhibit its metabolism to increase bioavailability and toxicity. • Inducers: Rifampicin, Phenytoin lower its blood levels so that transplant rejection may result. • Additive nephrotoxicity: NSAIDs, Aminoglycoside, AMB. TACROLIMUS M/A:- It binds to FK binding proteins to inhibit calcineurin. Prevents Interleukin 2 transcription and blocking activation and growth of T-cells. Uses :- 1. transplant rejection prophylaxis. 2. Autoimmune diseases e.g ulcerative colitis and vitiligo. Adverse effects Similar to Cyclosporine with the Nephrotoxicity and Neurotoxicity. Can increase risk of diabetes. It does not cause any hirsutism and gingival hyperplasia.

23. Drug interaction of Tacrolimus CYP3A4 inhibitor increses its concentration and leads to toxicity while inducer decreses its concentration and lead to failure of theray. SIROLIMUS(RAPAMYCIN) M/A :- Contrary to cyclosporine and tacrolimus, drugs that affect the first phase of T lymphocyte activation, sirolimus affects the second one ( signal transduction and lymphocyte clonal proliferation). It binds to FKBP1A like tacrolimus, however the complex does not inhibit calcineurin but another protein, mTOR (mammalian target of rapamycin). It indirectly inhibits several T-cell growth and activation by preventing their transition from G1 to S phase of the cell cycle. It prevents B cell differentiation into plasma cells, reducing production of IgM, IgG, and IgA antibodies.

25. Uses :- Anti-rejection drug that is used most commonly in kidney transplant recipients. Preferred over cyclosporine and tacrolimus for kidney transplant patients due to the latter drugs nephrotoxicity. Sirolimus does not cause nephrotoxicity. It is also used as a coating on cardiac stents to prevent restenosis following ballon angioplasty. Adverse effects: Can cause Interstitial Pneumonitis, Anemia, Thrombocytopenia, Leukopenia, Insulin resistance and hyperlipidemia. Drug Interactions of sirolimus : Inhibitors and inducers of CYP3A4 significantly alter its blood level, which needs to be monitored. Cyclosporine shares the same isozyme and raises the blood level of sirolimus.

26. EVEROLIMUSIt is similar to sirolimus in mechanism, clinicalefficacy, doses, toxicity and drug interactions, but is better absorbed orally and more bioavailability. The t½ is shorter (~40 hours) so that steady state levels can be reached earlier.

27. Antiproliferative and Antimetabolic drugs • Azathioprine • Mycophenolate Mofetil • Others: • Methotrexate • Cyclophosphamide • Chlorambucil

28. Azathioprine (Imuran ) M/A :- • An imidazolyl derivative of 6-MP • The main immunosuppressive cytotoxic substance. It is non-enzymatically cleaved to mercaptopurine, that acts as a purine analogue and an inhibitor of DNA synthesis. • By preventing the clonal expansion of lymphocytes in the induction phase of the immune response, it affects both the cell and the humoralimmunity. Uses • Prevention of organ transplant rejection • Rheumatoid arthritis, systemic lupus erythematosus.

29. Toxicity • Bone marrow suppression- leukopenia, thrombocytopenia, anemia. • Increased susceptibility to infection • Hepatotoxicity, • Alopecia, • GI toxicity • Drug interaction: • With Allopurinol – increases plasma level of 6-MP. • With alcohol - Nausea

30. Mycophenolate Mofetil M/A :- Prodrug  Mycophenolic acid Inhibits IMPDH – enzyme in guanine synthesis T, B cells are highly dependent on this pathway for cell proliferation Selectively inhibits lymphocyte proliferation, function – Antibody formation, cellular adhesion, migration. Uses :- Prophylaxis of transplant rejection In Combination Glucocorticoids. It is superior to azathioprine, MMF + glucocorticoid + sirolimus is a non-nephrotoxic combination that is utilized in patients developing renal toxicity with cyclosporine/tacrolimus.

31. Toxicity • GI, • Hematological Diarrhea • Leucopenia • Risk of Infection Drug Interaction Decreased absorption when co-administered with antacids Acyclovir, Gancyclovir compete with mycophenolate for tubular secretion Chlorambucil It has relatively weak immunosuppressant action. Utilized in autoimmune diseases and transplant maintenance regimens.

32. Methotrexate This folate antagonist is a potent immunosuppressant which markedly depresses cytokine production and cellular immunity, and has anti-inflammatory property. It has been used as a first line drug in many autoimmune diseases like rapidly progressing rheumatoid arthritis ,severe, psoriasis, pemphigus, myasthenia gravis, uveitis, chronic active hepatitis. Low dose Mtx maintenance therapy is relatively well tolerated.

33. Cyclophosphamide This cytotoxic drug has more marked effect on B cells and humoral immunity compared to that on T cells and CMI. It has been particularly utilized in bone marrow transplantation in which a short course with high dose is generally given. In other organ transplants it is employed only as a reserve drug. In rheumatoid arthritis, it is rarely used, only when systemic manifestations are marked. Low doses are occasionally employed for maintenance therapy in pemphigus, systemic lupus erythematosus and idiopathic thrombocytopenic purpura.

34. BIOLOGICAL AGENTS These are biotechnologically produced recombinant proteins or polyclonal/monoclonal antibodies directed to cytokines or lymphocyte surface antigens which play a key role in immune response. They are important in refractory cases of autoimmune diseases and graft versus host reaction. TNFα inhibitors TNFα is secreted by activated macrophages and other immune cells to act on TNF receptors (TNFR1, TNFR2) which are located on the surface of neutrophils, fibroblasts, endothelial cells as well as found in free soluble form in serum and serous fluids. TNFα amplifies immune inflammation by releasing other cytokines and enzymes like collagenases and metalloproteinase.

35. Etanercept This fusion protein of human TNF receptor and Fc portion of human IgG1 neutralizes both TNFa and TNFb. It prevents activation of macrophages and T-cells. It is used rheumatoid arthritis, severe/refractory ankylosing spondylitis, idiopathic juvenile arthritis and psoriasis. Infliximab It is monoclonal antibody against TNFα which binds and inactivates TNFα. Used in refractory rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis and ankylosing spondylitis. Adalimumab It is fully human recombinant anti-TNFα antibody indicated in the same range of autoimmune diseases as infliximab, and does not bind TNFβ, but is less antigenic.

36. IL-1 receptor antagonist Stimulated macrophages and other mononuclear cells elaborate IL-1 which activates helper T-cells and induces production of otherILs, metalloproteinases, etc. An endogenous IL-1 receptor antagonist has been isolated and several of its recombinant variants have been produced for clinical use. Anakinra This recombinant human IL-1 receptor antagonist prevents IL-1 binding to its receptor. Use in refractory rheumatoid arthritis not controlled by conventional DMARDs. Anakinra along with continued Mtx has been used alone as well as added to TNFα antagonists, because its clinical efficacy as monotherapy appears to be lower.

37. IL-2 receptor antagonist The CD-25 molecule is expressed on the surface of immunologically activated, but not resting T-cells. It acts as a high affinity receptor for IL-2 through which cell proliferation and differentiation are promoted. Some anti CD-25 antibodies have been developed as IL-2 receptor antagonist to specifically arrest the activated T-cells. Daclizumab and Basiliximab M/A :- Bind to IL-2 receptor on surface of activated T cells  Block IL-2 mediated T-cell activation and proliferation. Uses Prophylaxis of Acute organ rejection Toxicity Anaphylaxis, Opportunistic Infections

38. Anti-CD3 Monoclonal Antibody • Muromonab-CD3 • M/A :- Binds to CD3, a component of T-cell receptor involved in antigen recognition and cell signaling & proliferation. • Uses: • Treatment of of acute rejection of renal allografts as well as for corticosteroid-resistant acute allograft rejection in cardiac and hepatic transplant patients. • Toxicity • “Cytokine release syndrome: High fever, Chills, Headache, Tremor, myalgia, arthralgia, weakness

39. Polyclonal antibodies Antithymocyte globulin (ATG) M/A:- Purified gamma globulin from serum of rabbits immunized with human thymocytes Cytotoxic to lymphocytes & block lymphocyte function. Clinical uses: Combine with immune suppressive agents to prevent early allograft rejection, to treat severe rejection episodes or corticosteroid-resistant acute rejection. Adverse effects include chills, fever, leukopenia and thrombocytopenia.

40. Anti-D immune globulin (RHESUMAN, RHOGAM, IMOGAM) • It is human IgG antibodies against Rh (D) antigen. • It binds the Rho antigens and does not allow them to induce antibody formation in Rh negative individuals. • Used for the prevention of postpartum/post-abortion formation of antibodies in Rho-D negative, DU negative women who have delivered or aborted an Rho-D positive foetus. • Administered within 72 hours of delivery/ abortion, such treatment prevents Rh hemolytic disease in future offspring. • It has been given at 28th week of pregnancy. • Higher doses (1000–2000 μg) are needed for Rh negative recipients of which administered Rh positive blood. • It should never be given to the infant or to Rho-D positive, DU positive individuals.

41. MISCELLANEOUS Campath-1H (Alemtuzumab) • Targets CD52 – expressed on lymphocytes, monocytes, Macrophages and prolonged T & B cell depletion • Use in Renal transplantation. ECULIZUMAB • Antibody against complement protein C5. • Used in the treatment of Paroxysmal Nocturnal Haemoglobinuria. NATALIZUMAB • Antibody against Alpha4-integrin. • Used in the treatment of Multiple sclerosis and Crohn’s disease.

42. IMMUNOSTIMULANTS • Levamisole • Thalidomide • Vaccines – BCG • Immune Globulin • Rho (D) Immune Globulin • Recombinant Cytokines • Interferons • Interleukin-2

43. LEVAMISOLE • Anthelminthic • Restores depressed immune function of B, T cells, Monocytes, Macrophages • Adjuvant therapy with 5FU in colon cancer Toxicity • Agranulocytosis

44. Thalidomide • Birth defect • Contraindicated in women with childbearing potential • Enhanced T-cell production of cytokines – IL-2, IFN-γ • NK cell-mediated cytotoxicity against tumor cells USE: • Multiple myeloma

45. Bacillus Calmette-Guerin • Live, attenuated culture of BCG strain of Mycobacterium Bovis. • Carcinoma Bladder Adverse Effects • Hypersensitivity • Shock • Chills

46. Interferons • Antiviral • Immunomodulatory activity • Bind to cell surface receptors – initiate intracellular events • Enzyme induction • Inhibition of cell proliferation • Enhancement of immune activities • Increased Phagocytosis

47. Interferon alfa-2b • Hairy cell leukemia • Malignant melanoma • Kaposi sarcoma • Hepatitis B Adverse reactions • Flu-like symptoms – fever, chills, headache • CVS- hypotension, Arrhythmia • CNS- depression, confusion

48. Interleukin-2 (aldesleukin) • Proliferation of cellular immunity – Lymphocytosis, eosinophilia, release of multiple cytokines – TNF, IL-1, IFN-γ Uses • Metastatic renal cell carcinoma • Melanoma • Toxicity • Cardiovascular: capillary leak syndrome, Hypotension

49. Immunization Active immunization • Active – Stimulation with an Antigen • Passive – Preformed antibody Vaccines Administration of antigen as a whole, killed organism, or a specific protein or peptide constituent of an organism Booster doses Anticancer vaccines – immunizing patients with APCs expressing tumor antigen.