Monoclonal antibodies (MABs) have various applications in endocrinology. MABs are used in immunoassays to detect hormones and proteins. They can also be radiolabeled for diagnostic imaging techniques. Therapeutically, burosumab treats X-linked hypophosphatemic rickets by targeting FGF-23. Romosozumab increases bone mineral density by inhibiting sclerostin. Teprotumumab treats thyroid eye disease. Alirocumab and evolocumab lower cholesterol by inhibiting PCSK9. Side effects of immune checkpoint inhibitors include hypophysitis due to removal of CTLA-4 mediated immune tolerance. Cases of type 1 diabetes have also been reported following anti

1. Monoclonal Antibodies in
Endocrinology
Dr. Shinjan Patra

4. Effect Size?
• Effect Size= (Mean of Experimental Group-
Mean of Control Group)/Standard Deviation
• Effect size quantifies the size of the difference
between two groups, and may therefore be
said to be a true measure of the significance
of the difference

5. Monoclonal Antibodies in
Endocrinology
Dr. Shinjan Patra

6. Antibodies
• Protein used by immune system to identify
and neutralize foreign objects like bacteria and
viruses. Each antibody recognizes a specific
antigen unique to its target
• High specificity of antibodies makes them an
excellent tool for detecting and quantifying a
broad array of targets, from drugs to serum
proteins to microorganisms

8. Definition of Monoclonal Ab
• Identical immunoglobulins, generated from a
single B-cell clone
• Recognize unique epitopes on a single antigen
• Derivation from a single B-cell clones and
subsequent targeting of a single epitope is
what differentiates from polyclonal antibodies

9. Production
• B-cell clones of a single parent or a single
hybridoma cell line
• Formed by the fusion of one B-cell lymphocyte
with a myeloma cell

12. Basic Advantages
• Bind to specific diseased or damaged cells
needing treatment or diagnosis
• Side effects can be treated and reduced by
using mice-human hybrid cells or by using
fractions of antibodies
• Cross-reactivity markedly less

13. Basic Disadvantages
• Very expensive and non-availability
• Time consuming project - anywhere between
6 -9 months
• May not recognize the original antigen

14. Mab: History & Development
• Paul Enrlich at the beginning of 20th century
coined the term “magic bullets” and
postulated a selectively targeting agent
• In the 1970s, the B-cell multiple myeloma was
known to produce a single type of antibody

15. • In 1975, Kohler and Milstein provided the
proof of Hybridoma technology for which they
received Nobel prize in 1984
• Muromonab was the first FDA approved Mab
for human therapeutics in 1986 for acute
glucocorticoid rejection of allogenic liver,
heart and renal transplantation

17. Major Applications
• Diagnostic- Biochemical analysis
Diagnostic imaging
• Therapeutic- Targeting agents

20. Mab in Endocrinology
• Immunoassays
• Imaging techniques in Nuclear Medicine
• Mab-as a treatment for endocrine disorders
• Mab-induced endocrine disorders

21. Mab in immunoassays

22. Monoclonal Antibodies to receptors
• TSH receptor- To diagnose and prognosticate
Graves disease
• Estrogen receptor-Quantitation of estrogen
receptors in human tumors has been used to
predict response to endocrine therapy in
patients with breast cancer

23. Antibodies to hormones/factors
• PTH- Mab technique has enabled to quantify the
biologically active PTH fragments and intact-PTH
properly
• GH- Bundesen and coworkers detected monoclonal
anti-GH antibodies as immuno-assay agents
• Insulin- series of monoclonal antibodies to insulin have
been developed by Schroer. Markedly specific in
property
• MIS

24. Cross-reactivity with hPL

25. Antibodies to probe hormone action
• Guanylate cyclase
• Calmodulin
• Na/K ATPase
• Adipocyte plasma membrane
• Non-histone chromosomal protein

26. Use in Immunoassays
• Can be of two types- Competitive and Non-
competitive/sandwich
• Mab used for large analytes with multiple non
overlapping epitopes, by virtue of its epitope
specificity i.e. sandwich assays
• Problems may arise due to circulation of
heterogeneous mixtures of multiple
biologically active forms of hormone i.e. LH

29. Mab in Diagnostic imaging

30. Radio-labeling
• Monoclonal antibodies can be labeled with radionuclides
using established radio-iodination techniques or by newer
conjugation methods
• Chloramine-T, Iodogen, lactoperoxidase and Bolton-Hunter
reagent can all be used to covalently bond iodine-131
(131I), iodine-125 ( 125I), or iodine-123 (123I) to antibodies
• DTPA used to chelate metallic cations such as indium and
technetium to antibody molecules to prepare 111In
• Direct labeling with 99mTc by stannous

31. Effects
• Radiolabeling can cause significant alteration
in the biological activity
• The determination of the immunoreactive
fraction-an important quality control measure

32. Application of this Labeled Mab
Radiopharmaceutical Usage
Iodine 123 as sodium iodide Thyroid, adrenal
I 125 as sodium iodide Thyroid
I 131 as sodium iodide Thyroid, Adrenal
I 123 MIBG
Thyroid, adrenal, NET
I131 MIBG

33. Radiopharmaceutical Usage
Technetium 99 m pertechnate Thyroid
Tc 99m DMSA Thyroid esp MTC recurrence
Tc 99m sesatimbi Parathyroid
18 F FDG Thyroid/NET
Gallium 68 DOTA NET
Indium 111 NET

34. Other diagnostic uses of Mab

35. β-cell mass (BCM) measurement
• SPECT Scintigraphy- used the beta-cell specific
monoclonal antibody IC2, modified with a
radioisotope chelator to show BCM
• Radioimmunoscintigraphy with Anti-
ganglioside monoclonal antibodies attempted

36. Mab against sperm protein to detect
sperm damage
• Selected MAbs against intra-acrosomal
mammalian sperm proteins, cross-reacted
with mouse spermatozoa, used for
determination of the acrosome integrity

37. Therapeutic uses of
Monoclonal Antibodies: FDA
approved therapies

38. Burosumab therapy in X-linked
Hypophosphatemic Rickets

39. XLHR
• Characterized by increased secretion of FGF-
23, which leads to hypophosphatemia and
consequently rickets, osteomalacia and
skeletal deformities
• Cause- Inactivating-mutation of PHEX protein
• Burosumab targets FGF-23

41. Trial Design
• Diagnosed 52 XLHR patients were randomized
1:1 ratio to receive Burosumab
subcutaneously every 2 weeks or every 4
weeks during a 16-week dose-escalation
period, followed by a 48-week treatment
period
• Initial doses of Burosumab (0.1 mg/kg every 2
weeks or 0.2 mg/kg every 4 weeks)

45. Monoclonal Antibodies in
Osteoporosis

48. Romosozumab in Osteoporosis

50. Action of Sclerostin on Bone health
• Mechanical unloading stimulates the Wnt inhibitors
like Sclerostin which leads to increase bone resorption
• Sclerostin/DKK 1 binds to Lrp5/Lrp6 leading to
inhibition of β-catenin pathway as well as it negatively
regulates BMP pathway, downregulates PHEX and
increase RANKL/OPG ratio
• SFRP 1/2/3/4 (Secreted Fizzled Related Protein) are
Sclerostin like substances which also increases bone
resorption

56. Teprotumumab in TAO

61. Alirocumab/Evolocumab in Familial
Hypercholesterolemia &
Dyslipidemia

65. Proposed/Upcoming Monoclonal
Antibodies therapy in
Endocrinology

66. Name Mechanism Primary Indication
Frovocimab PCSK-9 inhibitors Hyperlipidemia
Crotedumab Glucagon receptor
antagonists
Type 2 DM
Evinacumab Blocking function of
Angiopoietin-like 3
(ANGPTL3)
Homozygous Familial
Hypercholesterolemia
Gevokizumab/Canakinumab Anti–IL-1β antibody Type 1 DM
Otelixizumab/Teplizumab Anti-CD3 antibody Type 1 DM

67. Monoclonal Antibody induced
Endocrinological dysfunction

68. Mab induced pituitary dysfunction

69. Hypophysitis
• Hypophysitis, a previously very rare disease,
has emerged as a distinctive side-effect of
ipilimumab and tremelimumab
• These inhibits the cytotoxic T-lymphocyte
antigen-4 receptor
• Occasionally seen with Nivolomumab
• Mostly irreversible

70. Basic mechanism
• CTLA4 contributes to control autoimmunity
and in the presence of cancer it limits the
expansion of tumor specific effector T-cells,
favoring cancer immune tolerance
• Anti-CTLA4 mAb results in the removal of the
negative immune-modulatory effect of CTLA4.
which elicits therapeutic benefit
• But it also remove CTLA4-mediated protection
from autoimmunity; resulting in immune-
related adverse events (IRAEs)

71. Uses of Ipilimumab
• Ipilimumab was approved by the FDA as first-
and second-line monotherapy for
unresectable or metastatic melanoma in 2011

72. Characteristics
• Mild to moderate in most cases (Incidence-
4.5% average) but fatal events due to
hypophysitis have also reported
• Dose-dependant
• Endocrine events typically occurs after 9
weeks (after 3rd dose)
• The median time to onset following drug
administration- 4 months, but a delay in up to
19 months also observed

74. Hormonal characteristics
• Secondary hypo-adrenalism commonest
followed by central hypo-thyroidism
• DI- Almost not reported
• Steroid- Best possible T/t
• Recovery of pituitary–thyroid function has
been reported in 37–50% of patients whereas
pituitary–gonadal axis function recovered in
57% of men

78. Anti–PD-1 and Anti–PDL-1
Monoclonal
Antibodies Causing Type 1
Diabetes

80. Case presentation
• 70-yr-male euglycemic started on PDL-1
antibody for advanced adenoCA of lung and
developed plasma glucose of > 500 after 15
weeks of therapy and subsequently developed
DKA
• 65-yr-female started on PD-1 antibody for
sarcomatoid squamous cell carcinoma of Jaw
developed DKA 7 weeks after starting therapy

82. Summary
• Mab: essential in Immuno-assays technique
• Imaging techniques are increasingly used in all
centres
• Among therapeutic uses- Denosumab widely
prescribed ; Burosumab has opened a
complete new direction for XLHR
• Ipilimumab induced hypophysitis: Well
documented and well characterized; Early
institution of T/t

83. Thank you……..