Advances in Monoclonal Antibody

1. Advances in
Monoclonal
Antibody in
Cancer
Therapy
Tumor immunology course.
Under the supervision of Prof. Dr. Hossam
Goniem.
Presented by Amira Hegazy.

2. introduction
 Monoclonal antibodies (mAbs) are highly specific, laboratory-produced
immunoglobulins that are derived from a single B-cell clone and therefore
recognize one unique epitope on an antigen.
 Monoclonal antibodies (mAbs) have reshaped cancer therapy by
introducing highly specific, immune-directed, and precision-based
treatments.
 Over the past decade, antibody engineering has rapidly expanded their
therapeutic impactbroadening their mechanisms of action, enhancing their
selectivity, and improving clinical outcomes across both solid tumors and
hematologic malignancies.
 Today, mAbs represent one of the most transformative platforms in
modern oncology, forming the foundation for next-generation
precision cancer treatments.

3. Why Monoclonal Antibodies Are
Important in Cancer Therapy
 mAbs recognize specific antigens that are overexpressed or uniquely expressed
on cancer cells (like HER2, PD-1/PD-L1).
1. High Target Specificity
2. Multiple Mechanisms of Tumor Killing
 They can attack cancer using several complementary pathways:
a. Antibody-Dependent Cellular Cytotoxicity (ADCC)
b. Antibody-Dependent Cellular Phagocytosis (ADCP)
Natural killer cells bind the antibody Fc region → kill the tumor cell.
Macrophages eat opsonized cancer cells.
• This allows precise killing of tumor cells while sparing most healthy tissue.
• Leads to fewer side effects than chemo.

4. c. Complement-Dependent Cytotoxicity (CDC)
d. Direct Signaling Blockade
e. Inducing Apoptosis
Activation of complement → membrane attack complex → tumor cell lysis.
2. Multiple Mechanisms of Tumor Killing
Some mAbs directly shut down survival
pathways:
EGFR inhibitors.
HER2 inhibitors.
 stop proliferation + induce apoptosis.
Some antibodies directly trigger cancer-
cell programmed death.

5.  One of the biggest approach in modern
oncology.
 Cancer uses PD-L1 or CTLA-4 pathways to hide
from the immune system.
 Checkpoint inhibitors (like nivolumab,
pembrolizumab, ipilimumab):
3. Immune Checkpoint Blockade
• Reactivate T-cells.
• Produce long-lasting antitumor immunity.
• Can lead to durable remission even in
advanced cancers.

6. 7. Personalization of Treatment
mAbs allow treatment based on tumor biomarkers (HER2+,
CD20+, PD-L1 high).
 Supports precision medicine.
 Determines which patients will benefit ,so improves
outcomes.
• Lower toxicity.
• Better quality of life.
• Can be used in patients who can't tolerate
standard treatment.
8. Safer, More Tolerable Alternatives to Chemotherapy
Because they are targeted:
so,
Monoclonal antibodies are essential in cancer therapy because they
precisely target tumor cells, activate immune killing, block survival
pathways, and deliver toxic payloads,so making treatment more
effective and less harmful.

7. Limitations of
Traditional mAbs
1. Limited Tumor Penetration
2. Antigen Heterogeneity
3. Resistance Development
• Large molecular size lead to poor penetration into solid
tumors.
• Reduced efficacy in deep tumor tissues.
• Tumor cells may express low or variable levels of the target
antigen.
• Leads to incomplete killing and tumor escape.
• Tumors can downregulate the target antigen.
• Activate alternative signaling pathways.
• Shed antigens that neutralize antibodies.

8. 4. Off-Target or On-Target Off-Tumor Toxicity
5. Slow Mechanisms in Aggressive Cancers
6. Limited Immune Activation
7. Ineffective Against “Immune-Evasive” Tumors
• ADCC/CDC may not be enough in rapidly proliferating
tumors.
• Limited direct cytotoxicity.
• Traditional mAbs rely heavily on Fc functions (ADCC/CDC).
• Less effective in immunosuppressive tumor microenvironments.
Normal tissues expressing low levels of the antigen.
 side effects like cardiotoxicity (HER2 therapy)

9. THE
ADVANCES
1. Enhanced Fc Engineering
2. Bispecific Antibodies
3. Antibody–Drug Conjugates (ADCs)
4. Trispecific Antibodies & Pre-CAR-T
5. Radioimmunoconjugates
6. Checkpoint-Targeting Antibodies
(2nd-Gen)
7. Immuno-liposome

10. Enhanced Fc
Engineering
01

11. Enhanced Fc Engineering
 The Fc region is responsible for recruiting immune effector mechanisms: e.g.
binding to Fc-receptors on immune cells (FcγRs), binding to the complement
system, or interacting with recycling receptors that determine how long the
antibody stays in the blood.
 The goal of “Fc engineering” is to modify the Fc region via amino-acid mutations,
glycosylation changes, to improve Fc-mediated functions.
Key Strategies in Enhanced Fc Engineering
1. Improving effector functions (ADCC, ADCP, CDC)
By mutating specific residues in Fc, or by changing glycosylation
(e.g. removing core fucose), antibodies gain stronger ability to:
• recruit immune cells to kill target cells (ADCC ).
• induce phagocytosis (ADCP ) or complement-mediated
lysis (CDC) .

12.  Fc interacts with the neonatal Fc receptor
(FcRn), which rescues IgG from degradation,so
antibodies remain longer in circulation.
 Engineering Fc for stronger or more optimal Fc–
FcRn binding (e.g. via mutations) can:
1. prolong serum half-life.
2. Reducing dosing frequency
3. Improving therapy efficacy.
2. Extending antibody half-life (pharmacokinetics)
 Many modern engineered antibodies employ
a “mix-and-match” approach: changes in
glycosylation plus amino-acid substitutions
in Fc, producing synergistic or additive
enhancements of effector functions.
3. Combining multiple modifications
(glycoengineering + mutations)

13.  Designed mainly for Fab antigen binding.
 Relied on natural Fc functions, which are often
weak or inconsistent.
 Now we can rationally design the Fc to:
Why Enhanced Fc Engineering =
Next-Generation Antibodies
 Removing fucose dramatically increases binding to
FcγRIIIa on NK cells.
 This leads to much stronger ADCC than traditional
antibodies like Rituximab.
Traditional mAbs (Limitations)
1. Increase efficacy.
2. Reduce side effects.
3. Precisely control immune activation.
Examples : Afucosylated antibodies
 Rituximab(anti-CD20) = fucosylated → weaker ADCC.
 Obinutuzumab(anti-CD20)/Tafasitamab(anti-CD19) = afucosylated → stronger ADCC.

14. 02
Bispecific
Antibodies

15.  Engineered antibodies designed to bind two different
antigens or epitopes .
 Allow functions not achievable by conventional
monoclonal antibodies.
Bispecific Antibodies (bsAbs)
Therapeutic Potential
1. Cancer immunotherapy:
2. Overcoming tumor escape:
3. Immune modulation:
Redirect T cells or NK cells to tumor cells
(direct killing).
Target two tumor antigens to avoid resistance.
Dual targeting of immune checkpoints or cytokines.

16. Bispecific Antibodies (bsAbs)
 which is used to treat some types of acute lymphocytic leukemia (ALL).
 One part of blinatumomab attaches to the CD19 protein, which is found on some
leukemia and lymphoma cells.
 Another part attaches to CD3, a protein found on T cells.
 By binding to both of these proteins, this drug brings the cancer cells and immune
cells together, which cause the immune system to attack the cancer cells.
Blinatumomab As example approved from FDA

17. Antibody–Drug
Conjugates
(ADCs)
03

18.  Targeted cancer therapies combining:
Monoclonal Antibody + Linker + a cytotoxic drug (payload)
Deliver potent chemotherapy directly to antigen-expressing tumor cells.
Antibody-Drug Conjugates (ADCs)
1. The mAb binds to the antigen on the
surface of cancer cell.
2. The ADC is internalized into the cell
(often via endocytosis).
3. Inside the cell, the linker is cleaved ,
releasing the cytotoxic drug.
How ADCs Work
• High specificity → reduced systemic toxicity.
• Increased therapeutic index.
• Can overcome limitations of traditional
chemotherapy.
• Effective in targeted precision oncology.
Key Advantages

19. 1. Off-target toxicity
2. Tumor heterogeneity & antigen variation
3. Linker stability & premature drug release
4. Manufacturing and design complexity
Limitations
1. Trastuzumab deruxtecan (Enhertu)
• Antibody: Trastuzumab (targets HER2).
• Payload: Deruxtecan (topoisomerase I inhibitor).
• Indications: HER2-positive breast cancer,
gastric cancer.
If antigen is expressed on normal cells.
Not all cancer cells may express the target antigen (or may express it variably).
Poorly designed linkers may release the toxin too early (in bloodstream ).
Examples of Approved ADC Drugs
2. Brentuximab-Vedotin (BV)
• Antibody: Anti-CD30.
• Payload: Monomethyl auristatin E .
• Indications: Hodgkin lymphoma, systemic anaplastic large-cell lymphoma.

20. Trispecific
Antibodies &
Pre-CAR-T
04

21.  Engineered antibodies that bind three distinct targets.
 Typically designed to:
Trispecific Antibodies & Pre-CAR-T
1. T-cell recruitment: One arm binds CD3 → brings cytotoxic T-cells to the tumor.
2. Dual tumor targeting: Two arms may target two different tumor antigens , reduces antigen
escape.
3. Enhanced immune activation: Third arm can provide co-stimulation or block checkpoint
pathways.
Clinical Relevance
• Greater specificity → less off-target toxicity.
• Overcomes tumor heterogeneity and antigen
escape.
• Investigational in hematologic malignancies
and some solid tumors.
As of late 2025, there aren't any fully FDA-
approved trispecific antibodies (TsAbs);
however, many are in advanced clinical trials .

22. Radio-
Immuno-
conjugates
05

23. 1. Highly specific tumor targeting.
2. Effective in hematologic
malignancies.
3. Minimal systemic radiation exposure
compared to external radiotherap.
Radioimmunoconjugates (Radioimmunotherapy)
 Monoclonal antibodies linked to radioactive
isotopes.
 Deliver targeted radiation directly to tumor cells.
 Combines specificity of antibodies with
cytotoxicity of radiation.
Advantages
FDA-Approved Examples
 Zevalin (ibritumomab tiuxetan): Targets CD20 antigen, approved for non-
Hodgkin lymphoma.
 Bexxar (tositumomab): targets CD20, approved for NHL but its commercial
availability has been discontinued in the US.

24. 06
Checkpoint-
Targeting
Antibodies
(2nd-Gen)

25.  Antibodies that target novel immune checkpoints beyond PD-1/PD-L1/CTLA-4.
 Examples: LAG-3, TIGIT, TIM-3, VISTA, NKG2A, CD47-SIRPα.
 2nd-gen targets often expressed on “exhausted” or “dysfunctional” T cells & other
immune cells, offering a way to revive or reprogram immune responses in resistant
tumors.
2nd-Gen Checkpoint-Targeting
Antibodies
Limitations of 1st Gen
‑
 Not all patients respond to 1st-gen inhibitors (PD-1/PD-L1, CTLA-4).
 Tumors can exploit multiple immune-suppressive pathways.
 2nd-gen antibodies aim to overcome resistance and immune evasion.
Many are still in preclinical or early clinical trials

26. FDA-Approved Examples
 Relatlimab: Anti-LAG-3 monoclonal antibody.
 Nivolumab: Anti-PD-1 monoclonal antibody.
 Combination effect: Synergistic activation of anti-tumor immunity.
 Approved for advanced
melanoma (first FDA-approved
LAG-3 + PD-1 combo).
 Represents the first successful
clinical use of 2nd-gen
checkpoint therapy.
Relatlimab + Nivolumab
Clinical Significance

27. 07
Immuno-
liposome

28. Immunoliposome-Based Monoclonal
Antibodies
 Liposomes are nanoscale carriers that can encapsulate drugs or antibodies for
targeted delivery.
 When coupled with monoclonal antibodies, they enhance specificity and reduce
systemic toxicity.
Concept:
1. Targeted delivery: Antibody guides liposome to tumor cells, sparing normal tissues.
2. Enhanced stability: Protects mAbs from degradation in circulation.
3. Combination payloads: Can carry chemotherapy drugs, siRNA, or imaging agents
alongside mAbs.
4. Improved efficacy in solid tumors: Better tissue penetration compared to free antibodies.
Advantages:

29. Immunoliposome
 Although immunoliposomes have been a very
active area of preclinical and earlyclinical research;
No immunoliposome drug has yet been approved by FDA.
 Potential use in triple-negative breast
cancer, ovarian cancer, and other resistant
tumors.
Clinical impact:

30. Clinical Benefits of Advanced
monoclonal
• Fc-optimized mAbs → stronger ADCC, ADCP.
• Bispecifics & trispecifics → dual/tri-target killing.
• ADCs → direct delivery of potent cytotoxics to tumor cells.
1. Higher Tumor Specificity
• Fc-engineering, bispecifics, ADCs → improved selective targeting.
• Reduced off-tumor toxicity compared to early mAbs.
• Better tumor penetration & retention.
2. Enhanced Anti-Tumor Potency
3. Overcoming Resistance Mechanisms
• Multispecific antibodies reduce antigen escape.
• Checkpoint-targeting combos (PD-1 + LAG-3) overcome immunotherapy
resistance.
• ADC linkers & payloads overcome chemotherapy resistance.

31. • Many next-gen mAbs show higher PFS & OS in solid and
hematologic cancers.
• Combination therapies produce deeper & more durable
responses.
4. Improved Survival Outcomes
• More precise targeting = lower systemic
toxicity.
• Fc modification reduces undesired
inflammation/complement activation.
• Tumor-selective activation reduces risk
of cytokine releas.
5. Better Safety Profiles

32.  Monoclonal antibodies (mAbs) have revolutionized cancer therapy, offering targeted
approaches with improved specificity.
 Advances include:
 Challenges remain:
 Future directions:
Conclusion
 Checkpoint inhibitors to reactivate the immune system.
 Bispecific & trispecific antibodies for dual/multi-targeting.
 Antibody-drug conjugates (ADCs) and Fc-engineered mAbs for enhanced
efficacy.
 Tumor resistance.
 Heterogeneity.
 Immune-related toxicities.
 Cost.
 Combination therapies.
 Improved delivery.
 Fc modifications.
 Patient-specific.

33. Resources
● Doctor using a microhttps://www.mdpi.com/2227-9059/11/6/1610
● https://blog.crownbio.com/antibody-drug-conjugates-concepts-and-challe
nges
● https://www.invivogen.com/review-engineered-pfuse-chig
● https://pmc.ncbi.nlm.nih.gov/articles/PMC7551545/?utm
● https://www.slideshare.net/slideshow/monoclonal-antibodies-71778862/7
1778862#21
● https://www.slideshare.net/slideshow/monoclonal-antibodies-in-cancer-th
erapy/191272128#8
● https://www.scielo.br/j/bjps/a/8zD4St5DzTyPVkNhk9yvZqx/?lang=en&utm