Chapter Four · failure evidence
What Monoclonal Antibody Therapeutics got wrong, from 31 dissertations
The records document technical limitations and therapeutic failures encountered during monoclonal antibody engineering, formulation, and in vivo administration. Across multiple therapeutic applications, antibodies frequently suffered from physiological delivery barriers, loss of binding affinity after chemical conjugation, insufficient intrinsic antitumor cytotoxicity, and failure of epitope binding to yield functional neutralization. These records come from PhD theses at 11 institutions, 2021 to 2026. Each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Systemic antibody administration is impeded by physiological barriers and poor tissue penetration
Therapeutic antibodies administered systemically failed to cross the intact blood-brain barrier and showed negligible accumulation in target tissues such as lymph nodes and lungs. Consequently, systemic routes were abandoned in favor of localized delivery methods or small molecules to avoid low bioavailability and severe systemic toxicity.
Considered and rejected
Considered and rejected: Rejected using bulky antibody targeting moieties due to reduced BBB permeability and tumor penetration compared to small molecules.
Polymeric Nanoparticles for Image Guided Drug Delivery to CNS Diseases: Design, Development, and Cellular Investigation · DSpace at SUNY Buffalo
Considered and rejected
Considered and rejected: Rejected antibody-based LAG3 therapeutics for early PD treatment due to blood-brain barrier penetration challenges, choosing small molecule inhibitors instead.
Kinetic Controlled Assembly of Nanoparticles for Delivery of Therapeutics · JScholarship
Considered and rejected
Considered and rejected: Rejected using systemic antibody-mediated depletion to clear brain Trm because antibodies cannot efficiently cross the intact blood-brain barrier to reach non-recirculating cells.
Tried and failed
systemic administration of monoclonal antibodies applied to lymph node biodistribution and accumulation. Outcome: worse than baseline. Reason: systemic delivery failed to achieve substantial antibody accumulation in lymph nodes compared to locoregional administration
Locoregional and systemic immunomodulation with intratumoral TCR agonism · Georgia Tech
Considered and rejected
Considered and rejected: Rejected aerosol nebulizer delivery for antibody pulmonary bioavailability in favor of nasal drip because aerosolization achieved negligible lung concentration (0.026 vs 7.66 µg/mL) and required far more protein.
Contributions of antibodies binding defined epitopes to protection against B. pertussis and SARS-CoV-2 · UT Austin
Considered and rejected
Considered and rejected: Systemic intravenous/retro-orbital administration of anti-CD11c blocking antibody was abandoned for long-term bone marrow B cell studies due to systemic toxicity/lethality and poor targeting of sinusoidal extravascular niches, favoring BM-targeted intrafemoral delivery.
Intrinsic and Extrinsic Regulation of Autoreactive B cell Responses in Systemic Lupus Erythematosus · Harvard
Chemical conjugation and sequence fusion impair antibody binding affinity and stability
High conjugation ratios, fluorophore additions, and peptide fusions sterically hindered antigen-binding complementary-determining regions and significantly reduced target binding affinity. In addition, alternative assembly formats resulted in antibody instability, aggregation, and suboptimal drug-to-antibody ratios.
Tried and failed
high density small molecule conjugation on antibodies applied to antibody-mediated cell targeting. Outcome: worse than baseline. Reason: excessive conjugation sterically hindered antigen-binding complementary-determining regions, reducing binding affinity and effector cytotoxicity
Small Molecule Specific CAR T/CAR NK Cell Therapy for Multiple Myeloma · Harvard
Considered and rejected
Considered and rejected: Controlled Fab-arm exchange format was abandoned due to low drug-to-antibody ratio (DAR=1) and antibody instability/aggregation.
Tried and failed
fluorophore conjugation to therapeutic antibody applied to cerebral blood flow restoration. Outcome: no signal. Reason: Fluorophore conjugation likely impaired antibody-receptor binding or biological activity compared to unconjugated antibody
Considered and rejected
Considered and rejected: Rejected peptide-to-antibody conjugation stoichiometry above 1:1 due to loss of antibody binding affinity to PD-1
ENGINEERED ACTIVITY SENSORS FOR PREDICTIVE IMMUNE MONITORING · Georgia Tech
Considered and rejected
Considered and rejected: Rejected b1s1e2-sm3e antibody fusion due to significantly reduced CTLA-4 binding affinity.
Mechanistic Elucidation and Therapeutic Improvement of Anti-CTLA-4 Therapies · MIT
Epitope binding fails to produce functional pathogen neutralization or bactericidal activity
Monoclonal antibodies raised against conserved subdomains, binary complex interfaces, or minimal linear epitopes successfully recognized target antigens but failed to neutralize authentic viral or parasitic infectivity. Similarly, antibodies selected from plasmablast sorting bound target antigens but failed to mediate serum bactericidal killing activity.
Tried and failed
blocking protein-protein interactions with monoclonal antibodies applied to inhibiting pathogen cellular invasion. Outcome: no signal. Reason: disrupting the binary protein complex interface did not translate to functional parasite neutralization in growth inhibition assays
Tried and failed
monoclonal antibody isolation against public linear epitopes applied to viral neutralization assays. Outcome: no signal. Reason: antibodies targeting the minimal linear public epitope failed to neutralize viral infectivity in plaque reduction assays
Tried and failed
cross-reactive monoclonal antibody isolation against conserved subdomains applied to heterologous viral neutralization. Outcome: no signal. Reason: antibodies binding conserved epitopes lacked neutralizing activity against authentic live virus and divergent strains
Contributions of antibodies binding defined epitopes to protection against B. pertussis and SARS-CoV-2 · UT Austin
Tried and failed
single-cell antibody discovery via plasmablast sorting applied to bacterial vaccine antigen identification. Outcome: no signal. Reason: isolated antigen-binding monoclonal antibodies failed to mediate serum bactericidal killing activity
Identification of meningococcal vaccine antigens using Reverse Vaccinology 2.0 · Imperial
Truncated antibody fragments fail to match the delivery potency and receptor clustering of full antibodies
Nanoparticles conjugated with scFv or F(ab')2 fragments showed inferior delivery and transfection efficiency compared to full monoclonal antibody conjugates. Additionally, monomeric fragments lacked the multivalent crosslinking capacity needed to cluster costimulatory receptors and activate downstream signaling.
Lost to a baseline
scFv-conjugated LNP formulations failed to outperform monoclonal antibody (104D2 mAb) conjugated LNPs in delivery
Tried and failed
scFv targeting moieties instead of full antibodies applied to targeted lipid nanoparticle delivery. Outcome: worse than baseline. Reason: scFv conjugated nanoparticles failed to outperform full monoclonal antibody conjugates in delivery potency
Tried and failed
Conjugating antibody fragments instead of full antibodies applied to targeted lipid nanoparticle delivery. Outcome: worse than baseline. Reason: F(ab')2 fragment conjugation resulted in lower transfection levels compared to full-length antibody conjugation
Tried and failed
monomeric antibody fragments for costimulatory receptor agonism applied to T cell activation and immunotherapy. Outcome: no signal. Reason: monomeric binding lacks the multivalent crosslinking required to cluster receptors and trigger downstream signaling
Collagen Anchoring Agonist Antibodies for Cancer Immunotherapy · MIT
Naked monoclonal antibodies lack sufficient intrinsic antitumor activity without cytotoxic payloads or combination partners
Unconjugated monoclonal antibodies targeted against surface antigens failed to produce cytotoxicity or inhibit tumor growth in vivo on their own. Effective tumor inhibition and reduced outgrowth instead required cytotoxic drug payload conjugation or combination with other delivery formulations.
Tried and failed
unconjugated monoclonal antibody therapy applied to surface target expressing solid tumors. Outcome: no signal. Reason: naked antibody lacked intrinsic cytotoxicity or tumor inhibition without an attached cytotoxic drug payload
Tried and failed
monoclonal antibody therapy without cytotoxic payload conjugation applied to in vivo tumor xenograft inhibition. Outcome: no signal. Reason: naked antibodies lacked sufficient intrinsic antitumor activity in vivo compared to cytotoxic conjugates
Lost to a baseline
In small 200 µm diameter spheroids, antibody alone achieved lower outgrowth than liposome combination.
Monoclonal antibody cell depletion fails due to rapid biological replenishment or non-specific clearance
Administering single monoclonal antibodies failed to sustain target cell clearance because rapid bone marrow replenishment quickly overcame depletion. Furthermore, depletion antibodies suffered from incomplete intratumoral penetration, off-target effects, and high dosage requirements.
Considered and rejected
Considered and rejected: Rejected anti-CCR3 antibody administration as a reliable primary tool for complete tumor eosinophil depletion due to incomplete intratumoral depletion efficiency.
Investigating the impact of eosinophils on pancreatic cancer growth and metastasis · Harvard
Considered and rejected
Considered and rejected: Rejected standard monoclonal antibodies (mAbs) for MDSC depletion due to lack of exclusive single-surface antigens, high cost, off-target depletion, and requirement for high dosages.
Immunomodulation Following Severe Musculoskeletal Trauma to Improve Functional Regeneration · Georgia Tech
Tried and failed
monoclonal antibody mediated cell depletion applied to in vivo neutrophil depletion. Reason: rapid bone marrow output overcame single antibody clearance, requiring a secondary antibody for effective depletion
Left open by the authors
Problems the authors named and did not get to.
Left open
Evaluate the antitumor efficacy of affinity-optimized anti-polySia antibodies in vivo using cell line- and patient-derived xenograft mouse models. Blocker: Requires wet lab access, animal housing facilities, CDX/PDX mouse models, and physical antibody samples.
DISCOVERY AND ENGINEERING OF ANTIBODIES TARGETING GLYCAN ANTIGENS · Cornell
Left open
Treat vavP-Bcl2 and DLBCL mice with CTSS-inhibiting antibody-peptide inhibitor conjugates to evaluate reduction in lymphoma-related mortality. Blocker: Requires wet lab, animal facility, synthesized APIC conjugates, and live mouse disease models
Left open
Test therapeutic efficacy of CTSK-inhibiting antibody-peptide inhibitor conjugates in animal models of bone metastasis, osteosarcoma, or osteoporosis. Blocker: Requires in vivo animal models and wet lab experimental facilities to synthesize conjugates and evaluate therapeutic outcomes
Left open
Test whether a simple cell or protein binding assay predicts loss of binding and in vivo transcytosis activity of antibody mutants. Blocker: Requires wet lab experiments with cell or protein binding assays and mutant antibodies
Left open
Test PHC-NPs in an in vivo murine collagen antibody-induced arthritis (CAIA) model of rheumatoid arthritis. Blocker: Requires wet lab, animal facility, synthesized nanoparticles, and live mice
An apoptotic body-inspired nanoparticle to modulate inflammatory macrophages · UT Austin
Left open
Synthesize antibody-nanoparticle conjugates with mAbs of varying affinity to test if high affinity restricts lymph node paracortex penetration via binding-site barrier. Blocker: Requires wet-lab chemical synthesis of antibody-nanoparticle conjugates and in vivo or tissue-level experimental validation.
Analysis of Nanomaterial Physiochemical Property Influences on Lymph Node Accumulation and Leukocyte Association · Georgia Tech
Left open
Evaluate collagen-anchored agonist antibodies engineered with FcγR-silent Fc domains to determine if collagen anchoring alone enables receptor clustering. Blocker: Requires wet-lab recombinant antibody engineering, in vitro receptor clustering assays, and in vivo animal experiments.
Collagen Anchoring Agonist Antibodies for Cancer Immunotherapy · MIT
Left open
Test reversed dosing sequence of aCD45-IL15 followed by aCD45-IL12 in vivo to isolate individual dose contributions to therapeutic efficacy. Blocker: Requires wet lab facilities, recombinant antibody-cytokine fusion proteins, and animal tumor models
Engineering cytokine immunotherapies via cell surface targeting · MIT
Left open
Optimize antibody-antibiotic conjugates with lower drug-to-antibody ratios using site-specific conjugation methods like sortase A or transglutaminase. Blocker: Requires wet-lab chemical synthesis, bioconjugation facilities, and in vivo animal testing.
Alternative Antimicrobial Agents Against Multidrug-Resistant Gram-Negative Bacteria · Cornell
Left open
Apply the microfluidic linkage method to compare the developability of natural paired antibody repertoires against synthetic combinatorial pairings. Blocker: Requires a wet lab, microfluidic droplet apparatus, and biological B-cell samples to generate and assay antibody libraries
Methods and Materials to Generate Antibody Repertoire Libraries · Harvard
Checking a claim in this area?
We can run the same search on any method or claim. If nothing turns up, we will say so, and that proves nothing on its own.