zagotenemab

Migration, Crosslink

📖

zagotenemab

active

wiki page Created: 2026-04-02T07:19:00 By: crosslink-migration Quality: 50% ✓ SciDEX ID: wiki-therapeutics-zagotenemab

📖 Wiki Page

therapeutic2054 wordssynced 2026-04-02

Zagotenemab (LY3303560)

<table class="infobox infobox-therapeutic">
<tr>
<th class="infobox-header" colspan="2">zagotenemab</th>
</tr>
<tr>
<td class="label">Parameter</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Name</td>
<td>PERISCOPE-ALZ (Phase 2)</td>
</tr>
<tr>
<td class="label">NCT ID</td>
<td>NCT04592874</td>
</tr>
<tr>
<td class="label">Population</td>
<td>Early Alzheimers disease (MCI due to AD or mild AD dementia)</td>
</tr>
<tr>
<td class="label">Enrollment</td>
<td>360 participants</td>
</tr>
<tr>
<td class="label">Design</td>
<td>Randomized, double-blind, placebo-controlled</td>
</tr>
<tr>
<td class="label">Duration</td>
<td>2 years (104 weeks)</td>
</tr>
<tr>
<td class="label">Dose Groups</td>
<td>1,400 mg IV monthly, 5,600 mg IV monthly, placebo</td>
</tr>
<tr>
<td class="label">Primary Endpoint</td>
<td>Change from baseline on integrated Alzheimers Disease Rating Scale (iADRS)</td>
</tr>
<tr>
<td class="label">Secondary Endpoints</td>
<td>Clinical measures (CDR-SB, ADAS-Cog13, ADCS-ADL), biomarker endpoints, tau PET</td>
</tr>
<tr>
<td class="label">Antibody</td>
<td>Company</td>
</tr>
<tr>
<td class="label">Zagotenemab (LY3303560)</td>
<td>Eli Lilly</td>
</tr>
<tr>
<td class="label">Semorinemab (RO7105685)</td>
<td>Genentech/Roche</td>
</tr>
<tr>
<td class="label">Gosuranemab (BIIB080)</td>
<td>Biogen</td>
</tr>
<tr>
<td class="label">Tilavonemab (ABBV-8E12)</td>
<td

...

Zagotenemab (LY3303560)

<table class="infobox infobox-therapeutic">
<tr>
<th class="infobox-header" colspan="2">zagotenemab</th>
</tr>
<tr>
<td class="label">Parameter</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Name</td>
<td>PERISCOPE-ALZ (Phase 2)</td>
</tr>
<tr>
<td class="label">NCT ID</td>
<td>NCT04592874</td>
</tr>
<tr>
<td class="label">Population</td>
<td>Early Alzheimers disease (MCI due to AD or mild AD dementia)</td>
</tr>
<tr>
<td class="label">Enrollment</td>
<td>360 participants</td>
</tr>
<tr>
<td class="label">Design</td>
<td>Randomized, double-blind, placebo-controlled</td>
</tr>
<tr>
<td class="label">Duration</td>
<td>2 years (104 weeks)</td>
</tr>
<tr>
<td class="label">Dose Groups</td>
<td>1,400 mg IV monthly, 5,600 mg IV monthly, placebo</td>
</tr>
<tr>
<td class="label">Primary Endpoint</td>
<td>Change from baseline on integrated Alzheimers Disease Rating Scale (iADRS)</td>
</tr>
<tr>
<td class="label">Secondary Endpoints</td>
<td>Clinical measures (CDR-SB, ADAS-Cog13, ADCS-ADL), biomarker endpoints, tau PET</td>
</tr>
<tr>
<td class="label">Antibody</td>
<td>Company</td>
</tr>
<tr>
<td class="label">Zagotenemab (LY3303560)</td>
<td>Eli Lilly</td>
</tr>
<tr>
<td class="label">Semorinemab (RO7105685)</td>
<td>Genentech/Roche</td>
</tr>
<tr>
<td class="label">Gosuranemab (BIIB080)</td>
<td>Biogen</td>
</tr>
<tr>
<td class="label">Tilavonemab (ABBV-8E12)</td>
<td>AbbVie</td>
</tr>
<tr>
<td class="label">Bepranemab (UCB0107)</td>
<td>UCB</td>
</tr>
<tr>
<td class="label">JNJ-63733657</td>
<td>Janssen</td>
</tr>
</table>

Overview

Zagotenemab (development code LY3303560) is a humanized anti-tau monoclonal antibody developed by [Eli Lilly and Company](/companies/eli-lilly) for the treatment of Alzheimers disease and potentially other tauopathies[@zagotenemab][@zagotenemaba]. Unlike conventional anti-tau antibodies that target linear epitopes on phosphorylated or total tau protein, zagotenemab specifically recognizes conformational epitopes present on early pathological tau aggregates, particularly oligomeric species considered to be the most toxic form of tau pathology[@mallipeddi2021][@taylor2021].

The therapeutic rationale for zagotenemab stems from the understanding that tau oligomers represent a critical pathogenic species in Alzheimers disease progression. While neurofibrillary tangles (NFTs) represent end-stage, relatively inert tau aggregates, soluble oligomers are highly toxic, propagate between neurons via trans-synaptic spread, and drive downstream neurodegeneration[@wu2020]. By targeting these early pathological conformations, zagotenemab aimed to intercept tau toxicity before extensive irreversible neuronal damage occurs.

The development of zagotenemab represents a significant effort in the tau immunotherapy field, combining cutting-edge antibody engineering with innovative clinical trial design. The PERISCOPE-ALZ Phase II trial provided the first large-scale clinical data on a conformer-specific anti-tau antibody, offering important insights into the challenges and opportunities of this therapeutic approach.

Tau Pathology in Alzheimers Disease

Normal Tau Biology

The tau protein is encoded by the [MAPT](/genes/mapt) (microtubule-associated protein tau) gene on chromosome 17q21 and plays essential roles in neuronal biology[@yoshiyama2013]:

Physiological Functions:

Promotes microtubule assembly and stabilizes axonal microtubules
Facilitates intracellular transport along axons
Regulates neuronal plasticity and signal transduction
Supports dendritic spine formation and maintenance

In the adult human brain, tau exists as six isoforms ranging from 352 to 441 amino acids, generated by alternative splicing of exons 2, 3, and 10. The isoforms differ in the number of microtubule-binding repeats (3 or 4) and the presence of N-terminal inserts.

Pathological Tau Transformations

In Alzheimers disease, tau undergoes dramatic transformations that lead to neurodegeneration[@wu2020][@himmelstein2012]:

Hyperphosphorylation:

Over 40 phosphorylation sites have been identified on tau
Kinases including [GSK-3β](/entities/gsk3-beta), [CDK5](/proteins/cdk5), and MAPKs hyperphosphorylate tau
Phosphorylation reduces taus microtubule-binding capacity
Phosphorylated tau dissociates from microtubules and accumulates in the soma

Oligomerization:

Hyperphosphorylated tau aggregates into soluble oligomers
Oligomers range from dimers to large prefibrillar aggregates
Tau oligomers are highly toxic to neurons
Oligomers can spread between neurons via extracellular vesicles and tunneling nanotubes

Fibril Formation:

Oligomers mature into paired helical filaments (PHFs) and straight filaments
PHFs aggregate into neurofibrillary tangles (NFTs)
NFTs accumulate in neuronal cell bodies
NFT burden correlates with cognitive impairment severity

The Importance of Targeting Tau Oligomers

The recognition that tau oligomers represent the most pathogenic species has shifted therapeutic strategies[@wu2020][@lowen]:

Why Oligomers Are Critical:

Toxicity: Oligomers are 100-1000x more toxic than monomeric or fibrillar tau

Propagation: Oligomers efficiently spread between neurons, driving disease progression

Reversibility: Targeting oligomers may prevent progression before extensive damage

Diagnostic potential: Oligomer-specific antibodies can detect early pathology

Conformational vs. Phosphorylated Epitopes:

Phospho-tau antibodies target specific phosphorylation sites (e.g., pT181, pT217, pT231)
Conformational antibodies recognize pathological 3D structures irrespective of phosphorylation
Early oligomers may not display all phosphorylated epitopes
Conformer-specific antibodies may detect a broader range of pathological species

Mechanism of Action

Antibody Characteristics

Zagotenemab was engineered to specifically recognize pathological conformational epitopes on early tau aggregates[@mallipeddi2021][@taylor2021]:

Epitope Specificity:

Targets conformational epitopes unique to aggregated tau
Recognizes soluble oligomeric and early fibrillar tau species
Minimal binding to monomeric tau or to mature NFTs
Does not require specific phosphorylation at known sites

Binding Properties:

High affinity for pathological tau conformations
Humanized IgG1 backbone for optimal effector function
Designed to minimize off-target effects

Origin:

Derived from the mouse MCI-1 monoclonal antibody
Humanized to reduce immunogenicity
Engineered for optimal brain penetration and half-life

Therapeutic Mechanisms

Zagotenemab achieves therapeutic benefit through multiple mechanisms[@sofruiti2019][@kolb2017]:

1. Antibody-Mediated Clearance:

Binds extracellular and interstitial pathological tau species
Facilitates Fc receptor-mediated uptake by microglia
Enhances clearance of toxic oligomers through the brains waste clearance systems

2. Prevention of Propagation:

Sequesters soluble tau oligomers in the extracellular space
Blocks templated conversion of normal tau to pathological forms
May prevent trans-synaptic spread of tau pathology

3. Neutralization of Toxic Species:

Binds and neutralizes extracellular oligomers
Prevents oligomer interaction with neuronal receptors
May reduce downstream inflammatory signaling

Brain Penetration Challenges

Like all anti-tau antibodies, zagotenemab faces the significant challenge of achieving adequate brain exposure[@butchart2019]:

Blood-Brain Barrier (BBB) Considerations:

Peripheral administration results in limited brain penetration
Typical brain:plasma ratios of 0.1-1% for conventional IgG antibodies
BBB transport depends on FcRn-mediated transcytosis
Higher dosing may partially overcome this limitation

Dosing Strategy:

Phase II used high monthly intravenous doses (1,400 mg and 5,600 mg)
These doses far exceed typical antibody therapeutics
Aim to achieve sufficient free antibody for target engagement

Clinical Development Program

Phase I Clinical Trials

First-in-human studies evaluated zagotenemab in healthy volunteers and patients with Alzheimers disease[@zagotenemab][@taylor2021]:

Study Design:

Randomized, double-blind, placebo-controlled
Single ascending dose (SAD) and multiple ascending dose (MAD) cohorts
Both healthy volunteers and early AD patients

Key Endpoints:

Safety and tolerability across dose ranges
Pharmacokinetic properties (Cmax, AUC, half-life)
Immunogenicity (anti-drug antibody formation)
Target engagement biomarkers (CSF tau species)
Preliminary clinical efficacy signals

Results:

Acceptable safety and tolerability profile at all doses tested
No dose-limiting toxicities observed
Evidence of target engagement (reductions in specific CSF tau species)
Supports advancement to Phase II evaluation

Phase II Trial: PERISCOPE-ALZ

The PERISCOPE-ALZ trial represented a major milestone in tau immunotherapy development[@zagotenemaba]:

Trial Design:

Results:

Primary endpoint: Did not meet — no statistically significant difference from placebo on iADRS
Biomarker findings: Dose-dependent increase in plasma tau (suggests target engagement)
Tau PET: No significant change in tau deposition
Safety: No dose-limiting adverse events; favorable safety profile
Status: Development discontinued in October 2021

Why Did Zagotenemab Fail?

The negative PERISCOPE-ALZ results provide critical insights into tau immunotherapy challenges:

Possible Contributing Factors:

Timing of intervention: Patients may have had too much irreversible damage

Early AD still represents relatively advanced pathology
Need to treat much earlier in the disease process

Insufficient brain penetration:

Despite high doses, antibody may not have reached adequate brain levels
Target engagement may have been inadequate

Biomarker-clinical disconnect:

Plasma tau increased (suggesting target engagement)
But this did not translate to clinical benefit
Indicates complex relationship between biomarker changes and clinical outcomes

Conformer specificity limitations:

May not have captured all relevant pathological species
Different conformations may dominate at different disease stages

Endpoints and sensitivity:

iADRS may not be sensitive enough to detect subtle effects
2-year treatment may be insufficient to show disease modification

Comparison with Other Anti-Tau Antibodies

The tau immunotherapy field has evolved significantly, with multiple antibodies targeting different epitopes[@bittlinger2021][@cummings2022]:

Shared Challenges:

None have demonstrated clear clinical efficacy to date
Similar issues with brain penetration and target engagement
Late-stage patient enrollment may be a universal problem

Differentiating Features of Zagotenemab:

Conformational epitope targeting (unique approach)
Targeting oligomeric species specifically
Higher dosing than most other programs

Lessons from the Zagotenemab Experience

Implications for Future Tau Immunotherapy

The PERISCOPE-ALZ results have important implications for the field[@cummings2022]:

Timing: Earlier intervention may be critical

Need to treat at pre-symptomatic or very early prodromal stages
Primary prevention trials may be necessary

Biomarker Development: Better biomarkers are needed

Plasma tau increase may not indicate meaningful target engagement
Need biomarkers that more directly reflect downstream effects

Combination Approaches: Single-target approaches may be insufficient

May need to combine anti-tau with anti-amyloid therapy
Multi-target strategies could address multiple pathological processes

Patient Selection: Better stratification is needed

Identify patients most likely to respond
Exclude those with "burned out" pathology

What Worked

Despite the negative trial, certain aspects of the program provided value:

Successful Elements:

Novel target (conformational epitopes) represents valid scientific approach

Demonstrated acceptable safety at high doses

Biomarker data provides valuable scientific insights

Contributed to understanding of tau immunotherapy challenges

Informed future trial designs in the field

Current Status and Future Directions

Program Status

Zagotenemab (LY3303560) development has been discontinued following the negative PERISCOPE-ALZ trial results. The program no longer active in clinical development.

Legacy and Contributions

The zagotenemab program contributed to the field in several ways:

Scientific Insights:

Validated conformer-specific antibody approach
Demonstrated safety of high-dose anti-tau therapy
Provided biomarker data on target engagement
Informed understanding of tau immunotherapy challenges

Clinical Trial Learnings:

Established Phase II trial design for anti-tau antibodies
Validated biomarker endpoints (plasma tau)
Demonstrated feasibility of large anti-tau trials

Several related efforts continue in the tau immunotherapy space:

Anti-tau antibodies targeting different epitopes
Small molecule tau aggregation inhibitors
Anti-sense oligonucleotides targeting MAPT
Gene therapy approaches
Combination strategies

References

[Zagotenemab Phase 1 characterization. AlzForum](https://www.alzforum.org/therapeutics/zagotenemab)

[Zagotenemab Phase 2 PERISCOPE-ALZ trial results. PMID:38490123](https://pubmed.ncbi.nlm.nih.gov/38490123/)

[Mallipeddi NJ, et al. Zagotenemab: anti-tau antibody targeting conformer-specific epitopes. J Prev Alzheimers Dis. 2021. PMID:34289012](https://pubmed.ncbi.nlm.nih.gov/34289012/)

[Taylor R, et al. Anti-tau antibody zagotenemab: Phase 1 results. Alzheimers Dement. 2021. PMID:34355678](https://pubmed.ncbi.nlm.nih.gov/34355678/)

[Colombo A, et al. Conformational tau antibodies in Alzheimers disease. Nat Rev Neurol. 2021. PMID:34326547](https://pubmed.ncbi.nlm.nih.gov/34326547/)

[Wu TY, et al. Tau oligomers as pathogenic species. Nat Rev Neurol. 2020. PMID:32251391](https://pubmed.ncbi.nlm.nih.gov/32251391/)

[Taylor et al. Tau conformation-specific antibodies for therapy. Sci Transl Med. 2021. PMID:34143723](https://pubmed.ncbi.nlm.nih.gov/34143723/)

[Sigurdsson EM. Tau immunotherapy: progress and challenges. Neurobiol Aging. 2016. PMID:26541328](https://pubmed.ncbi.nlm.nih.gov/26541328/)

[Boutajangout A, et al. Tau targeting passive immunotherapy. J Alzheimers Dis. 2011. PMID:21876547](https://pubmed.ncbi.nlm.nih.gov/21876547/)

[DeMattos RB, et al. Plaque-specific antibody clears beta-amyloid. J Neurosci. 2012. PMID:22279229](https://pubmed.ncbi.nlm.nih.gov/22279229/)

[Butchart J, et al. Tau antibody delivery to brain. J Pharmacol Exp Ther. 2019. PMID:31278167](https://pubmed.ncbi.nlm.nih.gov/31278167/)

[Kolb H, et al. Human antibody engineering for tau immunotherapy. MAbs. 2017. PMID:28071982](https://pubmed.ncbi.nlm.nih.com/28071982/)

[Sofruenti M, et al. Passive immunotherapy targeting tau. J Alzheimers Dis. 2019. PMID:31177226](https://pubmed.ncbi.nlm.nih.gov/31177226/)

[Yoshiyama Y, et al. Tau pathology and therapeutic strategies. Ann Neurol. 2013. PMID:23746536](https://pubmed.ncbi.nlm.nih.gov/23746536/)

[Himmelstein DS, et al. Tau immunotherapy: mechanisms. J Alzheimers Dis. 2012. PMID:22337850](https://pubmed.ncbi.nlm.nih.gov/22337850/)

[Moraru M, et al. Tau PET imaging in Alzheimers disease. Clin Transl Imaging. 2019. PMID:31126273](https://pubmed.ncbi.nlm.nih.gov/31126273/)

[Jack CR Jr, et al. NIA-AA research framework. Ann Neurol. 2018. PMID:29647937](https://pubmed.ncbi.nlm.nih.gov/29647937/)

[Blennow K, et al. CSF biomarkers for Alzheimers disease. Handb Clin Neurol. 2019. PMID:30682144](https://pubmed.ncbi.nlm.nih.gov/30682144/)

[Cummings J, et al. AD drug development pipeline 2022. Alzheimers Dement. 2022. PMID:35728091](https://pubmed.ncbi.nlm.nih.gov/35728091/)

[Alexander GC, et al. FDA approval of aducanumab. JAMA. 2021. PMID:34287642](https://pubmed.ncbi.nlm.nih.gov/34287642/)

[Bittlinger M, et al. Anti-tau antibody trials. Nat Rev Neurol. 2021. PMID:34226711](https://pubmed.ncbi.nlm.nih.gov/34226711/)

[Adolfsson O, et al. An antibody that targets tau oligomers. J Exp Med. 2012. PMID:22983441](https://pubmed.ncbi.nlm.nih.gov/22983441/)

slug	therapeutics-zagotenemab
kg_node_id	None
entity_type	therapeutic
origin_type	v1_polymorphic_backfill
source_table	wiki_pages
wiki_page_id	wp-a9188b1a6934
__merged_from	{'merged_at': '2026-05-13', 'unprefixed_id': 'therapeutics-zagotenemab'}
_schema_version	1

📗 Cite This Artifact

zagotenemab

Zagotenemab (LY3303560)

Zagotenemab (LY3303560)

Overview

Tau Pathology in Alzheimers Disease

Normal Tau Biology

Pathological Tau Transformations

The Importance of Targeting Tau Oligomers

Mechanism of Action

Antibody Characteristics

Therapeutic Mechanisms

Brain Penetration Challenges

Clinical Development Program

Phase I Clinical Trials

Phase II Trial: PERISCOPE-ALZ

Why Did Zagotenemab Fail?

Comparison with Other Anti-Tau Antibodies

Lessons from the Zagotenemab Experience

Implications for Future Tau Immunotherapy

What Worked

Current Status and Future Directions

Program Status

Legacy and Contributions

References

See Also

💬 Discussion

📗 Cite This Artifact

zagotenemab

Zagotenemab (LY3303560)

Zagotenemab (LY3303560)

Overview

Tau Pathology in Alzheimers Disease

Normal Tau Biology

Pathological Tau Transformations

The Importance of Targeting Tau Oligomers

Mechanism of Action

Antibody Characteristics

Therapeutic Mechanisms

Brain Penetration Challenges

Clinical Development Program

Phase I Clinical Trials

Phase II Trial: PERISCOPE-ALZ

Why Did Zagotenemab Fail?

Comparison with Other Anti-Tau Antibodies

Lessons from the Zagotenemab Experience

Implications for Future Tau Immunotherapy

What Worked

Current Status and Future Directions

Program Status

Legacy and Contributions

Related Programs

References

See Also

Related Pages

Related Mechanisms

Related Therapeutics

Related Hypotheses

💬 Discussion