CDP-20: [Funding] Dark Microglia and Lipidomics

One liner: Identification of toxic lipids from dark microglia through the integrated stress response (ISR) for a path to novel drug targets in Alzheimer's Disease.

Cerebrum DAO Deal Team

• Senior reviewers: Catherine Vaillant (Neuroscience), Klaus Beck (Clinical and commercial), Peter Groenen (Translational Science)
• Project Team: Peter Groenen, Maryna Polyakova, Brian Magierski
• Sourced by: Michele Gallia

Project Team

• Principal Investigator: Pinar Ayata
• Translational Neuroscience Advisor: Peter Groenen
• Project Team: Maryna Polyakova, Peter Groenen

Summary Deal Analysis

The concept of "Dark Microglia (DM)" is relatively new and well supported by additional scientific reports from the last few years. Ayata and colleagues have further characterized the DM. The integrated Stress Response (ISR) is activated in most of the DMs. Several engineered mouse models have clearly shown this direct relationship between ISR, lipid production and DMs as a microglial sub-population. While there is a correlation and there are causal relationships for the amyloid plaques, Tauopathies, Inflammation ISR and DMs, the identity of the (toxic) lipids and the associated pathology are less understood.

While neuroinflammation, tauopathies, amyloid plaques and the underlying pathways have been subject to decades of investigation of therapeutic interventions, with so far limited success, the ISR and the microglial subsets, in particular the DMs have been only since recently gained interest.

Problem

Neuroinflammation is a key pathological mechanism in most neurodegenerative diseases [1]. Current research indicates that sustained neuroinflammation is a driver of AD pathology along with amyloid and tau accumulation [2, 3]. With the limited clinical benefit by the currently approved treatments against amyloid pathology [4], a wider interest has emerged to treat the neuroinflammatory component. While several approved anti-inflammatory drugs treat diseases like multiple sclerosis (MS) there are currently no approved anti-inflammatory drugs for neuroinflammation that have reached market approval stage.

Microglia are the brain's primary immune cells and a leading causal cell type in AD [5, 6]. Particularly a well-defined microglial sub population defined as disease associated microglia (DAM) [7] are associated with pathology. DAM can be neuroprotective but also neurodegenerative when uncontrolled. This suggests further heterogeneity in the DAM population. Elucidation of the drivers and characteristics of these subpopulations presents a major challenge.

The studies on the heterogeneity in microglia reveal that AD pathology is much more complex and significantly more heterogeneous than previously attributed to mainly amyloid and Tau pathology. The rather limited clinical benefit from amyloid depletion in approved AD therapies urges to open other drug discovery efforts to provide a clinical benefit to subpopulations of AD.

Solution

Ayata and colleagues have focussed in their research on a subset of DAM: dark microglia [8]. Dark Microglia (DM) are a distinct microglial phenotype characterized by ultrastructural markers of cellular stress, including electron-dense cytoplasm/nucleoplasm and oxidative damage. First identified in 2016 [9], they become abundant in Alzheimer's disease (AD), chronic stress, and aging, where they actively remodel neuronal circuits through excessive synaptic interactions. They postulated that the integrated stress response (ISR) is the basic trigger that leads to the formation of these DMs. By Studying the ISR in AD biospecimen and mouse models they demonstrated a direct causative relationship. By generating specific ISR induced DAM populations, specifically the DMs, they also showed that DMs can propagate ISR to naïve neurons. There is a growing body of literature that points to lipids as cell-autonomous mediators [10, 11].

The project proposal aims at the elucidation of these lipids and their pathways to allow for more directed drug discovery efforts beyond those focussing on the ISR.

Competitive landscape

Company / Program	Focus area	Molecular target	Modality	Stage (Nov 7, 2025)	Status / Notes
Sanofi (acq. Vigil) VG-3927	Dark microglia / microglial activation	TREM2 (agonism)	Oral small molecule	Phase 1 completed; Phase 2 in AD planned/initiating 2025	First-in-class small-molecule TREM2 agonist; Sanofi deal closed 2025
Alector/AbbVie AL002 (INVOKE-2)	Dark microglia / microglial activation	TREM2 (agonist mAb)	Monoclonal antibody	Phase 2 completed	Phase 2 topline negative in early AD (Nov 2024)
Denali/Takeda DNL919 (TAK-920)	Dark microglia / microglial activation	TREM2 (agonist, ATV-enabled)	ATV-enabled mAb	Discontinued (2023)	Program discontinued Aug 2023
Denali DNL343	Integrated Stress Response (ISR)	eIF2B (activator)	Oral small molecule	Phase 2 (ALS); AD relevance preclinical/biological	CNS-penetrant ISR modulator; translational data 2025
Academic/Preclinical PERK pathway	Integrated Stress Response (ISR)	PERK eIF2 pathway	Small-molecule inhibitors (tool compounds)	Preclinical (tox constraints historically)	New astrocyte data in AD models; translatability under evaluation
Cognition Therapeutics CT1812 (zervimesine)	Lipid handling / cholesterol trafficking; synaptic protection	Sigma-2/TMEM97 complex (allosteric antagonist)	Oral small molecule	Multiple Phase 2 studies; EoP2 alignment with FDA in 2025	Mixed readouts historically; ongoing/enriched-population strategy
Various (academic/early biotech) Non-lipogenic LXR/ABCA1 inducers	Lipid biology (ApoE lipidation, cholesterol efflux)	LXR ABCA1/ABCG1 (induction)	Oral small molecules / delivery innovations	Preclinical; limited early clinical evidence historically	Active academic innovation to reduce lipogenic liability (NLAI); translational trend

Target Product Profile

	Minimum	Optimum
Primary product indication	Alzheimer's Dementia (AD)
Patient Population (diagnostic)	AD patients with an increase in the detected (toxic) lipids
Unmet medical need	Stabilize cognitive decline	Improvement of cognition
Major competitive threat
Differentiation
Benefits
Treatment Duration	Chronic	n.d.
Delivery Method	Oral
Dosage Form and strength	TBD	TBD
Regimen	BID (twice a day)	QD (Once a day)
Contraindications	NA
Efficacy
Risk/Side Effect
Therapeutic Modality	Small molecule

IP Roadmap

The work by Ayata and colleagues would open several avenues that would create "composition of matter" patents. The elucidation of the "toxic" lipids, and the pathway will help to define therapeutic intervention strategies. This research will lay a firm base for the second step where it will be more drug discovery focussed.

Experimental Plan

• Aim 1 (Month 1-6): Preparation of tissue and MALDI imaging: ~$1,000 per sample at NYU Metabolomics Core. We will image n=6 (3 male, 3 female) from 6 genotypes.
  Total: $36,000 (NYU Metabolomics core)
• Aim 2 in vitro work (Month 4-9): Custom-made lipids: ~$2000 per lipid. Inhibitors: ~$250 per lipid. siRNAs: ~$1,000 per gene. 2-3 candidates. Supplies for in vitro work. Total: $25,000 (reagents)
• Aim 2 in vivo work (Month: 1-12): Supplies for imaging:
  Total: $15,000 (reagents)
• Aim 2 (Month: 1-12): Imaging Core usage
  Total: $14,000 (Imaging Core)
• Mouse maintenance (Month: 1-12):
  Total: $10,000 (CMU core)

Total: Cores: $60,000; Reagents: $40,000

Total study costs; $100,000

Financing and Cerebrum DAO Funding Terms

Slide deck

Highlights

• Following well documented observations and the ISR as a pathway that has been extensively studied and targeted to treat AD, the focus on a subset of microglia, the so-called dark microglia is novel and the focus on lipids very timely as there's increasing evidence for lipids playing an important role in the pathophysiology.
• The team is very strong in several experimental in vivo analyses
• There is solid collaboration with experts in lipidomics.

Risks

• Correlation or causality. The lipids that increase might be a consequence rather than a cause.
• Big data sets, small sample size, underpowered study overinterpretation.
• Lipids may be difficult to target, the search for upstream targets is a next challenge

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Please visit the following link to view the full proposal, as the proposal content exceeds Snapshot's character limit: https://docs.google.com/document/d/1-vT84S6SAT3-z8_tmnv8mYfyKjcITqKSiXeY7mWphTA/edit?usp=sharing