Alzheimer's Disease Senolytic Therapy Companies

Overview

Overview

Senolytic therapies represent a novel and promising approach to treating Alzheimer's disease by targeting and eliminating senescent cells that accumulate with aging and in neurodegenerative conditions. These "zombie cells"—cells that have stopped dividing but remain metabolically active—secrete pro-inflammatory factors collectively known as the senescence-associated secretory phenotype (SASP), which drive chronic neuroinflammation and contribute to protein aggregation in AD["@senescence"].

The senolytic approach differs fundamentally from other AD therapeutic strategies:

• Rather than targeting amyloid or tau directly, senolytics address a root cause of disease progression
• By clearing senescent cells, the therapy may reduce multiple downstream pathological processes
• Potential for disease modification rather than just symptom management

Key Companies

Retro Biosciences

Retro Biosciences is a biotechnology company focused on cellular senescence and protein homeostasis in aging and age-related diseases[@retro_bio]:

| Attribute | Details |
|-----------|---------|
| Focus | Cellular senescence, protein homeostasis |
| Lead Candidate | RB-001 |
| Indication | Alzheimer's disease |
| Stage | Phase 1 |
| Mechanism | Dasatinib + Quercetin (D+Q) combination senolytic |

Scientific Rationale: The D+Q combination targets senescence through multiple pathways:

• Dasatinib: tyrosine kinase inhibitor with senolytic activity
• Quercetin: flavonoid with senolytic properties
• Combination shown to reduce senescent cell burden in preclinical models

Unity Biotechnology

Unity Biotechnology is a clinical-stage company developing senolytics for age-related diseases, initially in ophthalmology and orthopedics with expansion into CNS[@unity_bio]:

| Attribute | Details |
|-----------|---------|
| Focus | Ophthalmology, orthopedic conditions, expanding to CNS |
| Lead Candidates | UBX1325, UBX3457 |
| Stage | Phase 2 (eye/joints), Preclinical for CNS |
| Mechanism | Bcl-2 inhibitor senolytics |

Notes: Unity has demonstrated strong safety data in eye and joint diseases with their lead candidates. The company is developing brain-penetrant analogs of their senolytic molecules for AD and PD applications.

Clever Therapeutics

Clever Therapeutics is developing next-generation senolytic approaches:

| Attribute | Details |
|-----------|---------|
| Focus | Targeted senolytic conjugates |
| Mechanism | Antibody-senolytic conjugates for targeted delivery |
| Stage | Preclinical |

Innovation: Clever's approach uses antibody-based targeting to deliver senolytic agents specifically to senescent cells, potentially improving safety and efficacy compared to systemically administered senolytics.

SiWa Therapeutics

SiWa Therapeutics is exploring novel senolytic combinations:

| Attribute | Details |
|-----------|---------|
| Focus | Novel senolytic combinations |
| Mechanism | Small molecule combinations targeting multiple senescence pathways |
| Stage | Discovery |

Calico (Alphabet)

Calico is Alphabet's life sciences company focused on aging biology and neurodegeneration:

| Attribute | Details |
|-----------|---------|
| Focus | Aging biology and neurodegeneration |
| Mechanism | Multiple programs including autophagy enhancement |
| Stage | Research |

Approach: Calico's strategy includes understanding fundamental aging mechanisms and developing interventions that address multiple hallmarks of aging, including cellular senescence.

Additional Companies in Development

The senolytic field continues to evolve with additional players:

• Scripps Research: Academic research leading to potential spinouts
• Mayo Clinic: Pioneering senolytic research with clinical translation
• Wake Forest University: Senolytic compound development

Mechanism of Action

Senolytic drugs work through two main mechanistic approaches[@sasps]:

1. Direct Senolytics

Drugs that selectively induce apoptosis in senescent cells:

| Mechanism | Example | Status |
|-----------|---------|--------|
| Dasatinib + Quercetin | D+Q combination | Phase 1/2 |
| Bcl-2 inhibitors | ABT-263/Navitoclax | Preclinical |
| FOXO4-p53 interference | Peptide-based | Preclinical |
| Spiperone | Selective senolytic | Preclinical |

2. Senostatic Agents

Drugs that suppress SASP without directly killing senescent cells:

| Mechanism | Example | Status |
|-----------|---------|--------|
| mTOR inhibition | Rapamycin | Research |
| JAK inhibition | Ruxolitinib | Research |
| NF-κB inhibition | Various compounds | Research |

Why Target Senescence in AD?

Cellular senescence contributes to AD through multiple mechanisms:

Clinical Trial Landscape

| Company | Drug | Phase | Indication | Status |
|---------|------|-------|------------|--------|
| Retro Biosciences | RB-001 | Phase 1 | Alzheimer's disease | Pending |
| Unity Biotechnology | UBX3457 | Preclinical | AD/PD | Development |
| Unity Biotechnology | UBX1325 | Phase 2 | Eye disease | Completed |

Challenges in Clinical Development

• Brain penetration: Ensuring sufficient drug exposure in CNS
• Biomarker development: Identifying patients who would benefit most
• Efficacy endpoints: Demonstrating disease modification in early trials
• Safety considerations: Off-target effects on non-senescent cells

Scientific Rationale

The connection between cellular senescence and AD is supported by multiple lines of evidence:

Evidence of Senescence in AD Brain

• Senescent neurons and glia identified in AD postmortem tissue
• SASP factors elevated in AD cerebrospinal fluid
• p16INK4a (senescence marker) expression increases with age and disease

Preclinical Proof of Concept

• Senolytic administration reduces SASP in animal models
• Improved cognitive function in AD mouse models after senolytic treatment
• Reduced amyloid and tau pathology reported in some studies

Potential Advantages

• Disease-modifying potential (addresses upstream pathology)
• Possible benefit across multiple neurodegenerative conditions
• Relatively broad therapeutic index for some compounds

Cross-Links

• [Senolytics in Neurodegeneration](/therapeutics/senolytics)
• [Aging and Neurodegeneration](/mechanisms/aging-neurodegeneration)
• [Neuroinflammation](/mechanisms/neuroinflammation-pathway)
• [Emerging Novel Mechanism AD Companies](/companies/emerging-novel-mechanism-ad-companies-2024-2025)
• [Cellular Senescence](/mechanisms/cellular-senescence)
• [Dasatinib and Quercetin](/compounds/dasatinib-quercetin)

References