Two Drugs, Two Senescent Anti-Apoptotic Pathways
Dasatinib and quercetin hit different survival nodes senescent cells rely on.
- Src/BCR-ABL: Dasatinib target (tyrosine kinase inhibitor)
- BCL-2/PI3K: Quercetin target (flavonoid, multi-pathway)
- SCAP disruption: Combined mechanism (senescent cell anti-apoptotic pathway)
- Senescent > normal: Selectivity (apoptosis bias in target cells)
Why two drugs instead of one
Placeholder: senescent cells use redundant survival pathways requiring dual blockade.
Placeholder callout: neither drug alone clears senescent cells as efficiently as the pair.
Hit-and-Run: Why D+Q Is Dosed in Short Pulses
A brief high-exposure pulse clears senescent cells without continuous drug exposure.
- 2–3 days: Typical pulse length (per treatment cycle)
- 2–4 weeks: Typical interval (drug-free between pulses)
- Hit-and-run: Rationale (transient exposure, lasting effect)
- Minimized: Toxicity goal (vs. chronic daily dosing)
The pulse-and-rest logic
Placeholder: senolytics need only transient exposure to trigger apoptosis, unlike senostatics.
Placeholder callout: intermittent dosing schedule reduces cumulative drug burden.
The Clearance Window: Senescent Cells Undergo Apoptosis
During the pulse, senescent cells lose anti-apoptotic protection and die selectively.
- 0–72 hrs: Peak clearance window (post-pulse)
- ~30–60%: Senescent cell drop (in preclinical models)
- IL-6, IL-8 ↓: SASP factor decline (reduced inflammatory secretion)
- Minimal: Healthy cell impact (selective apoptosis)
What happens during the clearance pulse
Placeholder: dual pathway blockade tips senescent cells into apoptosis within days.
Placeholder callout: clearance is transient and requires repeated pulses.
The Drug-Free Interval: Tissue Remodeling and Repopulation
Between pulses, debris clears and healthy cells repopulate the tissue niche.
- 1–4 weeks: Recovery window (between pulses)
- Macrophage-mediated: Debris clearance (efferocytosis of dead cells)
- Gradual: Reaccumulation risk (senescent cells slowly return)
- Scheduled: Next pulse trigger (fixed interval protocol)
Why rest periods matter
Placeholder: recovery intervals let normal tissue repair before the next pulse.
Placeholder callout: reaccumulation of senescent cells motivates repeat pulsing.
Measuring Success: Trial Endpoints for D+Q Therapy
Clinical trials track physical function, biomarkers, and frailty over repeated cycles.
- Physical function: Primary endpoint (gait speed, chair-stand test)
- SASP panel: Biomarker endpoint (circulating inflammatory markers)
- Phase 2: Trial phase (2026) (multiple indications)
- 3–12: Dosing cycles studied (per trial protocol)
What trials actually measure
Placeholder: outcome measures combine function, biomarkers, and safety across cycles.
Placeholder callout: cumulative benefit may require multiple pulse cycles to detect.