Senolytics Should Be Pulsed, Not Dosed Continuously — The Senescent Cell Regrowth Kinetics Demand Hit-and-Run

The pharmacokinetics of senolytics matter more than their potency. Senescent cells take weeks to accumulate but can be cleared in hours. A single dose of dasatinib + quercetin clears >60% of senescent cells in fat tissue within 48 hours (Xu et al., 2018, Nature Medicine). Those cells don't come back for 2-4 weeks.

Continuous dosing doesn't improve efficacy but dramatically increases toxicity. Navitoclax given continuously causes sustained thrombocytopenia. D+Q given daily causes GI issues. But monthly pulses clear the same fraction of senescent cells with minimal side effects.

Hypothesis: The optimal senolytic regimen is a 2-3 day pulse every 4-6 weeks, titrated to senescent cell re-accumulation rate (measurable via circulating SASP factors like GDF15 and MMP3). Continuous dosing will prove inferior to pulsed dosing across all efficacy and safety endpoints.

Prediction: In a head-to-head trial, monthly 3-day D+Q pulses will show equivalent senescent cell clearance to daily dosing, with <10% of the adverse events.