Navitoclax as a Senolytic Therapy - Quick Reference Sheet

Navitoclax as a Senolytic Therapy

Created on 09/22/2026 – Quick Reference based on Evidence Review created using AI4L / Opus 5 Audit

Navitoclax blocks three proteins cells use to stay alive; worn-out senescent cells depend on two. In animals it clears them and restores aged stem cells; in people this has never been measured — every human result comes from cancer medicine. Platelet counts fall in proportion to the dose, capping how much can be administered. Not approved anywhere, available only in trials. (Full Review)

Protocol

Oncology monotherapy schedule
150 mg daily for 7 days, then 325 mg daily
Monotherapy schedule taken furthest, administered continuously in 21-day cycles; starting dose is set by platelet count
Preclinical senolytic schedule
No human equivalent established
Rodent senolysis work uses roughly 50 mg/kg daily for five to fourteen days per cycle, with cycles repeated after weeks of washout
Best time of day
Once daily, orally, morning with food
Terminal half-life of roughly 15–25 hours supports once-daily administration; no split-dose schedule has been evaluated
Time to effect
Spleen & Symptom Response
24 weeks
The point at which spleen and symptom responses were assessed in trials
Senescent-Cell Clearance
Within days
Measurable within days of a short course in rodents; never measured in people
Platelet Fall
Within hours
Begins within hours of the first dose; counts recover 1–2 weeks after stopping

Benefits

Contraindications
  • Baseline platelet count below 75 × 10⁹/L
  • Active bleeding, or hereditary or acquired bleeding disorder
  • Requirement for therapeutic anticoagulation or dual antiplatelet therapy
  • Severe hepatic impairment (Child-Pugh Class C)
  • Recent major surgery (within 28 days) or planned surgery during dosing
  • Pregnancy and lactation
  • Established osteoporosis (bone density T-score −2.5 or below)
  • Active uncontrolled infection, or absolute neutrophil count below 1.0 × 10⁹/L
Key Interactions
  • Strong CYP3A4 inducers (rifampin, carbamazepine, phenytoin, St John's wort)
  • Strong CYP3A4 inhibitors (ketoconazole, itraconazole, clarithromycin, ritonavir, grapefruit juice)
  • Over-the-counter non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, high-dose aspirin)
  • Marrow-suppressing chemotherapy (docetaxel, gemcitabine, irinotecan) and ruxolitinib
  • Supplements with antiplatelet activity (fish oil, high-dose vitamin E, ginkgo, garlic extract, curcumin, nattokinase)
  • Senolytic supplements (quercetin, fisetin) and the prescription senolytic dasatinib
  • Grapefruit, pomelo and Seville orange

Risk & Side Effects

  • High: Thrombocytopenia; neutropenia; gastrointestinal toxicity; lymphopenia and impaired antibody defence; fatigue
  • Medium: Anaemia; hepatic transaminase elevation
  • Low: Clinically significant bleeding; cardiac arrhythmia
  • Speculative: Trabecular bone loss and impaired bone formation; accelerated loss of ovarian reserve; worsening of pulmonary blood pressure through loss of lung endothelial cells; destabilisation of atherosclerotic plaque; loss of healthy cells that depend on BCL-xL

Monitoring

Marker Target Why
Platelet count 200–400 × 10⁹/L; hold below 75 × 10⁹/L Dose-limiting on-target toxicity
Absolute neutrophil count 2.0–5.0 × 10⁹/L Infection risk from progenitor loss
Absolute lymphocyte count 1.5–3.0 × 10⁹/L B- and T-cell depletion from BCL-2 inhibition
Haemoglobin 14.0–15.0 g/dL (men); 13.0–14.0 g/dL (women) Detects anaemia, common in combination use
Alanine aminotransferase (ALT) Below 25 U/L (men); below 20 U/L (women) Dose-limiting liver enzyme rise
Aspartate aminotransferase (AST) Below 25 U/L Confirms hepatic origin when alanine aminotransferase rises
Total bilirubin 0.3–1.0 mg/dL Detects impaired bile handling
Estimated glomerular filtration rate (eGFR) Above 90 mL/min/1.73 m² Protocol entry requirement and safety floor
Immunoglobulin M 40–230 mg/dL Tracks the sustained B-cell deficit
Senescent-cell burden (p16INK4a expression) No established target exists; track change from the individual's own baseline Gauges whether senolysis actually occurred

Cadence: Weekly during dose escalation, then every two weeks to week 8, then monthly; liver enzymes at weeks 2 and 4; immunoglobulins every 3 months; spleen and disease response at week 24 and every 12 weeks thereafter

Qualitative Assessment

  • Easy bruising, gum bleeding, nosebleeds or petechiae (pinpoint red skin spots) — the earliest visible sign of a falling platelet count
  • Frequency, duration and severity of infections, particularly during the lymphocyte nadir
  • Stool frequency and consistency, since diarrhoea is the most common non-blood adverse event
  • Energy levels and exercise tolerance, which fall early when haemoglobin drops
  • Appetite and nausea, which drive discontinuation more often than laboratory abnormalities