Intervention
Navitoclax (ABT-263)
Mechanism, regulatory status, and an honest, tiered evidence map.
○ Human lifespan evidence: none (animal/preclinical or mechanism only)
What it is
Class: Bcl-2/Bcl-xL inhibitor (targeted senolytic)
Also known as: ABT-263
Relationship to senescence: A BH3-mimetic that inhibits the anti-apoptotic proteins Bcl-2 and Bcl-xL, directly disabling a core SCAP and inducing apoptosis in many senescent cell types.
Regulatory status
An investigational oncology agent; not approved as a senolytic and not in routine human senolytic use. On-target Bcl-xL inhibition causes dose-limiting thrombocytopenia, a major barrier to systemic anti-aging use.
Mechanism
Prototypical targeted senolytic in animal models: clears senescent haematopoietic and muscle stem cells and rejuvenates aged tissue in mice. See /bcl2-bclxl-scaps.
Evidence — Mouse / in vitro
| Species / population | Aged and irradiated mice; cultured senescent human and mouse cells. |
| Exposure, route, schedule | Oral ABT-263 (intermittent). |
| Comparator / duration | Vehicle controls. |
| Endpoint / numeric result | Selective senescent-cell clearance; rejuvenation of aged haematopoietic and muscle stem cells (Chang 2016). |
| What it did NOT establish | No human senolytic outcome; systemic human use limited by thrombocytopenia. |
Negative or null findings
- Navitoclax caused trabecular bone loss and impaired osteoprogenitor function in aged mice (a senolytic-toxicity signal).
- Dose-limiting thrombocytopenia in humans (oncology data) has kept it from advancing as a systemic senolytic.