Senolytics Pipeline Tracker: Human Evidence, Trial Status, and Translational Limits

Evidence reviewed through: 2026-08-05

Research cutoff and status verification: 2026-08-05

1. Current pipeline summary

Senolytics are interventions intended to preferentially eliminate senescent cells. The concept is supported by extensive model evidence, but the human pipeline remains early, heterogeneous and indication specific. Small studies of dasatinib plus quercetin (D+Q) have reported feasibility, selected functional signals or changes consistent with proof of biology. Those studies do not establish a clinically proven senolytic treatment. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; D+Q bone Phase 2 RCT, PMID 38956196.)

The negative and null evidence materially shapes the current picture. A 60-participant randomized bone study did not meet its prespecified primary C-terminal telopeptide (CTx) endpoint: P=0.611. Exploratory subgroup findings cannot replace that primary result. (Sources: D+Q bone Phase 2 RCT, PMID 38956196; NCT04313634 skeletal health results.)

Fisetin has registered human programs, but efficacy is unestablished and one COVID-19 study terminated for futility. Unity Biotechnology’s UBX0101 knee-osteoarthritis program did not achieve its intended Phase 2 objectives and was terminated. These are not footnotes; they are direct tests of translation that constrain broad claims about the class. (Sources: NCT04313634 skeletal health results; NCT06431932 fisetin pilot.)

RLS-1496 was listed as recruiting in Phase 1 for actinic keratosis at the cutoff, with no results posted. FOXO4-related approaches, cardiac glycosides, navitoclax-related strategies and uPAR/CAR-T immune clearance remain mechanistically relevant but do not provide human rejuvenation evidence. (Sources: NCT07340697 RLS-1496; FOXO4-DRI mouse study, PMID 28340339.)

No included program has established human lifespan extension or generalized healthspan modification. Model clearance, a biomarker shift or early proof of biology is not proof of rejuvenation, broad disease modification or longer life. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; Unity UBX0101 Phase 2 result announcement.)

2. Status last verified

Pipeline status was last verified on 2026-08-05. Registered-trial status is controlled by the cited ClinicalTrials.gov record, not a sponsor pipeline page or announcement. Company statements are used only for chronology or corporate positioning unless a registry or peer-reviewed result supports the operational claim. (Sources: NCT04313634 skeletal health results; NCT06431932 fisetin pilot.)

“Recruiting” means that the registry reported recruitment at the verification date. It does not mean that every site is open, that enrollment will complete, or that efficacy has been shown. “Completed” means the operational record reached that status; it does not mean that results are positive or published. “Terminated” records why a study stopped but should not be generalized beyond that asset, dose, indication and endpoint. (Sources: NCT04313634 skeletal health results; NCT06431932 fisetin pilot.)

The tracker should be refreshed when a registry changes status, results are posted, a peer-reviewed report appears, an asset changes sponsor or indication, or a safety signal changes the translational assessment.

3. What qualifies as a senolytic

Cellular senescence is a state in which cells undergo durable cell-cycle arrest alongside context-dependent changes in metabolism, signaling and secretory activity. Senescent cells are heterogeneous: their phenotype depends on cell type, inducing stress, tissue and time. A senolytic claim therefore requires more than general toxicity or reduced expression of one marker. (Sources: FOXO4-DRI mouse study, PMID 28340339; Navitoclax senolytic identification, PMID 26711051.)

At minimum, a candidate should show preferential activity against an appropriately characterized senescent-cell population, a plausible target or vulnerability, and evidence that the effect is not merely broad cytotoxicity. Human translation raises additional requirements: exposure at the target tissue, tolerable dosing, a defensible pharmacodynamic signal and a clinically meaningful endpoint in a defined indication. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; D+Q bone Phase 2 RCT, PMID 38956196.)

The category also includes strategies that recruit immune clearance or modulate survival pathways rather than use a conventional small molecule. These approaches belong in the tracker when they have credible translational relevance, but their risks and evidence should not be collapsed into one class effect. (Sources: FOXO4-DRI mouse study, PMID 28340339; Navitoclax senolytic identification, PMID 26711051.)

4. Why model evidence is compelling

In animal models, removing or reducing selected senescent-cell burdens can improve tissue function or disease phenotypes. Genetic and pharmacologic experiments provide mechanistic coherence: senescent cells can contribute to fibrosis, inflammatory signaling and impaired regeneration in defined models. (Sources: FOXO4-DRI mouse study, PMID 28340339; uPAR CAR-T aging study, PMID 38267706.)

That evidence is compelling because it tests intervention against a defined biological target. It is still model evidence. Human senescent-cell populations may differ in abundance, vulnerability and consequence, while drug exposure and off-target toxicity constrain what can be attempted. Disease models also do not reproduce the complexity or duration of human aging. (Sources: FOXO4-DRI mouse study, PMID 28340339; Navitoclax senolytic identification, PMID 26711051.)

The translational question is not whether senescence biology exists. It is whether a particular intervention, dose and schedule can safely modify a clinically meaningful human outcome through the intended mechanism.

5. Human translation standard

Human evidence should progress from safety and exposure to proof of target engagement, then to controlled clinical outcomes. A credible program must state the population, indication, intervention, comparator, endpoint hierarchy and follow-up. Biomarkers can support mechanism, but they should not substitute for clinical benefit unless validated for that use. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; NCT04313634 skeletal health results.)

Early pilots can answer whether intermittent dosing is feasible or whether selected tissue markers change. They are usually too small to establish efficacy, uncommon harms or broad generalizability. Open-label improvement is particularly difficult to interpret when symptoms fluctuate or assessments are susceptible to expectation and regression to the mean. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; D+Q bone Phase 2 RCT, PMID 38956196.)

Randomized evidence deserves priority, including negative results. A missed primary endpoint cannot be rescued by presenting only a favorable subgroup or secondary measure. Similarly, sponsor language about “senolytic activity” should not be allowed to redefine a trial’s registered outcome. (Sources: D+Q bone Phase 2 RCT, PMID 38956196; NCT04313634 skeletal health results.)

6. Candidate and status matrix

7. Dasatinib plus quercetin

D+Q combines an oncology kinase inhibitor with a flavonoid and has become the most visible human senolytic regimen. Small studies in idiopathic pulmonary fibrosis, diabetic kidney disease, Alzheimer-related contexts and other populations have tested intermittent exposure, feasibility, selected function or tissue markers. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; D+Q bone Phase 2 RCT, PMID 38956196.)

These studies establish that human investigation is possible and that selected biological or functional signals have been reported. Their sample sizes, populations and designs do not establish general clinical efficacy or suitability outside research. The combination’s components also have distinct pharmacology and safety profiles; “natural plus repurposed” is not a safety classification. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; D+Q bone Phase 2 RCT, PMID 38956196.)

The randomized bone study is a critical counterweight. In 60 participants, the prespecified primary CTx endpoint was not met (P=0.611). Exploratory subgroup or secondary observations may generate hypotheses, but they cannot be presented as though the trial achieved its primary objective. (Sources: D+Q bone Phase 2 RCT, PMID 38956196; NCT04313634 skeletal health results.)

8. Fisetin

Fisetin is a flavonoid proposed to have senolytic activity in model systems. Human registry records cover varied contexts, doses and endpoints. That diversity prevents the word “fisetin” from standing in for one clinically validated intervention. (Sources: NCT04313634 skeletal health results; NCT06431932 fisetin pilot.)

One registered COVID-19 study terminated for futility. Other programs remain early or operationally incomplete at the cutoff. A registered trial demonstrates that a question is being tested; it does not demonstrate that fisetin clears senescent cells in people or improves an aging outcome. (Sources: NCT06431932 fisetin pilot; NCT04537299 COVID-FIS.)

Because fisetin is commercially accessible, public discussion can move faster than evidence. This tracker does not provide dosing or self-experimentation guidance. Future classification should depend on controlled results, verified exposure, pharmacodynamic evidence and safety—not availability.

9. UBX0101 and the negative Phase 2 translation

UBX0101 was developed as a locally administered inhibitor intended to target a senescent-cell survival pathway in knee osteoarthritis. Its Phase 2 program did not demonstrate the intended objectives, and related follow-up was terminated. (Sources: NCT04129944 UBX0101 knee OA; NCT04349956 UBX0101 follow-up.)

This result does not disprove every senolytic mechanism. It does show that compelling rationale and an indication-local delivery strategy did not translate into the expected clinical result for this asset and program. The appropriate class-level lesson is uncertainty, not dismissal or selective forgetting. (Sources: NCT04129944 UBX0101 knee OA; NCT04349956 UBX0101 follow-up.)

Negative translation helps define endpoint selection, target engagement and disease-context challenges. It belongs in any credible pipeline summary with prominence comparable to early positive signals.

10. RLS-1496 and other registered human programs

RLS-1496 is a topical GPX4-modulating candidate being studied for actinic keratosis. ClinicalTrials.gov listed NCT07340697 as recruiting Phase 1 at the cutoff. The registered objectives include early safety and lesion-related assessment; no results were posted. (Sources: NCT07340697 RLS-1496.)

The topical route and dermatologic indication may allow a different exposure/risk profile from systemic aging interventions. That distinction matters. Success or failure in actinic keratosis would be informative for the asset and local mechanism, but would not establish generalized rejuvenation. (Sources: NCT07340697 RLS-1496.)

Other registered early programs should enter the tracker only when their intervention, sponsor, identifier and operational status can be verified. Sponsor pipeline language alone is insufficient.

11. Navitoclax and BCL-2-family approaches

Navitoclax and related work target BCL-2-family survival pathways that can be important in selected senescent cells. Model evidence supports senolytic activity in some contexts. Human oncology experience also demonstrates clinically material thrombocytopenia from BCL-XL inhibition. (Sources: Navitoclax senolytic identification, PMID 26711051.)

This is a direct example of the selectivity problem: a vulnerability used by senescent cells may also be important in healthy cells. Targeted derivatives, local delivery or intermittent schedules may alter the balance, but those possibilities require empirical human evidence. (Sources: Navitoclax senolytic identification, PMID 26711051.)

The current classification is mechanistically relevant and systemically constrained—not a clinically suitable longevity senolytic.

12. FOXO4-related approaches

FOXO4-DRI work targets a proposed FOXO4–p53 interaction and has reported effects in preclinical models. The approach is scientifically notable because it proposes a different survival dependency from D+Q or BCL-2-family targeting. (Sources: FOXO4-DRI mouse study, PMID 28340339.)

Human delivery, selectivity, pharmacokinetics and safety remain unresolved. No approved packet source establishes a qualifying human rejuvenation program. Claims that FOXO4 peptides are established anti-aging therapies are unsupported. (Sources: FOXO4-DRI mouse study, PMID 28340339.)

13. Cardiac-glycoside strategies

Preclinical work has identified cardiac glycosides as potential senolytic agents through vulnerabilities related to ion homeostasis. These compounds have narrow therapeutic windows and clinically important pharmacology, making translation especially sensitive to exposure and selectivity. (Sources: Cardiac glycosides as senolytics, PMID 31636264.)

The presence of a familiar drug class does not reduce the need for registered human study. Until an appropriate program establishes dose, safety, target engagement and outcome, this remains a mechanistic strategy rather than a human pipeline success.

14. uPAR/CAR-T and immune-clearance strategies

uPAR-directed CAR-T work uses engineered immune cells to target uPAR-positive senescent-cell populations. Model studies in fibrosis and aging-related contexts demonstrate a different strategy: enlist immune clearance instead of delivering a conventional senolytic drug. (Sources: uPAR CAR-T senolytic proof, PMID 32555459; uPAR CAR-T aging study, PMID 38267706.)

Cell therapy introduces substantial risks, manufacturing requirements and target-specificity questions. uPAR expression is not a universal label for every harmful senescent cell, and removal of target-positive cells could have unintended effects. (Sources: uPAR CAR-T senolytic proof, PMID 32555459; uPAR CAR-T aging study, PMID 38267706.)

The approach is translationally important but remains preclinical for the aging claims considered here.

15. Safety and target-specificity limits

Senescent cells can also participate in wound healing, tissue remodeling and tumor suppression. The relevant question is not maximal clearance, but whether a specific harmful population can be modified at an acceptable risk. Heterogeneity makes both target identification and pharmacodynamic measurement difficult. (Sources: FOXO4-DRI mouse study, PMID 28340339; Navitoclax senolytic identification, PMID 26711051.)

Known compound risks remain compound risks. Dasatinib has oncology pharmacology; BCL-XL inhibition can cause thrombocytopenia; cardiac glycosides have narrow margins; CAR-T approaches carry cell-therapy risks. Intermittent dosing or local delivery may change exposure but does not erase those hazards. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; D+Q bone Phase 2 RCT, PMID 38956196.)

Small pilots cannot define uncommon or delayed harms. Safety evidence should be read at the tested dose, schedule, population and follow-up.

16. Published evidence versus sponsor claims

Peer-reviewed results and registry records control efficacy and operational status. Sponsor or investor material can document that a company announced a program, changed priorities or described a mechanism, but it cannot independently establish efficacy, trial status or target engagement. (Sources: NCT07340697 RLS-1496; NCT04349956 UBX0101 follow-up.)

The tracker should display contradiction openly. If a sponsor page describes an active pipeline while the registry reports termination, the registry status controls the operational statement and the older promotional claim is dated as superseded.

17. What this establishes

• Human senolytic investigation exists, led by small D+Q studies and early registered programs. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; D+Q bone Phase 2 RCT, PMID 38956196.)
• The D+Q bone trial missed its primary CTx endpoint. (Sources: D+Q bone Phase 2 RCT, PMID 38956196; NCT04313634 skeletal health results.)
• Fisetin efficacy remains unestablished, with one study terminated for futility. (Sources: NCT04313634 skeletal health results; NCT06431932 fisetin pilot.)
• UBX0101 is a material negative Phase 2 translation result. (Sources: NCT04129944 UBX0101 knee OA; NCT04349956 UBX0101 follow-up.)
• Multiple newer approaches remain mechanistic or preclinical. (Sources: FOXO4-DRI mouse study, PMID 28340339; uPAR CAR-T aging study, PMID 38267706.)

18. What this does not establish

• It does not establish that any included intervention rejuvenates humans.
• It does not establish generalized disease modification, healthspan extension or lifespan extension. (Sources: D+Q in idiopathic pulmonary fibrosis, PMID 30616998; Unity UBX0101 Phase 2 result announcement.)
• It does not support off-label treatment, supplement use, dosing or self-experimentation.
• It does not convert sponsor mechanism claims into clinical evidence.

19. Tracker fields and update triggers

Each tracked row should retain candidate, mechanism, sponsor, indication, human evidence, trial identifier, phase, operational status, status-verification date, primary endpoint, safety findings, evidence classification, contradictory older source and update trigger. Status should be rechecked at least quarterly and immediately after registry results, peer-reviewed publication, termination, sponsor change or material safety disclosure.