Standard disease frameworks are meeting their match as pioneers lean on functional metrics and pragmatic stepping stone indications.
The longevity landscape shifted in May at a landmark public meeting convened by the Reagan-Udall Foundation for the FDA. Co-sponsored by ARPA-H’s PROSPR program and the XPRIZE Foundation, the summit tackled the commercial ecosystem’s most stubborn bottleneck: translating structural geroscience breakthroughs into concrete, regulatorily approved human therapeutics. Over-reliance on traditional chronological endpoints or amorphous biomarkers is giving way to a more sophisticated strategy built on validated clinical outcome assessments (COAs) and targeted indications.
Longevity.Technology: The longevity space is growing up. For years the field talked itself in circles over whether aging is a “disease” or merely a “physiologic state” – a debate with all the urgency of arguing about the colour of the ship while it sinks. This meeting quietly retired that argument. By anchoring regulatory discussions to Intrinsic Capacity frameworks and pragmatic “stepping stone” pathways, the industry is building within the FDA’s existing architecture rather than lobbying for an entirely new one; sensible, if a touch less romantic than the founding mythology of the field. Regulators remain skeptical, as their job requires; the onus sits squarely with developers to show that halting muscle loss or restoring cognitive function delivers a benefit patients actually notice, not merely one a biomarker can be persuaded to report. Biological entertainment is giving way to something more exacting. That, rather than any grand unifying theory of aging, is what mainstream adoption will actually require.
What intrinsic capacity actually is
Before the afternoon’s case studies, the morning session did the more unglamorous work of defining terms. Dr Kelly Anderson’s account of ARPA-H’s consensus meeting is where intrinsic capacity stops being a slogan and starts resembling a spec sheet: gait speed and the short physical performance battery for locomotion; MoCA paired with a processing-speed measure for cognition; grip strength and respiratory function standing in, a little uneasily, for vitality. The group’s central decision – score each domain on its own rather than fold everything into a single composite – is not housekeeping. A composite that cannot be taken apart cannot tell a regulator which lever actually moved, and Anderson was equally plain that IC is not yet a validated surrogate of anything. It is a framework in waiting, not evidence already banked.
There was a numbers gap too, and numbers are what this field has been short on. Dr Jamie Justice’s Delphi survey – still gathering responses, but with early figures already in hand – found 90% of participating investigators rejecting an aging-as-disease framing outright, and 87% naming the absence of a validated surrogate endpoint as the single largest barrier to progress. Not funding; not trial design. The endpoint itself. Figures like these are what convert “the industry is maturing” from a mood into an argument.
Hallmarks, repurposed
Twelve hallmarks of aging underpin Nir Barzilai’s argument, and he is characteristically unwilling to let any one of them claim the throne; target one, he maintains, and the others shift regardless, which is rather the point of calling them hallmarks at all. His case rests less on theory than on drugs already sitting in medicine cabinets. SGLT2 inhibitors, developed for diabetes, turned out in a trial of some 4,000 largely non-diabetic patients to cut renal, cardiovascular and all-cause mortality outcomes by around 40% apiece; metformin, in COVID-era data, halved hospitalisation and death rates in a population that had nothing to do with blood sugar.
The implication Barzilai draws is not subtle: these molecules were quietly treating aging itself, and the FDA’s existing willingness to approve them for diabetes and kidney disease is proof that the regulatory door was open long before anyone thought to knock on it as a longevity claim.
When the endpoint fails and the field learns anyway
Dr Joan Mannick’s account of Novartis’s mTOR-inhibitor programme is the more chastening tale, and rather more interesting for it. Low-dose rapamycin analogues improved influenza vaccination response in older adults and, in early trials, appeared to cut respiratory tract infections across the board – a plausible route to boosting flagging immune senescence rather than merely suppressing it, as high-dose mTOR inhibition classically does. The FDA, though, balked at symptom-only endpoints once the programme reached Phase 3, insisting on laboratory-confirmed infection; older adults, it turns out, report qualifying respiratory symptoms with startling frequency even when nothing pathogenic is present, and the trial missed its mark.
What survived the disappointment was a sharper hypothesis: a small, unpublished nursing-home study during the earliest days of COVID-19, using lab-confirmed severity rather than symptom counts, found zero symptomatic cases in the treated arm against 23% severe disease – and four deaths – on placebo. A messy endpoint, discarded; a precise one, waiting in the wings. It is as good an illustration as any of how regulatory failure, properly diagnosed, can hand a field its next endpoint rather than close the door on it.
The case for counting mortality after all
David Allison took the least fashionable position of the morning, and made no apology for it. Composite scores and intrinsic capacity batteries are useful, he allowed, but none commands universal agreement – hand the same raw dataset to two statisticians and, given a large enough computer, each will construct a defensible composite that tells a different story. Mortality rate, by contrast, needs no committee to define it. His evidence was drawn from decades of rodent longevity work: full-length lifespan studies, when truncated at two years rather than run to completion, delivered much the same verdict as the full study, provided the sample size was inflated roughly fivefold to compensate.
Run that logic forward into human trials starting participants across a spread of ages, he argued, and a consistent reduction in mortality rate across every starting cohort would, for practical purposes, stand in for a longevity claim – without anyone needing to wait until the last participant has died to find out if it worked.
Intrinsic capacity at scale – XPRIZE and ARPA-H cases
The afternoon session showcased dynamic efforts designed to generate human evidence at an unprecedented scale. Dr Jamie Justice outlined how the $101 million XPRIZE Healthspan competition requires teams to demonstrate therapeutic restoration across three key functional pillars: muscle, cognitive and immune performance in one-year trials.
The diverse modalities competing for the prize demonstrate the breadth of modern geroscience:
- Mitochondrial therapeutics: Dr David Brown presented data from Stealth BioTherapeutics’ Mitochondrial All-Stars team. Their SHAPE trial evaluated elamipretide – a peptide targeting the inner mitochondrial membrane – showing encouraging open-label functional gains in older adults over a 30-day period.
- Multimodal interventions: Dr Zahi Fayad introduced the NYC-VITA 2030 platform, a combination trial utilizing rapamycin, spermidine and precise high-intensity interval training (HIIT) paired with resistance exercise to reverse age-related macrophage shifts and systemic inflammation.
- Bioelectric devices: Moving beyond small molecules, Dr Blake Rasmussen revealed striking preclinical and emerging clinical data using low-frequency ultrasound (LFU). In murine models, LFU reversed cellular senescence, extended lifespan and improved physical performance. Human testing is already underway at UT San Antonio.
Parallel to these efforts is ARPA-H’s PROSPR consortium. Dr Brianna Stubbs detailed the THRIVE team’s ambitious plan to submit an Intrinsic Capacity score suite to the FDA via the Drug Development Tool pathway. The framework leverages blood micro-sampling, digital health wearables and smart apps to shift clinical monitoring from institutional clinics straight into patients’ homes.
The stepping stone strategy
A recurring consensus emerged regarding clinical translation: developers cannot wait for decades-long mortality or survival data. Dr James Peyer, CEO of Cambrian Bio, outlined the strategic necessity of “stepping stone” indications – treating acute, rare, or recognized metabolic disorders first to validate safety and mechanistically prove efficacy before transitioning to broader preventative labels. Cambrian is applying this model to TOR-101, a highly selective mTORC1 inhibitor designed to avoid the harsh immunosuppressive off-target drawbacks of classic rapamycin by selectively leaving mTORC2 unperturbed.
Similarly, Dr George Kuchel shared progress on the RT-Age project, which repurposes the potent reverse transcriptase inhibitor censavudine (TPN-101) to inhibit LINE-1 retrotransposons – a fundamental driver of chronic, age-associated inflammation.
Straight talk from former regulators
The dialogue turned candid during a panel featuring former FDA officials Dr Sandra Kweder and Dr G Alexander Fleming. Kweder likened an amorphous, poorly defined longevity IND crossing an analyst’s desk to “releasing a chicken on a packed 737 flight” – an invitation to administrative chaos. Her prescription for avoiding it was resolutely unglamorous: a clear indication, a defined population, an honest accounting of risk that goes well beyond “well tolerated”, and – eventually, unavoidably – a serious conversation about chemistry, manufacturing and controls.
Fleming picked up where Kweder left off, noting that the agency was “ready, willing and waiting” for exactly the kind of specificity she’d just outlined – population, mechanism, dose, safety – and that what FDA wanted was “specific proposals… not grandiose proposals.” He was equally clear that the bar isn’t prevention in the absolute; it’s risk reduction, demonstrated through face-valid functional endpoints – walking speed, stair climbing – with regulatory precedent already behind them.
Industry alignment and the proteomic layer
Major pharmaceutical players are paying close attention. Panelists from Novo Nordisk, GSK and Regeneron emphasized that the science is steadily maturing. Novo Nordisk’s Jill Lee highlighted the lessons learned from the cardiometabolic space, where modern GLP-1 therapies are systematically moving indication-by-indication to prove multi-organ therapeutic benefits. Dr David Glass of Regeneron argued for common-sense functional metrics, noting that halting age-related muscle loss (sarcopenia) should hold a direct pathway to regulatory approval, much like bone mineral density functions as an accepted surrogate for osteoporosis risk.
Enabling these clinical parameters is a robust biological information layer. Evan Mills of Olink noted that substantial advancements in high-throughput plasma proteomics are providing the raw analytical horsepower needed to validate these multi-system functional changes. The deep longitudinal datasets generated by initiatives like the UK Biobank are successfully converting broad systemic aging signatures into highly sensitive, actionable tracking tools for therapeutic intervention.
The meeting established that the regulatory path forward for gerotherapeutics will not be paved with hypothetical longevity claims. Success belongs to the pragmatists anchoring their innovations to hard functional metrics, solid manufacturing standards and intentional, step-by-step clinical protocols.
