Partial Epigenetic Reprogramming
The most discussed emerging technology in longevity biology. Currently Grade D on EBL because the evidence is animal and mechanistic. The first patient in a Phase 1 safety trial was dosed in June 2026, and no results have been published. This page explains where the evidence is, where it needs to go, and exactly what would move the grade.
Every cell in your body carries the same DNA but expresses it differently based on epigenetic marks. Chemical modifications to DNA and histones that act as an instruction layer. As cells age, this epigenetic information becomes corrupted. Yamanaka factors (OCT4, SOX2, KLF4, and c-MYC) can reset these marks and reprogram a cell back toward an embryonic state. The risk: full reprogramming creates undifferentiated stem cells that can form tumors. Partial reprogramming uses three of the four factors (OSK: OCT4, SOX2, KLF4) transiently to reset epigenetic age while keeping cells committed to their original identity and function.
David Sinclair at Harvard proposes that aging is fundamentally a loss of epigenetic information, the cell no longer knows what genes to express and when. If this theory is correct, restoring the epigenetic information layer could reverse biological age at the cellular level. The 2020 Nature paper from Sinclair’s lab demonstrated this concept in mouse retinal cells, restoring vision after optic nerve injury by resetting epigenetic age using OSK. This is the experiment that led to Life Biosciences and the current human trial.
ER-100 delivers OSK (OCT4, SOX2, KLF4) via an adeno-associated virus vector injected directly into the eye. Systemic doxycycline activates OSK expression for 56 days. The vector has been engineered to remove infectious disease capability. c-MYC (the tumor-associated Yamanaka factor) is excluded. Intravitreal delivery limits systemic exposure.
Lu et al. (Nature, 2020; PMID 33268865): OSK restored vision in mouse models of glaucoma and aging, reversed epigenetic age in retinal cells. Non-human primate (NHP) data from Life Biosciences replicated the visual function restoration. Multiple independent labs have demonstrated partial reprogramming effects in mouse models across various tissues. All of this is Tier 5 evidence. EBL notes it for scientific context only. It does not enter the human evidence grade.
YouthBio (anti-Alzheimer’s application), Retro Biosciences (Sam Altman-backed, systemic reprogramming), Altos Labs (Jeff Bezos-backed, broad aging applications), Calico (Google-backed). None had published human reprogramming data as of September 2026. EBL will add Evidence Target pages for programs that reach human trials.
EBL’s grading criteria are explicit. Here is the specific evidence that would change this grade at each step. This is not a prediction that it will happen on any timeline. It is a statement of what the evidence would need to show.
Animal and mechanistic data only. The first patient was dosed in June 2026. No human safety or efficacy data has been published. The grade cannot change until human data is published in peer-reviewed literature.
A Phase 1 safety study in patients with a serious eye disease. Its primary question, over six months per patient, is whether the therapy is safe in a human eye. That is the only question being answered right now. Vision improvement is a secondary exploratory endpoint, not the primary question.
A longevity trial. A healthy aging study. Evidence that epigenetic reprogramming reverses aging in humans. The therapy is injected into one eye of patients with glaucoma or optic nerve damage. The leap from this to “reverse-aging drug works in humans” is the entire distance of future Phase 2 and Phase 3 trials that have not yet been designed.
This is a genuine scientific milestone. Partial epigenetic reprogramming reaching human trials means the regulatory, safety, and manufacturing hurdles for this class of therapy have been cleared for the first time. Safety data from this trial will inform every subsequent reprogramming program. The field just graduated from preclinical.
Phase 1 data: late 2026 or early 2027 if the trial proceeds without safety holds. Phase 2 trial design and execution: 2027 to 2029 at the earliest for a typical timeline. A Grade C on EBL based on published human Phase 2 data: realistically 2028 to 2030. This assumes no safety issues and that Phase 2 is designed with a biomarker endpoint EBL can grade.
EBL will update this grade when qualifying evidence is published.
Every EBL member receives a notification when a grade changes. If partial epigenetic reprogramming clears Phase 1 and moves toward Phase 2, you will know what was published, what endpoint was used, and exactly why the grade changed. No marketing. The evidence.
Pro members also receive early access to Evidence Target updates and can register interest in future trial recruitment for technologies at this stage.
Grade updates always free · Pro adds early access and trial interest